path: root/nuttx/Documentation/NuttX.html



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<title>NuttX</title>
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<table width ="100%">
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    <td>
      <h1><big><font color="#3c34ec"><i>NuttX RTOS</i></font></big></h1>
      <p>Last Updated: September 29, 2012</p>
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<hr><hr>
<table width ="100%">
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    <td>
  <h1>Table of Contents</h1>
    </td>
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<center><table width ="80%">
<tr>
<td>
<table>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#overview">Overview</a>.<br>
    What is NuttX?  Look at all those files and features... How can it be a tiny OS?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#group">NuttX Discussion Group</a>.<br>
    Do you want to talk about NuttX features?  Do you need some help?  Problems?  Bugs?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#downloads">Downloads</a>.<br>
    Where can I get NuttX?  What is the current development status?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#platforms">Supported Platforms</a>.<br>
    What target platforms has NuttX been ported to?
  </td>
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<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#environments">Development Environments</a>.<br>
    What kinds of host cross-development platforms can be used with NuttX?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#footprint">Memory Footprint</a>.<br>
    Just how big is it?  Do I have enough memory to use NuttX?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#licensing">Licensing</a>.<br>
    Are there any licensing restrictions for the use of NuttX? (Almost none)
    Will there be problems if I link my proprietary code with NuttX? (No)
  </td>
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<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#history">Release History</a><br>
    What has changed in the last release of NuttX?
    What unreleased changes are pending in SVN?
  </td>
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<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#TODO">Bugs, Issues, <i>Things-To-Do</i></a>.<br>
    Software is never finished nor ever tested well enough.
    (Do you want to help develop NuttX?  If so, send me an email).
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#documentation">Other Documentation</a>.<br>
    What other NuttX documentation is available?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#trademarks">Trademarks</a>.<br>
    Some of the words used in this document belong to other people.
  </td>
</tr>
</table>
</td>
</tr>
</table></center>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="overview"><h1>Overview</h1></a>
  </td>
  </tr>
</table>

<p>
  <b>Goals</b>.
  NuttX is a real timed embedded operating system (RTOS).
  Its goals are:
<p>
<center><table width="90%">
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  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Small Footprint</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      Usable in all but the tightest micro-controller environments,
      The focus is on the tiny-to-small, deeply embedded environment.
    </p>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Rich Feature OS Set</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      The goal is to provide implementations of most standard POSIX OS interfaces
      to support a rich, multi-threaded development environment for deeply embedded
      processors.
    </p>
      NON-GOALS: (1) It is not a goal to provide the level of OS features like those provided by Linux.
      In order to work with smaller MCUs, small footprint must be more important than an extensive feature set.
      But standard compliance is more important than small footprint.
      Surely a smaller RTOS could be produced by ignoring standards.
      Think of NuttX is a tiny Linux work-alike with a much reduced feature set.
      (2) There is no MMU-based support for processes.
      At present, NuttX assumes a flat address space.
    </p>
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  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Highly Scalable</b>
  </td>
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  <td><br></td>
  <td>
    <p>
      Fully scalable from tiny (8-bit) to moderate embedded (32-bit).
      Scalability with rich feature set is accomplished with:
      Many tiny source files, link from static libraries, highly configurable, use of
      weak symbols when available.
    </p>
</tr>
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  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Standards Compliance</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      NuttX strives to achieve a high degree of standards compliance.
      The primary governing standards are POSIX and ANSI standards.
      Additional standard APIs from Unix and other common RTOS's are
      adopted for functionality not available under these standards
      or for functionality that is not appropriate for the deeply-embedded
      RTOS (such as <code>fork()</code>).
    </p>
    <p>
      Because of this standards conformance, software developed under other
      standard OSs (such as Linux) should port easily to NuttX.
    </p>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Real-Time</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      Fully pre-emptible, fixed priority and round-robin scheduling.
    </p>
</tr>
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  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Totally Open</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      Non-restrictive BSD license.
    </p>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>GNU Toolchains</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      Compatible GNU toolchains based on <a href="http://buildroot.uclibc.org/">buildroot</a>
      available for
      <a href="https://sourceforge.net/projects/nuttx/files/">download</a>
      to provide a complete development environment for many architectures.
    </p>
</tr>
</table></center>

<p>
  <b>Feature Set</b>.
  Key features of NuttX include:
<p>
<center><table width="90%">

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Standards Compliant Core Task Management</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Fully pre-emptible.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Naturally scalable.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Highly configurable.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        Easily extensible to new processor architectures, SoC architecture, or board architectures.
        A <a href="NuttXPortingGuide.html">Porting Guide</a> is available.
      </li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>FIFO and round-robin scheduling.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Realtime, deterministic, with support for priority inheritance</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>POSIX/ANSI-like task controls, named message queues, counting semaphores, clocks/timers, signals, pthreads, environment variables, filesystem.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>VxWorks-like task management and watchdog timers.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>BSD socket interface.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Extensions to manage pre-emption.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Inheritable &quot;controlling terminals&quot; and I/O re-direction.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>On-demand paging.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <li>System logging.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>May be built either as an open, flat embedded RTOS or as a separtely built, secure micro-kernel with a system call interface.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Well documented in the NuttX <a href="NuttXUserGuide.html">User Guide</a>.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>File system</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Tiny, in-memory, root pseudo-file-system.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Virtual file system supports drivers and mountpoints.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        Mount-able volumes.  Bind mountpoint, filesystem, and block device driver.
      </li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Generic system logging (SYSLOG) support.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        FAT12/16/32 filesystem support with optional FAT long file name support<small><sup>1</sup></small>.
      </li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        NFS Client. Client side support for a Network File System (NFS, version 3, UDP).
      </li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        NXFFS. The tiny NuttX wear-leveling FLASH file system.
      </li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>ROMFS filesystem support.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li><a href="NuttXNxFlat.html">NXFLAT</a>.
      A new binary format call NXFLAT that can be used to 
      execute separately linked programs in place in a file system.
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p><small>
      <sup>1</sup>
      FAT long file name support may be subject to certain Microsoft patent restrictions if enabled.
      See the top-level <code>COPYING</code> file for details.
    </small></p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Device Drivers</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Supports character and block drivers as well as specialized driver interfaces.</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        Network, USB (host), USB (device), serial, CAN, ADC, DAC, PWM, Quadrature Encoder, and watchdog timer driver architectures.
      </li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        RAMDISK, pipes, FIFO, <code>/dev/null</code>, <code>/dev/zero</code>, and loop drivers.
      </li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Generic driver for SPI-based or SDIO-based MMC/SD/SDH cards.</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li><a href="NuttXPortingGuide.html#pwrmgmt">Power management</a> sub-system.</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>ModBus support provided by built-in <a href="http://freemodbus.berlios.de/">FreeModBus</a> version 1.5.0.</li>
    </p>
  </td>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>C Library</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Fully integrated into the OS.</li>
    </p>
  </td>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Networking</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>TCP/IP, UDP, ICMP, IGMPv2 (client) stacks.</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>SLIP</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Small footprint (based on uIP).</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>BSD compatible socket layer.</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Networking utilities (DHCP server and client, SMTP client, TELNET client, FTP server and client, TFTP client, HTTP server and client).  Inheritable TELNET sessions (as &quot;controlling terminal&quot;)</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        NFS Client. Client side support for a Network File System (NFS, version 3, UDP).
      </li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        A NuttX port of Jeff Poskanzer's <a href="http://acme.com/software/thttpd">THTTPD</a> HTTP server
        integrated with <a href="NuttXNxFlat.html">NXFLAT</a> to provide true, embedded CGI.
      </li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        UDP Network Discover (Contributed by Richard Cochran).
      </li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        XML RPC Server (Contributed by Richard Cochran).
      </li>
    </p>
  </td>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>FLASH Support</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li><i>MTD</i>-inspired interface for <i>M</i>emory <i>T</i>echnology <i>D</i>evices.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li><i>FTL</i>.  Simple <i>F</i>lash <i>T</i>ranslation <i>L</i>ayer support file systems on FLASH.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>NXFFS. the NuttX wear-leveling FLASH file system.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Support for SPI-based FLASH and FRAM devices.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>USB Host Support</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>USB host architecture for USB host controller drivers and device-dependent USB class drivers.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>USB host controller drivers available for the NXP LPC17xx.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Device-dependent USB class drivers available for USB mass storage and HID keyboard.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>USB Device Support</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li><i>Gadget</i>-like architecture for USB device controller drivers and device-dependent USB class drivers.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>USB device controller drivers available for the PIC32, NXP LPC17xx, LPC214x, LPC313x, LPC43xx, STMicro STM32 and TI DM320.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Device-dependent USB class drivers available for USB serial (CDC/ACM and a PL2303 emulation), for USB mass storage, and for a composite CDC/ACM and mass storage device.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Built-in <a href="UsbTrace.html">USB trace</a> functionality for USB debug.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Graphics Support</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Framebuffer drivers.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>LCD drivers for both parallel and SPI LCDs and OLEDs.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
         NX: A graphics library, tiny windowing system and tiny font support that works with either framebuffer or LCD drivers.
         Documented in the <a href="NXGraphicsSubsystem.html">NX Graphics Subsystem</a>
         manual.
      </li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Font management sub-system.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
         <a href="NxWidgets.html">NxWidgets</a>: NXWidgets is library of graphic objects, or &quot;widgets,&quot (labels, buttons, text boxes, images, sliders, progress bars, etc.). NXWidgets is written in C++ and integrates seamlessly with the NuttX NX graphics and font management subsystems.
      </li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
         <a href="NxWidgets.html">NxWM</a>: NxWM is the tiny NuttX window manager based on NX and NxWidgets.
      </li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Input Devices</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Touchscreen, USB keyboard, GPIO-based buttons and keypads. </li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Analog Devices</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Support for Analog-to-Digital conversion (ADC), Digital-to-Analog conversion (DAC), multiplexers, and amplifiers.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Motor Control</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Pulse width modulation (PWM) / Pulse count modulation.</li>
    </p>
</tr>
</table></center>

<p>
  <b>NuttX Add-Ons</b>.
  The following packages are available to extend the basic NuttX feature set:
</p>
<center><table width="90%">

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>NuttShell (NSH)</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>A small, scalable, bash-like shell for NuttX with rich feature set and small footprint.
        See the <a href="NuttShell.html">NuttShell User Guide</a>.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Pascal Compiler with NuttX runtime P-Code interpreter add-on</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>The Pascal add-on is available for download from the
        <a href="http://sourceforge.net/projects/nuttx/files/">SourceForge</a>
        website.</li>
    </p>
  </td>
</tr>
</table></center>

<p>
  <b>Look at all those files and features... How can it be a tiny OS?</b>.
  The NuttX feature list (above) is fairly long and if you look at the NuttX
  source tree, you will see that there are hundreds of source files comprising
  NuttX.  How can NuttX be a tiny OS with all of that?
</p>
<center><table width="90%">

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Lots of Features -- More can be smaller!</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      The philosophy behind that NuttX is that lots of features are great... <i>BUT</i>
      also that if you don't use those features, then you should not have to pay a penalty
      for the unused features.
      And, with NuttX, you don't!  If you don't use a feature, it will not
      be included in the final executable binary.
      You only have to pay the penalty of increased footprint for the features
      that you actually use.
    </p>
    <p>
      Using a variety of technologies, NuttX can scale from the very tiny to
      the moderate-size system.  I have executed NuttX with some simple applications
      in as little as 32K <i>total</i> memory (code and data).
      On the other hand, typical, richly featured NuttX builds require more like 64K
      (and if all of the features are used, this can push 100K).
    </p>
  </td>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Many, many files -- More really is smaller!</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      One may be intimidated by the size NuttX source tree.  There are hundreds of source files!
      How can that be a tiny OS?
      Actually, the large number of files is one of the tricks to keep NuttX small and
      as scalable as possible.
      Most files contain only a single function. 
      Sometimes just one tiny function with only a few lines of code.
      Why?
    </p>
    <ul>
      <li>
        <b>Static Libraries</b>.
        Because in the NuttX build processed, objects are compiled and saved into
        <i>static libraries</i> (<i>archives</i>).
        Then, when the file executable is linked, only the object files that are needed
        are extracted from the archive and added to the final executable.
        By having many, many tiny source files, you can assure that no code that you do
        not execute is ever included in the link.
        And by having many, tiny source files you have better granularity --
        if you don't use that tiny function of even just a few lines of code, it will
        not be included in the binary.
      </li>
    </ul>
  </td>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Other Tricks</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      As mentioned above, the use of many, tiny source files and linking from static
      libraries keeps the size of NuttX down.
      Other tricks used in NuttX include:
    </p>
    <ul>
      <li>
         <b>Configuration Files</b>.
         Before you build NuttX, you must provide a configuration file that specifies
         what features you plan to use and which features you do not.
         This configuration file contains a long list of settings that control
         what is built into NuttX and what is not.
         There are hundreds of such settings
         (see the <a href="NuttXPortingGuide.html#apndxconfigs">NuttX Porting Guide</a>
         for a partial list that excludes platform specific settings).
         These many, many configuration options allow NuttX to be highly tuned to
         meet size requirements.
         The downside to all of these configuration options is that it greatly
         complicates the maintenance of NuttX -- but that is my problem, not yours.
      </li>
      <li>
         <b>Weak Symbols</b>
         The GNU toolchain supports <i>weak</i> symbols and these also help to keep
         the size of NuttX down.
         Weak symbols prevent object files from being drawn into the link even if they
         are accessed from source code.
         Careful use of weak symbols is another trick for keep unused code out of the
         final binary.
      </li>
    </ul>
  </td>
</tr>

</table></center>


<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="group"><h1>NuttX Discussion Group</h1></a>
  </td>
  </tr>
</table>

<p>
  Most NuttX-related discussion occurs on the <a href="http://tech.groups.yahoo.com/group/nuttx/" target="_top"><i>Yahoo!</i> NuttX group</a>.
  You are cordially invited to <a href="http://groups.yahoo.com/group/nuttx/join" target="_top">join</a>.
  I make a special effort to answer any questions and provide any help that I can.
</p>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="downloads"><h1>Downloads</h1></a>
  </td>
  </tr>
</table>

<h2>NuttX-6.22 Release Notes</h2>
<p>
  The 89<sup>th</sup> release of NuttX, Version 6.22, was made on September 29, 2012, and is available for download from the
  <a href="http://sourceforge.net/projects/nuttx/files/">SourceForge</a> website.
  Note that the release consists of two tarballs:  <code>nuttx-6.22.tar.gz</code> and <code>apps-6.22.tar.gz</code>.
  Both may be needed (see the top-level <code>nuttx/README.txt</code> file for build information)
  The change log associated with the release is available <a href="#currentrelease">here</a>.
  Unreleased changes after this release are available in SVN.
  These unreleased changes are also listed <a href="#pendingchanges">here</a>.
</p>
<p>
  This release corresponds with SVN release number: r5206,
  Note that all SVN information has been stripped from the tarballs.
  If you need the SVN configuration, you should check out directly from SVN.
  Revision r5206 should equivalent to release 6.22 of NuttX 6.22:
</p>
<ul><pre>
svn checkout -r5206 svn://svn.code.sf.net/p/nuttx/code/trunk nuttx-code
</pre></ul>
<p>Or</p>
<ul><pre>
svn checkout -r5206 http://svn.code.sf.net/p/nuttx/code/trunk nuttx-code
</pre></ul>

<p>
  <b>Additional new features and extended functionality</b>
</p>
<ul>
  <li>
    <p>
      <b>RTOS</b>:
      Application entry point is no longer user_start, but can be configured using <code>CONFIG_USER_ENTRYPOINT</code>.
      NuttX now supports two work queues:  A lower priority work queue (for extended processing) and a higher priority work queue (for quick, high priority operations).
    </p>
  </li>
  <li>
    <p>
      <b>Memory Management</b>:
      Added a new granule-based allocated that can be used to manage, aligned and quantized DMA memory.
    </p>
  </li>
  <li>
    <p>
      <b>File System</b>:
      Add hooks to allocate I/O memory with and external allocated (need if required by DMA).
    </p>
  </li>
  <li>
    <p>
      <b>Networking</b>:
      ENC28J60 driver is (finally) verified.
    </p>
  </li>
  <li>
    <p>
      <b>Drivers</b>:
      Add hooks USB device drivers to allocate I/O memory with and external allocated (need if required by DMA).
      Driver for the Windbond SPI FLASH family (W25x16, W25x32, W25x64, and others).
      ADS7843E driver extended for TSC2046 and XPT2046 and verified.
    </p>
  </li>
  <li>
    <p>
      <b>ARMv7-M</b>:
      Added logic to reset the MCU using the NVIC.
    </p>
  </li>
  <li>
    <p>
      <b>STM32</b>:
      Add support for STM32F103VET6.
    </p>
  </li>
  <li>
    <p>
      <b>STM32 Drivers</b>:
      Add logic to re-initialize UARTs a second time to enable DMA (Mike Smith).
      I2C driver error recovery (Mike Smith).
    </p>
  </li>
  <li>
    <p>
      <b>STM32 boards</b>:
      Support for USB host added add to several configurations (or at least explained in README files).
      Support for the Shenzhou STM32F107 board (see www.armjishu.com).
      Support for M3 Wildfire STM32F103 board (v2 and v3).
    </p>
  </li>
  <li>
    <p>
      <b>Build System:</b>:
      Kconfig string de-quoting logic.
      Remove comments from <code>defconfig</code> files (Kate).
      Add tool to create NuttX-style symbol tables.
      Numerous changes to configuration logic as needed for the new <code>mconf</code>-based configuration (much of this from Richard Cochran).
      Refactor common <code>Make.defs</code> logic into <code>tools/Config.mk</code> (Richard Cochran).
    </p>
  </li>
  <li>
    <p>
      <b>Library</b>:
      Configurable terse output from <code>strerror()</code>.
      Added <code>perror()</code> (Kate).
      Add <code>%n</code> format to <code>sscanf()</code> (Kate).
    </p>
  </li>
  <li>
    <p>
      <b>Applications</b>:
      Numerous changes and extensions to the old uIP web server (from Kate and Max Holtzberg, see the ChangeLog for specific extensions).
      UDP network discovery utility (Max Holtzberg).
      Embeddable Lightweight XML-RPC Server (http://www.drdobbs.com/web-development/an-embeddable-lightweight-xml-rpc-server/184405364, Max Holtzberg).
    </p>
  </li>
</ul>
<p>
  <b>Bugfixes</b> (see the change log for details)
  Some of these are very important (marked <b><i>critical</i></b>):
</p>
<ul>
  <li>
    <p>
      <b>RTOS</b>:
      Fixes to priority inheritance logic (<b><i>critical</i></b>).
      <code>waitpid()</code> critical section.
      Assertion in <code>work_cancel()</code> (Mike Smith).
      <code>mmap()</code> (Kate).
    </p>
  </li>
  <li>
    <p>
      <b>FAT File System</b>:
      Improper Boolean expression caused un-necessary writes and performance issues (<b><i>critical</i></b>, Ronen Vainish).
    </p>
  </li>
  <li>
    <p>
      <b>Networking</b>:
      Remove an un-necessary delay from <code>recvfrom()</code>.
      This greatly improves network performance (<b><i>critical</i></b>, Max Holtzberg).
    </p>
  </li>
  <li>
    <p>
      <b>Graphics</b>:
      NX parameter checking errors.
    </p>
  </li>
  <li>
    <p>
      <b>Drivers</b>:
      Fix double release of memory in SDIO-based, MMC/SD driver (Ronen Vainish).
    </p>
  </li>
  <li>
    <p>
      <b>LPC17xx</b>:
      Ethernet driver fixes needed for certain PHYs (Kate).
    </p>
  </li>
  <li>
    <p>
      <b>AVR</b>:
      Fix build error (Richard Cochran).
    </p>
  </li>
  <li>
    <p>
      <b>STM32</b>:
      USB OTG FS host driver NAKing an retries.
      Power management compilation errors (Diego Sanchez).
      Missing SPI3 remap logic.
    </p>
  </li>
  <li>
    <p>
      <b>STM32 Drivers</b>:
      Fix for Ethernet errata for STM32F107 (<b><i>critical</i></b>).
      Ethernet buffer alignment check.
      Add &quot;kludge&quot; to Ethernet driver to handle DM9161 PHY which (at least on the Shenzhou board), sometimes does not come up correctly.
    </p>
  </li>
  <li>
    <p>
      <b>Applications</b>:
      THTTPD (Kate).
      NSH <code>ping</code> when IP address is on a different network (Darcy Gong).
    </p>
  </li>
  <li>
    <p>
      <b>Library</b>:
      <code>fread()</code>, <code>fflush()</code>, <code>fdopen()</code>: Fix error handling logic (Ronen Vainish).
      Fix some field-width handling issues in <code>sscanf()</code>
    </p>
  </li>
</ul>
<p>
  As well as other, less critical bugs.
  See the <a href="#currentrelease">ChangeLog</a> for additional, detailed changes.
</p>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="platforms"><h1>Supported Platforms</h1></a>
  </td>
  </tr>
</table>

<p>
  The short story (Number of ports follow in parentheses).
  The state of the various ports vary from board-to-board.
  Follow the links for the details:
</p>
<center><table width="90%">
<ul>
  <tr>
  <td bgcolor="#e4e4e4" valign="top">
  <li><a href="#linuxusermode">Linux user mode simulation</a> (1)</li>
  <li>ARM
    <ul>
      <li><a href="#arm7tdmi">ARM7TDMI</b></a> (5)</li>
      <li><a href="#arm920t">ARM920T</a> (1) </li>
      <li><a href="#arm926ejs">ARM926EJS</a> (3) </li>
      <li><a href="#armcortexm3">ARM Cortex-M3</a> (16)</li>
      <li><a href="#armcortexm4">ARM Cortex-M4</a> (5)</li>
    </ul>
  <li>Atmel AVR
    <ul>
      <li><a href="#atmelavr">Atmel 8-bit AVR</a> (3) </li>
      <li><a href="#atmelavr32">Atmel AVR32</a> (1) </li>
    </ul>
  </li>
  </td>
  <td bgcolor="#e4e4e4" valign="top">
  <li>Freescale <a href="#m68hcs12">M68HCS12</a> (2) </li>
  <li>Intel
    <ul>
      <li><a href="#8052">Intel 8052 Microcontroller</a> (1)</li>
      <li><a href="#80x86">Intel 80x86</a> (2)</li>
    </ul>
  </li>
  <li>MicroChip <a href="#pic32mips">PIC32MX</a> (MIPS) (4)</li>
  <li>Renesas/Hitachi:
    <ul>
        <li><a href="#superh">Renesas/Hitachi SuperH</a> (1/2)</li>
        <li><a href="#m16c">Renesas M16C/26</a> (1/2)</li>
    </ul>
  </li>
  </td>
  <td bgcolor="#e4e4e4" valign="top">
  <li>Zilog
    <ul>
        <li><a href="#zilogz16f">Zilog Z16F</a> (1)</li>
        <li><a href="#zilogez80acclaim">Zilog eZ80 Acclaim!</a> (1)</li>
        <li><a href="#zilogz8encore">Zilog Z8Encore!</a> (2)</li>
        <li><a href="#zilogz80">Zilog Z80</a> (2)</li>
    </ul>
  </li>
</ul>
  </tr>
</table></center>

<p>The details, caveats and fine print follow:</p>

<center><table width="90%">
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="linuxusermode"><b>Linux User Mode</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      A user-mode port of NuttX to the x86 Linux/Cygwin platform is available.
      The purpose of this port is primarily to support OS feature development.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        Does not support interrupts but is otherwise fully functional.
      </p>
    </ul>
   </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="arm7tdmi"><b>ARM7TDMI</b></a>.
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>TI TMS320C5471</b> (also called <b>C5471</b> or <b>TMS320DA180</b> or <b>DA180</b>).
      NuttX operates on the ARM7 of this dual core processor.
      This port uses the <a href="http://www.spectrumdigital.com/">Spectrum Digital</a>
      evaluation board with a GNU arm-elf toolchain* under Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        This port is complete, verified, and included in the initial NuttX release.
      </p>
    </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>TI Calypso</b>.
      This port supports the TI &quot;Calypso&quot; MCU used in various cell phones (and, in particular,
      by the <a href="http://bb.osmocom.org/trac/">Osmocom-bb project</a>).
      Like the c5471, NuttX operates on the  ARM7 of this dual core processor.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        This port was contributed by  Denis Carilki and includes the work of Denis, Alan Carvalho de Assis, and Stefan Richter.
        Calypso support first appeared in NuttX-6.17.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>NXP LPC214x</b>.
      Support is provided for the NXP LPC214x family of processors.  In particular,
      support is provided for the mcu123.com lpc214x evaluation board (LPC2148).
      This port also used the GNU arm-elf toolchain* under Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        This port boots and passes the OS test (apps/examples/ostest).
        The port is complete and verified.  As of NuttX 0.3.17, the port includes:
        timer interrupts, serial console, USB driver, and SPI-based MMC/SD card
        support.  A verified NuttShell (<a href="NuttShell.html">NSH</a>)
        configuration is also available.
      </p>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
        with Windows native toolchain (CodeSourcery or devkitARM).  A DIY toolchain for Linux
        or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a>
        package.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>NXP LPC2378</b>.
      Support is provided for the NXP LPC2378 MCU.  In particular,
      support is provided for the Olimex-LPC2378 development board.
      This port was contributed by Rommel Marcelo is was first released in NuttX-5.3.
      This port also used the GNU arm-elf toolchain* under Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        This port boots and passes the OS test (apps/examples/ostest) and includes a
        working implementation of the NuttShell (<a href="NuttShell.html">NSH</a>).
        The port is complete and verified.
        As of NuttX 5.3, the port includes only basic timer interrupts and serial console support.
      </p>
      <p>
        <b>Development Environments:</b> (Same as for the NXP LPC214x).
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STR71x</b>.
      Support is provided for the STMicro STR71x family of processors.  In particular,
      support is provided for the Olimex STR-P711 evaluation board.
      This port also used the GNU arm-elf toolchain* under Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        Integration is complete on the basic port (boot logic, system time, serial console).
        Two configurations have been verified: (1) The board boots and passes the OS test
        with console output visible on UART0, and the NuttShell (<a href="NuttShell.html">NSH</a>)
        is fully functional with interrupt driven serial console.  An SPI driver is available
        but only partially tested.  Additional features are needed: USB driver, MMC integration,
        to name two (the slot on the board appears to accept on MMC card dimensions; I have only
        SD cards).
        An SPI-based ENC28J60 Ethernet driver for add-on hardware is available and
        but has not been fully verified on the Olimex board (due to issues powering the ENC28J60 add-on board).
      </p>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
        with Windows native toolchain (CodeSourcery or devkitARM).  A DIY toolchain for Linux
        or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a>
        package.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="arm920t"><b>ARM920T</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Freescale MC9328MX1</b> or <b>i.MX1</b>.
      This port uses the Freescale MX1ADS development board with a GNU arm-elf toolchain*
      under either Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          This port has stalled due to development tool issues.
          Coding is complete on the basic port (timer, serial console, SPI).
      </p>
    </ul>
   </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="arm926ejs"><b>ARM926EJS</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>TI TMS320DM320</b> (also called <b>DM320</b>).
      NuttX operates on the ARM9 of this dual core processor.
      This port uses the
      <a href="http://wiki.neurostechnology.com/index.php/Developer_Welcome">Neuros OSD</a>
      with a GNU arm-elf toolchain* under Linux or Cygwin.
      The port was performed using the OSD v1.0, development board.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          The basic port (timer interrupts, serial ports, network, framebuffer, etc.) is complete.
          All implemented features have been verified with the exception of the USB device-side
          driver; that implementation is complete but untested.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <b>NXP <a href="http://ics.nxp.com/products/lpc3000/lpc313x.lpc314x.lpc315x/">LPC3131</a></b>.
    The port for the NXP LPC3131 on the <a href="http://www.embeddedartists.com/products/kits/lpc3131_kit.php">Embedded Artists EA3131</a> 
    development board was first released in NuttX-5.1 with a GNU arm-elf or arm-eabi toolchain* under Linux or Cygwin
    (but was not functional until NuttX-5.2).
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          The basic EA3131 port is complete and verified in NuttX-5.2 
          This basic port includes basic boot-up, serial console, and timer interrupts.
          This port was extended in NuttX 5.3 with a USB high speed driver contributed by David Hewson.
          David also contributed I2C and SPI drivers plus several important LPC313x USB bug fixes
          that appear in the NuttX 5.6 release.
          This port has been verified using the NuttX OS test, USB serial and mass storage
          tests and includes a working implementation of the NuttShell (<a href="NuttShell.html">NSH</a>).
      </p>
      <p>
          Support for <a href="NuttXDemandPaging.html">on-demand paging</a> has been developed for the EA3131.
      That support would all execute of a program in SPI FLASH by paging code sections out of SPI flash as needed.
      However, as of this writing, I have not had the opportunity to verify this new feature.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <b>NXP <a href="http://ics.nxp.com/products/lpc3000/lpc313x.lpc314x.lpc315x/">LPC315x</a></b>.
    Support for the NXP LPC315x family has been incorporated into the code base as of NuttX-6.4.
    Support has added for the Embedded Artists EA3152 board in NuttX-6.11.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          Basic support is in place for both the LPC3152 MCU and the EA3152 board.
          Verification of the port was deferred due to tool issues
          However, because of the high degree of compatibility between the LPC313x and LPC315x family, it
          is very likely that the support is in place (or at least very close).
          At this point, verification of the EA3152 port has been overcome by events and
          may never happen.
          However, the port is available for anyone who may want to use it.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="armcortexm3"><b>ARM Cortex-M3</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>TI Stellaris LM3S6432</b>.
      This is a port of NuttX to the Stellaris RDK-S2E Reference Design Kit and the MDL-S2E Ethernet to Serial module
      (contributed by Mike Smith).
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Luminary/TI Stellaris LM3S6918</b>.
      This port uses the <a href=" http://www.micromint.com/">Micromint</a> Eagle-100 development
      board with a GNU arm-elf toolchain* under either Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          The initial, release of this port was included in NuttX  version 0.4.6.
          The current port includes timer, serial console, Ethernet, SSI, and microSD support.
          There are working configurations the NuttX OS test, to run the <a href="NuttShell.html">NuttShell
          (NSH)</a>, the NuttX networking test, and the uIP web server.
      </p>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
        with Windows native toolchain (CodeSourcery or devkitARM).  A DIY toolchain for Linux
        or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a>
        package.
      </p>
     </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Luminary/TI Stellaris LM3S6965</b>.
      This port uses the Stellaris LM3S6965 Ethernet Evalution Kit with a GNU arm-elf toolchain*
      under either Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          This port was released in NuttX 5.5.  
          Features are the same as with the Eagle-100 LM3S6918 described above.
          The apps/examples/ostest configuration has been successfully verified and an
          NSH configuration with Telnet support is available.
          MMC/SD and Networking support was not been thoroughly verified:
          Current development efforts are focused on porting the NuttX window system (NX)
          to work with the Evaluation Kits OLED display.
      </p>
      <p><small>
         <b>NOTE</b>: As it is configured now, you MUST have a network connected.
         Otherwise, the NSH prompt will not come up because the Ethernet
         driver is waiting for the network to come up.
      </small></p>
      <p>
        <b>Development Environments:</b> See the Eagle-100 LM3S6918 above.
      </p>
     </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Luminary/TI Stellaris LM3S8962</b>.
      This port uses the Stellaris EKC-LM3S8962 Ethernet+CAN Evalution Kit with a GNU arm-elf toolchain*
      under either Linux or Cygwin.
      Contributed by Larry Arnold.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          This port was released in NuttX 5.10. 
          Features are the same as with the Eagle-100 LM3S6918 described above.
      </p>
     </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Luminary/TI Stellaris LM3S9B96</b>.
      Header file support was contributed by Tiago Maluta for this part.
      Jose Pablo Rojas V. is currently using those header file changes to port NuttX to the TI/Stellaris EKK-LM3S9B96.
      With any luck, that port should be working and available in the NuttX-6.20 release.
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>TI Stellaris LM3S6432S2E</b>.
      This port uses Serial-to-Ethernet Reference Design Kit (<a href="http://www.ti.com/tool/rdk-s2e">RDK-S2E</a>)
      and has similar support as for the other Stellaris family members.
      Configurations are available for the OS test and for the NuttShell (NSH)
      (see the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
      The NSH configuration including networking support with a Telnet NSH console.
      This port was contributed by Mike Smith.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          This port was will be released in NuttX 6.14. 
      </p>
     </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STM32F100x</b>.
      Chip support for these STM32 &quot;Value Line&quot; family was contributed by Mike Smith and users have reported that they have successful brought up NuttX on there proprietary boards using this logic.
      However, there is <i>no</i> specific board support for this chip families in the NuttX source tree.
    </p>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STM32F103x</b>.
      Support for four MCUs and four board configurations are available.
      MCU support includes all of the high density and connectivity line families.
      Board supported is available specifically for: STM32F103ZET6, STM32F103RET6, STM32F103VCT, and STM32F103VET6.
      Boards supported include:
    </p>
    <ol>
      <li>
        A port for the <a href=" http://www.st.com/">STMicro</a> STM3210E-EVAL development board that
        features the STM32F103ZET6 MCU.
      </li>
      <li>
        The ISOTEL NetClamps VSN V1.2 ready2go sensor network platform based on the
        STMicro STM32F103RET6.  Contributed by Uros Platise.
      </li>
      <li>
        A port for the HY-Mini STM32v board.  This board is based on the
        STM32F103VCT chip.  Contributed by Laurent Latil.
      </li>
      <li>
         The M3 Wildfire development board (STM32F103VET6), version 2.
         See <a href="http://firestm32.taobao.com">http://firestm32.taobao.com</a> (the current board is version 3).
      </li>
    </ol>
    <p>
      These ports uses a GNU arm-elf toolchain* under either Linux or Cygwin (with native Windows GNU
      tools or Cygwin-based GNU tools).
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
      </p>
      <ul>
        <li><b>Basic Support/Drivers</b>.
          The basic STM32 port was released in NuttX version 0.4.12. The basic port includes boot-up
          logic, interrupt driven serial console, and system timer interrupts.
          The 0.4.13 release added support for SPI, serial FLASH, and USB device.;
          The 4.14 release added support for buttons and SDIO-based MMC/SD and verifed DMA support.
          Verified configurations are available for NuttX OS test, the NuttShell (NSH) example,
          the USB serial device class, and the USB mass storage device class example.
        </li>
        <li><b>NetClamps VSN</b>.
          Support for the NetClamps VSN was included in version 5.18 of NuttX.
          Uros Platise added support for timers, RTC, I2C, FLASH, extended power management
          and other features.
        </li>
        <li><b>Additional Drivers</b>.
          Additional drivers and configurations were added in NuttX 6.13 and later releases for the STM32 F1 and F4.
          F1 compatible drivers include an Ethernet driver, ADC driver, DAC driver, PWM driver, IWDG, WWDG, and CAN drivers.
        </li>
        <li><b>M3 Wildfire</b>.
          Support for the Wildfire board was included in version 6.22 of NuttX.
          The board port is basically functional.
          Not all features have been verified.
          Support for FAT file system on an an SD card had been verified.
          The ENC28J60 network is functional (but required lifting the chip select pin on the W25x16 part).
          Customizations for the v3 version of the Wildfire board are selectable (but untested).
        </li>
      </ul>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
        with Windows native toolchain (RIDE7, CodeSourcery or devkitARM).  A DIY toolchain for Linux
        or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a>
        package.
      </p>
     </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STM32F107x</b>.
      Chip support for the STM32 F1 &quot;Connectivity Line&quot; family has been present in NuttX for some time and users have reported that they have successful brought up NuttX on there proprietary boards using this logic.
    </p>
    <p>
      <b>Olimex STM32-P107</b>
      Support for the <a href="https://www.olimex.com/dev/stm32-p107.html">Olimex STM32-P107</a> was contributed by Max Holtzberg and first appeared in NuttX-6.21.  That port features the STMicro STM32F107VC MCU.
      <ul>
        <b>STATUS:</b>
        Configurations for the basic OS test and NSH are available and verified.
        Networking is functional.
      </ul>
    </p>
    <p>
      <b>Shenzhou IV</b>
      Work is underway as of this writing to port NuttX to the Shenzhou IV development board (See <a href="http://www.armjishu.com">www.armjishu.com</a>) featuring the STMicro STM32F107VCT MCU.
      If all goes according to plan, this port should be verified and available in NuttX-6.22.
      <ul>
        <b>STATUS:</b>
        In progress.
        The following have been verified:
        (1) Basic Cortex-M3 port, 
        (2) Ethernet,
        (3) On-board LEDs
      </ul>
    </p>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STM32F207IG</b>.
      Support for the STMicro STM3220G-EVAL development board was contributed by Gary Teravskis and first released in NuttX-6.16.
    </p>
    <ul>
      <b>STATUS:</b>
      The peripherals of the STM32 F2 family are compatible with the STM32 F4 family.
      See discussion of the STM3240G-EVAL board below for further information.
      </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Atmel AT91SAM3U</b>.
      This port uses the <a href="http://www.atmel.com/">Atmel</a> SAM3U-EK
      development board that features the AT91SAM3U4E MCU.
      This port uses a GNU arm-elf or arm-eabi toolchain* under either Linux or Cygwin (with native Windows GNU
      tools or Cygwin-based GNU tools).
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        The basic SAM3U-EK port was released in NuttX version 5.1. The basic port includes boot-up
        logic, interrupt driven serial console, and system timer interrupts.
        That release passes the NuttX OS test and is proven to have a valid OS implementation.
        A configuration to support the NuttShell is also included.
        NuttX version 5.4 adds support for the HX8347 LCD on the SAM3U-EK board.
        This LCD support includes an example using the
        <a href=" http://nuttx.sourceforge.net/NXGraphicsSubsystem.html">NX graphics system</a>.
        NuttX version 6.10 adds SPI support.
      </p>
      <p>
        Subsequent NuttX releases will extend this port and add support for SDIO-based SD cards and
        USB device (and possible LCD support).
        These extensions may or may not happen soon as my plate is kind of full now.
      </p>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
        with Windows native toolchain (CodeSourcery or devkitARM).  A DIY toolchain for Linux
        or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a>
        package.
      </p>
     </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>NXP LPC1766, LPC1768, and LPC1769</b>.
      Drivers are available for CAN, DAC, Ethernet, GPIO, GPIO interrupts, I2C, UARTs, SPI, SSP, USB host, and USB device.
      Verified LPC17xx onfigurations are available for three boards.
      <ul>
        <li>
          The Nucleus 2G board from <a href="http://www.2g-eng.com/">2G Engineering</a> (LPC1768),
        </li>
        <li>
          The mbed board from <a href="http://mbed.org">mbed.org</a> (LPC1768, Contributed by Dave Marples), and
        </li>
        <li>
          The LPC1766-STK board from <a href="http://www.olimex.com/">Olimex</a> (LPC1766).
        </li>
        <li>
          The Embedded Artists base board with NXP LPCXpresso LPC1768.
        </li>
        <li>
          The <a href="http://micromint.com/">Micromint</a> Lincoln60 board with an NXP LPC1769.
        </li>
      </ul>
    </p>
    <p>
      The Nucleus 2G board, the mbed board, and the LPCXpresso all feature the NXP LPC1768 MCU;
      the Olimex LPC1766-STK board features an LPC1766.
      All use a GNU arm-elf or arm-eabi toolchain* under either Linux or Cygwin (with native Windows GNU tools or Cygwin-based GNU tools).
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        The following summarizes the features that has been developed and verified on individual LPC17xx-based boards.
        These features should, however, be common and available for all LPC17xx-based boards.
      </p>
      <ol>
        <li>
        <p><b>Nucleus2G LPC1768</b></p>
        <ul>
          <li>
            Some initial files for the LPC17xx family were released in NuttX 5.6, but
          </li>
          <li>
            The first functional release for the NXP LPC1768/Nucleus2G occured with NuttX 5.7 with
            Some additional enhancements through NuttX-5.9.
          </li>
        </ul>
      </p>
      <p>
        That initial, 5.6, basic release included <i>timer</i> interrupts and a <i>serial console</i> and was
        verified using the NuttX OS test (<code>apps/examples/ostest</code>).
        Configurations available include include a verified NuttShell (NSH) configuration
        (see the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
        The NSH configuration supports the Nucleus2G's microSD slot and additional configurations
        are available to exercise the the USB serial and USB mass storage devices.
        However, due to some technical reasons, neither the SPI nor the USB device drivers are fully verified.
        (Although they have since been verfiied on other platforms; this needs to be revisited on the Nucleus2G).
      </p>
      </li>
      <li>
        <p><b>mbed LPC1768</b></p>
        <ul>
          <li>
            Support for the mbed board was contributed by Dave Marples and released in NuttX-5.11.
          </li>
        </ul>
      </p>
      <p>
        This port includes a NuttX OS test configuration (see <code>apps/examples/ostest</code>).
      </p>
      </li>
      <li>
        <p><b>Olimex LPC1766-STK</b></p>
        <ul>
          <li>
            Support for that Olimex-LPC1766-STK board was added to NuttX 5.13.
          </li>
          <li>
            The NuttX-5.14 release extended that support with an <i>Ethernet driver</i>.
          </li>
          <li>
            The NuttX-5.15 release further extended the support with a functional <i>USB device driver</i> and <i>SPI-based micro-SD</i>.
          </li>
          <li>
            The NuttX-5.16 release added a functional <i>USB host controller driver</i> and <i>USB host mass storage class driver</i>.
          </li>
          <li>
            The NuttX-5.17 released added support for low-speed USB devicers, interrupt endpoints, and a <i>USB host HID keyboard class driver</i>.
          </li>
        </ul>
      </p>
      <p>
        Verified configurations are now available for the NuttX OS test,
        for the NuttShell with networking and microSD support(NSH, see the <a href="ttp://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>),
        for the NuttX network test, for the <a href="http://acme.com/software/thttpd">THTTPD</a> webserver,
        for USB serial deive and USB storage devices examples, and for the USB host HID keyboard driver.
        Support for the USB host mass storage device can optionally be configured for the NSH example.
        A driver for the <i>Nokia 6100 LCD</i> and an NX graphics configuration for the Olimex LPC1766-STK have been added.
        However, neither the LCD driver nor the NX configuration have been verified as of the the NuttX-5.17 release.
      </p>
      </li>
      <li>
        <p><b>Embedded Artists base board with NXP LPCXpresso LPC1768</b></p>
        <p>
           An fully verified board configuration is included in NuttX-6.2.
           The Code Red toolchain is supported under either Linux or Windows.
           Verifed configurations include DHCPD, the NuttShell (NSH), NuttX graphis (NX), the NuttX OS test, THTTPD, and USB mass storage device.
        </p>
      </li>
      <li>
        <p><b>Micromint Lincoln60 board with an NXP LPC1769</b></p>
        <p>
           This board configuration was contributed and made available in NuttX-6.20.
           As contributed board support, I am unsure of what all has been verfied and what has not.
           See the Microment website for more information about the <a href="http://micromint.com/Products/lincoln60.html">Lincoln60</a> board.
           More to come.
        </p>
      </li>
      </ol>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
        with Windows native toolchain (CodeSourcery devkitARM or Code Red).  A DIY toolchain for Linux
        or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a>
        package.
      </p>
   </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="armcortexm4"><b>ARM Cortex-M4</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>FreeScale Kinetis K40</b>.
      This port uses the Freescale Kinetis KwikStik K40.
      Refer to the <a href="http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=KWIKSTIK-K40">Freescale web site</a> for further information about this board.
      The Kwikstik is used with the FreeScale Tower System (mostly just to provide a simple UART connection)
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        The unverified KwikStik K40 first appeared in NuttX-6.8
        As of this writing, the basic port is complete but I accidentally locked my board during the initial bringup.
        Further development is stalled unless I learn how to unlock the device (or until I get another K40).
        Additional work remaining includes, among other things: (1) complete the basic bring-up,
        (2) bring up the NuttShell NSH, (3) develop support for the SDHC-based SD card,
        (4) develop support for USB host and device, and (2) develop an LCD driver.
        NOTE: Some of these remaining tasks are shared with the K60 work described below.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>FreeScale Kinetis K60</b>.
      This port uses the Freescale Kinetis TWR-K60N512 tower system.
      Refer to the <a href="http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=TWR-K60N512-KIT">Freescale web site</a> for further information about this board.
      The TWR-K60N51 includes with the FreeScale Tower System which provides (among other things) a DBP UART connection.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        As of this writing, the basic port is complete and passes the NuttX OS test.
        An additional, validated configuration exists for the NuttShell (NSH, see the
        <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
        This basic TWR-K60N512 first appeared in NuttX-6.8.
        Ethernet and SD card (SDHC) drivers also exist:
        The SDHC driver is partially integrated in to the NSH configuration but has some outstanding issues;
        the Ethernet driver is completely untested.
        Additional work remaining includes: (1) integrate the Ethernet and SDHC drivers, and (2) develop support for USB host and device.
        NOTE: Most of these remaining tasks (excluding the Ethernet driver) are the same as the pending K40 tasks described above.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STM3240G-EVAL</b>.
      This port uses the STMicro STM3240G-EVAL board featuring the STM32F407IGH6 MCU.
      Refer to the <a href="http://www.st.com/internet/evalboard/product/252216.jsp">STMicro web site</a> for further information about this board.
    </p>
    <p>
      <b>STATUS:</b>
      <ul>
        <li><b>NuttX-6.12</b>
          The basic port is complete and first appeared in NuttX-6.12.
          The initial port passes the NuttX OS test and includes a validated configuration for the NuttShell (NSH, see the
          <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>) as well as several other configurations.
        </li>
        <li><b>NuttX-6.13-6.16</b>
          Additional drivers and configurations were added in NuttX 6.13-6.16.
          Drivers include an Ethernet driver, ADC driver, DAC driver, PWM driver, CAN driver, F4 RTC driver, Quadrature Encoder, DMA, SDIO with DMA
          (these should all be compatible with the STM32 F2 family and many should also be compatible with the STM32 F1 family as well).
        </li>
        <li><b>NuttX-6.16</b>
          The NuttX 6.16 release also includes and logic for saving/restoring F4 FPU registers in context switches.
          Networking intensions include support for Telnet NSH sessions and new configurations for DHPCD and the networking test (nettest).
        </li>
        <li><b>NuttX-6.17</b>
          The USB OTG device controller driver, and LCD driver and a function I2C driver were added in NuttX 6.17.
        </li>
        <li><b>NuttX-6.18</b>
          STM32 IWDG and WWDG watchdog timer drivers were added in NuttX 6.18 (should be compatible with F1 and F2).
          An LCD driver and a touchscreen driver for the STM3240G-EVAL based on the STMPE811 I/O expander were also added in NuttX 6.18.
        </li>
        <li><b>NuttX-6.21</b>
          A USB OTG host controller driver was added in NuttX 6.21.
        </li>
      </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STM32F4-Discovery</b>.
      This port uses the STMicro STM32F4-Discovery board featuring the STM32F407VGT6 MCU.
      Refer to the <a href="http://www.st.com/internet/evalboard/product/252419.jsp">STMicro web site</a> for further information about this board.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        The basic port for the STM32F4-Discovery was contributed by Mike Smith and was first released in NuttX-6.14.
        Drivers listed for the STM3240G-EVAL may be usable on this plaform as well.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>NXG Technologies LPC4330-Xplorer</b>.
      This NuttX port is for the LPC4330-Xplorer board from NGX Technologies featuring the NXP LPC4330FET100 MCU.
      See the <a href="http://shop.ngxtechnologies.com/product_info.php?cPath=21_37&products_id=104">NXG website</a> for further information about this board.
    </p>
    <p>
      <b>STATUS:</b>
    </p>
    <ul>
      <li>
        <p><b>NuttX-6.20</b>
          The basic port is complete.
          The OS test configuration and the basic NSH configurations are present and fully verified.
          This includes verified support for:  SYSTICK system time,  pin and GPIO configuration, and a serial console.
        </p>
        <p>
          Several drivers have been copied from the related LPC17xx port but require integration into the LPC43xx:  ADC, DAC, GPDMA, I2C, SPI, and SSP.
          The registers for these blocks are the same in both the LPC43xx and the LPC17xx and they should integrate into the LPC43xx very easily by simply adapting the clocking and pin configuration logic.
        </p>
        <p>
          Other LPC17xx drivers were not brought into the LPC43xx port because these peripherals have been completely redesigned:  CAN, Ethernet, USB device, and USB host.
        </p>
        <p>
          So then there is no support for the following LPC43xx peripherals: SD/MMC, EMC, USB0,USB1, Ethernet, LCD, SCT, Timers 0-3, MCPWM, QEI, Alarm timer, WWDT, RTC, Event monitor, and CAN.
        </p>
        <p>
          Some of these can be leveraged from other MCUs that appear to support the same peripheral IP:
          <ul>
            <li>
              The LPC43xx USB0 peripheral appears to be the same as the USB OTG peripheral for the LPC31xx.
              The LPC31xx USB0 device-side driver has been copied from the LPC31xx port but also integration into the LPC43xx (clocking and pin configuration).
              It should be possible to complete poriting of this LPC31xx driver with a small porting effort.
            </li>
            <li>
              The Ethernet block looks to be based on the same IP as the STM32 Ethernet and, as a result, it should be possible to leverage the NuttX STM32 Ethernet driver with a little more effort.
            </li>
          </ul>
        </p>
      </li>
      <li>
        <p><b>NuttX-6.21</b>
        Added support for a SPIFI block driver and for RS-485 option to the serial driver.
      </li>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
  <p>
    <b>Development Environments:</b>
    1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU Cortex-M3 or 4toolchain, or 3) Cygwin with Windows native GNU Cortex-M3 or M4 toolchain (CodeSourcery or devkitARM).  A DIY toolchain for Linux or Cygwin is provided by the NuttX
    <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a> package.
    I use FreeScale's <i>CodeWarrior</i> IDE only to work with the JTAG debugger built into the Kinetis boards.
    I use the <i>Code Red</i> IDE with the some of the NXP parts and the <i>Atollic</i> toolchain with some of the STMicroelectronics parts.
  </p>
  </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="atmelavr"><b>Atmel AVR</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>SoC Robotics ATMega128</b>.
      This port of NuttX to the Amber Web Server from <a href="http://www.soc-robotics.com/index.htm">SoC Robotics</a>
      is partially completed.
      The Amber Web Server is based on an Atmel ATMega128.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         Work on this port has stalled due to toolchain issues.  Complete, but untested
         code for this port appears in the NuttX 6.5 release.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Micropendous 3 AT90USB64x</b> and <b>AT90USB6128x</b>.
      This port of NuttX to the Opendous Micropendous 3 board. The Micropendous3 is
      may be populated with an AT90USB646, 647, 1286, or 1287.  I have only the AT90USB647
      version for testing.  This version have very limited memory resources: 64K of
      FLASH and 4K of SRAM.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         The basic port was released in NuttX-6.5.  This basic port consists only of
         a &quot;Hello, World!!&quot; example that demonstrates initialization of the OS,
         creation of a simple task, and serial console output.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>PJRC Teensy++ 2.0 AT90USB1286</b>.
      This is a port of NuttX to the PJRC Teensy++ 2.0 board.
      This board was developed by <a href="http://pjrc.com/teensy/">PJRC</a>.
      The Teensy++ 2.0 is based on an Atmel AT90USB1286 MCU.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         The basic port was released in NuttX-6.5.  This basic port consists of
         a &quot;Hello, World!!&quot; example that demonstrates initialization of the OS,
         creation of a simple task, and serial console output as well as a somewhat
         simplified NuttShell (NSH) configuration (see the
         <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
      </p>
      <p>
         An SPI driver and a USB device driver exist for the AT90USB as well
         as a USB mass storage configureation.  However, this configuration is not
         fully debugged as of the NuttX-6.5 release.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p><b>AVR-Specific Issues</b>.
      The basic AVR port is solid and biggest issue for using AVR is its tiny SRAM memory and its Harvard architecture.
      Because of the Harvard architecture, constant data that resides to flash is inaccessible using &quot;normal&quot; memory reads and writes (only SRAM data can be accessed &quot;normally&quot;).
      Special AVR instructions are available for accessing data in FLASH, but these have not been integrated into the normal, general purpose OS.
    </p>
    <p>
      Most NuttX test applications are console-oriented with lots of strings used for printf and debug output.
      These strings are all stored in SRAM now due to these data accessing issues and even the smallest console-oriented applications can quickly fill a 4-8K memory.
      So, in order for the AVR port to be useful, one of two things would need to be done:
    </p>
    <ol>
      <li>
        Don't use console applications that required lots of strings.
        The basic AVR port is solid and your typical deeply embedded application should work fine.
        Or,
      </li>
      <li>
        Create a special version of printf that knows how to access strings that reside in FLASH (or EEPROM).
      </li>
    </ol>
</tr>
<tr>
  <td><br></td>
  <td>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin with Windows native toolchain. 
        All testing, however, has been performed using the NuttX DIY toolchain for Linux  or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a> package.
        As a result, that toolchain is recommended.
      </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><br></td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="atmelavr32"><b>Atmel AVR32</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>AV32DEV1</b>.
      This port uses the www.mcuzone.com AVRDEV1 board based on the Atmel AT32UC3B0256 MCU.
      This port requires a special GNU avr32 toolchain available from atmel.com website.
      This is a windows native toolchain and so can be used only under Cygwin on Windows.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         This port is has completed all basic development, but there is more that needs to be done.
         All code is complete for the basic NuttX port including header files for all AT32UC3* peripherals.
         The untested AVR32 code was present in the 5.12 release of NuttX.
         Since then, the basic RTOS port has solidified:
      </p>
      <ul>
        <li>
          The port successfully passes the NuttX OS test (apps/examples/ostest).
        </li>
        <li>
          A NuttShell (NSH) configuration is in place (see the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
          Testing of that configuration has been postponed (because it got bumped by the Olimex LPC1766-STK port).
          Current Status: I think I have a hardware problem with my serial port setup.
          There is a good chance that the NSH port is complete and functional, but I am not yet able to demonstrate that.
          At present, I get nothing coming in the serial RXD line (probably because the pins are configured wrong or I have the MAX232 connected wrong).
        </li>
      </ul>
      <p>
        The basic, port (including the verified apps/examples/ostest configuration) was be released in NuttX-5.13.
        A complete port will include drivers for additional AVR32 UC3 devices -- like SPI and USB --- and will be available in a later release,
        time permitting.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="m68hcs12"><b>Freescale M68HCS12</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>MC9S12NE64</b>.
      Support for the MC9S12NE64 MCU and two boards are included:
    </p>
    <ul>
      <li>
        The Freescale DEMO9S12NE64 Evaluation Board, and
      </li>
      <li>
        The Future Electronics Group NE64 /PoE Badge board.
      </li>
    </ul>
    <p>
      Both use a GNU arm-elf toolchain* under Linux or Cygwin.
      The NuttX <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a> provides a properly patched GCC 3.4.4 toolchain that is highly optimized for the m9s12x family.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         Coding is complete for the MC9S12NE64 and for the NE64 Badge board.
         However, testing has not yet begun due to issues with BDMs, Code Warrior, and
         the paging in the build process.
         Progress is slow, but I hope to see a fully verified MC9S12NE64 port in the near future.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="8052"><b>Intel 8052 Microcontroller</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>PJRC 87C52 Development Board</b>.
      This port uses the <a href="http://www.pjrc.com/">PJRC</a> 87C52 development system
      and the <a href="http://sdcc.sourceforge.net/">SDCC</a> toolchain under Linux or Cygwin.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
        This port is complete but not stable with timer interrupts enabled.
        There seems to be some issue when the stack pointer enters into the indirect IRAM
        address space during interrupt handling.
        This architecture has not been built in some time will likely have some compilation
        problems because of SDCC compiler differences.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="80x86"><b>Intel 80x86</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>QEMU/Bifferboard i486</b>.
      This port uses the <a href="http://wiki.qemu.org/Main_Page">QEMU</a> i486 and the native
      Linux, Cywgin, MinGW the GCC toolchain under Linux or Cygwin.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         The basic port was code-complete in NuttX-5.19 and verifed in NuttX-6.0.
         The port was verified using the OS and NuttShell (NSH) examples under QEMU.
         The port is reported to be functional on the <a href="http://bifferos.bizhat.com">Bifferboard</a> as well.
         This is a great, stable starting point for anyone interest in fleshing out the x86 port!
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>RGMP</b>.
      RGMP stands for RTOS and GPOS on Multi-Processor.
      RGMP is a project for  running GPOS and RTOS simultaneously on multi-processor platforms
      You can port your favorite RTOS to RGMP together with an unmodified Linux to form a hybrid operating system.
      This makes your application able to use both RTOS and GPOS features.
    </p>
    <p>
      See the <a href="http://rgmp.sourceforge.net/wiki/index.php/Main_Page">RGMP Wiki</a> for further information about RGMP.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         This initial port of NuttX to RGMP was provided in NuttX-6.3.
         This initial RGP port provides only minimal driver support and does not use the native NuttX interrupt system.
         This is a great, stable starting point for anyone interest in working with NuttX under RGMP!
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="pic32mips"><b>MicroChip PIC32 (MIPS)</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p><b>PIC32MX250F128D</b>.
      A port is in progress from the DTX1-4000L &quot;Mirtoo&quot; module from <a href="http://www.dimitech.com/" >Dimitech</a>.
      This module uses MicroChip PIC32MX250F128D and the Dimitech DTX1-4000L EV-kit1 V2.
      See the <a href="http://www.dimitech.com/">Dimitech</a> website for further information.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        The basic port is code complete.
        Two configurations are available:
        (1) An OS test configuration and a (2) configuration that support the NuttShell (NSH).
        The OS test configuration is fully functional and proves that we have a basically healthy NuttX port to the Mirtoo.
        The NSH configuration includes support for a serial console and for the SST25 serial FLASH and the PGA117 amplifier/multiplexer on board the module.
        The NSH configuration is set up to use the NuttX wear-leveling FLASH file system (NXFFS).
        The PGA117, however, is not yet fully integrated to support ADC sampling.
        See the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a> for further information about NSH.
        The first verified port to the Mirtoo module was available with the NuttX 6.20 release.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
   <p><b>PIC32MX460F512L</b>.  There one two board ports using this chip:</p>
   <ul>
    <li><b>PIC32MX Board from PCB Logic Design Co</b>.
      This port is for the PIC32MX board from PCB Logic Design Co. and used the PIC32MX460F512L.
      The board is a very simple -- little more than a carrier for the PIC32 MCU plus voltage regulation, debug interface, and an OTG connector.
    </li>
    <p>
      <b>STATUS:</b>
      The basic port is code complete and fully verified in NuttX 6.13.
      Available configurations include the OS test and the NuttShell (NSH - see the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
    </p>
    <li><b>UBW32 Board from Sparkfun</b>
      This is the port to the Sparkfun UBW32 board.
      This port uses the <a href="http://www.sparkfun.com/products/8971">original v2.5</a> board which is based on the MicroChip PIC32MX460F512L.
      This older version has been replaced with this <a href="http://www.sparkfun.com/products/9713">newer board</a>.
      See also the <a href="http://www.schmalzhaus.com/UBW32/">UBW32</a> web site.
    </li>
    <p>
      <b>STATUS:</b>
      The basic port is code complete and fully verified in NuttX 6.18.
      Available configurations include the OS test and the NuttShell (NSH - see the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
      USB has not yet been fully tested but on first pass appears to be functional.
    </p>
  </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>PIC32MX440F512H</b>.
        This port uses the &quot;Advanced USB Storage Demo Board,&quot; Model DB-DP11215, from <a href="http://www.sureelectronics.net">Sure Electronics</a>.
        This board features the MicroChip PIC32MX440F512H.
        See the <a href="http://www.sureelectronics.net/goods.php?id=1168">Sure website</a> for further information about the DB-DP11215 board.
        (I believe that that the DB-DP11215 may be obsoleted now but replaced with the very similar, DB-DP11212.
        The DB-DP11212 board differs, I believe, only in its serial port configuration.)
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
       This NuttX port is code complete and has considerable test testing.
       The port for this board was completed in NuttX 6.11, but still required a few bug fixes before it will be ready for prime time.
       The fully verified port first appeared in NuttX 6.13.
       Available configurations include the OS test and the NuttShell (NSH - see the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
       An untested USB device-side driver is available in the source tree.
       A more complete port would include support of the USB OTG port and of the LCD display on this board.
       Those drivers are not yet available as of this writing.
       </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>PIC32MX795F512L</b>.
        There one two board ports using this chip:
    </p>
    <ul>
      <li><b>Microchip PIC32 Ethernet Starter Kit</b>.
         This port uses the Microchip PIC32 Ethernet Starter Kit (DM320004) with the Expansion I/O board.
         See the <a href="http://ww.microchip.com">Microchip website</a> for further information.
      </li>
      <p>
       <b>STATUS:</b>
         This port was started and then shelved for some time until I received the Expansion I/O board.
         The basic Starter Kit (even with the Multimedia Expansion Board, MEB, DM320005)) has no serial port and most NuttX test configurations depend heavily on console output.
      </p>
      <p>
         Verified configurations for the OS test and the NuttShel (NSH) appeared in NuttX-6.16.
         Board support includes a verified USB (device-side) driver.
         Also included are a a verified Ethernet driver, a partially verified USB device controller driver, and an unverifed SPI driver.
         Stay tuned for updates.
      </p>
     <li><b>Mikroelektronika PIC32MX7 Mulitmedia Board (MMB)</b>.
        A port has been completed for the  Mikroelektronika PIC32MX7 Multimedia Board (MMB).
        See http://www.mikroe.com/ for further information about this board.
      </li>
      <p>
       <b>STATUS:</b>
         Two verified configurations are available:
         (1) The basic OS test configuration that verfies the correctness port of NuttX, and (2) an extensive <a href="NuttShell.html">NuttShell (NSH)</a> configuration.
         The NSH configuration includes:
         (1) Full network support,
         (2) Verified SPI driver,
         (3) SPI-based SD Card support,
         (4) USB device support (including configuration options for the USB mass storage device and the CDC/ACM serial class), and
         (5) Support for the MIO873QT2 LCD on the PIC32MX7 MMB.
       </p>
       </p>
         The PIC32MX7 MMB's touchscreen is connected directly to the MCU via ADC pins.
         A touchscreen driver has been developed using the PIC32's ADC capabilities and can be enabled in the NSH configuration.
         However, additional verification and tuning of this driver is required.
         Further display/touchscreen verification would require C++ support (for NxWidgets and NxWM).
         Since I there is no PIC32 C++ is the free version of the MPLAB C32 toolchain, further graphics development is stalled.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Development Environment:</b>
      These ports uses either:
    </p>
    <ol>
      <li>
        The <i>LITE</i> version of the PIC32MX toolchain available
        for download from the <a href="http://www.microchip.com">MicroChip</a> website, or
      </li>
      <li>
        The Pinguino MIPS ELF toolchain avaiable from the Pinquino <a href="http://code.google.com/p/pinguino32/downloads/list">website</a>.
      </li>
    </ol>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><br></td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="superh"><b>Renesas/Hitachi SuperH</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>SH-1 SH7032</b>.
      This port uses the Hitachi SH-1 Low-Cost Evaluation Board (SH1_LCEVB1), US7032EVB,
      with a GNU ELF toolchain* under Linux or Cygwin.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
        This port is available as of release 0.3.18 of NuttX.  The port is basically complete
        and many examples run correctly.  However, there are remaining instabilities that
        make the port un-usable.  The nature of these is not understood; the behavior is
        that certain SH-1 instructions stop working as advertised.  This could be a silicon
        problem, some pipeline issue that is not handled properly by the gcc 3.4.5 toolchain
        (which has very limit SH-1 support to begin with), or perhaps with the CMON debugger.
        At any rate, I have exhausted all of the energy that I am willing to put into this cool
        old processor for the time being.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="m16c"><b>Renesas M16C/26</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Renesas M16C/26 Microncontroller</b>.
      This port uses the Renesas SKP16C26 Starter kit and the GNU M32C toolchain. 
      The development environment is either Linux or Cygwin under WinXP.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        Initial source files released in nuttx-0.4.2.
        At this point, the port has not been integrated;    the target cannot be built
        because the GNU <code>m16c-elf-ld</code> link fails with  the following message:
      </p>
      <ul>
      <code>m32c-elf-ld: BFD (GNU Binutils) 2.19 assertion fail /home/Owner/projects/nuttx/buildroot/toolchain_build_m32c/binutils-2.19/bfd/elf32-m32c.c:482</code>
      </ul>
      <p>Where the reference line is:</p>
      <ul><pre>
/* If the symbol is out of range for a 16-bit address,
   we must have allocated a plt entry.  */
BFD_ASSERT (*plt_offset != (bfd_vma) -1);
</pre></ul>
      <p>
        No workaround is known at this time.  This is a show stopper for M16C for
        the time being.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="zilogz16f"><b>Zilog Z16F</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Zilog z16f Microncontroller</b>.
      This port use the Zilog z16f2800100zcog development kit and the Zilog
      ZDS-II Windows command line tools.
      The development environment is Cygwin under WinXP.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        The initial release of support for the z16f was made available in NuttX version 0.3.7.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="zilogez80acclaim"><b>Zilog eZ80 Acclaim!</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Zilog eZ80Acclaim! Microncontroller</b>.
      There are two eZ80Acclaim! ports:
    </p>
    <ul>
      <li>One uses the ZiLOG ez80f0910200kitg development kit, and
      <li>The other uses the ZiLOG ez80f0910200zcog-d development kit.
    </ul>
    <p>
      Both boards are based on the eZ80F091 part and both use the Zilog ZDS-II
      Windows command line tools.
      The development environment is Cygwin under WinXP.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        Integration and testing of NuttX on the  ZiLOG ez80f0910200zcog-d is complete.
        The first integrated version was released in NuttX version 0.4.2 (with important early bugfixes
        in 0.4.3 and 0.4.4).
        As of this writing, that port provides basic board support with a serial console, SPI, and eZ80F91 EMAC driver.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="zilogz8encore"><b>Zilog Z8Encore!</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Zilog Z8Encore! Microncontroller</b>.
      This port uses the either:
    </p>
    <ul>
      <li>Zilog z8encore000zco development kit, Z8F6403 part, or</li>
      <li>Zilog z8f64200100kit development kit, Z8F6423 part</li>
    </ul>
    <p>
      and the Zilog ZDS-II Windows command line tools.
      The development environment is Cygwin under WinXP.
    </p>
    <ul>
       <p>
         <b>STATUS:</b>
         This release has been verified only on the ZiLOG ZDS-II Z8Encore! chip simulation
         as of nuttx-0.3.9.
       </p>
     <ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="zilogz80"><b>Zilog Z80</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Z80 Instruction Set Simulator</b>.
      This port uses the <a href="http://sdcc.sourceforge.net/">SDCC</a> toolchain
      under Linux or Cygwin (verified using version 2.6.0).
      This port has been verified using only a Z80 instruction simulator.
      That simulator can be found in the NuttX SVN
      <a href="http://svn.code.sf.net/p/nuttx/code/trunk/misc/sims/z80sim/">here</a>.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
        This port is complete and stable to the extent that it can be tested
        using an instruction set simulator.
      </p>
    <ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>XTRS: TRS-80 Model I/III/4/4P Emulator for Unix</b>.
      A very similar Z80 port is available for <a href="http://www.tim-mann.org/xtrs.html">XTRS</a>,
      the TRS-80 Model I/III/4/4P Emulator for Unix.
      That port also uses the <a href="http://sdcc.sourceforge.net/">SDCC</a> toolchain
      under Linux or Cygwin (verified using version 2.6.0).
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
       Basically the same as for the Z80 instruction set simulator.
       This port was contributed by Jacques Pelletier.
      </p>
    <ul>
  </td>
</tr>
</table></center>

<blockquote>* A highly modified <a href="http://buildroot.uclibc.org/">buildroot</a>
is available that may be used to build a NuttX-compatible ELF toolchain under
Linux or Cygwin.  Configurations are available in that buildroot to support ARM, Cortex-M3,
avr, m68k, m68hc11, m68hc12, m9s12, blackfin, m32c, h8, and SuperH ports.</blockquote>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="environments"><h1>Development Environments</h1></a>
  </td>
  </tr>
</table>

<center><table width="90%">
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Linux + GNU <code>make</code> + GCC/binutils</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      The is the most natural development environment for NuttX.
      Any version of the GCC/binutils toolchain may be used.
      There is a  highly modified <a href="http://buildroot.uclibc.org/">buildroot</a>
      available for download from the
      <a href="http://sourceforge.net/projects/nuttx/files/">NuttX SourceForge</a>
      page.
      This download may be used to build a NuttX-compatible ELF toolchain under Linux or Cygwin.
      That toolchain will support ARM, m68k, m68hc11, m68hc12, and SuperH ports.
      The buildroot SVN may be accessed in the 
      <a href="http://svn.code.sf.net/p/nuttx/code/trunk/misc/buildroot/">NuttX SVN</a>.
    </p>
   </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Linux + GNU <code>make</code> + SDCC</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      Also very usable is the Linux environment using the 
      <a href="http://sdcc.sourceforge.net/">SDCC</a> compiler.
      The SDCC compiler provides support for the 8051/2, z80, hc08, and other microcontrollers.
      The SDCC-based logic is less well exercised and you will likely find some compilation
      issues if you use parts of NuttX with SDCC that have not been well-tested.
    </p>
   </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Cygwin + GNU <code>make</code> + GCC/binutils</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      This combination works well too.
      It works just as well as the native Linux environment except
      that compilation and build times are a little longer.
      The custom NuttX <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a> referenced above may be build in
      the Cygwin environment as well.
    </p>
  </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Cygwin + GNU <code>make</code> + SDCC</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
       I have never tried this combination, but it would probably work just fine.
    </p>
  </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Cygwin + GNU <code>make</code> + Windows Native Toolchain</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      This is a tougher environment.
      In this case, the Windows native toolchain is unaware of the
      Cygwin <i>sandbox</i> and, instead, operates in the native Windows environment.
      The primary difficulties with this are:
    </p>
    <ul>
      <li>
        <b>Paths</b>.
        Full paths for the native toolchain must follow Windows standards.
        For example, the path <code>/home/my\ name/nuttx/include</code> my have to be
        converted to something like <code>'C:\cygwin\home\my name\nuttx\include'</code>
        to be usable by the toolchain.
      </li>
      <p>
        Fortunately, this conversion is done simply using the <code>cygpath</code> utility.
      </p>
      <li>
        <b>Symbolic Links</b>
        NuttX depends on symbolic links to install platform-specific directories in the build system.
        On Linux, true symbolic links are used.
        On Cygwin, emulated symbolic links are used.
        Unfortunately, for native Windows applications that operate outside of the
        Cygwin <i>sandbox</i>, these symbolic links cannot be used.
      </li>
      <p>
        The NuttX make system works around this limitation by copying the platform
        specific directories in place.
        These copied directories make work a little more complex, but otherwise work well.
      </p>
      <p><small>
        NOTE: In this environment, it should be possible to use the NTFS <code>mklink</code> command to create links.
        This should only require a minor modification to the build scripts (see <code>tools/winlink.sh</code> script).
      </small></p>
      <li>
        <b>Dependencies</b>
        NuttX uses the GCC compiler's <code>-M</code> option to generate make dependencies.  These
        dependencies are retained in files called <code>Make.deps</code> throughout the system.
        For compilers other than GCC, there is no support for making dependencies in this way.
        For Windows native GCC compilers, the generated dependencies are windows paths and not
        directly usable in the Cygwin make.  By default, dependencies are surpressed for these
        compilers as well.
      </li>
      <p><small>
        NOTE: dependencies are suppress by setting the make variable <code>MKDEPS</code> to point
        to the do-nothing dependency script, <code>tools/mknulldeps.sh</code>.
        Dependencies can be enabled for the Windows native GCC compilers by setting
        <code>MKDEPS</code> to point to <code>$(TOPDIR)/tools/mkdeps.sh --winpaths $(TOPDIR)</code>.
      </small></p>
    </ul>
    <p>
      <b>Supported Windows Native Toolchains</b>.
      At present, only the Zilog Z16F, z8Encore, and eZ80Acclaim ports use a non-GCC native Windows
      toolchain(the Zilog ZDS-II toolchain).
      Support for Windows native GCC toolchains (CodeSourcery and devkitARM) is currently implemented
      for the NXP LPC214x, STMicro STR71x, and Luminary LMS6918 ARM ports.
      (but could easily be extended to any other GCC-based platform with a small effort).
    </p>
  </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Wine + GNU <code>make</code> + Windows Native Toolchain</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      I've never tried this one, but I off the following reported by an ez80 user using the ZiLOG ZDS-II Windows-native toolchain:
    </p>
    <blockquote>
      <p>
         &quot;I've installed ZDS-II 5.1.1 (IDE for ez80-based boards) on wine (windows emulator for UNIX) and to my surprise, not many changes were needed to make SVN snapshot of NuttX buildable...
         I've tried nsh profile and build process completed successfully.
         One remark is necessary: NuttX makefiles for ez80 are referencing <code>cygpath</code> utility.
         Wine provides similar thing called <code>winepath</code> which is compatible and offers compatible syntax.
         To use that, <code>winepath</code> (which itself is a shell script) has to be copied as <code>cygpath</code> somewhere in <code>$PATH</code>, and edited as in following patch:
       </p>
       <ul><pre>
# diff -u `which winepath` `which cygpath`
--- /usr/bin/winepath 2011-05-02 16:00:40.000000000 +0200
+++ /usr/bin/cygpath 2011-06-22 20:57:27.199351255 +0200
@@ -20,7 +20,7 @@
#

# determine the app Winelib library name
-appname=`basename "$0" .exe`.exe
+appname=winepath.exe

# first try explicit WINELOADER
if [ -x "$WINELOADER" ]; then exec "$WINELOADER" "$appname" "$@"; fi
</pre></ul>
      <p>
        &quot;Better solution would be replacing all <code>cygpath</code> references in  <code>Makefiles </code> with  <code>$(CONVPATH)</code> (or  <code>${CONVPATH}</code> in shell scripts) and setting <code>CONVPATH</code> to  <code>cygpath</code> or  <code>winepath</code> regarding to currently used environment.
      </p>
    </blockquote>
  </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Other Environments?
    Windows Native <code>make</code> + Windows Native Toolchain?</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Environment Dependencies</b>.
      The primary environmental dependency of NuttX are (1) GNU make,
      (2) bash scripting, and (3) Linux utilities (such as cat, sed, etc.).
      If you have other platforms that support GNU make or make
      utilities that are compatible with GNU make, then it is very
      likely that NuttX would work in that environment as well (with some
      porting effort). If GNU make is not supported, then some significant
      modification of the Make system would be required.
    </p>
    <p>
     <b>GNUWin32</b>.
      For example, with suitable make system changes, it should be possible to
      use native GNU tools (such as those from
      <a href="http://sourceforge.net/projects/gnuwin32/">GNUWin32</a>)
      to build NuttX.
      However, that environment has not been used as of this writing.
   </p>
      <p><small>
        NOTE: One of the members on the <a href="http://tech.groups.yahoo.com/group/nuttx/">NuttX forum</a>
        reported that they successful built NuttX using such a GNUWin32-based, Windows native environment.
        They reported that the only necessary change was to the use the NTFS mklink command to create links
        (see <code>tools/winlink.sh</code> script).
      </small></p>
  </td>
</tr>
</table></center>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="footprint"><h1>Memory Footprint</h1></a>
  </td>
  </tr>
</table>

<ul>
<p><b>C5471 (ARM7)</b>
  The build for this ARM7 target that includes most of the OS features and
  a broad range of OS tests.  The size of this executable as given by the
  Linux <tt>size</tt> command is (3/9/07):
</p>
<pre>
   text    data     bss     dec     hex filename
  53272     428    3568   57268    dfb4 nuttx
</pre>
<p><b>DM320 (ARM9)</b>
  This build for the ARM9 target includes a significant subset of OS
  features, a filesystem, Ethernet driver, full TCP/IP, UDP and (minimal)
  ICMP stacks (via uIP) and a small network test application: (11/8/07,
  configuration netconfig, apps/examples/nettest)
</p>
<pre>
   text    data     bss     dec     hex filename
  49472     296    3972   53740    d1ec nuttx
</pre>
<p>
  Another build for the ARM9 target includes a minimal OS feature
  set, Ethernet driver, full TCP/IP and (minimal) ICMP stacks, and
  a small webserver: (11/20/07, configuration uipconfig, apps/examples/uip)
</p>
<pre>
   text    data     bss     dec     hex filename
  52040      72    4148   56260    dbc4 nuttx
</pre>
<p><b>87C52</b>
  A reduced functionality OS test for the 8052 target requires only
  about 18-19K:
</p>
<pre>
Stack starts at: 0x21 (sp set to 0x20) with 223 bytes available.

Other memory:
   Name             Start    End      Size     Max
   ---------------- -------- -------- -------- --------
   PAGED EXT. RAM                         0      256
   EXTERNAL RAM     0x0100   0x02fd     510     7936
   ROM/EPROM/FLASH  0x2100   0x6e55   19798    24384
</pre>
</ul>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="licensing"><h1>Licensing</h1></a>
  </td>
  </tr>
</table>

<ul>
<p>
  NuttX is available under the highly permissive
  <a href="http://en.wikipedia.org/wiki/BSD_license">BSD license</a>.
  Other than some fine print that you agree to respect the copyright
  you should feel absolutely free to use NuttX in any environment and
  without any concern for jeopardizing any proprietary software that
  you may link with it.
</p>
</ul>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="history"><h1>Release History</h1></a>
  </td>
  </tr>
</table>

<ul>
<p>
   ChangeLog snapshots associated with the previous, current, and future release are available below.
</p>
</ul>

<center><table width ="80%">
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
   <td>
      <a href="ChangeLog.txt">Change logs for previous NuttX releases</a><br>
   </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
   <td>
      <a href="#currentrelease">ChangeLog for the current NuttX releases</a><br>
   </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
   <td>
      <a href="#pendingchanges">Unreleased changes</a>
   </td>
</tr>
</table></center>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="currentrelease">ChangeLog for the Current Release</a>
  </td>
  </tr>
</table>

<ul><pre>
nuttx-6.22 2012-09-29 Gregory Nutt &lt;gnutt@nuttx.org&gt;

    * include/semaphore.h, sched/sem_holders.c, and lib/semaphore/sem_init.c:
      Fix some strange (and probably wrong) list handling when
      CONFIG_PRIORITY_INHERITANCE and CONFIG_SEM_PREALLOCHOLDERS are defined.
      This list handling was probably causing errors reported by Mike Smith
    * sched/sched_waitpid.c: Fix a possible issue with logic logic that
      should be brought into a critical section (suggested by Mike Smith)
    * sched/sched_setuptaskfiles.c: Should be 'struct socket' not
      'struct sockets'.  How did this compile before? (found by Kate)
    * syscall/syscall.csv:  Fix prototype for usleep() and prctl() (also
      from Kate).
    * arch/arm/src/lpc17xx/lpc17_ethernet.c:  Conditionally elide setting PHY
      speed/duplex.  This does not work for certain PHYs.  Still some unresolved
      issues (also from Kate).
    * tools/Config.mk, Makefile, configs/*/Make.defs:  Add a new Makefile
      fragment to de-quote certain strings from the Kconfig logic that
      need to be used at path segments (Richard Cochran).
    * arch/arm/src/stm32/stm32_usbotghost.c:  The STM32 USB host driver only
      works with debug turned on.  The problem appears to be that with debug
      OFF, there are more NAKs occuring in more places than before and this
      reveals a variety of errors.  This check in improves NAK robustness
      for control transfers but does not resolve all of the issues.
    * configs/stm3220g-eval/*/defconfig:  Calibrated delay loop.  It had
      never been calibrated was way off.
    * sched/sem_holder.c: Add logic to handler some priority inheritance
      cases when sem_post() is called from an interrupt handler.  The
      logic is clearly wrong, but it is not known if this is the
      cause of any known bugs.
    * lib/stdio/lib_perror():  Add perror().  Contributed by Kate.
    * lib/string/lib_strerror():  Add option CONFIG_LIBC_STRERROR that
      is now required to enabled strerror().  Add an option
      CONFIG_LIBC_STRERROR_SHORT that can be used to output shortened
      strings by strerror().
    * arch/arm/src/stm32/stm32_usbotghost.c:  Finally... the USB OTG FS
      appears to handle NAKing correctly.
    * configs/stm32f4discovery/*:  Added and verifed support for USB OTG FS
      host on the STM32F4Discovery board.
    * configs/*/defconfig: Remove configuration documentation from config
      files.  It is redundant, error-prone, and difficult to maintain.
      Configuration documentation is available in configs/README.txt for
      common configurations and in configs/*/README.txt for board and MCU-
      specific configurations.
    * configs/stm3240g-eval: Add USB host support.
    * sched/os_bring.c, configs/*/defconfig, tools/mkconfig.c, and others:  Added
      configuration variable CONFIG_USER_ENTRYPOINT that may be used to change
      the default entry from user_start to some other symbol.  Contributed by
      Kate. NOTE: This change does introduce a minor backward incompatibility.
      For example, if your application uses NSH as its start-up program, then your
      build will now fail because it will be unable to find &quot;user_start&quot;.  The fix
      for this link failure is to add the following to your configuration file:
      CONFIG_USER_ENTRYPOINT=&quot;nsh_main&quot;.
    * libs/stdio/lib_libfread.c and lib_*flush*.c:  Correct a couple of
      error cases where the lib semaphore was not be released on error
      exits (thanks Ronen Vainish).  Also, improved some error reporting:
      the generic ERROR was being used instead of the specific errno
      value; the errno variable was not always set correctly.
    * tools/mkfsdata.pl: The uIP web server CGI image making perl script was
      moved from apps/netutils/webserver/makefsdata to nuttx/tools/mkfsdata.pl
      (Part of a larger change submitted by Max Holtzberg).
    * configs/stm3240g-eval/script/ld.script:  All of the identical ld.script
      files for the STM3240G-EVAL were replaced by one version in this directory.
    * configs/stm3240g-eval/webserver:  Configuration submitted by Max Holtzberg
      for testing the changes to the uIP web server (see apps/ChangeLog.txt).
    * lib/stdio/lib_perror.c:  Remove CONFIG_LIBC_PERROR_DEVNAME.  What was I
      thinking?  Arbitrary streams cannot be shared by different tasks.
    * tools/mksyscall.c, csvparser.c, and csvparser.h: Separate CSV parsing
      logic from mksyscall.c into files where it can be shared.
    * tools/mksymtab.c:  Add a tool that can be used to convert a CSV file
      into a NuttX-style symbol table.
    * sched/work_cancel.c:  Fix a bad assertion (reported by Mike Smith)
    * configs/stm3210e-eval/src/up_idle.c:  Correct some power management
      compilation errors (reported by Diego Sanchez).
    * include/nuttx/wqueue.h, sched/work*, and others:  Added logic to support
      a second, lower priority work queue (CONFIG_SCHED_LPWORK).
    * arch/arm/src/stm32/stm32_dma.c, chip/stm32*_memorymap.h:  FSMC SRAM is
      only 16-bits wide and the SDIO DMA must be set up differently.
    * arch/arm/src/stm32/stm32_dma.c:  Back out the 16-bit DMA change. It
      is incorrect.
    * configs/:  Make use of UART4/5 vs USART4/5 consistent in all places.
    * Kconfig: Serial 2STOP setting must be integer 0/1, not a boolean.
    * lib/misc/sendfile.c and include/sys/sendfile.h:  Add a Linux style
      sendfile() (non-standard!)
    * Kconfig: Refactor serial settings (moved from chip to drivers/serial).
      AVR &quot;teensy&quot; now builds with Kconfig (contributed by Richard Cochran).
    * Kconfig: Add configuration settings for the LPC17xx
    * Kconfig: Add configuration settings for the LM3S (from Richard Cochran).
    * Kconfig: Verify configuration settings for the STM32.  This includes
      changes in the way that the external SRAM is configured:  Define
      CONFIG_HEAP2_SIZE (decimal) instead of CONFIG_HEAP2_END (hex).
    * tools/configure.sh:  Don't append the apps directory path setting
      if the correct setting is already in defined in the defconfig file.
    * fs/fat/fs_utils.c:  Improperly constructed bool expression.  This
      would cause many unnecessary writes to FLASH (Thanks Ronen Vainish).
    * Kconfig: Verify configuration settings for the LPC43xx.  This includes
      some corrections to configuration variable names and defconfig settings.
    * Kconfig: Add and verify configuration settings for the LPC31xx.
    * arch/arm/src/stm32/stm32_uart.h and stm32_serial.c:  Add logic to
      re-initialize the console UART as needed to enable DMA on the
      console UART (contributed by Mike Smith).
    * net/recvfrom.c, net/Kconfig, include/nuttx/net/uipopt.h: Remove delay
      after receiving data.  That has historical reasons to be there (it
      was needed before read-ahead buffering was added), but kills performance.
      (Noted by Max Holtzberg).
    * configs/shenzhou:  Add beginnings of a board configuration for the
      Shenzhou STM32107 board (see www.armjishu.com).  Very little is in
      place as of this initial check-in.
    * QEMU: Fixes from Richard Cochran to build QEMU with Kconfig files.
    * arch/*/src/Makefile:  Remove some old logic that was kicked off
      when CONFIG_BOOT_RUNFROMFLASH=y.  The old logic used to use
      objcopy to move sections.  Newer logic changes the load position
      of sections in the the linker script.  As far as I can tell, there
      is nothing in the source tree now that depends on the old way of
      doing things (if I am wrong, they will need a change to the linker
      script).
    * configs/fire-stm32v2:  Configuration for the M3 Wildfire board.  I
      don't know very much about this board other than is has an
      STM32F103VET6 chip, LCD, touchscreen, and ENC28J60 network.  Very
      little is in place on the initial check-in.
    * configs/shenzhou: Coding for the Shenzhou board port is complete,
      but tested has been deferred until I get the right tools.
    * arch/arc/include/stm32/chip.h and arch/arm/src/stm32/chip.h:
      Add support for the STM32F103VET6.
    * fs/fs_fdopen.c: Bad check for failure to allocate memory.  (Noted
      by Ronen Vainish).
    * drivers/mmcsd/mmcsd_sdio.c: If the MMC/SD driver were ever
      uninitialized then there would be a double release of memory
      (Noted by Ronen Vainish).
    * fs/mmap/fs_rammap.c:  Fix logic error and errno check (contributed
      by Kate).
    * arch/avr/src: Fixes from AVR32 build errors that have crept in
      over the time; incorporated Kconfig for AVR3 (Richard Cochran).
    * fs/fat and include/nuttx/fs/fat.h: The FAT file system allocates
      memory for sector I/O buffers used to exchange data with the
      configured block driver.  In some contexts, the block driver may
      require DMA-capable memory.  If CONFIG_FAT_DMAMEMORY is defined,
      then the FAT FS will use platform-provided DMA memory allocators
      to allocate the block driver I/O buffers.
    * CONFIG_NET_ENC28J60 renamed CONFIG_ENC28J60 to be consistent
      in all places.
    * drivers/enc28j60.c, include/nuttx/net/enc28j60.h, and 
      olimex-strp711/src/up_enc28j60.c:  No longer passes IRQ number
      as a parameter.  Instead now passes a call table to manage
      ENC28J60 GPIO interrupts.  That is because GPIO interrupts are
      handled in different ways by different MCUs and some do not
      support IRQ numbers for GPIO interrupts.
    * mm/mm_gran* and include/nuttx/gran.h:  Add a simple granule-
      based allocator.  The intent of this allocator is to support
      simple allocation of DMA I/O buffers.  The initial check-in
      is code complete but untested (not event built into the
      mm/Makefile yet.
    * confgs/fire-stm32v2: The board port is basically functional.
      Not all features have been verified.  The ENC28J60 network
      is not yet functional.
    * configs/stm3240g-eval/discover:  A configuration for testing
      the UDP discovery utility.  Contributed by Max Holtzberg.
    * mm/README.txt:  Add a new README file.
    * include/nuttx/usb/usb.h, arch/*/src/*usb.c, and arch/*/src/*otg*.c:
      Add hooks to to use common, external DMA buffer allocation
      implementation.
    * net/recvfrom.c: Don't block in recvfrom if (1) read-ahead buffering
      is enabled and (2) some data was obtained from read-ahead buffers.
      Blocking is a bad idea in that case because there is no timeout!
      (submitted by Max Holtzberg).
    * configs/stm3240g-eval/xmlrpc: An example configuration for the
      Embeddable Lightweight XML-RPC Server at apps/examples/xmlrpc.
      See http://www.drdobbs.com/web-development/\
      an-embeddable-lightweight-xml-rpc-server/184405364 for more info.
      Contributed by Max Holtzberg.
    * configs/*/nxwm/defconfig and sched/task_exithook.c: Fixes for
      bugs that crept in during recent changes.  (Submitted by Max
      Holtzberg).
    * arch/arm/include/armv7-m/irq.h:  Fix a critical bug in irqsave().
      It looks like sometimes the compile will re-order some instructions
      inapproapriately.  This end result is that interrupts will get
      stuck off.
    * drivers/mtd/w25.c:  Beginning of a driver for the Windbond SPI
      FLASH family (W25x16, W25x32, and W25x64).  The initial check-in
      is basically just the SST25 driver with some name changes.
    * arch/arm/include/armv7-m/irq.h and arch/arm/src/stm32/stm32_spi.c:
      Back out the last change in irq.h.  It is (most likely) fine the
      way it was.  The really interrupt related problem was in stm32_spi.c:
      When SPI3 is not enabled, then the irqrestore() falls in the
      else clause.
    * include/nuttx/compiler.h and other files:  Moved always_inline
      and noinline __attributes__ here.  Also replaced all occurrences
      of explicit __atributes__ in other files with definitions from
      this header file.
    * drivers/mtd/w25.c:  The Windbond SPI FLASH W25 FLASH driver is
      code complete (but still untested).
    * arch/arm/src/stm32/stm32_i2c.c:  I2C improvements from Mike Smith.
      Unified configuration logic; dynamic timeout calculations;
      I2C reset logic to recover from locked devices on the bus.
    * configs/*/*/Make.defs, tools/Config.mk, Makefile:  Refactor all
      common make definitions from the various Make.defs files into
      the common tools/Config.mk.  Add support for a verbosity options:
      Specify V=1 on the make command line in order to see the exact
      commands used in the build (Contributed by Richard Cochran).
    * drivers/net/enc28j60.c:  The ENC28J60 Ethernet driver is
      now functional.
    * configs/fire-stm32v2:  Add support or the fire-stm32v3 board as
      well (untested because I do not have a v3 board).
    * lib/stdio/lib_sscanf.c:  Add %n psuedo-format (from Kate).
    * lib/stdio/lib_sscanf.c:  There is an issue of handling input
      when (1) no fieldwidth is provided and (2) there is no space
      seperating the input values.  No solutions is in place for this
      case now (either space or a fieldwidth must be provided).  But
      at least some of the bad logic that attempted to handle this
      case has been removed (noted by Kate).
    * arch/arm/src/stm32/stm32_eth.c:  DMA buffer sizes must be an
      even multiple of 4, 8, or 16 bytes.
    * arch/arm/src/stm32/stm32_idle.c:  Fixes STM32F107 DMA issues:
      We cannot go into sleep mode while Ethernet is actively DMAing.
    * configs/shenzhou/src/up_ssd1289.c:  Add infrastructure to support
      SSD1289 LCD.  Initial checkin is just a clone of the
      STM32F4Discovery's FSMC-based LCD interface.  The Shenzhou
      will need a completely need bit-banging interface; this
      initial check-in is only for the framework.
    * configs/shenzhou/src/up_ssd1289.c:  Bit-banging driver is
      code complete.
    * configs/shenzhou/src/up_lcd.c:  Oops. Shenzhou LCD does not
      have an SSD1289 controller.  Its an ILI93xx.  Ported the
      STM3240G-EVAL ILI93xx driver to work on the Shenzhou board.
    * configs/shenzhou/nxwm:  Added an NxWM configuration for the
      Shenzhou board.  This is untested on initial check-in.  It will
      be used to verify the Shenzhou LCD driver (and eventually the
      touchscreen driver).
    * configs/shenzhou/src/up_touchscreen.c:  Add ADS7843E touchscreen
      support for the Shenzhou board.  The initial check-in is untested
      and basically a clone of the the touchscreen support for the SAM-3U.
    * tools/cfgparser.c: There are some NxWidget configuration
      settings that must be de-quoted.
    * arch/arm/src/stm32/Kconfig: There is no SPI4.  Some platforms
      support SPI3 and some do not (still not clear).
    * nuttx/configs/shenzhou: Various fixes to build new NxWM
      configuration.
    * configs/shenzhou:  Oops.  The Shenzhou LCD is and SSD1289,
      not an ILI93xx.
    * configs/shenzhou/src/up_ssd1289.c: The LCD is basically functional
      on the Shenzhou board.
    * graphics/nxmu:  Correct some bad parameter checking that caused
      failures when DEBUG was enabled.
    * arch/arm/src/armv7-m/nvic.h:  Add bit definitions for the AIRCR
      register.
    * drivers/input/ads7843.c:  Need semaphore protection in logic
      that samples the position.
    * drivers/lcd/ssd1289.c:  On some platforms we are unable to
      read the device ID -- reason unknown; workaround in place.
    * drivers/input/ads7843.c:  Add thresholding options and an
      option to swap X and Y positions.  Fix some logic errors in
      the SPI locking/selecting logic.
    * arch/arm/src/armv7-m/up_systemreset.c:  Add logic to reset
      the Cortex-Mx using the AIRCR register.  Contributed by Darcy
      Gong.
    * arch/arm/src/stm32/up_eth.c:  Add logic specifically for the
      DM9161 PHY.  If the DM9161 failed to initialize, then use the
      up_sysemreset() logic to reset the MCU.  Contributed by Darcy
      Gong.
    * arch/arm/src/stm32/stm32_gpio.c:  Add missing logic to set bit
      for SPI3 remap.  This fixes the XPT2046 touchscreen driver using
      drivers/input/ads7843.c
    * configs/shenzhou/src/up_ssd1289.c:  Fix naming error in
      conditional compilation.
    * configs/shenzhou/nxwm/defconfig:  Disable reading from the LCD.
      This does not work.  The hardware and the driver support the
      capability, but there is some bug that causes memory corruption.
      The work around for now:  Just disable reading from the LCD.
    * drivers/lcd/ssd1289.c:  Add some logic to reduce the amount of
      output when CONFIG_DEBUG_LCD is enabled.
    * configs/shenzhou/nxwm/defconfig:  Bug found and fixed... The
      original configuration had too much stuff turned on.  Reducing
      stack sizes, some features, and buffer sizes made the
      configuration reliable (Reading from the LCD is still disabled).
    * net/uip/uip_icmpping.c:  Fix problem that prevented ping from
      going outside of local network.  Submitted by Darcy Gong

apps-6.22 2012-09-29 Gregory Nutt &lt;gnutt@nuttx.org&gt;

    * apps/netutils/thttpd/thttpd_cgi.c:  Missing NULL in argv[]
      list (contributed by Kate).
    * apps/nshlib/nsh_parse.c: CONFIG_NSH_DISABLE_WGET not CONFIG_NSH_DISABLE_GET
      in one location (found by Kate).
    * apps/examples/ostest/prioinherit.c:  Limit the number of test
      threads to no more than 3 of each priority.  Bad things happen
      when the existing logic tried to created several hundred test
      treads!
    * apps/nshlib/nsh.h:  Both CONFIG_LIBC_STRERROR and CONFIG_NSH_STRERROR
      must be defined to use strerror() with NSH.
    * apps/examples/*/*_main.c, system/i2c/i2c_main.c, and others:  Added
      configuration variable CONFIG_USER_ENTRYPOINT that may be used to change
      the default entry from user_start to some other symbol.  Contributed by
      Kate.
    * apps/netutils/webserver/httpd/c:  Fix a typo that as introduced in
      version r4402:  'lese' instead of 'else' (Noted by Max Holtzberg).
    * tools/mkfsdata.pl: The uIP web server CGI image making perl script was
      moved from apps/netutils/webserver/makefsdata to nuttx/tools/mkfsdata.pl
      (Part of a larger change submitted by Max Holtzberg).
    * apps/netutils/webserver, apps/examples/uip, and apps/include/netutils/httpd.h:
      The &quot;canned&quot; version of the uIP web servers content that was at 
      netutils/webserver/httpd_fsdata.c has been replaced with a dynamically
      built configuration located at apps/examples/uip (Contributed by
      Max Holtzberg).
    * apps/netutils/webserver:  Several inenhancements from Kate including the
      ability to elide scripting and SERVER headers and the ability to map
      files into memory before transferring them.
    * apps/netutils/webserver:  Add ability to map a URL to CGI function.
      Contributed by Kate.
    * apps/nshlib/nsh_mntcmds.c: The changes of 6.21 introduced holes in the
      error handling:  Now the number of arguments to mount can be 0 or 4.
      Additional parameter checking is required to prevent mysterious errors
      (submiteed by Kate).
    * apps/netutils/webserver/httpd_mmap.c:  Fix errors when the mmap()
      length is zero (submitted by Kate).
    * apps/netutils/webserver/httpd_sendfile.c:  Add and option,
      CONFIG_NETUTILS_HTTPD_SENDFILE to transfer files using the NuttX
      sendfile() interface.
    * apps/netutils/discover:  A UDP network discovery utility contributed
      by Max Holtzberg.
    * apps/examples/discover:  A test example for the UDP network discovery
      utility (also contribed by Max Holtzberg).
    * apps/examples/*/main.c:  Too many files called main.c.  Each renamed
      to something unique so that they will not collide in the archive.
    * apps/netutils/xmlrpc: The Embeddable Lightweight XML-RPC Server
      discussed at http://www.drdobbs.com/web-development/\
      an-embeddable-lightweight-xml-rpc-server/184405364.  Contributed by
      Max Holtzberg.
    * apps/netutils/uip_listenon.c:  Logic in uip_server.c that creates
      the listening socket was moved to this new file to support re-use.
      Contributed by Kate.
    * apps/netutils/webserver/httpd.c:  The option CONFIG_NETUTILS_HTTPD_SINGLECONNECT
      can now be used to limit the server to a single thread.  Option
      CONFIG_NETUTILS_HTTPD_TIMEOUT can be used to generate HTTP 408 errors.
      Both from Kate.
    * apps/netutils/webserver/httpd.c:  Improvements to HTTP parser from
      Kate.
    * apps/netutils/webserver/httpd.c:  Add support for Keep-alive connections
      (from Kate).
    * apps/NxWidget/Kconfig:  This is a kludge.  I created this NxWidgets
      directory that ONLY contains Kconfig.  NxWidgets does not live in
      either the nuttx/ or the apps/ source trees.  This kludge makes it
      possible to configure NxWidgets/NxWM without too much trouble (with
      the tradeoff being a kind ugly structure and some maintenance issues).
    * apps/examples/Make.defs: Missing support for apps/examples/watchdog.
    * apps/NxWidgets/Kconfig:  Add option to turn on the memory monitor
      feature of the NxWidgets/NxWM unit tests.

NxWidgets-1.3 2012-09-29 Gregory Nutt &lt;gnutt@nuttx.org&gt;

    * UnitTests/*/main.cxx:  Change entry point name to be consistent
      with with entry point naming conventions introduced in NuttX
      6.22.
    * Kconfig:  Added a mconfig configuration file.  Eventually, NxWidgets
      needs to get hooked into the NuttX mconf configuration.  Still not
      exactly sure how to do that.
    * libnxwidgets/Makefile and NxWidgets/nxwm/Makefile:  Need updates
      for consistency with recent changes to NuttX build system (&gt;= 6.22)
    * Kconfig:  Add option to turn on the memory monitor feature of the
      NxWidgets/NxWM unit tests.

pascal-3.0 2011-05-15 Gregory Nutt &lt;gnutt@nuttx.org&gt;

    * nuttx/:  The Pascal add-on module now installs and builds under the
      apps/interpreters directory.  This means that the pascal-2.1 module is
      incompatible with will all releases of NuttX prior to nuttx-6.0 where the 
      apps/ module was introduced.

buildroot-1.10 2011-05-06 &lt;gnutt@nuttx.org&gt;

    * Add patch submitted by Dimiter Georgiev to work around problems in building
      GDB 6.8 with versions of Cygwin &gt; 1.7.
    * configs/i486-defconfig-4.3.3 - Builds an i486 cross development toolchain
      using gcc 4.3.3.  Why wouldyou want such a thing?  On Linux, of course,
      such a thing is not needed because you can use the installed GCC to build
      i486 ELF binaries.  But that will not work under Cygwin!  The Cygwin
      toolchain (and probably MinGW), build DOS MZ format executables (i.e.,
      .exe files).  That is probably not usable for most NuttX targets.
      Instead, you should use this i486-elf-gcc to generate true ELF binaries
      under Cygwin.
    * Makefile - Alter copy arguments to avoid permissions problems when
      copying NuttX header files.
    * toolchain/nxflat/nxflat.mk and Makefile - Fix include paths.
    * toolchain/gcc/3.3.6 - Added a patch to fixed compilation error on Ubuntu
      9.10.
    * toolchain/nxflat/Makefile - Correct static library link order.
    * configs/arm920t-defconfig-4.3.3 - Enable support for NXFLAT tools.
    * toolchain/binutils/2.21 and toolchain/gcc/4.5.2 - Add support for GCC
      4.5.2 with binutils 2.21.
    * configs/arm920t-eabi-defconfig-4.5.2 - Add a configuration to build a
      GCC 4.5.2 EABI ARM toolchain for the ARM920t.
</pre></ul>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="pendingchanges">Unreleased Changes</a>
  </td>
  </tr>
</table>

<ul>
  <li><b>nuttx-6.18</b>.
    The ChangeLog for the not-yet-released version 6.18 is available at the bottom of the ChangeLog file that can viewed in the <a href="http://svn.code.sf.net/p/nuttx/code/trunk/nuttx/ChangeLog?view=log">SourceForge SVN</a>.
  </li>
  <li><b>apps-6.18</b>.
    The ChangeLog for the not-yet-released version 6.18 is available at the bottom of the ChangeLog file that can viewed in the <a href="http://svn.code.sf.net/p/nuttx/code/trunk/apps/ChangeLog.txt?view=log">SourceForge SVN</a>.
  </li>
  <li><b>NxWidgets-1.1</b>.
    The ChangeLog for the not-yet-released version 1.1 is available at the bottom of the ChangeLog file that can viewed in the <a href="http://svn.code.sf.net/p/nuttx/code/trunk/NxWidgets/ChangeLog?view=log">SourceForge SVN</a>.
  </li>
  <li><b>pascal-1.1</b>.
    The ChangeLog for the not-yet-released version 1.1 is available at the bottom of the ChangeLog file that can viewed in the <a href="http://svn.code.sf.net/p/nuttx/code/trunk/misc/pascal/ChangeLog?view=log">SourceForge SVN</a>.
  </li>
  <li><b>buildroot-1.11</b>.
    The ChangeLog for the not-yet-released version 1.11 is available at the bottom of the ChangeLog file that can viewed in the <a href="http://svn.code.sf.net/p/nuttx/code/trunk/misc/buildroot/ChangeLog?view=log">SourceForge SVN</a>.
  </li>
</ul>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="TODO"><h1>Bugs, Issues, <i>Things-To-Do</i></h1></a>
  </td>
  </tr>
</table>

<ul>
<p>
   The current list of NuttX <i>Things-To-Do</i> in SVN <a href="http://svn.code.sf.net/p/nuttx/code/trunk/nuttx/TODO?view=log">here</a>.
   A snapshot of the <i>To-Do</i> list associated with the current release are available <a href="TODO.txt">here</a>.
</p>
</ul>
<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="documentation"><h1>Other Documentation</h1></a>
  </td>
  </tr>
</table>

<ul><table>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NuttXGettingStarted.html">Getting Started</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NuttXUserGuide.html">User Guide</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NuttXPortingGuide.html">Porting Guide</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NuttShell.html">NuttShell (NSH)</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NuttXNxFlat.html">NXFLAT</a> Binary Format</td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NXGraphicsSubsystem.html">NX Graphics Subsystem</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NxWidgets.html">NxWidgets</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NuttXDemandPaging.html">Demand Paging</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="README.html">NuttX README Files</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="ChangeLog.txt">Change Log</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="TODO.txt">To-Do List</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="UsbTrace.html">USB Device Driver Tracing</a></td>
</tr>
</center></ul>

<small>
<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="trademarks"><h1>Trademarks</h1></a>
  </td>
  </tr>
</table>
<ul>
  <li>ARM, ARM7 ARM7TDMI, ARM9, ARM920T, ARM926EJS Cortex-M3 are trademarks of Advanced RISC Machines, Limited.</li>
  <li>Cygwin is a trademark of Red Hat, Incorporated.</li>
  <li>Linux is a registered trademark of Linus Torvalds.</li>
  <li>Eagle-100 is a trademark of <a href=" http://www.micromint.com/">Micromint USA, LLC</a>.
  <li>LPC2148 is a trademark of NXP Semiconductors.</li>
  <li>TI is a tradename of Texas Instruments Incorporated.</li>
  <li>UNIX is a registered trademark of The Open Group.</li>
  <li>VxWorks is a registered trademark of Wind River Systems, Incorporated.</li>
  <li>ZDS, ZNEO, Z16F, Z80, and Zilog are a registered trademark of Zilog, Inc.</li>
</ul>
<p>
  NOTE: NuttX is <i>not</i> licensed to use the POSIX trademark.  NuttX uses the POSIX
  standard as a development guideline only.
</p>
</small>

</body>
</html>
<html>
<head>
<title>NuttX</title>
</head>
<body background="backgd.gif">
<hr><hr>
<table width ="100%">
  <tr align="center" bgcolor="#e4e4e4">
    <td>
      <h1><big><font color="#3c34ec"><i>NuttX RTOS</i></font></big></h1>
      <p>Last Updated: September 29, 2012</p>
    </td>
  </tr>
</table>
<hr><hr>
<table width ="100%">
  <tr bgcolor="#e4e4e4">
    <td>
  <h1>Table of Contents</h1>
    </td>
  </tr>
</table>

<center><table width ="80%">
<tr>
<td>
<table>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#overview">Overview</a>.<br>
    What is NuttX?  Look at all those files and features... How can it be a tiny OS?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#group">NuttX Discussion Group</a>.<br>
    Do you want to talk about NuttX features?  Do you need some help?  Problems?  Bugs?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#downloads">Downloads</a>.<br>
    Where can I get NuttX?  What is the current development status?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#platforms">Supported Platforms</a>.<br>
    What target platforms has NuttX been ported to?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#environments">Development Environments</a>.<br>
    What kinds of host cross-development platforms can be used with NuttX?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#footprint">Memory Footprint</a>.<br>
    Just how big is it?  Do I have enough memory to use NuttX?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#licensing">Licensing</a>.<br>
    Are there any licensing restrictions for the use of NuttX? (Almost none)
    Will there be problems if I link my proprietary code with NuttX? (No)
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#history">Release History</a><br>
    What has changed in the last release of NuttX?
    What unreleased changes are pending in SVN?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#TODO">Bugs, Issues, <i>Things-To-Do</i></a>.<br>
    Software is never finished nor ever tested well enough.
    (Do you want to help develop NuttX?  If so, send me an email).
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#documentation">Other Documentation</a>.<br>
    What other NuttX documentation is available?
  </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td>
    <a href="#trademarks">Trademarks</a>.<br>
    Some of the words used in this document belong to other people.
  </td>
</tr>
</table>
</td>
</tr>
</table></center>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="overview"><h1>Overview</h1></a>
  </td>
  </tr>
</table>

<p>
  <b>Goals</b>.
  NuttX is a real timed embedded operating system (RTOS).
  Its goals are:
<p>
<center><table width="90%">
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Small Footprint</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      Usable in all but the tightest micro-controller environments,
      The focus is on the tiny-to-small, deeply embedded environment.
    </p>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Rich Feature OS Set</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      The goal is to provide implementations of most standard POSIX OS interfaces
      to support a rich, multi-threaded development environment for deeply embedded
      processors.
    </p>
      NON-GOALS: (1) It is not a goal to provide the level of OS features like those provided by Linux.
      In order to work with smaller MCUs, small footprint must be more important than an extensive feature set.
      But standard compliance is more important than small footprint.
      Surely a smaller RTOS could be produced by ignoring standards.
      Think of NuttX is a tiny Linux work-alike with a much reduced feature set.
      (2) There is no MMU-based support for processes.
      At present, NuttX assumes a flat address space.
    </p>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Highly Scalable</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      Fully scalable from tiny (8-bit) to moderate embedded (32-bit).
      Scalability with rich feature set is accomplished with:
      Many tiny source files, link from static libraries, highly configurable, use of
      weak symbols when available.
    </p>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Standards Compliance</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      NuttX strives to achieve a high degree of standards compliance.
      The primary governing standards are POSIX and ANSI standards.
      Additional standard APIs from Unix and other common RTOS's are
      adopted for functionality not available under these standards
      or for functionality that is not appropriate for the deeply-embedded
      RTOS (such as <code>fork()</code>).
    </p>
    <p>
      Because of this standards conformance, software developed under other
      standard OSs (such as Linux) should port easily to NuttX.
    </p>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Real-Time</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      Fully pre-emptible, fixed priority and round-robin scheduling.
    </p>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Totally Open</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      Non-restrictive BSD license.
    </p>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>GNU Toolchains</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      Compatible GNU toolchains based on <a href="http://buildroot.uclibc.org/">buildroot</a>
      available for
      <a href="https://sourceforge.net/projects/nuttx/files/">download</a>
      to provide a complete development environment for many architectures.
    </p>
</tr>
</table></center>

<p>
  <b>Feature Set</b>.
  Key features of NuttX include:
<p>
<center><table width="90%">

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Standards Compliant Core Task Management</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Fully pre-emptible.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Naturally scalable.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Highly configurable.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        Easily extensible to new processor architectures, SoC architecture, or board architectures.
        A <a href="NuttXPortingGuide.html">Porting Guide</a> is available.
      </li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>FIFO and round-robin scheduling.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Realtime, deterministic, with support for priority inheritance</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>POSIX/ANSI-like task controls, named message queues, counting semaphores, clocks/timers, signals, pthreads, environment variables, filesystem.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>VxWorks-like task management and watchdog timers.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>BSD socket interface.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Extensions to manage pre-emption.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Inheritable &quot;controlling terminals&quot; and I/O re-direction.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>On-demand paging.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <li>System logging.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>May be built either as an open, flat embedded RTOS or as a separtely built, secure micro-kernel with a system call interface.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Well documented in the NuttX <a href="NuttXUserGuide.html">User Guide</a>.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>File system</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Tiny, in-memory, root pseudo-file-system.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Virtual file system supports drivers and mountpoints.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        Mount-able volumes.  Bind mountpoint, filesystem, and block device driver.
      </li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Generic system logging (SYSLOG) support.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        FAT12/16/32 filesystem support with optional FAT long file name support<small><sup>1</sup></small>.
      </li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        NFS Client. Client side support for a Network File System (NFS, version 3, UDP).
      </li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        NXFFS. The tiny NuttX wear-leveling FLASH file system.
      </li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>ROMFS filesystem support.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li><a href="NuttXNxFlat.html">NXFLAT</a>.
      A new binary format call NXFLAT that can be used to 
      execute separately linked programs in place in a file system.
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p><small>
      <sup>1</sup>
      FAT long file name support may be subject to certain Microsoft patent restrictions if enabled.
      See the top-level <code>COPYING</code> file for details.
    </small></p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Device Drivers</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Supports character and block drivers as well as specialized driver interfaces.</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        Network, USB (host), USB (device), serial, CAN, ADC, DAC, PWM, Quadrature Encoder, and watchdog timer driver architectures.
      </li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        RAMDISK, pipes, FIFO, <code>/dev/null</code>, <code>/dev/zero</code>, and loop drivers.
      </li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Generic driver for SPI-based or SDIO-based MMC/SD/SDH cards.</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li><a href="NuttXPortingGuide.html#pwrmgmt">Power management</a> sub-system.</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>ModBus support provided by built-in <a href="http://freemodbus.berlios.de/">FreeModBus</a> version 1.5.0.</li>
    </p>
  </td>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>C Library</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Fully integrated into the OS.</li>
    </p>
  </td>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Networking</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>TCP/IP, UDP, ICMP, IGMPv2 (client) stacks.</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>SLIP</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Small footprint (based on uIP).</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>BSD compatible socket layer.</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Networking utilities (DHCP server and client, SMTP client, TELNET client, FTP server and client, TFTP client, HTTP server and client).  Inheritable TELNET sessions (as &quot;controlling terminal&quot;)</li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        NFS Client. Client side support for a Network File System (NFS, version 3, UDP).
      </li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        A NuttX port of Jeff Poskanzer's <a href="http://acme.com/software/thttpd">THTTPD</a> HTTP server
        integrated with <a href="NuttXNxFlat.html">NXFLAT</a> to provide true, embedded CGI.
      </li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        UDP Network Discover (Contributed by Richard Cochran).
      </li>
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
        XML RPC Server (Contributed by Richard Cochran).
      </li>
    </p>
  </td>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>FLASH Support</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li><i>MTD</i>-inspired interface for <i>M</i>emory <i>T</i>echnology <i>D</i>evices.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li><i>FTL</i>.  Simple <i>F</i>lash <i>T</i>ranslation <i>L</i>ayer support file systems on FLASH.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>NXFFS. the NuttX wear-leveling FLASH file system.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Support for SPI-based FLASH and FRAM devices.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>USB Host Support</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>USB host architecture for USB host controller drivers and device-dependent USB class drivers.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>USB host controller drivers available for the NXP LPC17xx.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Device-dependent USB class drivers available for USB mass storage and HID keyboard.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>USB Device Support</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li><i>Gadget</i>-like architecture for USB device controller drivers and device-dependent USB class drivers.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>USB device controller drivers available for the PIC32, NXP LPC17xx, LPC214x, LPC313x, LPC43xx, STMicro STM32 and TI DM320.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Device-dependent USB class drivers available for USB serial (CDC/ACM and a PL2303 emulation), for USB mass storage, and for a composite CDC/ACM and mass storage device.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Built-in <a href="UsbTrace.html">USB trace</a> functionality for USB debug.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Graphics Support</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Framebuffer drivers.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>LCD drivers for both parallel and SPI LCDs and OLEDs.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
         NX: A graphics library, tiny windowing system and tiny font support that works with either framebuffer or LCD drivers.
         Documented in the <a href="NXGraphicsSubsystem.html">NX Graphics Subsystem</a>
         manual.
      </li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Font management sub-system.</li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
         <a href="NxWidgets.html">NxWidgets</a>: NXWidgets is library of graphic objects, or &quot;widgets,&quot (labels, buttons, text boxes, images, sliders, progress bars, etc.). NXWidgets is written in C++ and integrates seamlessly with the NuttX NX graphics and font management subsystems.
      </li>
    </p>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>
         <a href="NxWidgets.html">NxWM</a>: NxWM is the tiny NuttX window manager based on NX and NxWidgets.
      </li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Input Devices</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Touchscreen, USB keyboard, GPIO-based buttons and keypads. </li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Analog Devices</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Support for Analog-to-Digital conversion (ADC), Digital-to-Analog conversion (DAC), multiplexers, and amplifiers.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Motor Control</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <li>Pulse width modulation (PWM) / Pulse count modulation.</li>
    </p>
</tr>
</table></center>

<p>
  <b>NuttX Add-Ons</b>.
  The following packages are available to extend the basic NuttX feature set:
</p>
<center><table width="90%">

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>NuttShell (NSH)</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>A small, scalable, bash-like shell for NuttX with rich feature set and small footprint.
        See the <a href="NuttShell.html">NuttShell User Guide</a>.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Pascal Compiler with NuttX runtime P-Code interpreter add-on</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>The Pascal add-on is available for download from the
        <a href="http://sourceforge.net/projects/nuttx/files/">SourceForge</a>
        website.</li>
    </p>
  </td>
</tr>
</table></center>

<p>
  <b>Look at all those files and features... How can it be a tiny OS?</b>.
  The NuttX feature list (above) is fairly long and if you look at the NuttX
  source tree, you will see that there are hundreds of source files comprising
  NuttX.  How can NuttX be a tiny OS with all of that?
</p>
<center><table width="90%">

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Lots of Features -- More can be smaller!</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      The philosophy behind that NuttX is that lots of features are great... <i>BUT</i>
      also that if you don't use those features, then you should not have to pay a penalty
      for the unused features.
      And, with NuttX, you don't!  If you don't use a feature, it will not
      be included in the final executable binary.
      You only have to pay the penalty of increased footprint for the features
      that you actually use.
    </p>
    <p>
      Using a variety of technologies, NuttX can scale from the very tiny to
      the moderate-size system.  I have executed NuttX with some simple applications
      in as little as 32K <i>total</i> memory (code and data).
      On the other hand, typical, richly featured NuttX builds require more like 64K
      (and if all of the features are used, this can push 100K).
    </p>
  </td>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Many, many files -- More really is smaller!</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      One may be intimidated by the size NuttX source tree.  There are hundreds of source files!
      How can that be a tiny OS?
      Actually, the large number of files is one of the tricks to keep NuttX small and
      as scalable as possible.
      Most files contain only a single function. 
      Sometimes just one tiny function with only a few lines of code.
      Why?
    </p>
    <ul>
      <li>
        <b>Static Libraries</b>.
        Because in the NuttX build processed, objects are compiled and saved into
        <i>static libraries</i> (<i>archives</i>).
        Then, when the file executable is linked, only the object files that are needed
        are extracted from the archive and added to the final executable.
        By having many, many tiny source files, you can assure that no code that you do
        not execute is ever included in the link.
        And by having many, tiny source files you have better granularity --
        if you don't use that tiny function of even just a few lines of code, it will
        not be included in the binary.
      </li>
    </ul>
  </td>
</tr>

<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Other Tricks</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      As mentioned above, the use of many, tiny source files and linking from static
      libraries keeps the size of NuttX down.
      Other tricks used in NuttX include:
    </p>
    <ul>
      <li>
         <b>Configuration Files</b>.
         Before you build NuttX, you must provide a configuration file that specifies
         what features you plan to use and which features you do not.
         This configuration file contains a long list of settings that control
         what is built into NuttX and what is not.
         There are hundreds of such settings
         (see the <a href="NuttXPortingGuide.html#apndxconfigs">NuttX Porting Guide</a>
         for a partial list that excludes platform specific settings).
         These many, many configuration options allow NuttX to be highly tuned to
         meet size requirements.
         The downside to all of these configuration options is that it greatly
         complicates the maintenance of NuttX -- but that is my problem, not yours.
      </li>
      <li>
         <b>Weak Symbols</b>
         The GNU toolchain supports <i>weak</i> symbols and these also help to keep
         the size of NuttX down.
         Weak symbols prevent object files from being drawn into the link even if they
         are accessed from source code.
         Careful use of weak symbols is another trick for keep unused code out of the
         final binary.
      </li>
    </ul>
  </td>
</tr>

</table></center>


<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="group"><h1>NuttX Discussion Group</h1></a>
  </td>
  </tr>
</table>

<p>
  Most NuttX-related discussion occurs on the <a href="http://tech.groups.yahoo.com/group/nuttx/" target="_top"><i>Yahoo!</i> NuttX group</a>.
  You are cordially invited to <a href="http://groups.yahoo.com/group/nuttx/join" target="_top">join</a>.
  I make a special effort to answer any questions and provide any help that I can.
</p>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="downloads"><h1>Downloads</h1></a>
  </td>
  </tr>
</table>

<h2>NuttX-6.22 Release Notes</h2>
<p>
  The 89<sup>th</sup> release of NuttX, Version 6.22, was made on September 29, 2012, and is available for download from the
  <a href="http://sourceforge.net/projects/nuttx/files/">SourceForge</a> website.
  Note that the release consists of two tarballs:  <code>nuttx-6.22.tar.gz</code> and <code>apps-6.22.tar.gz</code>.
  Both may be needed (see the top-level <code>nuttx/README.txt</code> file for build information)
  The change log associated with the release is available <a href="#currentrelease">here</a>.
  Unreleased changes after this release are available in SVN.
  These unreleased changes are also listed <a href="#pendingchanges">here</a>.
</p>
<p>
  This release corresponds with SVN release number: r5206,
  Note that all SVN information has been stripped from the tarballs.
  If you need the SVN configuration, you should check out directly from SVN.
  Revision r5206 should equivalent to release 6.22 of NuttX 6.22:
</p>
<ul><pre>
svn checkout -r5206 svn://svn.code.sf.net/p/nuttx/code/trunk nuttx-code
</pre></ul>
<p>Or</p>
<ul><pre>
svn checkout -r5206 http://svn.code.sf.net/p/nuttx/code/trunk nuttx-code
</pre></ul>

<p>
  <b>Additional new features and extended functionality</b>
</p>
<ul>
  <li>
    <p>
      <b>RTOS</b>:
      Application entry point is no longer user_start, but can be configured using <code>CONFIG_USER_ENTRYPOINT</code>.
      NuttX now supports two work queues:  A lower priority work queue (for extended processing) and a higher priority work queue (for quick, high priority operations).
    </p>
  </li>
  <li>
    <p>
      <b>Memory Management</b>:
      Added a new granule-based allocated that can be used to manage, aligned and quantized DMA memory.
    </p>
  </li>
  <li>
    <p>
      <b>File System</b>:
      Add hooks to allocate I/O memory with and external allocated (need if required by DMA).
    </p>
  </li>
  <li>
    <p>
      <b>Networking</b>:
      ENC28J60 driver is (finally) verified.
    </p>
  </li>
  <li>
    <p>
      <b>Drivers</b>:
      Add hooks USB device drivers to allocate I/O memory with and external allocated (need if required by DMA).
      Driver for the Windbond SPI FLASH family (W25x16, W25x32, W25x64, and others).
      ADS7843E driver extended for TSC2046 and XPT2046 and verified.
    </p>
  </li>
  <li>
    <p>
      <b>ARMv7-M</b>:
      Added logic to reset the MCU using the NVIC.
    </p>
  </li>
  <li>
    <p>
      <b>STM32</b>:
      Add support for STM32F103VET6.
    </p>
  </li>
  <li>
    <p>
      <b>STM32 Drivers</b>:
      Add logic to re-initialize UARTs a second time to enable DMA (Mike Smith).
      I2C driver error recovery (Mike Smith).
    </p>
  </li>
  <li>
    <p>
      <b>STM32 boards</b>:
      Support for USB host added add to several configurations (or at least explained in README files).
      Support for the Shenzhou STM32F107 board (see www.armjishu.com).
      Support for M3 Wildfire STM32F103 board (v2 and v3).
    </p>
  </li>
  <li>
    <p>
      <b>Build System:</b>:
      Kconfig string de-quoting logic.
      Remove comments from <code>defconfig</code> files (Kate).
      Add tool to create NuttX-style symbol tables.
      Numerous changes to configuration logic as needed for the new <code>mconf</code>-based configuration (much of this from Richard Cochran).
      Refactor common <code>Make.defs</code> logic into <code>tools/Config.mk</code> (Richard Cochran).
    </p>
  </li>
  <li>
    <p>
      <b>Library</b>:
      Configurable terse output from <code>strerror()</code>.
      Added <code>perror()</code> (Kate).
      Add <code>%n</code> format to <code>sscanf()</code> (Kate).
    </p>
  </li>
  <li>
    <p>
      <b>Applications</b>:
      Numerous changes and extensions to the old uIP web server (from Kate and Max Holtzberg, see the ChangeLog for specific extensions).
      UDP network discovery utility (Max Holtzberg).
      Embeddable Lightweight XML-RPC Server (http://www.drdobbs.com/web-development/an-embeddable-lightweight-xml-rpc-server/184405364, Max Holtzberg).
    </p>
  </li>
</ul>
<p>
  <b>Bugfixes</b> (see the change log for details)
  Some of these are very important (marked <b><i>critical</i></b>):
</p>
<ul>
  <li>
    <p>
      <b>RTOS</b>:
      Fixes to priority inheritance logic (<b><i>critical</i></b>).
      <code>waitpid()</code> critical section.
      Assertion in <code>work_cancel()</code> (Mike Smith).
      <code>mmap()</code> (Kate).
    </p>
  </li>
  <li>
    <p>
      <b>FAT File System</b>:
      Improper Boolean expression caused un-necessary writes and performance issues (<b><i>critical</i></b>, Ronen Vainish).
    </p>
  </li>
  <li>
    <p>
      <b>Networking</b>:
      Remove an un-necessary delay from <code>recvfrom()</code>.
      This greatly improves network performance (<b><i>critical</i></b>, Max Holtzberg).
    </p>
  </li>
  <li>
    <p>
      <b>Graphics</b>:
      NX parameter checking errors.
    </p>
  </li>
  <li>
    <p>
      <b>Drivers</b>:
      Fix double release of memory in SDIO-based, MMC/SD driver (Ronen Vainish).
    </p>
  </li>
  <li>
    <p>
      <b>LPC17xx</b>:
      Ethernet driver fixes needed for certain PHYs (Kate).
    </p>
  </li>
  <li>
    <p>
      <b>AVR</b>:
      Fix build error (Richard Cochran).
    </p>
  </li>
  <li>
    <p>
      <b>STM32</b>:
      USB OTG FS host driver NAKing an retries.
      Power management compilation errors (Diego Sanchez).
      Missing SPI3 remap logic.
    </p>
  </li>
  <li>
    <p>
      <b>STM32 Drivers</b>:
      Fix for Ethernet errata for STM32F107 (<b><i>critical</i></b>).
      Ethernet buffer alignment check.
      Add &quot;kludge&quot; to Ethernet driver to handle DM9161 PHY which (at least on the Shenzhou board), sometimes does not come up correctly.
    </p>
  </li>
  <li>
    <p>
      <b>Applications</b>:
      THTTPD (Kate).
      NSH <code>ping</code> when IP address is on a different network (Darcy Gong).
    </p>
  </li>
  <li>
    <p>
      <b>Library</b>:
      <code>fread()</code>, <code>fflush()</code>, <code>fdopen()</code>: Fix error handling logic (Ronen Vainish).
      Fix some field-width handling issues in <code>sscanf()</code>
    </p>
  </li>
</ul>
<p>
  As well as other, less critical bugs.
  See the <a href="#currentrelease">ChangeLog</a> for additional, detailed changes.
</p>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="platforms"><h1>Supported Platforms</h1></a>
  </td>
  </tr>
</table>

<p>
  The short story (Number of ports follow in parentheses).
  The state of the various ports vary from board-to-board.
  Follow the links for the details:
</p>
<center><table width="90%">
<ul>
  <tr>
  <td bgcolor="#e4e4e4" valign="top">
  <li><a href="#linuxusermode">Linux user mode simulation</a> (1)</li>
  <li>ARM
    <ul>
      <li><a href="#arm7tdmi">ARM7TDMI</b></a> (5)</li>
      <li><a href="#arm920t">ARM920T</a> (1) </li>
      <li><a href="#arm926ejs">ARM926EJS</a> (3) </li>
      <li><a href="#armcortexm3">ARM Cortex-M3</a> (16)</li>
      <li><a href="#armcortexm4">ARM Cortex-M4</a> (5)</li>
    </ul>
  <li>Atmel AVR
    <ul>
      <li><a href="#atmelavr">Atmel 8-bit AVR</a> (3) </li>
      <li><a href="#atmelavr32">Atmel AVR32</a> (1) </li>
    </ul>
  </li>
  </td>
  <td bgcolor="#e4e4e4" valign="top">
  <li>Freescale <a href="#m68hcs12">M68HCS12</a> (2) </li>
  <li>Intel
    <ul>
      <li><a href="#8052">Intel 8052 Microcontroller</a> (1)</li>
      <li><a href="#80x86">Intel 80x86</a> (2)</li>
    </ul>
  </li>
  <li>MicroChip <a href="#pic32mips">PIC32MX</a> (MIPS) (4)</li>
  <li>Renesas/Hitachi:
    <ul>
        <li><a href="#superh">Renesas/Hitachi SuperH</a> (1/2)</li>
        <li><a href="#m16c">Renesas M16C/26</a> (1/2)</li>
    </ul>
  </li>
  </td>
  <td bgcolor="#e4e4e4" valign="top">
  <li>Zilog
    <ul>
        <li><a href="#zilogz16f">Zilog Z16F</a> (1)</li>
        <li><a href="#zilogez80acclaim">Zilog eZ80 Acclaim!</a> (1)</li>
        <li><a href="#zilogz8encore">Zilog Z8Encore!</a> (2)</li>
        <li><a href="#zilogz80">Zilog Z80</a> (2)</li>
    </ul>
  </li>
</ul>
  </tr>
</table></center>

<p>The details, caveats and fine print follow:</p>

<center><table width="90%">
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="linuxusermode"><b>Linux User Mode</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      A user-mode port of NuttX to the x86 Linux/Cygwin platform is available.
      The purpose of this port is primarily to support OS feature development.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        Does not support interrupts but is otherwise fully functional.
      </p>
    </ul>
   </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="arm7tdmi"><b>ARM7TDMI</b></a>.
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>TI TMS320C5471</b> (also called <b>C5471</b> or <b>TMS320DA180</b> or <b>DA180</b>).
      NuttX operates on the ARM7 of this dual core processor.
      This port uses the <a href="http://www.spectrumdigital.com/">Spectrum Digital</a>
      evaluation board with a GNU arm-elf toolchain* under Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        This port is complete, verified, and included in the initial NuttX release.
      </p>
    </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>TI Calypso</b>.
      This port supports the TI &quot;Calypso&quot; MCU used in various cell phones (and, in particular,
      by the <a href="http://bb.osmocom.org/trac/">Osmocom-bb project</a>).
      Like the c5471, NuttX operates on the  ARM7 of this dual core processor.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        This port was contributed by  Denis Carilki and includes the work of Denis, Alan Carvalho de Assis, and Stefan Richter.
        Calypso support first appeared in NuttX-6.17.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>NXP LPC214x</b>.
      Support is provided for the NXP LPC214x family of processors.  In particular,
      support is provided for the mcu123.com lpc214x evaluation board (LPC2148).
      This port also used the GNU arm-elf toolchain* under Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        This port boots and passes the OS test (apps/examples/ostest).
        The port is complete and verified.  As of NuttX 0.3.17, the port includes:
        timer interrupts, serial console, USB driver, and SPI-based MMC/SD card
        support.  A verified NuttShell (<a href="NuttShell.html">NSH</a>)
        configuration is also available.
      </p>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
        with Windows native toolchain (CodeSourcery or devkitARM).  A DIY toolchain for Linux
        or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a>
        package.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>NXP LPC2378</b>.
      Support is provided for the NXP LPC2378 MCU.  In particular,
      support is provided for the Olimex-LPC2378 development board.
      This port was contributed by Rommel Marcelo is was first released in NuttX-5.3.
      This port also used the GNU arm-elf toolchain* under Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        This port boots and passes the OS test (apps/examples/ostest) and includes a
        working implementation of the NuttShell (<a href="NuttShell.html">NSH</a>).
        The port is complete and verified.
        As of NuttX 5.3, the port includes only basic timer interrupts and serial console support.
      </p>
      <p>
        <b>Development Environments:</b> (Same as for the NXP LPC214x).
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STR71x</b>.
      Support is provided for the STMicro STR71x family of processors.  In particular,
      support is provided for the Olimex STR-P711 evaluation board.
      This port also used the GNU arm-elf toolchain* under Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        Integration is complete on the basic port (boot logic, system time, serial console).
        Two configurations have been verified: (1) The board boots and passes the OS test
        with console output visible on UART0, and the NuttShell (<a href="NuttShell.html">NSH</a>)
        is fully functional with interrupt driven serial console.  An SPI driver is available
        but only partially tested.  Additional features are needed: USB driver, MMC integration,
        to name two (the slot on the board appears to accept on MMC card dimensions; I have only
        SD cards).
        An SPI-based ENC28J60 Ethernet driver for add-on hardware is available and
        but has not been fully verified on the Olimex board (due to issues powering the ENC28J60 add-on board).
      </p>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
        with Windows native toolchain (CodeSourcery or devkitARM).  A DIY toolchain for Linux
        or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a>
        package.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="arm920t"><b>ARM920T</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Freescale MC9328MX1</b> or <b>i.MX1</b>.
      This port uses the Freescale MX1ADS development board with a GNU arm-elf toolchain*
      under either Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          This port has stalled due to development tool issues.
          Coding is complete on the basic port (timer, serial console, SPI).
      </p>
    </ul>
   </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="arm926ejs"><b>ARM926EJS</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>TI TMS320DM320</b> (also called <b>DM320</b>).
      NuttX operates on the ARM9 of this dual core processor.
      This port uses the
      <a href="http://wiki.neurostechnology.com/index.php/Developer_Welcome">Neuros OSD</a>
      with a GNU arm-elf toolchain* under Linux or Cygwin.
      The port was performed using the OSD v1.0, development board.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          The basic port (timer interrupts, serial ports, network, framebuffer, etc.) is complete.
          All implemented features have been verified with the exception of the USB device-side
          driver; that implementation is complete but untested.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <b>NXP <a href="http://ics.nxp.com/products/lpc3000/lpc313x.lpc314x.lpc315x/">LPC3131</a></b>.
    The port for the NXP LPC3131 on the <a href="http://www.embeddedartists.com/products/kits/lpc3131_kit.php">Embedded Artists EA3131</a> 
    development board was first released in NuttX-5.1 with a GNU arm-elf or arm-eabi toolchain* under Linux or Cygwin
    (but was not functional until NuttX-5.2).
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          The basic EA3131 port is complete and verified in NuttX-5.2 
          This basic port includes basic boot-up, serial console, and timer interrupts.
          This port was extended in NuttX 5.3 with a USB high speed driver contributed by David Hewson.
          David also contributed I2C and SPI drivers plus several important LPC313x USB bug fixes
          that appear in the NuttX 5.6 release.
          This port has been verified using the NuttX OS test, USB serial and mass storage
          tests and includes a working implementation of the NuttShell (<a href="NuttShell.html">NSH</a>).
      </p>
      <p>
          Support for <a href="NuttXDemandPaging.html">on-demand paging</a> has been developed for the EA3131.
      That support would all execute of a program in SPI FLASH by paging code sections out of SPI flash as needed.
      However, as of this writing, I have not had the opportunity to verify this new feature.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <b>NXP <a href="http://ics.nxp.com/products/lpc3000/lpc313x.lpc314x.lpc315x/">LPC315x</a></b>.
    Support for the NXP LPC315x family has been incorporated into the code base as of NuttX-6.4.
    Support has added for the Embedded Artists EA3152 board in NuttX-6.11.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          Basic support is in place for both the LPC3152 MCU and the EA3152 board.
          Verification of the port was deferred due to tool issues
          However, because of the high degree of compatibility between the LPC313x and LPC315x family, it
          is very likely that the support is in place (or at least very close).
          At this point, verification of the EA3152 port has been overcome by events and
          may never happen.
          However, the port is available for anyone who may want to use it.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="armcortexm3"><b>ARM Cortex-M3</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>TI Stellaris LM3S6432</b>.
      This is a port of NuttX to the Stellaris RDK-S2E Reference Design Kit and the MDL-S2E Ethernet to Serial module
      (contributed by Mike Smith).
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Luminary/TI Stellaris LM3S6918</b>.
      This port uses the <a href=" http://www.micromint.com/">Micromint</a> Eagle-100 development
      board with a GNU arm-elf toolchain* under either Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          The initial, release of this port was included in NuttX  version 0.4.6.
          The current port includes timer, serial console, Ethernet, SSI, and microSD support.
          There are working configurations the NuttX OS test, to run the <a href="NuttShell.html">NuttShell
          (NSH)</a>, the NuttX networking test, and the uIP web server.
      </p>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
        with Windows native toolchain (CodeSourcery or devkitARM).  A DIY toolchain for Linux
        or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a>
        package.
      </p>
     </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Luminary/TI Stellaris LM3S6965</b>.
      This port uses the Stellaris LM3S6965 Ethernet Evalution Kit with a GNU arm-elf toolchain*
      under either Linux or Cygwin.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          This port was released in NuttX 5.5.  
          Features are the same as with the Eagle-100 LM3S6918 described above.
          The apps/examples/ostest configuration has been successfully verified and an
          NSH configuration with Telnet support is available.
          MMC/SD and Networking support was not been thoroughly verified:
          Current development efforts are focused on porting the NuttX window system (NX)
          to work with the Evaluation Kits OLED display.
      </p>
      <p><small>
         <b>NOTE</b>: As it is configured now, you MUST have a network connected.
         Otherwise, the NSH prompt will not come up because the Ethernet
         driver is waiting for the network to come up.
      </small></p>
      <p>
        <b>Development Environments:</b> See the Eagle-100 LM3S6918 above.
      </p>
     </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Luminary/TI Stellaris LM3S8962</b>.
      This port uses the Stellaris EKC-LM3S8962 Ethernet+CAN Evalution Kit with a GNU arm-elf toolchain*
      under either Linux or Cygwin.
      Contributed by Larry Arnold.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          This port was released in NuttX 5.10. 
          Features are the same as with the Eagle-100 LM3S6918 described above.
      </p>
     </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Luminary/TI Stellaris LM3S9B96</b>.
      Header file support was contributed by Tiago Maluta for this part.
      Jose Pablo Rojas V. is currently using those header file changes to port NuttX to the TI/Stellaris EKK-LM3S9B96.
      With any luck, that port should be working and available in the NuttX-6.20 release.
    </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>TI Stellaris LM3S6432S2E</b>.
      This port uses Serial-to-Ethernet Reference Design Kit (<a href="http://www.ti.com/tool/rdk-s2e">RDK-S2E</a>)
      and has similar support as for the other Stellaris family members.
      Configurations are available for the OS test and for the NuttShell (NSH)
      (see the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
      The NSH configuration including networking support with a Telnet NSH console.
      This port was contributed by Mike Smith.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
          This port was will be released in NuttX 6.14. 
      </p>
     </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STM32F100x</b>.
      Chip support for these STM32 &quot;Value Line&quot; family was contributed by Mike Smith and users have reported that they have successful brought up NuttX on there proprietary boards using this logic.
      However, there is <i>no</i> specific board support for this chip families in the NuttX source tree.
    </p>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STM32F103x</b>.
      Support for four MCUs and four board configurations are available.
      MCU support includes all of the high density and connectivity line families.
      Board supported is available specifically for: STM32F103ZET6, STM32F103RET6, STM32F103VCT, and STM32F103VET6.
      Boards supported include:
    </p>
    <ol>
      <li>
        A port for the <a href=" http://www.st.com/">STMicro</a> STM3210E-EVAL development board that
        features the STM32F103ZET6 MCU.
      </li>
      <li>
        The ISOTEL NetClamps VSN V1.2 ready2go sensor network platform based on the
        STMicro STM32F103RET6.  Contributed by Uros Platise.
      </li>
      <li>
        A port for the HY-Mini STM32v board.  This board is based on the
        STM32F103VCT chip.  Contributed by Laurent Latil.
      </li>
      <li>
         The M3 Wildfire development board (STM32F103VET6), version 2.
         See <a href="http://firestm32.taobao.com">http://firestm32.taobao.com</a> (the current board is version 3).
      </li>
    </ol>
    <p>
      These ports uses a GNU arm-elf toolchain* under either Linux or Cygwin (with native Windows GNU
      tools or Cygwin-based GNU tools).
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
      </p>
      <ul>
        <li><b>Basic Support/Drivers</b>.
          The basic STM32 port was released in NuttX version 0.4.12. The basic port includes boot-up
          logic, interrupt driven serial console, and system timer interrupts.
          The 0.4.13 release added support for SPI, serial FLASH, and USB device.;
          The 4.14 release added support for buttons and SDIO-based MMC/SD and verifed DMA support.
          Verified configurations are available for NuttX OS test, the NuttShell (NSH) example,
          the USB serial device class, and the USB mass storage device class example.
        </li>
        <li><b>NetClamps VSN</b>.
          Support for the NetClamps VSN was included in version 5.18 of NuttX.
          Uros Platise added support for timers, RTC, I2C, FLASH, extended power management
          and other features.
        </li>
        <li><b>Additional Drivers</b>.
          Additional drivers and configurations were added in NuttX 6.13 and later releases for the STM32 F1 and F4.
          F1 compatible drivers include an Ethernet driver, ADC driver, DAC driver, PWM driver, IWDG, WWDG, and CAN drivers.
        </li>
        <li><b>M3 Wildfire</b>.
          Support for the Wildfire board was included in version 6.22 of NuttX.
          The board port is basically functional.
          Not all features have been verified.
          Support for FAT file system on an an SD card had been verified.
          The ENC28J60 network is functional (but required lifting the chip select pin on the W25x16 part).
          Customizations for the v3 version of the Wildfire board are selectable (but untested).
        </li>
      </ul>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
        with Windows native toolchain (RIDE7, CodeSourcery or devkitARM).  A DIY toolchain for Linux
        or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a>
        package.
      </p>
     </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STM32F107x</b>.
      Chip support for the STM32 F1 &quot;Connectivity Line&quot; family has been present in NuttX for some time and users have reported that they have successful brought up NuttX on there proprietary boards using this logic.
    </p>
    <p>
      <b>Olimex STM32-P107</b>
      Support for the <a href="https://www.olimex.com/dev/stm32-p107.html">Olimex STM32-P107</a> was contributed by Max Holtzberg and first appeared in NuttX-6.21.  That port features the STMicro STM32F107VC MCU.
      <ul>
        <b>STATUS:</b>
        Configurations for the basic OS test and NSH are available and verified.
        Networking is functional.
      </ul>
    </p>
    <p>
      <b>Shenzhou IV</b>
      Work is underway as of this writing to port NuttX to the Shenzhou IV development board (See <a href="http://www.armjishu.com">www.armjishu.com</a>) featuring the STMicro STM32F107VCT MCU.
      If all goes according to plan, this port should be verified and available in NuttX-6.22.
      <ul>
        <b>STATUS:</b>
        In progress.
        The following have been verified:
        (1) Basic Cortex-M3 port, 
        (2) Ethernet,
        (3) On-board LEDs
      </ul>
    </p>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STM32F207IG</b>.
      Support for the STMicro STM3220G-EVAL development board was contributed by Gary Teravskis and first released in NuttX-6.16.
    </p>
    <ul>
      <b>STATUS:</b>
      The peripherals of the STM32 F2 family are compatible with the STM32 F4 family.
      See discussion of the STM3240G-EVAL board below for further information.
      </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Atmel AT91SAM3U</b>.
      This port uses the <a href="http://www.atmel.com/">Atmel</a> SAM3U-EK
      development board that features the AT91SAM3U4E MCU.
      This port uses a GNU arm-elf or arm-eabi toolchain* under either Linux or Cygwin (with native Windows GNU
      tools or Cygwin-based GNU tools).
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        The basic SAM3U-EK port was released in NuttX version 5.1. The basic port includes boot-up
        logic, interrupt driven serial console, and system timer interrupts.
        That release passes the NuttX OS test and is proven to have a valid OS implementation.
        A configuration to support the NuttShell is also included.
        NuttX version 5.4 adds support for the HX8347 LCD on the SAM3U-EK board.
        This LCD support includes an example using the
        <a href=" http://nuttx.sourceforge.net/NXGraphicsSubsystem.html">NX graphics system</a>.
        NuttX version 6.10 adds SPI support.
      </p>
      <p>
        Subsequent NuttX releases will extend this port and add support for SDIO-based SD cards and
        USB device (and possible LCD support).
        These extensions may or may not happen soon as my plate is kind of full now.
      </p>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
        with Windows native toolchain (CodeSourcery or devkitARM).  A DIY toolchain for Linux
        or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a>
        package.
      </p>
     </ul>
   </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>NXP LPC1766, LPC1768, and LPC1769</b>.
      Drivers are available for CAN, DAC, Ethernet, GPIO, GPIO interrupts, I2C, UARTs, SPI, SSP, USB host, and USB device.
      Verified LPC17xx onfigurations are available for three boards.
      <ul>
        <li>
          The Nucleus 2G board from <a href="http://www.2g-eng.com/">2G Engineering</a> (LPC1768),
        </li>
        <li>
          The mbed board from <a href="http://mbed.org">mbed.org</a> (LPC1768, Contributed by Dave Marples), and
        </li>
        <li>
          The LPC1766-STK board from <a href="http://www.olimex.com/">Olimex</a> (LPC1766).
        </li>
        <li>
          The Embedded Artists base board with NXP LPCXpresso LPC1768.
        </li>
        <li>
          The <a href="http://micromint.com/">Micromint</a> Lincoln60 board with an NXP LPC1769.
        </li>
      </ul>
    </p>
    <p>
      The Nucleus 2G board, the mbed board, and the LPCXpresso all feature the NXP LPC1768 MCU;
      the Olimex LPC1766-STK board features an LPC1766.
      All use a GNU arm-elf or arm-eabi toolchain* under either Linux or Cygwin (with native Windows GNU tools or Cygwin-based GNU tools).
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        The following summarizes the features that has been developed and verified on individual LPC17xx-based boards.
        These features should, however, be common and available for all LPC17xx-based boards.
      </p>
      <ol>
        <li>
        <p><b>Nucleus2G LPC1768</b></p>
        <ul>
          <li>
            Some initial files for the LPC17xx family were released in NuttX 5.6, but
          </li>
          <li>
            The first functional release for the NXP LPC1768/Nucleus2G occured with NuttX 5.7 with
            Some additional enhancements through NuttX-5.9.
          </li>
        </ul>
      </p>
      <p>
        That initial, 5.6, basic release included <i>timer</i> interrupts and a <i>serial console</i> and was
        verified using the NuttX OS test (<code>apps/examples/ostest</code>).
        Configurations available include include a verified NuttShell (NSH) configuration
        (see the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
        The NSH configuration supports the Nucleus2G's microSD slot and additional configurations
        are available to exercise the the USB serial and USB mass storage devices.
        However, due to some technical reasons, neither the SPI nor the USB device drivers are fully verified.
        (Although they have since been verfiied on other platforms; this needs to be revisited on the Nucleus2G).
      </p>
      </li>
      <li>
        <p><b>mbed LPC1768</b></p>
        <ul>
          <li>
            Support for the mbed board was contributed by Dave Marples and released in NuttX-5.11.
          </li>
        </ul>
      </p>
      <p>
        This port includes a NuttX OS test configuration (see <code>apps/examples/ostest</code>).
      </p>
      </li>
      <li>
        <p><b>Olimex LPC1766-STK</b></p>
        <ul>
          <li>
            Support for that Olimex-LPC1766-STK board was added to NuttX 5.13.
          </li>
          <li>
            The NuttX-5.14 release extended that support with an <i>Ethernet driver</i>.
          </li>
          <li>
            The NuttX-5.15 release further extended the support with a functional <i>USB device driver</i> and <i>SPI-based micro-SD</i>.
          </li>
          <li>
            The NuttX-5.16 release added a functional <i>USB host controller driver</i> and <i>USB host mass storage class driver</i>.
          </li>
          <li>
            The NuttX-5.17 released added support for low-speed USB devicers, interrupt endpoints, and a <i>USB host HID keyboard class driver</i>.
          </li>
        </ul>
      </p>
      <p>
        Verified configurations are now available for the NuttX OS test,
        for the NuttShell with networking and microSD support(NSH, see the <a href="ttp://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>),
        for the NuttX network test, for the <a href="http://acme.com/software/thttpd">THTTPD</a> webserver,
        for USB serial deive and USB storage devices examples, and for the USB host HID keyboard driver.
        Support for the USB host mass storage device can optionally be configured for the NSH example.
        A driver for the <i>Nokia 6100 LCD</i> and an NX graphics configuration for the Olimex LPC1766-STK have been added.
        However, neither the LCD driver nor the NX configuration have been verified as of the the NuttX-5.17 release.
      </p>
      </li>
      <li>
        <p><b>Embedded Artists base board with NXP LPCXpresso LPC1768</b></p>
        <p>
           An fully verified board configuration is included in NuttX-6.2.
           The Code Red toolchain is supported under either Linux or Windows.
           Verifed configurations include DHCPD, the NuttShell (NSH), NuttX graphis (NX), the NuttX OS test, THTTPD, and USB mass storage device.
        </p>
      </li>
      <li>
        <p><b>Micromint Lincoln60 board with an NXP LPC1769</b></p>
        <p>
           This board configuration was contributed and made available in NuttX-6.20.
           As contributed board support, I am unsure of what all has been verfied and what has not.
           See the Microment website for more information about the <a href="http://micromint.com/Products/lincoln60.html">Lincoln60</a> board.
           More to come.
        </p>
      </li>
      </ol>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin
        with Windows native toolchain (CodeSourcery devkitARM or Code Red).  A DIY toolchain for Linux
        or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a>
        package.
      </p>
   </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="armcortexm4"><b>ARM Cortex-M4</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>FreeScale Kinetis K40</b>.
      This port uses the Freescale Kinetis KwikStik K40.
      Refer to the <a href="http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=KWIKSTIK-K40">Freescale web site</a> for further information about this board.
      The Kwikstik is used with the FreeScale Tower System (mostly just to provide a simple UART connection)
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        The unverified KwikStik K40 first appeared in NuttX-6.8
        As of this writing, the basic port is complete but I accidentally locked my board during the initial bringup.
        Further development is stalled unless I learn how to unlock the device (or until I get another K40).
        Additional work remaining includes, among other things: (1) complete the basic bring-up,
        (2) bring up the NuttShell NSH, (3) develop support for the SDHC-based SD card,
        (4) develop support for USB host and device, and (2) develop an LCD driver.
        NOTE: Some of these remaining tasks are shared with the K60 work described below.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>FreeScale Kinetis K60</b>.
      This port uses the Freescale Kinetis TWR-K60N512 tower system.
      Refer to the <a href="http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=TWR-K60N512-KIT">Freescale web site</a> for further information about this board.
      The TWR-K60N51 includes with the FreeScale Tower System which provides (among other things) a DBP UART connection.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        As of this writing, the basic port is complete and passes the NuttX OS test.
        An additional, validated configuration exists for the NuttShell (NSH, see the
        <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
        This basic TWR-K60N512 first appeared in NuttX-6.8.
        Ethernet and SD card (SDHC) drivers also exist:
        The SDHC driver is partially integrated in to the NSH configuration but has some outstanding issues;
        the Ethernet driver is completely untested.
        Additional work remaining includes: (1) integrate the Ethernet and SDHC drivers, and (2) develop support for USB host and device.
        NOTE: Most of these remaining tasks (excluding the Ethernet driver) are the same as the pending K40 tasks described above.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STM3240G-EVAL</b>.
      This port uses the STMicro STM3240G-EVAL board featuring the STM32F407IGH6 MCU.
      Refer to the <a href="http://www.st.com/internet/evalboard/product/252216.jsp">STMicro web site</a> for further information about this board.
    </p>
    <p>
      <b>STATUS:</b>
      <ul>
        <li><b>NuttX-6.12</b>
          The basic port is complete and first appeared in NuttX-6.12.
          The initial port passes the NuttX OS test and includes a validated configuration for the NuttShell (NSH, see the
          <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>) as well as several other configurations.
        </li>
        <li><b>NuttX-6.13-6.16</b>
          Additional drivers and configurations were added in NuttX 6.13-6.16.
          Drivers include an Ethernet driver, ADC driver, DAC driver, PWM driver, CAN driver, F4 RTC driver, Quadrature Encoder, DMA, SDIO with DMA
          (these should all be compatible with the STM32 F2 family and many should also be compatible with the STM32 F1 family as well).
        </li>
        <li><b>NuttX-6.16</b>
          The NuttX 6.16 release also includes and logic for saving/restoring F4 FPU registers in context switches.
          Networking intensions include support for Telnet NSH sessions and new configurations for DHPCD and the networking test (nettest).
        </li>
        <li><b>NuttX-6.17</b>
          The USB OTG device controller driver, and LCD driver and a function I2C driver were added in NuttX 6.17.
        </li>
        <li><b>NuttX-6.18</b>
          STM32 IWDG and WWDG watchdog timer drivers were added in NuttX 6.18 (should be compatible with F1 and F2).
          An LCD driver and a touchscreen driver for the STM3240G-EVAL based on the STMPE811 I/O expander were also added in NuttX 6.18.
        </li>
        <li><b>NuttX-6.21</b>
          A USB OTG host controller driver was added in NuttX 6.21.
        </li>
      </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>STMicro STM32F4-Discovery</b>.
      This port uses the STMicro STM32F4-Discovery board featuring the STM32F407VGT6 MCU.
      Refer to the <a href="http://www.st.com/internet/evalboard/product/252419.jsp">STMicro web site</a> for further information about this board.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        The basic port for the STM32F4-Discovery was contributed by Mike Smith and was first released in NuttX-6.14.
        Drivers listed for the STM3240G-EVAL may be usable on this plaform as well.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>NXG Technologies LPC4330-Xplorer</b>.
      This NuttX port is for the LPC4330-Xplorer board from NGX Technologies featuring the NXP LPC4330FET100 MCU.
      See the <a href="http://shop.ngxtechnologies.com/product_info.php?cPath=21_37&products_id=104">NXG website</a> for further information about this board.
    </p>
    <p>
      <b>STATUS:</b>
    </p>
    <ul>
      <li>
        <p><b>NuttX-6.20</b>
          The basic port is complete.
          The OS test configuration and the basic NSH configurations are present and fully verified.
          This includes verified support for:  SYSTICK system time,  pin and GPIO configuration, and a serial console.
        </p>
        <p>
          Several drivers have been copied from the related LPC17xx port but require integration into the LPC43xx:  ADC, DAC, GPDMA, I2C, SPI, and SSP.
          The registers for these blocks are the same in both the LPC43xx and the LPC17xx and they should integrate into the LPC43xx very easily by simply adapting the clocking and pin configuration logic.
        </p>
        <p>
          Other LPC17xx drivers were not brought into the LPC43xx port because these peripherals have been completely redesigned:  CAN, Ethernet, USB device, and USB host.
        </p>
        <p>
          So then there is no support for the following LPC43xx peripherals: SD/MMC, EMC, USB0,USB1, Ethernet, LCD, SCT, Timers 0-3, MCPWM, QEI, Alarm timer, WWDT, RTC, Event monitor, and CAN.
        </p>
        <p>
          Some of these can be leveraged from other MCUs that appear to support the same peripheral IP:
          <ul>
            <li>
              The LPC43xx USB0 peripheral appears to be the same as the USB OTG peripheral for the LPC31xx.
              The LPC31xx USB0 device-side driver has been copied from the LPC31xx port but also integration into the LPC43xx (clocking and pin configuration).
              It should be possible to complete poriting of this LPC31xx driver with a small porting effort.
            </li>
            <li>
              The Ethernet block looks to be based on the same IP as the STM32 Ethernet and, as a result, it should be possible to leverage the NuttX STM32 Ethernet driver with a little more effort.
            </li>
          </ul>
        </p>
      </li>
      <li>
        <p><b>NuttX-6.21</b>
        Added support for a SPIFI block driver and for RS-485 option to the serial driver.
      </li>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
  <p>
    <b>Development Environments:</b>
    1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU Cortex-M3 or 4toolchain, or 3) Cygwin with Windows native GNU Cortex-M3 or M4 toolchain (CodeSourcery or devkitARM).  A DIY toolchain for Linux or Cygwin is provided by the NuttX
    <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a> package.
    I use FreeScale's <i>CodeWarrior</i> IDE only to work with the JTAG debugger built into the Kinetis boards.
    I use the <i>Code Red</i> IDE with the some of the NXP parts and the <i>Atollic</i> toolchain with some of the STMicroelectronics parts.
  </p>
  </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="atmelavr"><b>Atmel AVR</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>SoC Robotics ATMega128</b>.
      This port of NuttX to the Amber Web Server from <a href="http://www.soc-robotics.com/index.htm">SoC Robotics</a>
      is partially completed.
      The Amber Web Server is based on an Atmel ATMega128.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         Work on this port has stalled due to toolchain issues.  Complete, but untested
         code for this port appears in the NuttX 6.5 release.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Micropendous 3 AT90USB64x</b> and <b>AT90USB6128x</b>.
      This port of NuttX to the Opendous Micropendous 3 board. The Micropendous3 is
      may be populated with an AT90USB646, 647, 1286, or 1287.  I have only the AT90USB647
      version for testing.  This version have very limited memory resources: 64K of
      FLASH and 4K of SRAM.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         The basic port was released in NuttX-6.5.  This basic port consists only of
         a &quot;Hello, World!!&quot; example that demonstrates initialization of the OS,
         creation of a simple task, and serial console output.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>PJRC Teensy++ 2.0 AT90USB1286</b>.
      This is a port of NuttX to the PJRC Teensy++ 2.0 board.
      This board was developed by <a href="http://pjrc.com/teensy/">PJRC</a>.
      The Teensy++ 2.0 is based on an Atmel AT90USB1286 MCU.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         The basic port was released in NuttX-6.5.  This basic port consists of
         a &quot;Hello, World!!&quot; example that demonstrates initialization of the OS,
         creation of a simple task, and serial console output as well as a somewhat
         simplified NuttShell (NSH) configuration (see the
         <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
      </p>
      <p>
         An SPI driver and a USB device driver exist for the AT90USB as well
         as a USB mass storage configureation.  However, this configuration is not
         fully debugged as of the NuttX-6.5 release.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p><b>AVR-Specific Issues</b>.
      The basic AVR port is solid and biggest issue for using AVR is its tiny SRAM memory and its Harvard architecture.
      Because of the Harvard architecture, constant data that resides to flash is inaccessible using &quot;normal&quot; memory reads and writes (only SRAM data can be accessed &quot;normally&quot;).
      Special AVR instructions are available for accessing data in FLASH, but these have not been integrated into the normal, general purpose OS.
    </p>
    <p>
      Most NuttX test applications are console-oriented with lots of strings used for printf and debug output.
      These strings are all stored in SRAM now due to these data accessing issues and even the smallest console-oriented applications can quickly fill a 4-8K memory.
      So, in order for the AVR port to be useful, one of two things would need to be done:
    </p>
    <ol>
      <li>
        Don't use console applications that required lots of strings.
        The basic AVR port is solid and your typical deeply embedded application should work fine.
        Or,
      </li>
      <li>
        Create a special version of printf that knows how to access strings that reside in FLASH (or EEPROM).
      </li>
    </ol>
</tr>
<tr>
  <td><br></td>
  <td>
      <p>
        <b>Development Environments:</b>
        1) Linux with native Linux GNU toolchain, 2) Cygwin with Cygwin GNU toolchain, or 3) Cygwin with Windows native toolchain. 
        All testing, however, has been performed using the NuttX DIY toolchain for Linux  or Cygwin is provided by the NuttX
        <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a> package.
        As a result, that toolchain is recommended.
      </p>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><br></td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="atmelavr32"><b>Atmel AVR32</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>AV32DEV1</b>.
      This port uses the www.mcuzone.com AVRDEV1 board based on the Atmel AT32UC3B0256 MCU.
      This port requires a special GNU avr32 toolchain available from atmel.com website.
      This is a windows native toolchain and so can be used only under Cygwin on Windows.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         This port is has completed all basic development, but there is more that needs to be done.
         All code is complete for the basic NuttX port including header files for all AT32UC3* peripherals.
         The untested AVR32 code was present in the 5.12 release of NuttX.
         Since then, the basic RTOS port has solidified:
      </p>
      <ul>
        <li>
          The port successfully passes the NuttX OS test (apps/examples/ostest).
        </li>
        <li>
          A NuttShell (NSH) configuration is in place (see the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
          Testing of that configuration has been postponed (because it got bumped by the Olimex LPC1766-STK port).
          Current Status: I think I have a hardware problem with my serial port setup.
          There is a good chance that the NSH port is complete and functional, but I am not yet able to demonstrate that.
          At present, I get nothing coming in the serial RXD line (probably because the pins are configured wrong or I have the MAX232 connected wrong).
        </li>
      </ul>
      <p>
        The basic, port (including the verified apps/examples/ostest configuration) was be released in NuttX-5.13.
        A complete port will include drivers for additional AVR32 UC3 devices -- like SPI and USB --- and will be available in a later release,
        time permitting.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="m68hcs12"><b>Freescale M68HCS12</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>MC9S12NE64</b>.
      Support for the MC9S12NE64 MCU and two boards are included:
    </p>
    <ul>
      <li>
        The Freescale DEMO9S12NE64 Evaluation Board, and
      </li>
      <li>
        The Future Electronics Group NE64 /PoE Badge board.
      </li>
    </ul>
    <p>
      Both use a GNU arm-elf toolchain* under Linux or Cygwin.
      The NuttX <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a> provides a properly patched GCC 3.4.4 toolchain that is highly optimized for the m9s12x family.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         Coding is complete for the MC9S12NE64 and for the NE64 Badge board.
         However, testing has not yet begun due to issues with BDMs, Code Warrior, and
         the paging in the build process.
         Progress is slow, but I hope to see a fully verified MC9S12NE64 port in the near future.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="8052"><b>Intel 8052 Microcontroller</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>PJRC 87C52 Development Board</b>.
      This port uses the <a href="http://www.pjrc.com/">PJRC</a> 87C52 development system
      and the <a href="http://sdcc.sourceforge.net/">SDCC</a> toolchain under Linux or Cygwin.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
        This port is complete but not stable with timer interrupts enabled.
        There seems to be some issue when the stack pointer enters into the indirect IRAM
        address space during interrupt handling.
        This architecture has not been built in some time will likely have some compilation
        problems because of SDCC compiler differences.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="80x86"><b>Intel 80x86</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>QEMU/Bifferboard i486</b>.
      This port uses the <a href="http://wiki.qemu.org/Main_Page">QEMU</a> i486 and the native
      Linux, Cywgin, MinGW the GCC toolchain under Linux or Cygwin.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         The basic port was code-complete in NuttX-5.19 and verifed in NuttX-6.0.
         The port was verified using the OS and NuttShell (NSH) examples under QEMU.
         The port is reported to be functional on the <a href="http://bifferos.bizhat.com">Bifferboard</a> as well.
         This is a great, stable starting point for anyone interest in fleshing out the x86 port!
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>RGMP</b>.
      RGMP stands for RTOS and GPOS on Multi-Processor.
      RGMP is a project for  running GPOS and RTOS simultaneously on multi-processor platforms
      You can port your favorite RTOS to RGMP together with an unmodified Linux to form a hybrid operating system.
      This makes your application able to use both RTOS and GPOS features.
    </p>
    <p>
      See the <a href="http://rgmp.sourceforge.net/wiki/index.php/Main_Page">RGMP Wiki</a> for further information about RGMP.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
         This initial port of NuttX to RGMP was provided in NuttX-6.3.
         This initial RGP port provides only minimal driver support and does not use the native NuttX interrupt system.
         This is a great, stable starting point for anyone interest in working with NuttX under RGMP!
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="pic32mips"><b>MicroChip PIC32 (MIPS)</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p><b>PIC32MX250F128D</b>.
      A port is in progress from the DTX1-4000L &quot;Mirtoo&quot; module from <a href="http://www.dimitech.com/" >Dimitech</a>.
      This module uses MicroChip PIC32MX250F128D and the Dimitech DTX1-4000L EV-kit1 V2.
      See the <a href="http://www.dimitech.com/">Dimitech</a> website for further information.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        The basic port is code complete.
        Two configurations are available:
        (1) An OS test configuration and a (2) configuration that support the NuttShell (NSH).
        The OS test configuration is fully functional and proves that we have a basically healthy NuttX port to the Mirtoo.
        The NSH configuration includes support for a serial console and for the SST25 serial FLASH and the PGA117 amplifier/multiplexer on board the module.
        The NSH configuration is set up to use the NuttX wear-leveling FLASH file system (NXFFS).
        The PGA117, however, is not yet fully integrated to support ADC sampling.
        See the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a> for further information about NSH.
        The first verified port to the Mirtoo module was available with the NuttX 6.20 release.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
   <p><b>PIC32MX460F512L</b>.  There one two board ports using this chip:</p>
   <ul>
    <li><b>PIC32MX Board from PCB Logic Design Co</b>.
      This port is for the PIC32MX board from PCB Logic Design Co. and used the PIC32MX460F512L.
      The board is a very simple -- little more than a carrier for the PIC32 MCU plus voltage regulation, debug interface, and an OTG connector.
    </li>
    <p>
      <b>STATUS:</b>
      The basic port is code complete and fully verified in NuttX 6.13.
      Available configurations include the OS test and the NuttShell (NSH - see the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
    </p>
    <li><b>UBW32 Board from Sparkfun</b>
      This is the port to the Sparkfun UBW32 board.
      This port uses the <a href="http://www.sparkfun.com/products/8971">original v2.5</a> board which is based on the MicroChip PIC32MX460F512L.
      This older version has been replaced with this <a href="http://www.sparkfun.com/products/9713">newer board</a>.
      See also the <a href="http://www.schmalzhaus.com/UBW32/">UBW32</a> web site.
    </li>
    <p>
      <b>STATUS:</b>
      The basic port is code complete and fully verified in NuttX 6.18.
      Available configurations include the OS test and the NuttShell (NSH - see the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
      USB has not yet been fully tested but on first pass appears to be functional.
    </p>
  </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>PIC32MX440F512H</b>.
        This port uses the &quot;Advanced USB Storage Demo Board,&quot; Model DB-DP11215, from <a href="http://www.sureelectronics.net">Sure Electronics</a>.
        This board features the MicroChip PIC32MX440F512H.
        See the <a href="http://www.sureelectronics.net/goods.php?id=1168">Sure website</a> for further information about the DB-DP11215 board.
        (I believe that that the DB-DP11215 may be obsoleted now but replaced with the very similar, DB-DP11212.
        The DB-DP11212 board differs, I believe, only in its serial port configuration.)
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
       This NuttX port is code complete and has considerable test testing.
       The port for this board was completed in NuttX 6.11, but still required a few bug fixes before it will be ready for prime time.
       The fully verified port first appeared in NuttX 6.13.
       Available configurations include the OS test and the NuttShell (NSH - see the <a href="http://nuttx.sourceforge.net/NuttShell.html">NSH User Guide</a>).
       An untested USB device-side driver is available in the source tree.
       A more complete port would include support of the USB OTG port and of the LCD display on this board.
       Those drivers are not yet available as of this writing.
       </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>PIC32MX795F512L</b>.
        There one two board ports using this chip:
    </p>
    <ul>
      <li><b>Microchip PIC32 Ethernet Starter Kit</b>.
         This port uses the Microchip PIC32 Ethernet Starter Kit (DM320004) with the Expansion I/O board.
         See the <a href="http://ww.microchip.com">Microchip website</a> for further information.
      </li>
      <p>
       <b>STATUS:</b>
         This port was started and then shelved for some time until I received the Expansion I/O board.
         The basic Starter Kit (even with the Multimedia Expansion Board, MEB, DM320005)) has no serial port and most NuttX test configurations depend heavily on console output.
      </p>
      <p>
         Verified configurations for the OS test and the NuttShel (NSH) appeared in NuttX-6.16.
         Board support includes a verified USB (device-side) driver.
         Also included are a a verified Ethernet driver, a partially verified USB device controller driver, and an unverifed SPI driver.
         Stay tuned for updates.
      </p>
     <li><b>Mikroelektronika PIC32MX7 Mulitmedia Board (MMB)</b>.
        A port has been completed for the  Mikroelektronika PIC32MX7 Multimedia Board (MMB).
        See http://www.mikroe.com/ for further information about this board.
      </li>
      <p>
       <b>STATUS:</b>
         Two verified configurations are available:
         (1) The basic OS test configuration that verfies the correctness port of NuttX, and (2) an extensive <a href="NuttShell.html">NuttShell (NSH)</a> configuration.
         The NSH configuration includes:
         (1) Full network support,
         (2) Verified SPI driver,
         (3) SPI-based SD Card support,
         (4) USB device support (including configuration options for the USB mass storage device and the CDC/ACM serial class), and
         (5) Support for the MIO873QT2 LCD on the PIC32MX7 MMB.
       </p>
       </p>
         The PIC32MX7 MMB's touchscreen is connected directly to the MCU via ADC pins.
         A touchscreen driver has been developed using the PIC32's ADC capabilities and can be enabled in the NSH configuration.
         However, additional verification and tuning of this driver is required.
         Further display/touchscreen verification would require C++ support (for NxWidgets and NxWM).
         Since I there is no PIC32 C++ is the free version of the MPLAB C32 toolchain, further graphics development is stalled.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Development Environment:</b>
      These ports uses either:
    </p>
    <ol>
      <li>
        The <i>LITE</i> version of the PIC32MX toolchain available
        for download from the <a href="http://www.microchip.com">MicroChip</a> website, or
      </li>
      <li>
        The Pinguino MIPS ELF toolchain avaiable from the Pinquino <a href="http://code.google.com/p/pinguino32/downloads/list">website</a>.
      </li>
    </ol>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><br></td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="superh"><b>Renesas/Hitachi SuperH</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>SH-1 SH7032</b>.
      This port uses the Hitachi SH-1 Low-Cost Evaluation Board (SH1_LCEVB1), US7032EVB,
      with a GNU ELF toolchain* under Linux or Cygwin.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
        This port is available as of release 0.3.18 of NuttX.  The port is basically complete
        and many examples run correctly.  However, there are remaining instabilities that
        make the port un-usable.  The nature of these is not understood; the behavior is
        that certain SH-1 instructions stop working as advertised.  This could be a silicon
        problem, some pipeline issue that is not handled properly by the gcc 3.4.5 toolchain
        (which has very limit SH-1 support to begin with), or perhaps with the CMON debugger.
        At any rate, I have exhausted all of the energy that I am willing to put into this cool
        old processor for the time being.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="m16c"><b>Renesas M16C/26</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Renesas M16C/26 Microncontroller</b>.
      This port uses the Renesas SKP16C26 Starter kit and the GNU M32C toolchain. 
      The development environment is either Linux or Cygwin under WinXP.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        Initial source files released in nuttx-0.4.2.
        At this point, the port has not been integrated;    the target cannot be built
        because the GNU <code>m16c-elf-ld</code> link fails with  the following message:
      </p>
      <ul>
      <code>m32c-elf-ld: BFD (GNU Binutils) 2.19 assertion fail /home/Owner/projects/nuttx/buildroot/toolchain_build_m32c/binutils-2.19/bfd/elf32-m32c.c:482</code>
      </ul>
      <p>Where the reference line is:</p>
      <ul><pre>
/* If the symbol is out of range for a 16-bit address,
   we must have allocated a plt entry.  */
BFD_ASSERT (*plt_offset != (bfd_vma) -1);
</pre></ul>
      <p>
        No workaround is known at this time.  This is a show stopper for M16C for
        the time being.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="zilogz16f"><b>Zilog Z16F</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Zilog z16f Microncontroller</b>.
      This port use the Zilog z16f2800100zcog development kit and the Zilog
      ZDS-II Windows command line tools.
      The development environment is Cygwin under WinXP.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        The initial release of support for the z16f was made available in NuttX version 0.3.7.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="zilogez80acclaim"><b>Zilog eZ80 Acclaim!</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Zilog eZ80Acclaim! Microncontroller</b>.
      There are two eZ80Acclaim! ports:
    </p>
    <ul>
      <li>One uses the ZiLOG ez80f0910200kitg development kit, and
      <li>The other uses the ZiLOG ez80f0910200zcog-d development kit.
    </ul>
    <p>
      Both boards are based on the eZ80F091 part and both use the Zilog ZDS-II
      Windows command line tools.
      The development environment is Cygwin under WinXP.
    </p>
    <ul>
      <p>
        <b>STATUS:</b>
        Integration and testing of NuttX on the  ZiLOG ez80f0910200zcog-d is complete.
        The first integrated version was released in NuttX version 0.4.2 (with important early bugfixes
        in 0.4.3 and 0.4.4).
        As of this writing, that port provides basic board support with a serial console, SPI, and eZ80F91 EMAC driver.
      </p>
    </ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="zilogz8encore"><b>Zilog Z8Encore!</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Zilog Z8Encore! Microncontroller</b>.
      This port uses the either:
    </p>
    <ul>
      <li>Zilog z8encore000zco development kit, Z8F6403 part, or</li>
      <li>Zilog z8f64200100kit development kit, Z8F6423 part</li>
    </ul>
    <p>
      and the Zilog ZDS-II Windows command line tools.
      The development environment is Cygwin under WinXP.
    </p>
    <ul>
       <p>
         <b>STATUS:</b>
         This release has been verified only on the ZiLOG ZDS-II Z8Encore! chip simulation
         as of nuttx-0.3.9.
       </p>
     <ul>
  </td>
</tr>
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <a name="zilogz80"><b>Zilog Z80</b>.</a>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Z80 Instruction Set Simulator</b>.
      This port uses the <a href="http://sdcc.sourceforge.net/">SDCC</a> toolchain
      under Linux or Cygwin (verified using version 2.6.0).
      This port has been verified using only a Z80 instruction simulator.
      That simulator can be found in the NuttX SVN
      <a href="http://svn.code.sf.net/p/nuttx/code/trunk/misc/sims/z80sim/">here</a>.
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
        This port is complete and stable to the extent that it can be tested
        using an instruction set simulator.
      </p>
    <ul>
  </td>
</tr>
<tr>
  <td><br></td>
  <td><hr></td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>XTRS: TRS-80 Model I/III/4/4P Emulator for Unix</b>.
      A very similar Z80 port is available for <a href="http://www.tim-mann.org/xtrs.html">XTRS</a>,
      the TRS-80 Model I/III/4/4P Emulator for Unix.
      That port also uses the <a href="http://sdcc.sourceforge.net/">SDCC</a> toolchain
      under Linux or Cygwin (verified using version 2.6.0).
    </p>
    <ul>
      <p>
       <b>STATUS:</b>
       Basically the same as for the Z80 instruction set simulator.
       This port was contributed by Jacques Pelletier.
      </p>
    <ul>
  </td>
</tr>
</table></center>

<blockquote>* A highly modified <a href="http://buildroot.uclibc.org/">buildroot</a>
is available that may be used to build a NuttX-compatible ELF toolchain under
Linux or Cygwin.  Configurations are available in that buildroot to support ARM, Cortex-M3,
avr, m68k, m68hc11, m68hc12, m9s12, blackfin, m32c, h8, and SuperH ports.</blockquote>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="environments"><h1>Development Environments</h1></a>
  </td>
  </tr>
</table>

<center><table width="90%">
<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Linux + GNU <code>make</code> + GCC/binutils</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      The is the most natural development environment for NuttX.
      Any version of the GCC/binutils toolchain may be used.
      There is a  highly modified <a href="http://buildroot.uclibc.org/">buildroot</a>
      available for download from the
      <a href="http://sourceforge.net/projects/nuttx/files/">NuttX SourceForge</a>
      page.
      This download may be used to build a NuttX-compatible ELF toolchain under Linux or Cygwin.
      That toolchain will support ARM, m68k, m68hc11, m68hc12, and SuperH ports.
      The buildroot SVN may be accessed in the 
      <a href="http://svn.code.sf.net/p/nuttx/code/trunk/misc/buildroot/">NuttX SVN</a>.
    </p>
   </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Linux + GNU <code>make</code> + SDCC</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      Also very usable is the Linux environment using the 
      <a href="http://sdcc.sourceforge.net/">SDCC</a> compiler.
      The SDCC compiler provides support for the 8051/2, z80, hc08, and other microcontrollers.
      The SDCC-based logic is less well exercised and you will likely find some compilation
      issues if you use parts of NuttX with SDCC that have not been well-tested.
    </p>
   </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Cygwin + GNU <code>make</code> + GCC/binutils</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      This combination works well too.
      It works just as well as the native Linux environment except
      that compilation and build times are a little longer.
      The custom NuttX <a href="http://sourceforge.net/projects/nuttx/files/buildroot/">buildroot</a> referenced above may be build in
      the Cygwin environment as well.
    </p>
  </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Cygwin + GNU <code>make</code> + SDCC</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
       I have never tried this combination, but it would probably work just fine.
    </p>
  </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Cygwin + GNU <code>make</code> + Windows Native Toolchain</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      This is a tougher environment.
      In this case, the Windows native toolchain is unaware of the
      Cygwin <i>sandbox</i> and, instead, operates in the native Windows environment.
      The primary difficulties with this are:
    </p>
    <ul>
      <li>
        <b>Paths</b>.
        Full paths for the native toolchain must follow Windows standards.
        For example, the path <code>/home/my\ name/nuttx/include</code> my have to be
        converted to something like <code>'C:\cygwin\home\my name\nuttx\include'</code>
        to be usable by the toolchain.
      </li>
      <p>
        Fortunately, this conversion is done simply using the <code>cygpath</code> utility.
      </p>
      <li>
        <b>Symbolic Links</b>
        NuttX depends on symbolic links to install platform-specific directories in the build system.
        On Linux, true symbolic links are used.
        On Cygwin, emulated symbolic links are used.
        Unfortunately, for native Windows applications that operate outside of the
        Cygwin <i>sandbox</i>, these symbolic links cannot be used.
      </li>
      <p>
        The NuttX make system works around this limitation by copying the platform
        specific directories in place.
        These copied directories make work a little more complex, but otherwise work well.
      </p>
      <p><small>
        NOTE: In this environment, it should be possible to use the NTFS <code>mklink</code> command to create links.
        This should only require a minor modification to the build scripts (see <code>tools/winlink.sh</code> script).
      </small></p>
      <li>
        <b>Dependencies</b>
        NuttX uses the GCC compiler's <code>-M</code> option to generate make dependencies.  These
        dependencies are retained in files called <code>Make.deps</code> throughout the system.
        For compilers other than GCC, there is no support for making dependencies in this way.
        For Windows native GCC compilers, the generated dependencies are windows paths and not
        directly usable in the Cygwin make.  By default, dependencies are surpressed for these
        compilers as well.
      </li>
      <p><small>
        NOTE: dependencies are suppress by setting the make variable <code>MKDEPS</code> to point
        to the do-nothing dependency script, <code>tools/mknulldeps.sh</code>.
        Dependencies can be enabled for the Windows native GCC compilers by setting
        <code>MKDEPS</code> to point to <code>$(TOPDIR)/tools/mkdeps.sh --winpaths $(TOPDIR)</code>.
      </small></p>
    </ul>
    <p>
      <b>Supported Windows Native Toolchains</b>.
      At present, only the Zilog Z16F, z8Encore, and eZ80Acclaim ports use a non-GCC native Windows
      toolchain(the Zilog ZDS-II toolchain).
      Support for Windows native GCC toolchains (CodeSourcery and devkitARM) is currently implemented
      for the NXP LPC214x, STMicro STR71x, and Luminary LMS6918 ARM ports.
      (but could easily be extended to any other GCC-based platform with a small effort).
    </p>
  </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Wine + GNU <code>make</code> + Windows Native Toolchain</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      I've never tried this one, but I off the following reported by an ez80 user using the ZiLOG ZDS-II Windows-native toolchain:
    </p>
    <blockquote>
      <p>
         &quot;I've installed ZDS-II 5.1.1 (IDE for ez80-based boards) on wine (windows emulator for UNIX) and to my surprise, not many changes were needed to make SVN snapshot of NuttX buildable...
         I've tried nsh profile and build process completed successfully.
         One remark is necessary: NuttX makefiles for ez80 are referencing <code>cygpath</code> utility.
         Wine provides similar thing called <code>winepath</code> which is compatible and offers compatible syntax.
         To use that, <code>winepath</code> (which itself is a shell script) has to be copied as <code>cygpath</code> somewhere in <code>$PATH</code>, and edited as in following patch:
       </p>
       <ul><pre>
# diff -u `which winepath` `which cygpath`
--- /usr/bin/winepath 2011-05-02 16:00:40.000000000 +0200
+++ /usr/bin/cygpath 2011-06-22 20:57:27.199351255 +0200
@@ -20,7 +20,7 @@
#

# determine the app Winelib library name
-appname=`basename "$0" .exe`.exe
+appname=winepath.exe

# first try explicit WINELOADER
if [ -x "$WINELOADER" ]; then exec "$WINELOADER" "$appname" "$@"; fi
</pre></ul>
      <p>
        &quot;Better solution would be replacing all <code>cygpath</code> references in  <code>Makefiles </code> with  <code>$(CONVPATH)</code> (or  <code>${CONVPATH}</code> in shell scripts) and setting <code>CONVPATH</code> to  <code>cygpath</code> or  <code>winepath</code> regarding to currently used environment.
      </p>
    </blockquote>
  </td>
</tr>

<tr>
  <td valign="top"><img height="20" width="20" src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Other Environments?
    Windows Native <code>make</code> + Windows Native Toolchain?</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>Environment Dependencies</b>.
      The primary environmental dependency of NuttX are (1) GNU make,
      (2) bash scripting, and (3) Linux utilities (such as cat, sed, etc.).
      If you have other platforms that support GNU make or make
      utilities that are compatible with GNU make, then it is very
      likely that NuttX would work in that environment as well (with some
      porting effort). If GNU make is not supported, then some significant
      modification of the Make system would be required.
    </p>
    <p>
     <b>GNUWin32</b>.
      For example, with suitable make system changes, it should be possible to
      use native GNU tools (such as those from
      <a href="http://sourceforge.net/projects/gnuwin32/">GNUWin32</a>)
      to build NuttX.
      However, that environment has not been used as of this writing.
   </p>
      <p><small>
        NOTE: One of the members on the <a href="http://tech.groups.yahoo.com/group/nuttx/">NuttX forum</a>
        reported that they successful built NuttX using such a GNUWin32-based, Windows native environment.
        They reported that the only necessary change was to the use the NTFS mklink command to create links
        (see <code>tools/winlink.sh</code> script).
      </small></p>
  </td>
</tr>
</table></center>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="footprint"><h1>Memory Footprint</h1></a>
  </td>
  </tr>
</table>

<ul>
<p><b>C5471 (ARM7)</b>
  The build for this ARM7 target that includes most of the OS features and
  a broad range of OS tests.  The size of this executable as given by the
  Linux <tt>size</tt> command is (3/9/07):
</p>
<pre>
   text    data     bss     dec     hex filename
  53272     428    3568   57268    dfb4 nuttx
</pre>
<p><b>DM320 (ARM9)</b>
  This build for the ARM9 target includes a significant subset of OS
  features, a filesystem, Ethernet driver, full TCP/IP, UDP and (minimal)
  ICMP stacks (via uIP) and a small network test application: (11/8/07,
  configuration netconfig, apps/examples/nettest)
</p>
<pre>
   text    data     bss     dec     hex filename
  49472     296    3972   53740    d1ec nuttx
</pre>
<p>
  Another build for the ARM9 target includes a minimal OS feature
  set, Ethernet driver, full TCP/IP and (minimal) ICMP stacks, and
  a small webserver: (11/20/07, configuration uipconfig, apps/examples/uip)
</p>
<pre>
   text    data     bss     dec     hex filename
  52040      72    4148   56260    dbc4 nuttx
</pre>
<p><b>87C52</b>
  A reduced functionality OS test for the 8052 target requires only
  about 18-19K:
</p>
<pre>
Stack starts at: 0x21 (sp set to 0x20) with 223 bytes available.

Other memory:
   Name             Start    End      Size     Max
   ---------------- -------- -------- -------- --------
   PAGED EXT. RAM                         0      256
   EXTERNAL RAM     0x0100   0x02fd     510     7936
   ROM/EPROM/FLASH  0x2100   0x6e55   19798    24384
</pre>
</ul>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="licensing"><h1>Licensing</h1></a>
  </td>
  </tr>
</table>

<ul>
<p>
  NuttX is available under the highly permissive
  <a href="http://en.wikipedia.org/wiki/BSD_license">BSD license</a>.
  Other than some fine print that you agree to respect the copyright
  you should feel absolutely free to use NuttX in any environment and
  without any concern for jeopardizing any proprietary software that
  you may link with it.
</p>
</ul>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="history"><h1>Release History</h1></a>
  </td>
  </tr>
</table>

<ul>
<p>
   ChangeLog snapshots associated with the previous, current, and future release are available below.
</p>
</ul>

<center><table width ="80%">
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
   <td>
      <a href="ChangeLog.txt">Change logs for previous NuttX releases</a><br>
   </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
   <td>
      <a href="#currentrelease">ChangeLog for the current NuttX releases</a><br>
   </td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
   <td>
      <a href="#pendingchanges">Unreleased changes</a>
   </td>
</tr>
</table></center>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="currentrelease">ChangeLog for the Current Release</a>
  </td>
  </tr>
</table>

<ul><pre>
nuttx-6.22 2012-09-29 Gregory Nutt &lt;gnutt@nuttx.org&gt;

    * include/semaphore.h, sched/sem_holders.c, and lib/semaphore/sem_init.c:
      Fix some strange (and probably wrong) list handling when
      CONFIG_PRIORITY_INHERITANCE and CONFIG_SEM_PREALLOCHOLDERS are defined.
      This list handling was probably causing errors reported by Mike Smith
    * sched/sched_waitpid.c: Fix a possible issue with logic logic that
      should be brought into a critical section (suggested by Mike Smith)
    * sched/sched_setuptaskfiles.c: Should be 'struct socket' not
      'struct sockets'.  How did this compile before? (found by Kate)
    * syscall/syscall.csv:  Fix prototype for usleep() and prctl() (also
      from Kate).
    * arch/arm/src/lpc17xx/lpc17_ethernet.c:  Conditionally elide setting PHY
      speed/duplex.  This does not work for certain PHYs.  Still some unresolved
      issues (also from Kate).
    * tools/Config.mk, Makefile, configs/*/Make.defs:  Add a new Makefile
      fragment to de-quote certain strings from the Kconfig logic that
      need to be used at path segments (Richard Cochran).
    * arch/arm/src/stm32/stm32_usbotghost.c:  The STM32 USB host driver only
      works with debug turned on.  The problem appears to be that with debug
      OFF, there are more NAKs occuring in more places than before and this
      reveals a variety of errors.  This check in improves NAK robustness
      for control transfers but does not resolve all of the issues.
    * configs/stm3220g-eval/*/defconfig:  Calibrated delay loop.  It had
      never been calibrated was way off.
    * sched/sem_holder.c: Add logic to handler some priority inheritance
      cases when sem_post() is called from an interrupt handler.  The
      logic is clearly wrong, but it is not known if this is the
      cause of any known bugs.
    * lib/stdio/lib_perror():  Add perror().  Contributed by Kate.
    * lib/string/lib_strerror():  Add option CONFIG_LIBC_STRERROR that
      is now required to enabled strerror().  Add an option
      CONFIG_LIBC_STRERROR_SHORT that can be used to output shortened
      strings by strerror().
    * arch/arm/src/stm32/stm32_usbotghost.c:  Finally... the USB OTG FS
      appears to handle NAKing correctly.
    * configs/stm32f4discovery/*:  Added and verifed support for USB OTG FS
      host on the STM32F4Discovery board.
    * configs/*/defconfig: Remove configuration documentation from config
      files.  It is redundant, error-prone, and difficult to maintain.
      Configuration documentation is available in configs/README.txt for
      common configurations and in configs/*/README.txt for board and MCU-
      specific configurations.
    * configs/stm3240g-eval: Add USB host support.
    * sched/os_bring.c, configs/*/defconfig, tools/mkconfig.c, and others:  Added
      configuration variable CONFIG_USER_ENTRYPOINT that may be used to change
      the default entry from user_start to some other symbol.  Contributed by
      Kate. NOTE: This change does introduce a minor backward incompatibility.
      For example, if your application uses NSH as its start-up program, then your
      build will now fail because it will be unable to find &quot;user_start&quot;.  The fix
      for this link failure is to add the following to your configuration file:
      CONFIG_USER_ENTRYPOINT=&quot;nsh_main&quot;.
    * libs/stdio/lib_libfread.c and lib_*flush*.c:  Correct a couple of
      error cases where the lib semaphore was not be released on error
      exits (thanks Ronen Vainish).  Also, improved some error reporting:
      the generic ERROR was being used instead of the specific errno
      value; the errno variable was not always set correctly.
    * tools/mkfsdata.pl: The uIP web server CGI image making perl script was
      moved from apps/netutils/webserver/makefsdata to nuttx/tools/mkfsdata.pl
      (Part of a larger change submitted by Max Holtzberg).
    * configs/stm3240g-eval/script/ld.script:  All of the identical ld.script
      files for the STM3240G-EVAL were replaced by one version in this directory.
    * configs/stm3240g-eval/webserver:  Configuration submitted by Max Holtzberg
      for testing the changes to the uIP web server (see apps/ChangeLog.txt).
    * lib/stdio/lib_perror.c:  Remove CONFIG_LIBC_PERROR_DEVNAME.  What was I
      thinking?  Arbitrary streams cannot be shared by different tasks.
    * tools/mksyscall.c, csvparser.c, and csvparser.h: Separate CSV parsing
      logic from mksyscall.c into files where it can be shared.
    * tools/mksymtab.c:  Add a tool that can be used to convert a CSV file
      into a NuttX-style symbol table.
    * sched/work_cancel.c:  Fix a bad assertion (reported by Mike Smith)
    * configs/stm3210e-eval/src/up_idle.c:  Correct some power management
      compilation errors (reported by Diego Sanchez).
    * include/nuttx/wqueue.h, sched/work*, and others:  Added logic to support
      a second, lower priority work queue (CONFIG_SCHED_LPWORK).
    * arch/arm/src/stm32/stm32_dma.c, chip/stm32*_memorymap.h:  FSMC SRAM is
      only 16-bits wide and the SDIO DMA must be set up differently.
    * arch/arm/src/stm32/stm32_dma.c:  Back out the 16-bit DMA change. It
      is incorrect.
    * configs/:  Make use of UART4/5 vs USART4/5 consistent in all places.
    * Kconfig: Serial 2STOP setting must be integer 0/1, not a boolean.
    * lib/misc/sendfile.c and include/sys/sendfile.h:  Add a Linux style
      sendfile() (non-standard!)
    * Kconfig: Refactor serial settings (moved from chip to drivers/serial).
      AVR &quot;teensy&quot; now builds with Kconfig (contributed by Richard Cochran).
    * Kconfig: Add configuration settings for the LPC17xx
    * Kconfig: Add configuration settings for the LM3S (from Richard Cochran).
    * Kconfig: Verify configuration settings for the STM32.  This includes
      changes in the way that the external SRAM is configured:  Define
      CONFIG_HEAP2_SIZE (decimal) instead of CONFIG_HEAP2_END (hex).
    * tools/configure.sh:  Don't append the apps directory path setting
      if the correct setting is already in defined in the defconfig file.
    * fs/fat/fs_utils.c:  Improperly constructed bool expression.  This
      would cause many unnecessary writes to FLASH (Thanks Ronen Vainish).
    * Kconfig: Verify configuration settings for the LPC43xx.  This includes
      some corrections to configuration variable names and defconfig settings.
    * Kconfig: Add and verify configuration settings for the LPC31xx.
    * arch/arm/src/stm32/stm32_uart.h and stm32_serial.c:  Add logic to
      re-initialize the console UART as needed to enable DMA on the
      console UART (contributed by Mike Smith).
    * net/recvfrom.c, net/Kconfig, include/nuttx/net/uipopt.h: Remove delay
      after receiving data.  That has historical reasons to be there (it
      was needed before read-ahead buffering was added), but kills performance.
      (Noted by Max Holtzberg).
    * configs/shenzhou:  Add beginnings of a board configuration for the
      Shenzhou STM32107 board (see www.armjishu.com).  Very little is in
      place as of this initial check-in.
    * QEMU: Fixes from Richard Cochran to build QEMU with Kconfig files.
    * arch/*/src/Makefile:  Remove some old logic that was kicked off
      when CONFIG_BOOT_RUNFROMFLASH=y.  The old logic used to use
      objcopy to move sections.  Newer logic changes the load position
      of sections in the the linker script.  As far as I can tell, there
      is nothing in the source tree now that depends on the old way of
      doing things (if I am wrong, they will need a change to the linker
      script).
    * configs/fire-stm32v2:  Configuration for the M3 Wildfire board.  I
      don't know very much about this board other than is has an
      STM32F103VET6 chip, LCD, touchscreen, and ENC28J60 network.  Very
      little is in place on the initial check-in.
    * configs/shenzhou: Coding for the Shenzhou board port is complete,
      but tested has been deferred until I get the right tools.
    * arch/arc/include/stm32/chip.h and arch/arm/src/stm32/chip.h:
      Add support for the STM32F103VET6.
    * fs/fs_fdopen.c: Bad check for failure to allocate memory.  (Noted
      by Ronen Vainish).
    * drivers/mmcsd/mmcsd_sdio.c: If the MMC/SD driver were ever
      uninitialized then there would be a double release of memory
      (Noted by Ronen Vainish).
    * fs/mmap/fs_rammap.c:  Fix logic error and errno check (contributed
      by Kate).
    * arch/avr/src: Fixes from AVR32 build errors that have crept in
      over the time; incorporated Kconfig for AVR3 (Richard Cochran).
    * fs/fat and include/nuttx/fs/fat.h: The FAT file system allocates
      memory for sector I/O buffers used to exchange data with the
      configured block driver.  In some contexts, the block driver may
      require DMA-capable memory.  If CONFIG_FAT_DMAMEMORY is defined,
      then the FAT FS will use platform-provided DMA memory allocators
      to allocate the block driver I/O buffers.
    * CONFIG_NET_ENC28J60 renamed CONFIG_ENC28J60 to be consistent
      in all places.
    * drivers/enc28j60.c, include/nuttx/net/enc28j60.h, and 
      olimex-strp711/src/up_enc28j60.c:  No longer passes IRQ number
      as a parameter.  Instead now passes a call table to manage
      ENC28J60 GPIO interrupts.  That is because GPIO interrupts are
      handled in different ways by different MCUs and some do not
      support IRQ numbers for GPIO interrupts.
    * mm/mm_gran* and include/nuttx/gran.h:  Add a simple granule-
      based allocator.  The intent of this allocator is to support
      simple allocation of DMA I/O buffers.  The initial check-in
      is code complete but untested (not event built into the
      mm/Makefile yet.
    * confgs/fire-stm32v2: The board port is basically functional.
      Not all features have been verified.  The ENC28J60 network
      is not yet functional.
    * configs/stm3240g-eval/discover:  A configuration for testing
      the UDP discovery utility.  Contributed by Max Holtzberg.
    * mm/README.txt:  Add a new README file.
    * include/nuttx/usb/usb.h, arch/*/src/*usb.c, and arch/*/src/*otg*.c:
      Add hooks to to use common, external DMA buffer allocation
      implementation.
    * net/recvfrom.c: Don't block in recvfrom if (1) read-ahead buffering
      is enabled and (2) some data was obtained from read-ahead buffers.
      Blocking is a bad idea in that case because there is no timeout!
      (submitted by Max Holtzberg).
    * configs/stm3240g-eval/xmlrpc: An example configuration for the
      Embeddable Lightweight XML-RPC Server at apps/examples/xmlrpc.
      See http://www.drdobbs.com/web-development/\
      an-embeddable-lightweight-xml-rpc-server/184405364 for more info.
      Contributed by Max Holtzberg.
    * configs/*/nxwm/defconfig and sched/task_exithook.c: Fixes for
      bugs that crept in during recent changes.  (Submitted by Max
      Holtzberg).
    * arch/arm/include/armv7-m/irq.h:  Fix a critical bug in irqsave().
      It looks like sometimes the compile will re-order some instructions
      inapproapriately.  This end result is that interrupts will get
      stuck off.
    * drivers/mtd/w25.c:  Beginning of a driver for the Windbond SPI
      FLASH family (W25x16, W25x32, and W25x64).  The initial check-in
      is basically just the SST25 driver with some name changes.
    * arch/arm/include/armv7-m/irq.h and arch/arm/src/stm32/stm32_spi.c:
      Back out the last change in irq.h.  It is (most likely) fine the
      way it was.  The really interrupt related problem was in stm32_spi.c:
      When SPI3 is not enabled, then the irqrestore() falls in the
      else clause.
    * include/nuttx/compiler.h and other files:  Moved always_inline
      and noinline __attributes__ here.  Also replaced all occurrences
      of explicit __atributes__ in other files with definitions from
      this header file.
    * drivers/mtd/w25.c:  The Windbond SPI FLASH W25 FLASH driver is
      code complete (but still untested).
    * arch/arm/src/stm32/stm32_i2c.c:  I2C improvements from Mike Smith.
      Unified configuration logic; dynamic timeout calculations;
      I2C reset logic to recover from locked devices on the bus.
    * configs/*/*/Make.defs, tools/Config.mk, Makefile:  Refactor all
      common make definitions from the various Make.defs files into
      the common tools/Config.mk.  Add support for a verbosity options:
      Specify V=1 on the make command line in order to see the exact
      commands used in the build (Contributed by Richard Cochran).
    * drivers/net/enc28j60.c:  The ENC28J60 Ethernet driver is
      now functional.
    * configs/fire-stm32v2:  Add support or the fire-stm32v3 board as
      well (untested because I do not have a v3 board).
    * lib/stdio/lib_sscanf.c:  Add %n psuedo-format (from Kate).
    * lib/stdio/lib_sscanf.c:  There is an issue of handling input
      when (1) no fieldwidth is provided and (2) there is no space
      seperating the input values.  No solutions is in place for this
      case now (either space or a fieldwidth must be provided).  But
      at least some of the bad logic that attempted to handle this
      case has been removed (noted by Kate).
    * arch/arm/src/stm32/stm32_eth.c:  DMA buffer sizes must be an
      even multiple of 4, 8, or 16 bytes.
    * arch/arm/src/stm32/stm32_idle.c:  Fixes STM32F107 DMA issues:
      We cannot go into sleep mode while Ethernet is actively DMAing.
    * configs/shenzhou/src/up_ssd1289.c:  Add infrastructure to support
      SSD1289 LCD.  Initial checkin is just a clone of the
      STM32F4Discovery's FSMC-based LCD interface.  The Shenzhou
      will need a completely need bit-banging interface; this
      initial check-in is only for the framework.
    * configs/shenzhou/src/up_ssd1289.c:  Bit-banging driver is
      code complete.
    * configs/shenzhou/src/up_lcd.c:  Oops. Shenzhou LCD does not
      have an SSD1289 controller.  Its an ILI93xx.  Ported the
      STM3240G-EVAL ILI93xx driver to work on the Shenzhou board.
    * configs/shenzhou/nxwm:  Added an NxWM configuration for the
      Shenzhou board.  This is untested on initial check-in.  It will
      be used to verify the Shenzhou LCD driver (and eventually the
      touchscreen driver).
    * configs/shenzhou/src/up_touchscreen.c:  Add ADS7843E touchscreen
      support for the Shenzhou board.  The initial check-in is untested
      and basically a clone of the the touchscreen support for the SAM-3U.
    * tools/cfgparser.c: There are some NxWidget configuration
      settings that must be de-quoted.
    * arch/arm/src/stm32/Kconfig: There is no SPI4.  Some platforms
      support SPI3 and some do not (still not clear).
    * nuttx/configs/shenzhou: Various fixes to build new NxWM
      configuration.
    * configs/shenzhou:  Oops.  The Shenzhou LCD is and SSD1289,
      not an ILI93xx.
    * configs/shenzhou/src/up_ssd1289.c: The LCD is basically functional
      on the Shenzhou board.
    * graphics/nxmu:  Correct some bad parameter checking that caused
      failures when DEBUG was enabled.
    * arch/arm/src/armv7-m/nvic.h:  Add bit definitions for the AIRCR
      register.
    * drivers/input/ads7843.c:  Need semaphore protection in logic
      that samples the position.
    * drivers/lcd/ssd1289.c:  On some platforms we are unable to
      read the device ID -- reason unknown; workaround in place.
    * drivers/input/ads7843.c:  Add thresholding options and an
      option to swap X and Y positions.  Fix some logic errors in
      the SPI locking/selecting logic.
    * arch/arm/src/armv7-m/up_systemreset.c:  Add logic to reset
      the Cortex-Mx using the AIRCR register.  Contributed by Darcy
      Gong.
    * arch/arm/src/stm32/up_eth.c:  Add logic specifically for the
      DM9161 PHY.  If the DM9161 failed to initialize, then use the
      up_sysemreset() logic to reset the MCU.  Contributed by Darcy
      Gong.
    * arch/arm/src/stm32/stm32_gpio.c:  Add missing logic to set bit
      for SPI3 remap.  This fixes the XPT2046 touchscreen driver using
      drivers/input/ads7843.c
    * configs/shenzhou/src/up_ssd1289.c:  Fix naming error in
      conditional compilation.
    * configs/shenzhou/nxwm/defconfig:  Disable reading from the LCD.
      This does not work.  The hardware and the driver support the
      capability, but there is some bug that causes memory corruption.
      The work around for now:  Just disable reading from the LCD.
    * drivers/lcd/ssd1289.c:  Add some logic to reduce the amount of
      output when CONFIG_DEBUG_LCD is enabled.
    * configs/shenzhou/nxwm/defconfig:  Bug found and fixed... The
      original configuration had too much stuff turned on.  Reducing
      stack sizes, some features, and buffer sizes made the
      configuration reliable (Reading from the LCD is still disabled).
    * net/uip/uip_icmpping.c:  Fix problem that prevented ping from
      going outside of local network.  Submitted by Darcy Gong

apps-6.22 2012-09-29 Gregory Nutt &lt;gnutt@nuttx.org&gt;

    * apps/netutils/thttpd/thttpd_cgi.c:  Missing NULL in argv[]
      list (contributed by Kate).
    * apps/nshlib/nsh_parse.c: CONFIG_NSH_DISABLE_WGET not CONFIG_NSH_DISABLE_GET
      in one location (found by Kate).
    * apps/examples/ostest/prioinherit.c:  Limit the number of test
      threads to no more than 3 of each priority.  Bad things happen
      when the existing logic tried to created several hundred test
      treads!
    * apps/nshlib/nsh.h:  Both CONFIG_LIBC_STRERROR and CONFIG_NSH_STRERROR
      must be defined to use strerror() with NSH.
    * apps/examples/*/*_main.c, system/i2c/i2c_main.c, and others:  Added
      configuration variable CONFIG_USER_ENTRYPOINT that may be used to change
      the default entry from user_start to some other symbol.  Contributed by
      Kate.
    * apps/netutils/webserver/httpd/c:  Fix a typo that as introduced in
      version r4402:  'lese' instead of 'else' (Noted by Max Holtzberg).
    * tools/mkfsdata.pl: The uIP web server CGI image making perl script was
      moved from apps/netutils/webserver/makefsdata to nuttx/tools/mkfsdata.pl
      (Part of a larger change submitted by Max Holtzberg).
    * apps/netutils/webserver, apps/examples/uip, and apps/include/netutils/httpd.h:
      The &quot;canned&quot; version of the uIP web servers content that was at 
      netutils/webserver/httpd_fsdata.c has been replaced with a dynamically
      built configuration located at apps/examples/uip (Contributed by
      Max Holtzberg).
    * apps/netutils/webserver:  Several inenhancements from Kate including the
      ability to elide scripting and SERVER headers and the ability to map
      files into memory before transferring them.
    * apps/netutils/webserver:  Add ability to map a URL to CGI function.
      Contributed by Kate.
    * apps/nshlib/nsh_mntcmds.c: The changes of 6.21 introduced holes in the
      error handling:  Now the number of arguments to mount can be 0 or 4.
      Additional parameter checking is required to prevent mysterious errors
      (submiteed by Kate).
    * apps/netutils/webserver/httpd_mmap.c:  Fix errors when the mmap()
      length is zero (submitted by Kate).
    * apps/netutils/webserver/httpd_sendfile.c:  Add and option,
      CONFIG_NETUTILS_HTTPD_SENDFILE to transfer files using the NuttX
      sendfile() interface.
    * apps/netutils/discover:  A UDP network discovery utility contributed
      by Max Holtzberg.
    * apps/examples/discover:  A test example for the UDP network discovery
      utility (also contribed by Max Holtzberg).
    * apps/examples/*/main.c:  Too many files called main.c.  Each renamed
      to something unique so that they will not collide in the archive.
    * apps/netutils/xmlrpc: The Embeddable Lightweight XML-RPC Server
      discussed at http://www.drdobbs.com/web-development/\
      an-embeddable-lightweight-xml-rpc-server/184405364.  Contributed by
      Max Holtzberg.
    * apps/netutils/uip_listenon.c:  Logic in uip_server.c that creates
      the listening socket was moved to this new file to support re-use.
      Contributed by Kate.
    * apps/netutils/webserver/httpd.c:  The option CONFIG_NETUTILS_HTTPD_SINGLECONNECT
      can now be used to limit the server to a single thread.  Option
      CONFIG_NETUTILS_HTTPD_TIMEOUT can be used to generate HTTP 408 errors.
      Both from Kate.
    * apps/netutils/webserver/httpd.c:  Improvements to HTTP parser from
      Kate.
    * apps/netutils/webserver/httpd.c:  Add support for Keep-alive connections
      (from Kate).
    * apps/NxWidget/Kconfig:  This is a kludge.  I created this NxWidgets
      directory that ONLY contains Kconfig.  NxWidgets does not live in
      either the nuttx/ or the apps/ source trees.  This kludge makes it
      possible to configure NxWidgets/NxWM without too much trouble (with
      the tradeoff being a kind ugly structure and some maintenance issues).
    * apps/examples/Make.defs: Missing support for apps/examples/watchdog.
    * apps/NxWidgets/Kconfig:  Add option to turn on the memory monitor
      feature of the NxWidgets/NxWM unit tests.

NxWidgets-1.3 2012-09-29 Gregory Nutt &lt;gnutt@nuttx.org&gt;

    * UnitTests/*/main.cxx:  Change entry point name to be consistent
      with with entry point naming conventions introduced in NuttX
      6.22.
    * Kconfig:  Added a mconfig configuration file.  Eventually, NxWidgets
      needs to get hooked into the NuttX mconf configuration.  Still not
      exactly sure how to do that.
    * libnxwidgets/Makefile and NxWidgets/nxwm/Makefile:  Need updates
      for consistency with recent changes to NuttX build system (&gt;= 6.22)
    * Kconfig:  Add option to turn on the memory monitor feature of the
      NxWidgets/NxWM unit tests.

pascal-3.0 2011-05-15 Gregory Nutt &lt;gnutt@nuttx.org&gt;

    * nuttx/:  The Pascal add-on module now installs and builds under the
      apps/interpreters directory.  This means that the pascal-2.1 module is
      incompatible with will all releases of NuttX prior to nuttx-6.0 where the 
      apps/ module was introduced.

buildroot-1.10 2011-05-06 &lt;gnutt@nuttx.org&gt;

    * Add patch submitted by Dimiter Georgiev to work around problems in building
      GDB 6.8 with versions of Cygwin &gt; 1.7.
    * configs/i486-defconfig-4.3.3 - Builds an i486 cross development toolchain
      using gcc 4.3.3.  Why wouldyou want such a thing?  On Linux, of course,
      such a thing is not needed because you can use the installed GCC to build
      i486 ELF binaries.  But that will not work under Cygwin!  The Cygwin
      toolchain (and probably MinGW), build DOS MZ format executables (i.e.,
      .exe files).  That is probably not usable for most NuttX targets.
      Instead, you should use this i486-elf-gcc to generate true ELF binaries
      under Cygwin.
    * Makefile - Alter copy arguments to avoid permissions problems when
      copying NuttX header files.
    * toolchain/nxflat/nxflat.mk and Makefile - Fix include paths.
    * toolchain/gcc/3.3.6 - Added a patch to fixed compilation error on Ubuntu
      9.10.
    * toolchain/nxflat/Makefile - Correct static library link order.
    * configs/arm920t-defconfig-4.3.3 - Enable support for NXFLAT tools.
    * toolchain/binutils/2.21 and toolchain/gcc/4.5.2 - Add support for GCC
      4.5.2 with binutils 2.21.
    * configs/arm920t-eabi-defconfig-4.5.2 - Add a configuration to build a
      GCC 4.5.2 EABI ARM toolchain for the ARM920t.
</pre></ul>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="pendingchanges">Unreleased Changes</a>
  </td>
  </tr>
</table>

<ul>
  <li><b>nuttx-6.18</b>.
    The ChangeLog for the not-yet-released version 6.18 is available at the bottom of the ChangeLog file that can viewed in the <a href="http://svn.code.sf.net/p/nuttx/code/trunk/nuttx/ChangeLog?view=log">SourceForge SVN</a>.
  </li>
  <li><b>apps-6.18</b>.
    The ChangeLog for the not-yet-released version 6.18 is available at the bottom of the ChangeLog file that can viewed in the <a href="http://svn.code.sf.net/p/nuttx/code/trunk/apps/ChangeLog.txt?view=log">SourceForge SVN</a>.
  </li>
  <li><b>NxWidgets-1.1</b>.
    The ChangeLog for the not-yet-released version 1.1 is available at the bottom of the ChangeLog file that can viewed in the <a href="http://svn.code.sf.net/p/nuttx/code/trunk/NxWidgets/ChangeLog?view=log">SourceForge SVN</a>.
  </li>
  <li><b>pascal-1.1</b>.
    The ChangeLog for the not-yet-released version 1.1 is available at the bottom of the ChangeLog file that can viewed in the <a href="http://svn.code.sf.net/p/nuttx/code/trunk/misc/pascal/ChangeLog?view=log">SourceForge SVN</a>.
  </li>
  <li><b>buildroot-1.11</b>.
    The ChangeLog for the not-yet-released version 1.11 is available at the bottom of the ChangeLog file that can viewed in the <a href="http://svn.code.sf.net/p/nuttx/code/trunk/misc/buildroot/ChangeLog?view=log">SourceForge SVN</a>.
  </li>
</ul>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="TODO"><h1>Bugs, Issues, <i>Things-To-Do</i></h1></a>
  </td>
  </tr>
</table>

<ul>
<p>
   The current list of NuttX <i>Things-To-Do</i> in SVN <a href="http://svn.code.sf.net/p/nuttx/code/trunk/nuttx/TODO?view=log">here</a>.
   A snapshot of the <i>To-Do</i> list associated with the current release are available <a href="TODO.txt">here</a>.
</p>
</ul>
<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="documentation"><h1>Other Documentation</h1></a>
  </td>
  </tr>
</table>

<ul><table>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NuttXGettingStarted.html">Getting Started</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NuttXUserGuide.html">User Guide</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NuttXPortingGuide.html">Porting Guide</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NuttShell.html">NuttShell (NSH)</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NuttXNxFlat.html">NXFLAT</a> Binary Format</td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NXGraphicsSubsystem.html">NX Graphics Subsystem</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NxWidgets.html">NxWidgets</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="NuttXDemandPaging.html">Demand Paging</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="README.html">NuttX README Files</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="ChangeLog.txt">Change Log</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="TODO.txt">To-Do List</a></td>
</tr>
<tr>
  <td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
  <td><a href="UsbTrace.html">USB Device Driver Tracing</a></td>
</tr>
</center></ul>

<small>
<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="trademarks"><h1>Trademarks</h1></a>
  </td>
  </tr>
</table>
<ul>
  <li>ARM, ARM7 ARM7TDMI, ARM9, ARM920T, ARM926EJS Cortex-M3 are trademarks of Advanced RISC Machines, Limited.</li>
  <li>Cygwin is a trademark of Red Hat, Incorporated.</li>
  <li>Linux is a registered trademark of Linus Torvalds.</li>
  <li>Eagle-100 is a trademark of <a href=" http://www.micromint.com/">Micromint USA, LLC</a>.
  <li>LPC2148 is a trademark of NXP Semiconductors.</li>
  <li>TI is a tradename of Texas Instruments Incorporated.</li>
  <li>UNIX is a registered trademark of The Open Group.</li>
  <li>VxWorks is a registered trademark of Wind River Systems, Incorporated.</li>
  <li>ZDS, ZNEO, Z16F, Z80, and Zilog are a registered trademark of Zilog, Inc.</li>
</ul>
<p>
  NOTE: NuttX is <i>not</i> licensed to use the POSIX trademark.  NuttX uses the POSIX
  standard as a development guideline only.
</p>
</small>

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