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<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: December 5, 2007</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><img src="favicon.ico"></td>
  <td><a href="#overview">Overview</a></td>
</tr>
<tr>
  <td><img src="favicon.ico"></td>
  <td><a href="#downloads">Downloads</a></td>
</tr>
<tr>
  <td><img src="favicon.ico"></td>
  <td><a href="#platforms">Supported Platforms</a></td>
</tr>
<tr>
  <td><img src="favicon.ico"></td>
  <td><a href="#footprint">Memory Footprint</a></td>
</tr>
<tr>
  <td><img src="favicon.ico"></td>
  <td><a href="#licensing">Licensing</a></td>
</tr>
<tr>
  <td><img src="favicon.ico"></td>
  <td><a href="#history">Release History</a></td>
</tr>
<tr>
  <td><img src="favicon.ico"></td>
  <td><a href="#documentation">Other Documentation</a></td>
</tr>
<tr>
  <td><img src="favicon.ico"></td>
  <td><a href="#trademarks">Trademarks</a></td>
</tr>
</table>
</td>
</td>
</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="18"><img 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="18"><img 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 rich level of OS
      features like those provided with Linux.
      Small footprint is more important than features.
      Standard compliance is more important than small footprint.
      (2) There is no MMU-based support for processes.
      At present, NuttX assumes a flat address space.
    </p>
</tr>
<tr>
  <td valign="top" width="18"><img 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="18"><img 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 functionaly 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="18"><img 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="18"><img 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>
</table></center>

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

<tr>
  <td valign="top" width="18"><img src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Standards Compliant Core Task Management</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Modular, micro-kernel</li>
    </p>
</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>Easily extensible to new processor architectures, SoC architecture, or board architectures.</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.</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>Well documented in the NuttX <a href="NuttxUserGuide.html">User Guide</a>.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="18"><img 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>Supports character and block drivers.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Network and serial driver architecture.</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>VFAT filesystem support.</li>
    </p>
</tr>

<tr>
  <td valign="top" width="18"><img 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>
</tr>

<tr>
  <td valign="top" width="18"><img src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Networking</b>
  </td>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>TCP/IP, UDP, ICMP stacks.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Small footprint (based on uIP).</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>BSD compatible socket layer.</li>
    </p>
</tr>

<tr>
  <td><br></td>
  <td>
    <p>
      <li>Networking utilities.</li>
    </p>
</tr>
</table></center>

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

<p>
  The 15th release of NuttX (nuttx-0.3.3) is available for download
  from the <a href="http://sourceforge.net/project/showfiles.php?group_id=189573">SourceForge</a>
  website.
  The change log associated with the release is available <a href="#currentrelease">here</a>.
  Unreleased changes after this release are avalable in CVS.
  These unreleased changes are listed <a href="#pendingchanges">here</a>.
</p>
<p>
  NuttX 0.3.3 is the 4th release containing the integration of a network
  subsystem and the uIP TCP/IP, UDP, and ICMP stacks based on
  <a href="http://www.sics.se/~adam/uip/index.php/Main_Page">uIP</a>
  into NuttX.
</p>
<p>
  Many network-related problems have been fixed from version 0.3.2
  and the implementation has matured significantly.
  Changes in this release include:
</p>
<ul>
<li>TCP-related bug-fixes for disconnecting sockets,</li>
<li>Correction of some TCP read-ahead logic,<li>
<li>TCP performance improvements,</li>
<li>Initial UDP integration, and</li>
<li>IMisc. additions and cleanup (See the ChangeLog for a complete list of
  changes).</li>
</ul>
<p>
  The level of network reliability is at an early beta release level.  The
  baseline functionality of NuttX continues to mature and remains at
  post-beta. Open network-related issues include only:
</p>
<ul>
<li>Some minor unimplemented BSD socket functionality,</li>
<li>Thread safety issues: the same socket cannot be used concurrently on
  different threads, </li>
<li>Pending design changes necessary to support multiple network interfaces, and </li>
<li>IPv6 support is incomplete.</li>
</ul>
<p>
  This release has been verified only on the Neuros OSD (DM320 ARM9)
  platform using the DM90x0 driver. Any feedback for improving the network
  reliability/performance would be greatly appreciated.
</p>

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

<center><table width="90%">
<tr>
  <td valign="top"><img src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Linux User Mode</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      A user-mode port of NuttX to the x86 Linux platform is available.
      The purpose of this port is primarily to support OS feature developement.
    </p>
    <p>
      <b>STATUS:</b>
      Does not support interrupts but is otherwise fully functional.
    </p>
   </td>
</tr>
<tr>
  <td valign="top"><img src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>ARM7TDMI</b>.
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      <b>TI TMS320C5471</b> (also called a <b>C5471</b> or <b>TMS320DM180</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*.
    </p>
    <p>
      <b>STATUS:</b>
      This port is complete, verified, and included in the initial NuttX release.
    </p>
   </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-eld toolchain*.
    </p>
    <p>
      <b>STATUS:</b>
        Initial coding of this port code complete but has not yet been verified.
    </p>
  </td>
</tr>
<tr>
  <td valign="top"><img src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>ARM926EJS</b>.
  </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*.
    </p>
    <p>
      <b>STATUS:</b>
        This port is complete and verified.
    </p>
   </td>
</tr>
<tr>
  <td valign="top"><img src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>8052 Microcontroller</b>
  </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.
    </p>
    <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>
   </td>
</tr>
<tr>
  <td valign="top"><img src="favicon.ico"></td>
  <td bgcolor="#5eaee1">
    <b>Other ports</b>
  </td>
</tr>
<tr>
  <td><br></td>
  <td>
    <p>
      There are partial ports for the TI TMS320DM270 and for MIPS.
    </p>
   </td>
</tr>
</table></center>

<blockquote>* A highly modified <a href="http://buildroot.uclibc.org/">buildroot</a>
is available that be used to build a NuttX-compatible arm-elf toolchain.</blockquote>

<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, 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, 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 18-19Kb:
</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>

<center><table width ="80%">
<tr>
  <td><img src="favicon.ico"></td>
   <td>
      <a href="#olderreleases">Change Logs for Older Releases</a><br>
   </td>
</tr>
<tr>
  <td><img src="favicon.ico"></td>
   <td>
      <a href="#currentrelease">ChangeLog for Current Release</a><br>
   </td>
</tr>
<tr>
  <td><img src="favicon.ico"></td>
   <td>
      <a href="#pendingchanges">Unreleased Changes</a>
   </td>
</tr>
</table></center>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="olderreleases">Change Logs for Older Releases</a>
  </td>
  </tr>
</table>

<ul><pre>
0.1.0 2007-03-09  Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;

	* Initial Release
	* Support for Linux user mode simulation and TI
	  TMS320C5471 (Arm7) provided

0.1.1 2007-03-14  Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;

	* Corrected an error in interrupt level context switching
	  for C5471
	* Added fgets() and gets() logic; verified c5471 console read.
	* Corrected error in reading from the C5471 serial port:
          Improper use of semaphore can cause deadlock.
	* Fixed an error in the memory cleanup:  The idle task
	  cannot take sempahores (because it must always be ready
	  to run).
	* Tasks can now accept a configurable maximum number of
	  input parameters (argc)
	* _task_init() was divided into separate functions that
	  require fewer parameters.  This was necessary to keep
	  the stack usage down for the 8051/2 (which has only
	  256 bytes of stack).
	* Attempts to use C5471 console from interrupt handlers
	  can cause errors. Added a special path for this case.
	* Refuse calls to sem_wait and sem_trywait from interrupt
	  handlers.  This was happening because interrupt handlers
	  were calling printf-like functions.
	* Added strtok() and strtok_r()
	* Added a simple shell called nsh (see examples/nsh).
	* Platform support for 8052 is complete but not stable
	  when the timer interrupt is enabled.  Seems to be an
	  issue when SP enters indirect address space.
	* Documentation updates

0.1.2 2007-03-19  Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;

	* Add dirent.h, opendir(), readdir(), closedir(), etc.
	* Add strerror()
	* Added 'ls' command to nsh
	* Added C5471 watchdog driver
	* Fixed another bug where free() is called from IDLE task.
	  Can't do this; the caller must be able to wait for access
	  to memory.
	* Fixed bugs associated with debug output:
          Cannot do dbg() in middle of context switch logic.
	  because it may require use of semaphores and cause
	  additional context switches. lldbg() is safe.
	* Interrupt must be disabled throughout all context switches.
	* Separated C5471 serial driver; a shareable part is
	  in drivers/. ; the C5471 specific part is in arch/C5471.
	  serial.h defines the interface.
	* Fixed mq_receive() and mq_send() -- bad memcpy()
	* Fixed C5471 signal deliver logic: use of dbg() and
          other actions by use signal handler can alter errno.
          need to protect errno during signal handling.
	* Fixed uninitialized variable in filesystem that could
	  cause various problems
	* Added a test for roundrobin scheduler.

0.2.1 2007-03-22  Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;

	* Fix error in handing signed decimal in vsprintf().
	* Major restructuring of header files to get closer to
	  POSIX compliance.
	* Eliminate compilation warnings that that crept into
	  recent check-ins
	* Add kill()
	* Added support for POSIX timers
	* Some Documentation updates
	* Added support for the Neuros OSD / DM320

0.2.2 2007-03-26 Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
	* Created the configs/ directory; separated board configuration
	  from processor architecture logic
	* Add memory leak detection test to examples/ostest
	* Corrected memory leak in OS pthread join logic
	* Corrected memory leaks in examples/ostest due to failures
	  to join or detach from pthreads.
	* Added pthread_once(), pthread_kill(), pthread_sigmask()
	* Added pthread_barrierattr_*() APIs
	* Added pthread_barrier_init(), pthread_barrier_destroy(), and
	  pthread_barrier_wait();
	* Added pthread barrier test
	* Added protection so that errno cannot be modified from
	  interrupt handling.
	* sched_setparam(), sched_setscheduler() now correctly set
	  errno; pthread_setscheduler() now returns the correct errno.
	* Added pthread_setschedprio().
	* Added directories to hold board-specific header files
	* Added directories to hold board-specific drivers

0.2.3 2007-03-29 Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;

	* mq_receive and mq_send now return errno's appropriately
	* mq_receive and mq_send are now correctly awakened by signals.
	* Fixed an unmatched sched_lock/unlock pair in task_delete().
	* sched_lock must be called in _exit() because operation of
	  task_delete() can cause pending tasks to be merged and a
	  context switch to occur.
	* Added mq_timedreceive() and mq_timedsend()
	* signal mask is now inherited by both child tasks and threads.
	* Improved sharebility of stdout among pthreads (only).  Nothing
	  was broken, but by moving the mutual exclusion logic to a
	  higher level, the printf output is more readable.
	* Fixed a bug in file system cleanup:  A list was being deleted
	  before the buffers contained in the list.
	* Fixed a bug in the wait-for-message-queue-not-empty logic.
	* Added a test of timed mqueue operations; detected and corrected
	  some mqueue errors.
	* Identified and corrected a race condition associated with
	  pthread_join.  In the failure condition, memory was being
	  deallocated while still in use.

0.2.4 2007-04-28 Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;

	* Verfied c5471 build under Cygwin on WinXP
	* Makesystem changes to better support different SoCs.
	* Made arch/c5471/include and arch/dm320/include identical in
	  preparation for merging into arch/arm
	* Logic from arch/c5471 and arch/dm320 combined into arch/arm.
	  arch/c5471 and arch/dm320 are deprecated and will be removed
	  when the new c5471 and dm320 logic is verified.

0.2.5 2007-05-19 Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;

	* Corrected some build/configuration issues introduced with the
	  last release.
	* Added support for the NXP 214x processor on the mcu123.com lpc214x
	  development board (untested)
	* Added support for block devices.
	* Simulated target now exports a VFAT filesystem
	* Begin support for VFAT filesystem (missing functionalit)
	* Added mount() and umount()
	* Fix bug in memcmp return value
	* Fix errors in timeslice calculation (several places)
	* Added missing irqrestore() in timer_deletall().
	* close() was not closing the underlying device.
	* Added fsync()
	* Added strspn() and strcspn()

0.2.6 2007-05-26 Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;

	* Added unlink(), mkdir(), rmdir(), and rename()
	* Fixed several serious FAT errors with oflags handling (&& instead of &)
	* Added FAT support for unlink(), mkdir(), rmdir(), and rename
	* Added FAT support for opendir(), closedir(), readdir(), seekdir(),
	  telldir(), rewindir().
	* Fixed ARM compilation errors introduced in 0.2.5 (that is what I get
	  for only testing on the simulation).

0.2.7 2007-06-09 Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;

	* Added stat() to fs layer and to FAT
	* Fixed reference counting errors associated with mounted filesystems
	* Added fat_getattrib() and fat_setattrib()
	* Added statfs() to fs layer and to FAT
	* Correct file name extension in tools/zipme.sh
	* Fix error in dependencies in 8051/2 Makefile
	* sched/Makefile: Don't build sleep() or usleep() if signals are disabled
	* sched/sched_setparam.c: Remove redundant disabling of interrupts
	* sched/usleep.c: Fixed nsec calculation
	* lib/lib_strcspn.c: Function incorrectly named strspn().
	* examples/ostest/main.c:  Errors in SDCC version of a memcpy() call
	* examples/ostest/sighand.c: Don't call fflush() if streams are disabled
	* include/limits.h, include/time.h, sched/clock_internal.h: A support for
	  using selectable system timer frequency.
	* Fixed error in mountpoint related conditional compilation introduced
	  in 0.2.5
	* Restructured some Makefiles to better handle enabling and disabling
	  NuttX features without having so much conditional compilation in the
	  source files.
	* tools/mkconfig.c: No longer depends on asprintf() and _GNU_SOURCE and
	  so should now build in non-GNU, non-GLIBC environments.
	* include/nuttx/compiler.h: Fix for using SDCC with the Z80.
	* include/assert.h & arch/pjrc-8051/src/up_assert.c: SDCC does support
	  __FILE__and __LINE__ (not tested)
	* examples/ostest/barrier.c: Don't call usleep() when signals are
	  disabled.

0.2.8 2007-07-02 Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
	* tools/Makefile.mkconfig: Under Cygwin, executable has a different name
	* tools/mkdeps.sh & arch/arm/src/Makefile: Corrected a problem makeing dependencies
	* tools/zipme.sh: Force directory name to be nuttx-xx.yy.zz
	* fs/fs_opendir.c: Correct errors in semaphore usage that can cause deadlock.
	* lib/lib_getopt.c: Added getopt() support
	* examples/nsh/:  NSH now supports cat, mount, umount, and mkdir.  ls supports
	  -l -s, and -R
	* Added basic OS support to manage environment variables:  environment
	  storage, cloning on task creation, sharing on pthread creation, destruction
	  on thread/task exit.
	* Add environment variables APIs:  environ, getenv, putenv, clearenv, setenv,
	  unsetenv
	* Correct an error in realloc() when the block is extended "down" in memory.
	  In this case, the old memory contents need to be copied to the new location
	  and an allocated bit was not being set.
	* examples/ostest/: Added an environment variable test.
	* examples/nsh/: Break into several files.
	* lib/: Added strrchr, basename, dirname
	* examples/nsh/: Add cp, rm, rmdir, set, unset commands. echo will now print
	  environment variables.

0.3.0 2007-11-06 Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;

	* Imported uIP into the tree (see
	   http://www.sics.se/~adam/uip/index.php/Main_Page)
	* Adding socket(), bind(), connect()
	* Added snprintf()
	* Added send() and sendto(); integrate write() and close() with socket descriptors.
        * Added recv() and recvfrom().
	* Added getsockopt() and setsockopt()
	* Documentation updated to address socket interfaces.
	* Implemented receive timeouts via setsockopt(SO_RCVTIMEO).
	* Provide support for multiple network devices
	* Implement socket ioctl() calls to set addresses
	* Added listen() and accept()
	* Added DM90x0 ethernet driver
	* ARP timer is now built into the network layer
	* Basic client functionality verified: socket(), bind(), connect(), recv(), send().

0.3.1 2007-11-19 Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;

	* Separated net/uip/uip.c into several functions in several files.
	* Corrected a TCP problem where packets were dropped because there was no
	  recv() in place but the packet was being ACKed.  There are still TCP
	  recv buffering issues, but this is part of a larger buffering issue.
	* Basic server functionality verified: listen(), accept()
	* Fix DM90x0 driver problem that caused TX overruns
	* Add strncmp()
	* Added TCP/IP read-ahead buffer to minimize failed ACKs and packet loss.

0.3.2 2007-11-23 Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;

	* Add strcat() and strncat()
	* Integrated uIP micro webserver
	* Corrected a serious bug in TCP queue management
	* Fix leak in socket close logic
	* Add TX notification to driver so that it can respond faster to
	  the availability of TX data.
	* Moved urgent data info into device structure.
	* TCP and ICMP protocols can now be disabled.
	* Added UDP test in examples/udp
	* Verified/debugged UDP socket(), bind(), sendto() and recvfrom() logic
	  using examples/udp
	* recvfrom() and accept() now correctly return the remote address.
	* Fixed computation error in ntohl().
</pre></ul>

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

<pre><ul>
0.3.3 2007-11-28 Gregory Nutt <spudmonkey@racsa.co.cr>

	* Removed unused uIP files
	* sched/, mm/, and net/ subystem debug can not be selectively enabled/disabled
	* Correct socket close logic -- needs to disconnect TCP socket on close
	* uIP webserver now seems to be fully functional
	* fs/ and lib/ subystem debug can not be selectively enabled/disabled
	* Added vsnprintf
	* Integrated uIP telnetd
	* Add missing logic to readahead buffer logic
	* examples/nettest uses larger buffers
	* Improved ACK handling in send() to better hander deferred acknowledgements
	  and polling intervals.  Greatly improves send performance.
</pre></ul>

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

<pre><ul>
0.3.4 2007-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>

	* Added and partially verified DHCP server logic (netutils/dhcpd)
	* Fix BROADCAST=y compilation problems
	* Fix UDP recvfrom timeout bug
	* Correct processing of input UDP broadcast packets.
	* Verfied basic DHCP client functionality (netutils/dhcpc)
	* Implemented send() timeout logic
	* Add TELNETD front end to NSH (examples/nsh)
	* Add a skeleton Ethernet device driver (drivers/net/skeleton.c)
	* Added C5471 Ethernet device driver (arch/arm/src/c5471/c5471_ethernet.c)
	* Improved utilization of read-ahead buffers
</pre></ul>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
  <td>
    <a name="documentation"><h1>Other Documentation</h1></a>
  </td>
  </tr>
</table>

<ul><table>
<tr>
  <td><img src="favicon.ico"></td>
  <td><a href="NuttxUserGuide.html">User Guide</td>
</tr>
<tr>
  <td><img src="favicon.ico"></td>
  <td><a href="NuttxPortingGuide.html">Porting Guide</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, ARM926EJS 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>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>
</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>