Add basic directory structure for the Shenzhou STM32107 board (not much there yet)

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5108 42af7a65-404d-4744-a932-0658087f49c3

8 files changed, 1145 insertions, 7 deletions

diff --git a/nuttx/ChangeLog b/nuttx/ChangeLog
index 5f27953c9..19a0bcaae 100644
--- a/nuttx/ChangeLog
+++ b/nuttx/ChangeLog
@@ -3281,3 +3281,7 @@
 	  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.
+
diff --git a/nuttx/Documentation/NuttX.html b/nuttx/Documentation/NuttX.html
index 8fd164b88..287c702d2 100644
--- a/nuttx/Documentation/NuttX.html
+++ b/nuttx/Documentation/NuttX.html
@@ -1799,12 +1799,25 @@
   <td>
     <p>
       <b>STMicro STM32F107x</b>.
-      Chip support for the STM32 F1 &quot;Connectivity Line&quot; family has been present in NuttX and users have reported that they have successful brought up NuttX on there proprietary boards using this logic.
-      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.
-    <ul>
-      <b>STATUS:</b>
-      Configurations for the basic OS test and NSH are available and verified.
-    </ul>
+      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.
+      </ul>
+    </p>
+    <p>
+      <b>Shenzhou</b>
+      Work is underway as of this writing to port NuttX to the Shenzhou 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 avaialble in NuttX-6.22.
+      <ul>
+        <b>STATUS:</b>
+        In progress.
+      </ul>
+    </p>
    </td>
 </tr>
 <tr>
diff --git a/nuttx/Documentation/NuttXLinks.html b/nuttx/Documentation/NuttXLinks.html
index 128ee5d2d..b2206050c 100644
--- a/nuttx/Documentation/NuttXLinks.html
+++ b/nuttx/Documentation/NuttXLinks.html
@@ -22,6 +22,7 @@
       <li><a href="http://sourceforge.net/projects/nuttx/develop" target="_top">SourceForge</a></li>
       <li><a href="http://freshmeat.net/projects/nuttx/" target="_top">FreshMeat</a></li>
       <li><a href="http://tech.groups.yahoo.com/group/nuttx/" target="_top">Forum</a></li>
+      <li><a href="http://www.oschina.net/p/nuttx" target="_top">OSChina</a></li>
       <li><a href="http://sourceforge.net/projects/nuttx/files/" target="_top">Downloads</a></li>
       <li><a href="http://www.nx-engineering.com/nuttx-wiki/" target="_top">Wiki</a></li>
       <li><a href="http://sourceforge.net/projects/nuttx/files/buildroot" target="_top">Toolchains</a></li>
diff --git a/nuttx/Documentation/README.html b/nuttx/Documentation/README.html
index abb54ab60..c18dd9ad8 100644
--- a/nuttx/Documentation/README.html
+++ b/nuttx/Documentation/README.html
@@ -166,6 +166,8 @@
  |   |   |   |- <a href="http://nuttx.svn.sourceforge.net/viewvc/nuttx/trunk/nuttx/configs/sim/include/README.txt?view=log">include/README.txt</a>
  |   |   |   |- <a href="http://nuttx.svn.sourceforge.net/viewvc/nuttx/trunk/nuttx/configs/sim/src/README.txt?view=log">src/README.txt</a>
  |   |   |   `- <a href="http://nuttx.svn.sourceforge.net/viewvc/nuttx/trunk/nuttx/configs/sim/README.txt?view=log"><b><i>README.txt</i></b></a>
+ |   |   |- shenzhou/
+ |   |   |   `- <a href="http://nuttx.svn.sourceforge.net/viewvc/nuttx/trunk/nuttx/configs/shenzhou/README.txt?view=log"><b><i>README.txt</i></b></a>
  |   |   |- skp16c26/
  |   |   |   |- <a href="http://nuttx.svn.sourceforge.net/viewvc/nuttx/trunk/nuttx/configs/skp16c26/include/README.txt?view=log">include/README.txt</a>
  |   |   |   |- <a href="http://nuttx.svn.sourceforge.net/viewvc/nuttx/trunk/nuttx/configs/skp16c26/src/README.txt?view=log">src/README.txt</a>
diff --git a/nuttx/README.txt b/nuttx/README.txt
index 28b4fba03..596451128 100644
--- a/nuttx/README.txt
+++ b/nuttx/README.txt
@@ -735,6 +735,8 @@ nuttx
  |   |   |- include/README.txt
  |   |   |- src/README.txt
  |   |   `- README.txt
+ |   |- shenzhou/
+ |   |   `- README.txt
  |   |- skp16c26/
  |   |   |- include/README.txt
  |   |   |- src/README.txt
diff --git a/nuttx/configs/README.txt b/nuttx/configs/README.txt
index 6cd5eef3f..c8b02711a 100644
--- a/nuttx/configs/README.txt
+++ b/nuttx/configs/README.txt
@@ -1709,6 +1709,10 @@ configs/sim
   This port does not support interrupts or a real timer (and hence no
   round robin scheduler)  Otherwise, it is complete.
 
+configs/shenzhou
+  This is the port of NuttX to the Shenzhou development board from
+  www.armjishu.com. This board features the STMicro STM32F107VCT MCU.
+
 configs/skp16c26
   Renesas M16C processor on the Renesas SKP16C26 StarterKit.  This port
   uses the GNU m32c toolchain.  STATUS:  The port is complete but untested
diff --git a/nuttx/configs/shenzhou/README.txt b/nuttx/configs/shenzhou/README.txt
new file mode 100755
index 000000000..bda76a783
--- /dev/null
+++ b/nuttx/configs/shenzhou/README.txt
@@ -0,0 +1,1110 @@
+README
+======
+
+This README discusses issues unique to NuttX configurations for the Shenzhou
+development board from www.armjishu.com featuring the STMicro STM32F107VCT
+MCU.  On-board features:
+
+  - STM32F107VCT
+  - 10/100M PHY (DM9161AEP)
+  - TFT LCD Connector
+  - USB OTG
+  - CAN (CAN1=2)
+  - USART connectos (USART1-2)
+  - RS-485
+  - SD card slot
+  - Audio DAC (PCM1770)
+  - SPI Flash (W25X16)
+  - (4) LEDs (LED1-4)
+  - 2.4G Wireless (NRF24L01 SPI module)
+  - 315MHz Wireless (module)
+  - (4) Buttons (KEY1-4, USERKEY2, USERKEY, TEMPER, WAKEUP)
+  - VBUS/external +4V select
+  - 5V/3.3V power conversion
+  - Extension connector
+  - JTAG
+
+Contents
+========
+
+  - STM32F107VCT Pin Usage
+  - Development Environment
+  - GNU Toolchain Options
+  - IDEs
+  - NuttX buildroot Toolchain
+  - Shenzhou-specific Configuration Options
+  - LEDs
+  - Shenzhou-specific Configuration Options
+  - Configurations
+
+STM32F107VCT Pin Usage
+======================
+
+23 PA0  WAKEUP         Connected to KEY4.  Active low: Closing KEY4 pulls WAKEUP to ground.
+24 PA1  MII_RX_CLK
+        RMII_REF_CLK
+25 PA2  MII_MDIO
+26 PA3  315M_VT
+29 PA4  DAC_OUT1
+30 PA5  DAC_OUT2       JP10
+        SPI1_SCK
+31 PA6  SPI1_MISO
+32 PA7  SPI1_MOSI
+67 PA8  MCO
+68 PA9  USB_VBUS       JP3
+        USART1_TX
+69 PA10 USB_ID         JP5
+        USART1TX
+70 PA11 USB_DM
+71 PA12 USB_DP
+72 PA13 TMS/SWDIO
+76 PA14 TCK/SWCLK
+77 PA15 TDI
+
+35 PB0  ADC_IN1
+36 PB1  ADC_IN2
+37 PB2  DATA_LE
+        BOOT1          JP13
+89 PB3  TDO/SWO
+90 PB4  TRST
+91 PB5  CAN2_RX
+92 PB6  CAN2_TX        JP11
+        I2C1_SCL
+93 PB7  I2C1_SDA
+95 PB8  USB_PWR
+96 PB9  F_CS
+47 PB10 USERKEY
+48 PB11 MII_TX_EN
+51 PB12 I2S_WS
+        MII_TXD0
+52 PB13 I2S_CK
+        MII_TXD1
+53 PB14 SD_CD
+54 PB15 I2S_DIN
+
+15 PC0  POTENTIO_METER
+16 PC1  MII_MDC
+17 PC2  WIRELESS_INT
+18 PC3  WIRELESS_CE
+33 PC4  USERKEY2
+34 PC5  TP_INT         JP6
+        MII_INT
+63 PC6  I2S_MCK        Pulled high
+64 PC7  LCD_CS         Pulled high
+65 PC8  LCD_CS         Pulled high
+66 PC9  TP_CS          Pulled hight
+78 PC10 SPI3_SCK
+79 PC11 SPI3_MISO
+80 PC12 SPI3_MOSI
+7  PC13 TAMPER
+8  PC14 OSC32_IN       Y1 32.768Khz XTAL
+9  PC15 OSC32_OUT      Y1 32.768Khz XTAL
+
+81 PD0  CAN1_RX
+82 PD1  CAN1_TX
+83 PD2  LED1
+84 PD3  LED2
+85 PD4  LED3
+86 PD5  485_TX
+        USART2_TX
+87 PD6  485_RX         JP4
+        USART2_RX
+88 PD7  LED4
+        485_DIR
+55 PD8  MII_RX_DV
+        RMII_CRSDV
+56 PD9  MII_RXD0
+57 PD10 MII_RXD1
+58 PD11 SD_CS
+59 PD12 WIRELESS_CS
+60 PD13 LCD_RS
+61 PD14 LCD_WR
+62 PD15 LCD_RD
+
+97 PE0  DB00
+98 PE1  DB01
+1  PE2  DB02
+2  PE3  DB03
+3  PE4  DB04
+4  PE5  DB05
+5  PE6  DB06
+38 PE7  DB07
+39 PE8  DB08
+40 PE9  DB09
+41 PE10 DB10
+42 PE11 DB11
+43 PE12 DB12
+44 PE13 DB13
+45 PE14 DB14
+46 PE15 DB15
+
+73 N/C
+
+12 OSC_IN              Y2 25Mhz XTAL
+13 OSC_OUT             Y2 25Mhz XTAL
+
+94 BOOT0               JP15 (3.3V or GND)
+14 RESET               S5
+6  VBAT                JP14 (3.3V or battery)
+
+49 VSS_1               GND
+74 VSS_2               GND
+99 VSS_3               GND
+27 VSS_4               GND
+10 VSS_5               GND
+19 VSSA                VSSA
+20 VREF-               VREF-
+
+
+Development Environment
+=======================
+
+  Either Linux or Cygwin on Windows can be used for the development environment.
+  The source has been built only using the GNU toolchain (see below).  Other
+  toolchains will likely cause problems. Testing was performed using the Cygwin
+  environment because the development tools that I used only work under Windows.
+
+GNU Toolchain Options
+=====================
+
+  Toolchain Configurations
+  ------------------------
+  The NuttX make system has been modified to support the following different
+  toolchain options.
+
+  1. The CodeSourcery GNU toolchain,
+  2. The Atollic Toolchain,
+  3. The devkitARM GNU toolchain,
+  4. Raisonance GNU toolchain, or
+  5. The NuttX buildroot Toolchain (see below).
+
+  Most testing has been conducted using the CodeSourcery toolchain for Windows and
+  that is the default toolchain in most configurations.  To use the Atollic,
+  devkitARM, Raisonance GNU, or NuttX buildroot toolchain, you simply need to
+  add one of the following configuration options to your .config (or defconfig)
+  file:
+
+    CONFIG_STM32_CODESOURCERYW=y  : CodeSourcery under Windows
+    CONFIG_STM32_CODESOURCERYL=y  : CodeSourcery under Linux
+    CONFIG_STM32_ATOLLIC_LITE=y   : The free, "Lite" version of Atollic toolchain under Windows
+    CONFIG_STM32_ATOLLIC_PRO=y    : The paid, "Pro" version of Atollic toolchain under Windows
+    CONFIG_STM32_DEVKITARM=y      : devkitARM under Windows
+    CONFIG_STM32_RAISONANCE=y     : Raisonance RIDE7 under Windows
+    CONFIG_STM32_BUILDROOT=y      : NuttX buildroot under Linux or Cygwin (default)
+
+  If you change the default toolchain, then you may also have to modify the PATH in
+  the setenv.h file if your make cannot find the tools.
+
+  NOTE: the CodeSourcery (for Windows), Atollic, devkitARM, and Raisonance toolchains are
+  Windows native toolchains.  The CodeSourcery (for Linux) and NuttX buildroot
+  toolchains are Cygwin and/or Linux native toolchains. There are several limitations
+  to using a Windows based toolchain in a Cygwin environment.  The three biggest are:
+
+  1. The Windows toolchain cannot follow Cygwin paths.  Path conversions are
+     performed automatically in the Cygwin makefiles using the 'cygpath' utility
+     but you might easily find some new path problems.  If so, check out 'cygpath -w'
+
+  2. Windows toolchains cannot follow Cygwin symbolic links.  Many symbolic links
+     are used in Nuttx (e.g., include/arch).  The make system works around these
+     problems for the Windows tools by copying directories instead of linking them.
+     But this can also cause some confusion for you:  For example, you may edit
+     a file in a "linked" directory and find that your changes had no effect.
+     That is because you are building the copy of the file in the "fake" symbolic
+     directory.  If you use a Windows toolchain, you should get in the habit of
+     making like this:
+
+       make clean_context all
+
+     An alias in your .bashrc file might make that less painful.
+
+  3. Dependencies are not made when using Windows versions of the GCC.  This is
+     because the dependencies are generated using Windows pathes which do not
+     work with the Cygwin make.
+
+     Support has been added for making dependencies with the windows-native toolchains.
+     That support can be enabled by modifying your Make.defs file as follows:
+
+    -  MKDEP                = $(TOPDIR)/tools/mknulldeps.sh
+    +  MKDEP                = $(TOPDIR)/tools/mkdeps.sh --winpaths "$(TOPDIR)"
+
+     If you have problems with the dependency build (for example, if you are not
+     building on C:), then you may need to modify tools/mkdeps.sh
+
+  The CodeSourcery Toolchain (2009q1)
+  -----------------------------------
+  The CodeSourcery toolchain (2009q1) does not work with default optimization
+  level of -Os (See Make.defs).  It will work with -O0, -O1, or -O2, but not with
+  -Os.
+
+  The Atollic "Pro" and "Lite" Toolchain
+  --------------------------------------
+  One problem that I had with the Atollic toolchains is that the provide a gcc.exe
+  and g++.exe in the same bin/ file as their ARM binaries.  If the Atollic bin/ path
+  appears in your PATH variable before /usr/bin, then you will get the wrong gcc
+  when you try to build host executables.  This will cause to strange, uninterpretable
+  errors build some host binaries in tools/ when you first make.
+
+  The Atollic "Lite" Toolchain
+  ----------------------------
+  The free, "Lite" version of the Atollic toolchain does not support C++ nor
+  does it support ar, nm, objdump, or objdcopy. If you use the Atollic "Lite"
+  toolchain, you will have to set:
+
+    CONFIG_HAVE_CXX=n
+
+  In order to compile successfully.  Otherwise, you will get errors like:
+
+    "C++ Compiler only available in TrueSTUDIO Professional"
+
+  The make may then fail in some of the post link processing because of some of
+  the other missing tools.  The Make.defs file replaces the ar and nm with
+  the default system x86 tool versions and these seem to work okay.  Disable all
+  of the following to avoid using objcopy:
+
+    CONFIG_RRLOAD_BINARY=n
+    CONFIG_INTELHEX_BINARY=n
+    CONFIG_MOTOROLA_SREC=n
+    CONFIG_RAW_BINARY=n
+
+  devkitARM
+  ---------
+  The devkitARM toolchain includes a version of MSYS make.  Make sure that the
+  the paths to Cygwin's /bin and /usr/bin directories appear BEFORE the devkitARM
+  path or will get the wrong version of make.
+
+IDEs
+====
+
+  NuttX is built using command-line make.  It can be used with an IDE, but some
+  effort will be required to create the project.
+
+  Makefile Build
+  --------------
+  Under Eclipse, it is pretty easy to set up an "empty makefile project" and
+  simply use the NuttX makefile to build the system.  That is almost for free
+  under Linux.  Under Windows, you will need to set up the "Cygwin GCC" empty
+  makefile project in order to work with Windows (Google for "Eclipse Cygwin" -
+  there is a lot of help on the internet).
+
+  Native Build
+  ------------
+  Here are a few tips before you start that effort:
+
+  1) Select the toolchain that you will be using in your .config file
+  2) Start the NuttX build at least one time from the Cygwin command line
+     before trying to create your project.  This is necessary to create
+     certain auto-generated files and directories that will be needed.
+  3) Set up include pathes:  You will need include/, arch/arm/src/stm32,
+     arch/arm/src/common, arch/arm/src/armv7-m, and sched/.
+  4) All assembly files need to have the definition option -D __ASSEMBLY__
+     on the command line.
+
+  Startup files will probably cause you some headaches.  The NuttX startup file
+  is arch/arm/src/stm32/stm32_vectors.S.  With RIDE, I have to build NuttX
+  one time from the Cygwin command line in order to obtain the pre-built
+  startup object needed by RIDE.
+
+NuttX buildroot Toolchain
+=========================
+
+  A GNU GCC-based toolchain is assumed.  The files */setenv.sh should
+  be modified to point to the correct path to the Cortex-M3 GCC toolchain (if
+  different from the default in your PATH variable).
+
+  If you have no Cortex-M3 toolchain, one can be downloaded from the NuttX
+  SourceForge download site (https://sourceforge.net/project/showfiles.php?group_id=189573).
+  This GNU toolchain builds and executes in the Linux or Cygwin environment.
+
+  1. You must have already configured Nuttx in <some-dir>/nuttx.
+
+     cd tools
+     ./configure.sh shenzhou/<sub-dir>
+
+  2. Download the latest buildroot package into <some-dir>
+
+  3. unpack the buildroot tarball.  The resulting directory may
+     have versioning information on it like buildroot-x.y.z.  If so,
+     rename <some-dir>/buildroot-x.y.z to <some-dir>/buildroot.
+
+  4. cd <some-dir>/buildroot
+
+  5. cp configs/cortexm3-defconfig-4.3.3 .config
+
+  6. make oldconfig
+
+  7. make
+
+  8. Edit setenv.h, if necessary, so that the PATH variable includes
+     the path to the newly built binaries.
+
+  See the file configs/README.txt in the buildroot source tree.  That has more
+  detailed PLUS some special instructions that you will need to follow if you are
+  building a Cortex-M3 toolchain for Cygwin under Windows.
+
+LEDs
+====
+
+The Shenzhou board has four LEDs labeled LED1, LED2, LED3 and LED4 on the
+board. These LEDs are not used by the board port unless CONFIG_ARCH_LEDS is
+defined.  In that case, the usage by the board port is defined in
+include/board.h and src/up_leds.c. The LEDs are used to encode OS-related
+events as follows:
+
+    SYMBOL               Meaning                 LED1*   LED2    LED3    LED4****
+    -------------------  ----------------------- ------- ------- ------- ------
+    LED_STARTED          NuttX has been started  ON      OFF     OFF     OFF
+    LED_HEAPALLOCATE     Heap has been allocated OFF     ON      OFF     OFF
+    LED_IRQSENABLED      Interrupts enabled      ON      ON      OFF     OFF
+    LED_STACKCREATED     Idle stack created      OFF     OFF     ON      OFF
+    LED_INIRQ            In an interrupt**       ON      N/C     N/C     OFF
+    LED_SIGNAL           In a signal handler***  N/C     ON      N/C     OFF
+    LED_ASSERTION        An assertion failed     ON      ON      N/C     OFF
+    LED_PANIC            The system has crashed  N/C     N/C     N/C     ON
+    LED_IDLE             STM32 is is sleep mode  (Optional, not used)
+
+   * If LED1, LED2, LED3 are statically on, then NuttX probably failed to boot
+     and these LEDs will give you some indication of where the failure was
+  ** The normal state is LED3 ON and LED1 faintly glowing.  This faint glow
+     is because of timer interupts that result in the LED being illuminated
+     on a small proportion of the time.
+ *** LED2 may also flicker normally if signals are processed.
+**** LED4 may not be available if RS-485 is also used it will then indicate
+     the RS-485 direction.
+
+Shenzhou-specific Configuration Options
+============================================
+
+    CONFIG_ARCH - Identifies the arch/ subdirectory.  This should
+       be set to:
+
+       CONFIG_ARCH=arm
+
+    CONFIG_ARCH_family - For use in C code:
+
+       CONFIG_ARCH_ARM=y
+
+    CONFIG_ARCH_architecture - For use in C code:
+
+       CONFIG_ARCH_CORTEXM3=y
+
+    CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory
+
+       CONFIG_ARCH_CHIP=stm32
+
+    CONFIG_ARCH_CHIP_name - For use in C code to identify the exact
+       chip:
+
+       CONFIG_ARCH_CHIP_STM32F107VCT=y
+
+    CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG - Enables special STM32 clock
+       configuration features.
+
+       CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG=n
+
+    CONFIG_ARCH_BOARD - Identifies the configs subdirectory and
+       hence, the board that supports the particular chip or SoC.
+
+       CONFIG_ARCH_BOARD=shenzhou (for the Shenzhou development board)
+
+    CONFIG_ARCH_BOARD_name - For use in C code
+
+       CONFIG_ARCH_BOARD_SHENZHOU=y
+
+    CONFIG_ARCH_LOOPSPERMSEC - Must be calibrated for correct operation
+       of delay loops
+
+    CONFIG_ENDIAN_BIG - define if big endian (default is little
+       endian)
+
+    CONFIG_DRAM_SIZE - Describes the installed DRAM (SRAM in this case):
+
+       CONFIG_DRAM_SIZE=0x00010000 (64Kb)
+
+    CONFIG_DRAM_START - The start address of installed DRAM
+
+       CONFIG_DRAM_START=0x20000000
+
+    CONFIG_STM32_CCMEXCLUDE - Exclude CCM SRAM from the HEAP
+
+    In addition to internal SRAM, SRAM may also be available through the FSMC.
+    In order to use FSMC SRAM, the following additional things need to be
+    present in the NuttX configuration file:
+
+    CONFIG_STM32_FSMC_SRAM - Indicates that SRAM is available via the
+      FSMC (as opposed to an LCD or FLASH).
+
+    CONFIG_HEAP2_BASE - The base address of the SRAM in the FSMC address space (hex)
+
+    CONFIG_HEAP2_END - The size of the SRAM in the FSMC address space (decimal)
+
+    CONFIG_ARCH_IRQPRIO - The STM32107xxx supports interrupt prioritization
+
+       CONFIG_ARCH_IRQPRIO=y
+
+    CONFIG_ARCH_LEDS - Use LEDs to show state. Unique to boards that
+       have LEDs
+
+    CONFIG_ARCH_INTERRUPTSTACK - This architecture supports an interrupt
+       stack. If defined, this symbol is the size of the interrupt
+        stack in bytes.  If not defined, the user task stacks will be
+      used during interrupt handling.
+
+    CONFIG_ARCH_STACKDUMP - Do stack dumps after assertions
+
+    CONFIG_ARCH_LEDS -  Use LEDs to show state. Unique to board architecture.
+
+    CONFIG_ARCH_CALIBRATION - Enables some build in instrumentation that
+       cause a 100 second delay during boot-up.  This 100 second delay
+       serves no purpose other than it allows you to calibratre
+       CONFIG_ARCH_LOOPSPERMSEC.  You simply use a stop watch to measure
+       the 100 second delay then adjust CONFIG_ARCH_LOOPSPERMSEC until
+       the delay actually is 100 seconds.
+
+  Individual subsystems can be enabled:
+
+    AHB1
+    ----
+    CONFIG_STM32_CRC
+    CONFIG_STM32_BKPSRAM
+    CONFIG_STM32_CCMDATARAM
+    CONFIG_STM32_DMA1
+    CONFIG_STM32_DMA2
+    CONFIG_STM32_ETHMAC
+    CONFIG_STM32_OTGHS
+
+    AHB2
+    ----
+    CONFIG_STM32_DCMI
+    CONFIG_STM32_CRYP
+    CONFIG_STM32_HASH
+    CONFIG_STM32_RNG
+    CONFIG_STM32_OTGFS
+
+    AHB3
+    ----
+    CONFIG_STM32_FSMC
+
+    APB1
+    ----
+    CONFIG_STM32_TIM2
+    CONFIG_STM32_TIM3
+    CONFIG_STM32_TIM4
+    CONFIG_STM32_TIM5
+    CONFIG_STM32_TIM6
+    CONFIG_STM32_TIM7
+    CONFIG_STM32_TIM12
+    CONFIG_STM32_TIM13
+    CONFIG_STM32_TIM14
+    CONFIG_STM32_WWDG
+    CONFIG_STM32_IWDG
+    CONFIG_STM32_SPI2
+    CONFIG_STM32_SPI3
+    CONFIG_STM32_USART2
+    CONFIG_STM32_USART3
+    CONFIG_STM32_UART4
+    CONFIG_STM32_UART5
+    CONFIG_STM32_I2C1
+    CONFIG_STM32_I2C2
+    CONFIG_STM32_I2C3
+    CONFIG_STM32_CAN1
+    CONFIG_STM32_CAN2
+    CONFIG_STM32_DAC1
+    CONFIG_STM32_DAC2
+    CONFIG_STM32_PWR -- Required for RTC
+
+    APB2
+    ----
+    CONFIG_STM32_TIM1
+    CONFIG_STM32_TIM8
+    CONFIG_STM32_USART1
+    CONFIG_STM32_USART6
+    CONFIG_STM32_ADC1
+    CONFIG_STM32_ADC2
+    CONFIG_STM32_ADC3
+    CONFIG_STM32_SDIO
+    CONFIG_STM32_SPI1
+    CONFIG_STM32_SYSCFG
+    CONFIG_STM32_TIM9
+    CONFIG_STM32_TIM10
+    CONFIG_STM32_TIM11
+
+  Timer devices may be used for different purposes.  One special purpose is
+  to generate modulated outputs for such things as motor control.  If CONFIG_STM32_TIMn
+  is defined (as above) then the following may also be defined to indicate that
+  the timer is intended to be used for pulsed output modulation, ADC conversion,
+  or DAC conversion. Note that ADC/DAC require two definition:  Not only do you have
+  to assign the timer (n) for used by the ADC or DAC, but then you also have to
+  configure which ADC or DAC (m) it is assigned to.
+
+    CONFIG_STM32_TIMn_PWM   Reserve timer n for use by PWM, n=1,..,14
+    CONFIG_STM32_TIMn_ADC   Reserve timer n for use by ADC, n=1,..,14
+    CONFIG_STM32_TIMn_ADCm  Reserve timer n to trigger ADCm, n=1,..,14, m=1,..,3
+    CONFIG_STM32_TIMn_DAC   Reserve timer n for use by DAC, n=1,..,14
+    CONFIG_STM32_TIMn_DACm  Reserve timer n to trigger DACm, n=1,..,14, m=1,..,2
+
+  For each timer that is enabled for PWM usage, we need the following additional
+  configuration settings:
+
+    CONFIG_STM32_TIMx_CHANNEL - Specifies the timer output channel {1,..,4}
+
+  NOTE: The STM32 timers are each capable of generating different signals on
+  each of the four channels with different duty cycles.  That capability is
+  not supported by this driver:  Only one output channel per timer.
+
+  JTAG Enable settings (by default JTAG-DP and SW-DP are disabled):
+
+    CONFIG_STM32_JTAG_FULL_ENABLE - Enables full SWJ (JTAG-DP + SW-DP)
+    CONFIG_STM32_JTAG_NOJNTRST_ENABLE - Enables full SWJ (JTAG-DP + SW-DP)
+      but without JNTRST.
+    CONFIG_STM32_JTAG_SW_ENABLE - Set JTAG-DP disabled and SW-DP enabled
+
+  STM32107xxx specific device driver settings
+
+    CONFIG_U[S]ARTn_SERIAL_CONSOLE - selects the USARTn (n=1,2,3) or UART
+           m (m=4,5) for the console and ttys0 (default is the USART1).
+    CONFIG_U[S]ARTn_RXBUFSIZE - Characters are buffered as received.
+       This specific the size of the receive buffer
+    CONFIG_U[S]ARTn_TXBUFSIZE - Characters are buffered before
+       being sent.  This specific the size of the transmit buffer
+    CONFIG_U[S]ARTn_BAUD - The configure BAUD of the UART.  Must be
+    CONFIG_U[S]ARTn_BITS - The number of bits.  Must be either 7 or 8.
+    CONFIG_U[S]ARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity
+    CONFIG_U[S]ARTn_2STOP - Two stop bits
+
+    CONFIG_STM32_SPI_INTERRUPTS - Select to enable interrupt driven SPI
+      support. Non-interrupt-driven, poll-waiting is recommended if the
+      interrupt rate would be to high in the interrupt driven case.
+    CONFIG_STM32_SPI_DMA - Use DMA to improve SPI transfer performance.
+      Cannot be used with CONFIG_STM32_SPI_INTERRUPT.
+
+    CONFIG_SDIO_DMA - Support DMA data transfers.  Requires CONFIG_STM32_SDIO
+      and CONFIG_STM32_DMA2.
+    CONFIG_SDIO_PRI - Select SDIO interrupt prority.  Default: 128
+    CONFIG_SDIO_DMAPRIO - Select SDIO DMA interrupt priority.
+      Default:  Medium
+    CONFIG_SDIO_WIDTH_D1_ONLY - Select 1-bit transfer mode.  Default:
+      4-bit transfer mode.
+
+    CONFIG_STM32_PHYADDR - The 5-bit address of the PHY on the board
+    CONFIG_STM32_MII - Support Ethernet MII interface
+    CONFIG_STM32_MII_MCO1 - Use MCO1 to clock the MII interface
+    CONFIG_STM32_MII_MCO2 - Use MCO2 to clock the MII interface
+    CONFIG_STM32_RMII - Support Ethernet RMII interface
+    CONFIG_STM32_AUTONEG - Use PHY autonegotion to determine speed and mode
+    CONFIG_STM32_ETHFD - If CONFIG_STM32_AUTONEG is not defined, then this
+      may be defined to select full duplex mode. Default: half-duplex
+    CONFIG_STM32_ETH100MBPS - If CONFIG_STM32_AUTONEG is not defined, then this
+      may be defined to select 100 MBps speed.  Default: 10 Mbps
+    CONFIG_STM32_PHYSR - This must be provided if CONFIG_STM32_AUTONEG is
+      defined.  The PHY status register address may diff from PHY to PHY.  This
+      configuration sets the address of the PHY status register.
+    CONFIG_STM32_PHYSR_SPEED - This must be provided if CONFIG_STM32_AUTONEG is
+      defined.  This provides bit mask indicating 10 or 100MBps speed.
+    CONFIG_STM32_PHYSR_100MBPS - This must be provided if CONFIG_STM32_AUTONEG is
+      defined.  This provides the value of the speed bit(s) indicating 100MBps speed.
+    CONFIG_STM32_PHYSR_MODE - This must be provided if CONFIG_STM32_AUTONEG is
+      defined.  This provide bit mask indicating full or half duplex modes.
+    CONFIG_STM32_PHYSR_FULLDUPLEX - This must be provided if CONFIG_STM32_AUTONEG is
+      defined.  This provides the value of the mode bits indicating full duplex mode.
+    CONFIG_STM32_ETH_PTP - Precision Time Protocol (PTP).  Not supported
+      but some hooks are indicated with this condition.
+
+  Shenzhou CAN Configuration
+
+    CONFIG_CAN - Enables CAN support (one or both of CONFIG_STM32_CAN1 or
+      CONFIG_STM32_CAN2 must also be defined)
+    CONFIG_CAN_FIFOSIZE - The size of the circular buffer of CAN messages.
+      Default: 8
+    CONFIG_CAN_NPENDINGRTR - The size of the list of pending RTR requests.
+      Default: 4
+    CONFIG_CAN_LOOPBACK - A CAN driver may or may not support a loopback
+      mode for testing. The STM32 CAN driver does support loopback mode.
+    CONFIG_CAN1_BAUD - CAN1 BAUD rate.  Required if CONFIG_STM32_CAN1 is defined.
+    CONFIG_CAN2_BAUD - CAN1 BAUD rate.  Required if CONFIG_STM32_CAN2 is defined.
+    CONFIG_CAN_TSEG1 - The number of CAN time quanta in segment 1. Default: 6
+    CONFIG_CAN_TSEG2 - the number of CAN time quanta in segment 2. Default: 7
+    CONFIG_CAN_REGDEBUG - If CONFIG_DEBUG is set, this will generate an
+      dump of all CAN registers.
+
+  Shenzhou LCD Hardware Configuration
+
+  The LCD driver supports the following LCDs on the STM324xG_EVAL board:
+
+    AM-240320L8TNQW00H (LCD_ILI9320 or LCD_ILI9321) OR
+    AM-240320D5TOQW01H (LCD_ILI9325)
+
+  Configuration options.
+
+    CONFIG_LCD_LANDSCAPE - Define for 320x240 display "landscape"
+      support. Default is this 320x240 "landscape" orientation
+      For the Shenzhou board, the edge opposite from the row of buttons
+      is used as the top of the display in this orientation.
+    CONFIG_LCD_RLANDSCAPE - Define for 320x240 display "reverse
+      landscape" support. Default is this 320x240 "landscape"
+      orientation
+      For the Shenzhou board, the edge next to the row of buttons
+      is used as the top of the display in this orientation.
+    CONFIG_LCD_PORTRAIT - Define for 240x320 display "portrait"
+      orientation support.  In this orientation, the STM3210E-EVAL's
+      LCD ribbon cable is at the bottom of the display. Default is
+      320x240 "landscape" orientation.
+      In this orientation, the top of the display is to the left
+      of the buttons (if the board is held so that the buttons are at the
+      botton of the board).
+    CONFIG_LCD_RPORTRAIT - Define for 240x320 display "reverse
+      portrait" orientation support.  In this orientation, the
+      STM3210E-EVAL's LCD ribbon cable is at the top of the display.
+      Default is 320x240 "landscape" orientation.
+      In this orientation, the top of the display is to the right
+      of the buttons (if the board is held so that the buttons are at the
+      botton of the board).
+    CONFIG_LCD_RDSHIFT - When reading 16-bit gram data, there appears
+      to be a shift in the returned data.  This value fixes the offset.
+      Default 5.
+
+    The LCD driver dynamically selects the LCD based on the reported LCD
+    ID value.  However, code size can be reduced by suppressing support for
+    individual LCDs using:
+
+    CONFIG_STM32_ILI9320_DISABLE (includes ILI9321)
+    CONFIG_STM32_ILI9325_DISABLE
+
+  STM32 USB OTG FS Host Driver Support
+
+  Pre-requisites
+ 
+   CONFIG_USBHOST         - Enable USB host support
+   CONFIG_STM32_OTGFS     - Enable the STM32 USB OTG FS block
+   CONFIG_STM32_SYSCFG    - Needed
+   CONFIG_SCHED_WORKQUEUE - Worker thread support is required
+ 
+  Options:
+ 
+   CONFIG_STM32_OTGFS_RXFIFO_SIZE - Size of the RX FIFO in 32-bit words.
+     Default 128 (512 bytes)
+   CONFIG_STM32_OTGFS_NPTXFIFO_SIZE - Size of the non-periodic Tx FIFO
+     in 32-bit words.  Default 96 (384 bytes)
+   CONFIG_STM32_OTGFS_PTXFIFO_SIZE - Size of the periodic Tx FIFO in 32-bit
+     words.  Default 96 (384 bytes)
+   CONFIG_STM32_OTGFS_DESCSIZE - Maximum size of a descriptor.  Default: 128
+   CONFIG_STM32_OTGFS_SOFINTR - Enable SOF interrupts.  Why would you ever
+     want to do that?
+   CONFIG_STM32_USBHOST_REGDEBUG - Enable very low-level register access
+     debug.  Depends on CONFIG_DEBUG.
+   CONFIG_STM32_USBHOST_PKTDUMP - Dump all incoming and outgoing USB
+     packets. Depends on CONFIG_DEBUG.
+
+Configurations
+==============
+
+Each Shenzhou configuration is maintained in a sudirectory and
+can be selected as follow:
+
+    cd tools
+    ./configure.sh shenzhou/<subdir>
+    cd -
+    . ./setenv.sh
+
+Where <subdir> is one of the following:
+
+  dhcpd:
+  -----
+
+    This builds the DCHP server using the apps/examples/dhcpd application
+    (for execution from FLASH.) See apps/examples/README.txt for information
+    about the dhcpd example.  The server address is 10.0.0.1 and it serves
+    IP addresses in the range 10.0.0.2 through 10.0.0.17 (all of which, of
+    course, are configurable).
+
+    CONFIG_STM32_CODESOURCERYW=y  : CodeSourcery under Windows
+
+  nettest:
+  -------
+
+    This configuration directory may be used to verify networking performance
+    using the STM32's Ethernet controller. It uses apps/examples/nettest to excercise the
+    TCP/IP network.
+
+    CONFIG_EXAMPLE_NETTEST_SERVER=n                       : Target is configured as the client
+    CONFIG_EXAMPLE_NETTEST_PERFORMANCE=y                  : Only network performance is verified.
+    CONFIG_EXAMPLE_NETTEST_IPADDR=(10<<24|0<<16|0<<8|2)   : Target side is IP: 10.0.0.2
+    CONFIG_EXAMPLE_NETTEST_DRIPADDR=(10<<24|0<<16|0<<8|1) : Host side is IP: 10.0.0.1
+    CONFIG_EXAMPLE_NETTEST_CLIENTIP=(10<<24|0<<16|0<<8|1) : Server address used by which ever is client.
+
+  nsh:
+  ---
+    Configures the NuttShell (nsh) located at apps/examples/nsh.  The
+    Configuration enables both the serial and telnet NSH interfaces.
+
+    CONFIG_STM32_CODESOURCERYW=y              : CodeSourcery under Windows
+    CONFIG_NSH_DHCPC=n                        : DHCP is disabled
+    CONFIG_NSH_IPADDR=(10<<24|0<<16|0<<8|2)   : Target IP address 10.0.0.2
+    CONFIG_NSH_DRIPADDR=(10<<24|0<<16|0<<8|1) : Host IP address 10.0.0.1
+
+    NOTES:
+    1. This example assumes that a network is connected.  During its
+       initialization, it will try to negotiate the link speed.  If you have
+       no network connected when you reset the board, there will be a long
+       delay (maybe 30 seconds?) before anything happens.  That is the timeout
+       before the networking finally gives up and decides that no network is
+       available.
+
+    2. This example supports the ADC test (apps/examples/adc) but this must
+       be manually enabled by selecting:
+
+       CONFIG_ADC=y             : Enable the generic ADC infrastructure
+       CONFIG_STM32_ADC3=y      : Enable ADC3
+       CONFIG_STM32_TIM1=y      : Enable Timer 1
+       CONFIG_STM32_TIM1_ADC=y  : Indicate that timer 1 will be used to trigger an ADC
+       CONFIG_STM32_TIM1_ADC3=y : Assign timer 1 to drive ADC3 sampling
+       CONFIG_STM32_ADC3_SAMPLE_FREQUENCY=100 : Select a sampling frequency
+
+       See also apps/examples/README.txt
+
+       General debug for analog devices (ADC/DAC):
+
+       CONFIG_DEBUG_ANALOG
+
+    3. This example supports the PWM test (apps/examples/pwm) but this must
+       be manually enabled by selecting eeither
+
+       CONFIG_PWM=y                : Enable the generic PWM infrastructure
+       CONFIG_PWM_PULSECOUNT=n     : Disable to support for TIM1/8 pulse counts
+       CONFIG_STM32_TIM4=y         : Enable TIM4
+       CONFIG_STM32_TIM4_PWM=y     : Use TIM4 to generate PWM output
+       CONFIG_STM32_TIM4_CHANNEL=2 : Select output on TIM4, channel 2
+
+       If CONFIG_STM32_FSMC is disabled, output will appear on CN3, pin 32.
+       Ground is available on CN3, pin1.
+
+       Or..
+
+       CONFIG_PWM=y                : Enable the generic PWM infrastructure
+       CONFIG_PWM_PULSECOUNT=y     : Enable to support for TIM1/8 pulse counts
+       CONFIG_STM32_TIM8=y         : Enable TIM8
+       CONFIG_STM32_TIM8_PWM=y     : Use TIM8 to generate PWM output
+       CONFIG_STM32_TIM8_CHANNEL=4 : Select output on TIM8, channel 4
+
+       If CONFIG_STM32_FSMC is disabled, output will appear on CN3, pin 17
+       Ground is available on CN23 pin1.
+
+       See also include/board.h and apps/examples/README.txt
+
+       Special PWM-only debug options:
+
+       CONFIG_DEBUG_PWM
+
+    4. This example supports the CAN loopback test (apps/examples/can) but this
+       must be manually enabled by selecting:
+
+       CONFIG_CAN=y             : Enable the generic CAN infrastructure
+       CONFIG_CAN_EXID=y or n   : Enable to support extended ID frames
+       CONFIG_STM32_CAN1=y      : Enable CAN1
+       CONFIG_CAN_LOOPBACK=y    : Enable CAN loopback mode
+
+       See also apps/examples/README.txt
+
+       Special CAN-only debug options:
+
+       CONFIG_DEBUG_CAN
+       CONFIG_CAN_REGDEBUG
+
+    5. This example can support an FTP client.  In order to build in FTP client
+       support simply uncomment the following lines in the appconfig file (before
+       configuring) or in the apps/.config file (after configuring):
+
+       #CONFIGURED_APPS += netutils/ftpc
+       #CONFIGURED_APPS += examples/ftpc
+
+    6. This example can support an FTP server.  In order to build in FTP server
+       support simply uncomment the following lines in the appconfig file (before
+       configuring) or in the apps/.config file (after configuring):
+
+       #CONFIGURED_APPS += netutils/ftpd
+       #CONFIGURED_APPS += examples/ftpd
+
+       And enable poll() support in the NuttX configuration file:
+
+       CONFIG_DISABLE_POLL=n
+
+    7. This example supports the watchdog timer test (apps/examples/watchdog)
+       but this must be manually enabled by selecting:
+
+       CONFIG_WATCHDOG=y         : Enables watchdog timer driver support
+       CONFIG_STM32_WWDG=y       : Enables the WWDG timer facility, OR
+       CONFIG_STM32_IWDG=y       : Enables the IWDG timer facility (but not both)
+
+       The WWDG watchdog is driven off the (fast) 42MHz PCLK1 and, as result,
+       has a maximum timeout value of 49 milliseconds.  For WWDG watchdog, you
+       should also add the fillowing to the configuration file:
+
+       CONFIG_EXAMPLES_WATCHDOG_PINGDELAY=20
+       CONFIG_EXAMPLES_WATCHDOG_TIMEOUT=49
+
+       The IWDG timer has a range of about 35 seconds and should not be an issue.
+
+    7. Adding LCD and graphics support:
+
+       appconfig (apps/.config):  Enable the application configurations that you
+       want to use.  Asexamples:
+
+       CONFIGURED_APPS += examples/nx       : Pick one or more
+       CONFIGURED_APPS += examples/nxhello  :
+       CONFIGURED_APPS += examples/nximage  :
+       CONFIGURED_APPS += examples/nxlines  :
+
+       defconfig (nuttx/.config):
+
+       CONFIG_STM32_FSMC=y                  : FSMC support is required for the LCD
+       CONFIG_NX=y                          : Enable graphics suppport
+       CONFIG_MM_REGIONS=3                  : When FSMC is enabled, so is the on-board SRAM memory region
+
+    8. USB OTG FS Device or Host Support
+ 
+       CONFIG_USBDEV          - Enable USB device support, OR
+       CONFIG_USBHOST         - Enable USB host support
+       CONFIG_STM32_OTGFS     - Enable the STM32 USB OTG FS block
+       CONFIG_STM32_SYSCFG    - Needed
+       CONFIG_SCHED_WORKQUEUE - Worker thread support is required
+
+    9. USB OTG FS Host Support.  The following changes will enable support for
+       a USB host on the STM32F4Discovery, including support for a mass storage
+       class driver:
+
+       CONFIG_USBDEV=n          - Make sure tht USB device support is disabled
+       CONFIG_USBHOST=y         - Enable USB host support
+       CONFIG_STM32_OTGFS=y     - Enable the STM32 USB OTG FS block
+       CONFIG_STM32_SYSCFG=y    - Needed for all USB OTF FS support
+       CONFIG_SCHED_WORKQUEUE=y - Worker thread support is required for the mass
+                                  storage class driver.
+       CONFIG_NSH_ARCHINIT=y    - Architecture specific USB initialization
+                                  is needed for NSH
+       CONFIG_FS_FAT=y          - Needed by the USB host mass storage class.
+
+       With those changes, you can use NSH with a FLASH pen driver as shown
+       belong.  Here NSH is started with nothing in the USB host slot:
+
+       NuttShell (NSH) NuttX-x.yy
+       nsh> ls /dev
+       /dev:
+        console
+        null
+        ttyS0
+
+       After inserting the FLASH drive, the /dev/sda appears and can be
+       mounted like this:
+
+       nsh> ls /dev
+       /dev:
+        console
+        null
+        sda
+        ttyS0
+       nsh> mount -t vfat /dev/sda /mnt/stuff
+       nsh> ls /mnt/stuff
+       /mnt/stuff:
+        -rw-rw-rw-   16236 filea.c
+
+       And files on the FLASH can be manipulated to standard interfaces:
+
+       nsh> echo "This is a test" >/mnt/stuff/atest.txt
+       nsh> ls /mnt/stuff
+       /mnt/stuff:
+        -rw-rw-rw-   16236 filea.c
+        -rw-rw-rw-      16 atest.txt
+       nsh> cat /mnt/stuff/atest.txt
+       This is a test
+       nsh> cp /mnt/stuff/filea.c fileb.c
+       nsh> ls /mnt/stuff
+       /mnt/stuff:
+        -rw-rw-rw-   16236 filea.c
+        -rw-rw-rw-      16 atest.txt
+        -rw-rw-rw-   16236 fileb.c
+
+       To prevent data loss, don't forget to un-mount the FLASH drive
+       before removing it:
+
+       nsh> umount /mnt/stuff
+
+    11. This configuration requires that jumper JP22 be set to enable RS-232
+       operation.
+
+  nsh2:
+  -----
+
+    This is an alternative NSH configuration.  One limitation of the Shenzhou
+    board is that you cannot have both a UART-based NSH console and SDIO support.
+    The nsh2 differs from the nsh configuration in the following ways:
+
+    -CONFIG_STM32_USART3=y      : USART3 is disabled
+    +CONFIG_STM32_USART3=n
+
+    -CONFIG_STM32_SDIO=n        : SDIO is enabled
+    +CONFIG_STM32_SDIO=y
+
+    Logically, these are the only differences:  This configuration has SDIO (and
+    the SD card) enabled and the serial console disabled. There is ONLY a
+    Telnet console!.
+
+    There are some special settings to make life with only a Telnet
+
+    CONFIG_SYSLOG=y - Enables the System Logging feature.
+    CONFIG_RAMLOG=y - Enable the RAM-based logging feature.
+    CONFIG_RAMLOG_CONSOLE=y - Use the RAM logger as the default console.
+      This means that any console output from non-Telnet threads will
+      go into the circular buffer in RAM.
+    CONFIG_RAMLOG_SYSLOG - This enables the RAM-based logger as the
+      system logger.  This means that (1) in addition to the console
+      output from other tasks, ALL of the debug output will also to
+      to the circular buffer in RAM, and (2) NSH will now support a
+      command called 'dmesg' that can be used to dump the RAM log.
+
+    There are a few other configuration differences as necessary to support
+    this different device configuration. Just the do the 'diff' if you are
+    curious.
+
+    NOTES:
+    1. See the notes for the nsh configuration.  Most also apply to the nsh2
+       configuration.  Like the nsh configuration, this configuration can
+       be modified to support a variety of additional tests.
+
+    2. RS-232 is disabled, but Telnet is still available for use as a console.
+       Since RS-232 and SDIO use the same pins (one controlled by JP22), RS232
+       and SDIO cannot be used concurrently.
+
+    3. This configuration requires that jumper JP22 be set to enable SDIO
+       operation.  To enable MicroSD Card, which shares same I/Os with RS-232,
+       JP22 is not fitted.
+
+    4. In order to use SDIO without overruns, DMA must be used.  The STM32 F4
+       has 192Kb of SRAM in two banks:  112Kb of "system" SRAM located at
+       0x2000:0000 and 64Kb of "CCM" SRAM located at 0x1000:0000. It appears
+       that you cannot perform DMA from CCM SRAM.  The work around that I have now
+       is simply to omit the 64Kb of CCM SRAM from the heap so that all memory is
+       allocated from System SRAM.  This is done by setting:
+
+       CONFIG_MM_REGIONS=1
+
+       Then DMA works fine. The downside is, of course, is that we lose 64Kb
+       of precious SRAM.
+
+    5. Another SDIO/DMA issue.  This one is probably a software bug.  This is
+       the bug as stated in the TODO list:
+
+       "If you use a large I/O buffer to access the file system, then the
+        MMCSD driver will perform multiple block SD transfers.  With DMA
+        ON, this seems to result in CRC errors detected by the hardware
+        during the transfer.  Workaround:  CONFIG_MMCSD_MULTIBLOCK_DISABLE=y"
+
+       For this reason, CONFIG_MMCSD_MULTIBLOCK_DISABLE=y appears in the defconfig
+       file.
+
+    6. Another DMA-related concern.  I see this statement in the reference
+       manual:  "The burst configuration has to be selected in order to respect
+       the AHB protocol, where bursts must not cross the 1 KB address boundary
+       because the minimum address space that can be allocated to a single slave
+       is 1 KB. This means that the 1 KB address boundary should not be crossed
+       by a burst block transfer, otherwise an AHB error would be generated,
+       that is not reported by the DMA registers."
+
+       There is nothing in the DMA driver to prevent this now.
+
+  nxconsole:
+  ----------
+    This is yet another NSH configuration.  This NSH configuration differs
+    from the others, however, in that it uses the NxConsole driver to host
+    the NSH shell.
+
+    Some of the differences in this configuration and the normal nsh configuration
+    include these settings in the defconfig file:
+
+    These select NX Multi-User mode:
+
+      CONFG_NX_MULTIUSER=y
+      CONFIG_DISABLE_MQUEUE=n
+
+    The following definition in the defconfig file to enables the NxConsole
+    driver:
+
+      CONFIG_NXCONSOLE=y
+
+    The appconfig file selects examples/nxconsole instead of examples/nsh:
+
+      CONFIGURED_APPS += examples/nxconsole
+
+    Other configuration settings:
+
+      CONFIG_STM32_CODESOURCERYW=y  : CodeSourcery under Windows
+      CONFIG_LCD_LANDSCAPE=y        : 320x240 landscape
+
+  nxwm
+  ----
+    This is a special configuration setup for the NxWM window manager
+    UnitTest.  The NxWM window manager can be found here:
+
+      trunk/NxWidgets/nxwm
+
+    The NxWM unit test can be found at:
+
+      trunk/NxWidgets/UnitTests/nxwm
+
+    Documentation for installing the NxWM unit test can be found here:
+
+      trunk/NxWidgets/UnitTests/README.txt
+
+    Here is the quick summary of the build steps:
+
+    1. Intall the nxwm configuration
+
+       $ cd ~/nuttx/trunk/nuttx/tools
+       $ ./configure.sh shenzhou/nxwm
+
+    2. Make the build context (only)
+
+       $ cd ..
+       $ . ./setenv.sh
+       $ make context
+       ...
+
+    3. Install the nxwm unit test
+
+       $ cd ~/nuttx/trunk/NxWidgets
+       $ tools/install.sh ~/nuttx/trunk/apps nxwm
+       Creating symbolic link
+        - To ~/nuttx/trunk/NxWidgets/UnitTests/nxwm
+        - At ~/nuttx/trunk/apps/external
+
+    4. Build the NxWidgets library
+
+       $ cd ~/nuttx/trunk/NxWidgets/libnxwidgets
+       $ make TOPDIR=~/nuttx/trunk/nuttx
+       ...
+
+    5. Build the NxWM library
+
+       $ cd ~/nuttx/trunk/NxWidgets/nxwm
+       $ make TOPDIR=~//nuttx/trunk/nuttx
+       ...
+
+    6. Built NuttX with the installed unit test as the application
+
+       $ cd ~/nuttx/trunk/nuttx
+       $ make
+
+  ostest:
+  ------
+    This configuration directory, performs a simple OS test using
+    examples/ostest.  By default, this project assumes that you are
+    using the DFU bootloader.
+
+      CONFIG_STM32_CODESOURCERYW=y  : CodeSourcery under Windows
+
+  telnetd:
+  --------
+
+    A simple test of the Telnet daemon(see apps/netutils/README.txt,
+    apps/examples/README.txt, and apps/examples/telnetd).  This is
+    the same daemon that is used in the nsh configuration so if you
+    use NSH, then you don't care about this.  This test is good for
+    testing the Telnet daemon only because it works in a simpler
+    environment than does the nsh configuration.
diff --git a/nuttx/net/recvfrom.c b/nuttx/net/recvfrom.c
index 6b9eb9a90..8bb658f48 100644
--- a/nuttx/net/recvfrom.c
+++ b/nuttx/net/recvfrom.c
@@ -371,7 +371,7 @@ static int recvfrom_timeout(struct recvfrom_s *pstate)
    * 1) This delay function has been enabled with CONFIG_NET_TCP_RECVDELAY > 0
    * 2) Some data has already been received from the socket.  Since this can
    *    only be true for a TCP/IP socket, this logic applies only to TCP/IP
-   *    sockets, and either
+   *    sockets.  And either
    * 3) There is no configured receive timeout, or
    * 4) The configured receive timeout is greater than than the delay
    */
@@ -598,7 +598,9 @@ static uint16_t recvfrom_tcpinterrupt(struct uip_driver_s *dev, void *conn,
 
           /* Report an error only if no data has been received */
 
+#if CONFIG_NET_TCP_RECVDELAY > 0
           if (pstate->rf_recvlen == 0)
+#endif
             {
               /* Report the timeout error */