This is a simple tool designed to create a uClinux distribution for STM32f429 Discovery board from STMicroelectronics. STM32F429 MCU offers the performance of ARM Cortex M4 core (with floating point unit) running at 180 MHz while reaching reasonably lower static power consumption.

The builder requires that various tools and packages be available for use in the build procedure:

• OpenOCD
  • OpenOCD 0.7.0 (and the 0.7.0-2 from Debian) can't write romfs to flash because of a post-0.7.0-stable bug (bad flash detection on stm32f429). You need to use 0.8.0 development version.

    git clone git://git.code.sf.net/p/openocd/code openocd
    cd openocd
    ./bootstrap
    ./configure --prefix=/usr/local --enable-stlink
    echo -e "all:\ninstall:" > doc/Makefile
    make
    sudo make install

• Set ARM/uClinux Toolchain:
  • Download arm-2010q1-189-arm-uclinuxeabi-i686-pc-linux-gnu.tar.bz2 from Mentor Graphics
  • only arm-2010q1 is known to work; don't use SourceryG++ arm-2011.03

    tar jxvf arm-2010q1-189-arm-uclinuxeabi-i686-pc-linux-gnu.tar.bz2
    export PATH=`pwd`/arm-2010q1/bin:$PATH

• genromfs

    sudo apt-get install genromfs

• Simply execute make, and it will fetch and build u-boot, linux kernel, and busybox from scratch:

    make

• Once STM32F429 Discovery board is properly connected via USB wire to Linux host, you can execute make install to flash the device. Note: you have to ensure the installation of the latest OpenOCD in advance.

    make install

Be patient when OpenOCD is flashing. Typically, it takes about 55 seconds. Use make help to get detailed build targets.

The STM32F429 Discovery is equipped with various USARTs. USART stands for Universal Synchronous Asynchronous Receiver Transmitter. The USARTs on the STM32F429 support a wide range of serial protocols, the usual asynchronous ones, plus things like IrDA, SPI etc. Since the STM32 works on 3.3V levels, a level shifting component is needed to connect the USART of the STM32F429 to a PC serial port.

Most PCs today come without an native RS232 port, thus an USB to serial converter is also needed.

For example, we can simply connect the RX of the STM32 USART3 to the TX of the converter, and the TX of the USART3 to the RX of the converter:

• pin PC10 -> TXD
• pin PC11 -> RXD

U-Boot 2010.03-00003-g934021a ( Feb 09 2014 - 17:42:47)

CPU  : STM32F4 (Cortex-M4)
Freqs: SYSCLK=180MHz,HCLK=180MHz,PCLK1=45MHz,PCLK2=90MHz
Board: STM32F429I-DISCOVERY board,Rev 1.0
DRAM:   8 MB
Using default environment

Hit any key to stop autoboot:  0 
## Booting kernel from Legacy Image at 08020000 ...
...

Starting kernel ...

Linux version 2.6.33-arm1 (jserv@venux) (gcc version 4.4.1 (Sourcery G++ Lite 2010q1-189) ) #2 Sun Feb 9 17:54:20 CST 2014
CPU: ARMv7-M Processor [410fc241] revision 1 (ARMv7M)
CPU: NO data cache, NO instruction cache
Machine: STMicro STM32
...
VFS: Mounted root (romfs filesystem) readonly on device 31:0.
Freeing init memory: 16K
starting pid 25, tty '/dev/ttyS2': '/bin/login -f root'
Welcome to
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    _   _| |  | | _ ____  _   _  _  _ 
   | | | | |  | || |  _ \| | | |\ \/ /
   | |_| | |__| || | | | | |_| |/    \
   |  ___\____|_||_|_| |_|\____|\_/\_/
   | |
   |_|

For further information check:
http://www.uclinux.org/