View source for STM32 VLDISCOVERY

= Using STM32 VLDISCOVERY with GNU/Linux tools =
In this tutorial I will try to explain basic steps you have to do to successfully program STM32 microprocessor using GNU/Linux tools.



=== What is STM32 VLDISCOVERY ===
STM32 VLDISCOVERY is low-cost STM32F100 (ARM Cortex-M3) development board. There is ST-link programmer on the board, which is not supported under Linux.

* [http://www.st.com/internet/evalboard/product/250863.jsp STM32 VLDISCOVERY]
* [http://www.st.com/internet/mcu/product/216844.jsp STM32F100RB]



== How to write source code ==
 [http://kormus.cz/data/blinkenlight_example/blinkenlight_example.tar.bz2 Download example project]

You can write your source code in whatever text editor you like. Life will be much easier when you use:
* STM32 hardware specific header file (<tt>stm32f10x.h</tt> in example project)
* C Startup code (included in example project)



== How to compile your program ==
You will need to have GCC ARM cross compiler and tools installed on your computer ([[Cross_compilers]])

Use <tt>Makefile</tt> (and <tt>stm32.ld</tt>) from example project. To compile run:
 make



== How to flash it ==
There are many possible ways how to flash STM32 microprocessor embedded on STM32 VLDISCOVERY board.

* Using ST-Link (Windows only)
* Using bootloader
* Using JTAG
* (Using SWD?)



== Flashing using bootloader ==
[http://gostm32.blogspot.com/ Nice tutorial] how to use bootloader.


To use bootloader, you have to:
* Change logic value of <tt>BOOT0</tt> pin
* Have <tt>USB<->USART</tt> convertor (with TTL logic levels) or ...
* (Have <tt>USB<->RS232</tt> convertor + MAX232 logic level convertor)
* Use [http://code.google.com/p/stm32flash/ Stm32flash]



== Flashing using JTAG ==
U will need JTAG debugger/programmer. This tutorial is for FT2232 JTAG debugger only.

For flashing microprocessor
* Install openocd on your computer (compiling newest version preferred) 
* Copy <tt>openocd.cfg</tt> from example project into your working directory
* Connect JTAG programmer to your computer (without connecting it to microprocessor)
* Run
 make openocd
* If the output is like
 ...
 make: *** [openocd] Error 1
Try to reconnect JTAG programmer and rerun the command mentioned above.
* If it writes something like
 ...
 Polling target failed, GDB will be halted. Polling again in 1500ms
Hit <tt>Ctrl+C</tt> and connect JTAG to microprocessor, then rerun the command. The output should be like
 ...
 Info : clock speed 1000 kHz
 Info : JTAG tap: stm32.cpu tap/device found: 0x3ba00477 (mfg: 0x23b, part: 0xba00, ver: 0x3)
 Info : JTAG tap: stm32.bs tap/device found: 0x06420041 (mfg: 0x020, part: 0x6420, ver: 0x0)
 ...

* Open another console. Copy <tt>stm32-prog.script</tt> into your working directory. Run
 telnet localhost 4444
Inside telnet run 
 script stm32-prog.script
The output should be something like
 > script stm32-prog.script
 JTAG tap: stm32.cpu tap/device found: 0x3ba00477 (mfg: 0x23b, part: 0xba00, ver: 0x3)
 JTAG tap: stm32.bs tap/device found: 0x06420041 (mfg: 0x020, part: 0x6420, ver: 0x0)
 target state: halted
 target halted due to debug-request, current mode: Thread 
 xPSR: 0x01000000 pc: 0xfffffffe msp: 0xfffffffc
 device id = 0x10016420
 flash size = 128kbytes
 stm32x mass erase complete
 wrote 400 bytes from file main.elf in 0.165895s (2.355 KiB/s)
 JTAG tap: stm32.cpu tap/device found: 0x3ba00477 (mfg: 0x23b, part: 0xba00, ver: 0x3)
 JTAG tap: stm32.bs tap/device found: 0x06420041 (mfg: 0x020, part: 0x6420, ver: 0x0)

And your application is running on the microprocessor



== How to debug ==
It should be possible to use GDB (run "<tt>make gdb</tt>" in example project directory), but I had some problems (with breakpoints etc.). 

I used mostly USART and LEDs for debugging.



== Tips & Tricks ==
Be aware of pins <tt>PC13, 14, 15</tt> -- they are not regular IO pins (for more information see chapter "<tt>4.1.2 Battery backup domain</tt>" in STM32 VLDISCOVERY manual).

Pins <tt>PA13, PA14, PA15, PB3</tt> and <tt>PB4</tt> are used for JTAG and SWD, so they can't be (easy) used as GPIO.