STM32/ARM Cortex-M3 HOWTO: Development under Ubuntu (Debian)

Compile Olimex blinky

At this point you have created the toolchain and flashed a program into your board.

Now let's do a quick test to see that our gcc toolchain is working, and we are going to test it on the same blinky example as before.

mkdir -p ~/stm32/stm32-example
cd ~/stm32/stm32-example
wget http://olimex.com/dev/soft/arm/STR/STM32-BLINK-LED-GCC-ECLIPSE-projects.rar
unrar x STM32-BLINK-LED-GCC-ECLIPSE-projects.rar 
cd projects/stm_h103/

And now let's recompile and see what we get.

make clean 
make

And hopefully you don't get any compile warnings at this point....

But let's check what we got.

ls --sort=time -1

Then the top of the list should be something like this:

main.bin
main.list
main.o
main.out
stm32f10x_gpio.o
stm32f10x_rcc.o
....

main.bin

So what are those files anyway? main.bin is a good file to know about since that is the file you are going to flash onto the board.

main.out

With the strange .out name, we find the elf-file. In there we have a lot of funny stuff to play with, and and since it is a elf this file is often called main.elf. But first let's check that we did produce code for the Cortex-M3, and for that we can use readelf from binutils.

arm-none-eabi-readelf -A main.out

then we something like this:

Attribute Section: aeabi
File Attributes
  Tag_CPU_name: "CORTEX-M3"
  Tag_CPU_arch: v7
  Tag_CPU_arch_profile: Microcontroller
  Tag_THUMB_ISA_use: Thumb-2
  Tag_ABI_PCS_wchar_t: 4
  Tag_ABI_FP_denormal: Needed
  Tag_ABI_FP_exceptions: Needed
  Tag_ABI_FP_number_model: IEEE 754
  Tag_ABI_align8_needed: Yes
  Tag_ABI_align8_preserved: Yes, except leaf SP
  Tag_ABI_enum_size: small
  Tag_ABI_optimization_goals: Aggressive Debug

main.list

Another fun thing is to use objdump to look at the elf with the -S flag.

arm-none-eabi-objdump -S main.out

The makefile does this for us and the result is stored in main.list. Here you can find both assembler and c-code interleaved so you can check the compiler results. You can open it in a normal editor and have a quick look.

vi main.list

That's that, we compiled the blinky... now let's move forward to the next part and see if we can't actually get something on to the board.

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