In May, Kevin Cuzner posted instructions on bootstrapping a Cortex M3 microcontroller without a dev board. It hit Hackaday and grabbed my attention because I happened to have a couple of those chips on boards I’d been using to play with Forth.

He’s done the hard work of carving the neccessary include files out of ST’s SDK, and wraps the whole thing up in an easy to use Makefile. Great! I made one little tweak (for Ubuntu Xenial support), and it all builds smoothly.

He’s included an openocd.cfg config file, but I don’t have an ST-Link device to load the output with. Luckily, you can kind of smush the instructions Jean-Claude Wippler put together to upload your program.

Grab stm32loader from GitHub. Put BOOT0 in the 1 position, and BOOT1 in the 0 position. Reset your board and run the following to upload the .bin that make generated to 0x80000000.

lappy:~/Repo/stm32f103c8-blink aaron$ python -a 0x08000000 \
    -g 0x08000000 -p /dev/ttyUSB0 -e -w bin/blink.bin
Bootloader version 22
Chip id: 0x410 (STM32 Medium-density)
Write 256 bytes at 0x8000000
Write 256 bytes at 0x8000100
Write 256 bytes at 0x8000200
Write 256 bytes at 0x8000300
Write 256 bytes at 0x8000400
Write 256 bytes at 0x8000500
Write 256 bytes at 0x8000600
Write 256 bytes at 0x8000700
Write 256 bytes at 0x8000800
Write 256 bytes at 0x8000900
Write 256 bytes at 0x8000A00
Write 256 bytes at 0x8000B00

And you’re done! I can confirm that I have a blinking LED on port PB0.