This is the code accompanying this blog post. Head there for some more details on what is going on here.
Requires arm toolchain and stlink.
Then connect your st-link to computer and run:
sh build.sh
This will attempt to compile and flash your firmware.
Then, you can try debugging with GDB and OpenOCD
First, start openocd with:
openocd -f openocd.cfg
Then start gdb with:
arm-none-eabi-gdb -q -x openocd.gdb target/thumbv7m-none-eabi/release/stm32f103c8t6-rust-starter
In gdb type continue to start the program.
If your debugger supports SWO, you can read it with:
itmdump --follow -f itm.fifo