https://github.com/stm32-rs/stm32f1xx-hal/tree/master
Flash with pyocd by copying target/thumbv7m-none-eabi/debug/soft to target/thumbv7m-none-eabi/debug/soft.elf and executing pyocd flash soft.elf --target stm32f103c8
cp target/thumbv7m-none-eabi/debug/soft target/thumbv7m-none-eabi/debug/soft.elf && pyocd flash target/thumbv7m-none-eabi/debug/soft.elf --target stm32f103c8