Start a new libopencm3 based project for Blue Pill STM32F103C8 board

start_libopencm3.sh

#!/usr/bin/sh

# Start a new libopencm3 based project for Blue Pill STM32F103C8 board.
# Takes project name as a parameter.

EXAMPLES_MASTER=\
"https://raw.githubusercontent.com/libopencm3/libopencm3-examples/master"

mkdir "$1"
cd "$1"

git init .
git submodule add https://github.com/libopencm3/libopencm3

cat << EOF > ".gitignore"
*.a
*.bin
*.d
*.elf
*.hex
*.list
*.map
*.o
*.srec
EOF

cd libopencm3
make
cd ..

wget "${EXAMPLES_MASTER}/examples/rules.mk" -O libopencm3.rules.mk
  
wget "${EXAMPLES_MASTER}/examples/stm32/f1/Makefile.include" \
  -O libopencm3.target.mk

sed -i 's|include ../../../../rules.mk|include ../libopencm3.rules.mk|g' \
  libopencm3.target.mk

mkdir src
cd src

cat << EOF > "Makefile"
BINARY = $1

OPENCM3_DIR=../libopencm3
LDSCRIPT = \$(OPENCM3_DIR)/lib/stm32/f1/stm32f103x8.ld

include ../libopencm3.target.mk
EOF

cat << EOF > "$1.c"
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/gpio.h>

int main(void)
{
    int i;
    rcc_periph_clock_enable(RCC_GPIOC);
    gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_2_MHZ,
        GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
      
    /* Blink the LED (PC13) on the board. */
    while (1) {
        gpio_toggle(GPIOC, GPIO13);
        for (i = 0; i < 800000; i++)
            __asm__("nop");
    }
    return 0;
}
EOF

Thank you! This was very helpful. To get this to run correctly on MacOS Mojave, I had to change

sed -i 's|include ../../../../rules.mk|include ../libopencm3.rules.mk|g' \
  libopencm3.target.mk

to

sed -i '' 's|include ../../../../rules.mk|include ../libopencm3.rules.mk|g' \
  libopencm3.target.mk

It is very subtle, but I had to add a '' after sed -i.