This repository is based on https://github.com/TG9541/stm8ef .
Thomas supplied a Makefile that gets you started in no time:
hook up a ST-link-V2 to your stm8 board
run "make" in terminal and you are ready to go.
i2c.fs: I2C communication
ssd1306.fs: I2C oled display
rtc.fs: I2C RealTimeClock modules
sdinit.fs: Initialise SD card for SPI communication
sdfat.fs: SD card FAT32 communication
io.fs: GPIO manipulation