Open-Source STM8S Toolchain (SDCC + Makefile)

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Open-source build system for STM8 microcontrollers (tested and used with STM8S). Supports Linux, Windows, and macOS.

Includes / Supports / Can do:

• build using the free SDCC compiler
• flash via OpenOCD or stm8flash
• debug with GDB and cgdb
• SPL integration and VS Code / clangd support via compile_commands.json

How does it work?

• It is essentially "just" a starter source code tree and Makefile (not only) for teaching Microprocessor Technology with STM8S.
• Designed for the SDCC compiler (or SDCC-gas).
• The Standard Peripheral Library SPL should (for licensing reasons) be downloaded separately from the manufacturer's website and use the patch. But I think if you run make spl it won't be a sin.
• Competition and inspiration:
  • https://gitlab.com/wykys/stm8-tools
  • https://github.com/matejkrenek/stm8-toolchain

Usage

First, you need to configure the microprocessor and its frequency in the Makefile; optionally the path to SDCC installation, or STVP.

#DEVICE_FLASH=stm8s103f3
DEVICE_FLASH=stm8s208rb

F_CPU=16000000

ifeq ($(OS),Windows_NT)
	CC_ROOT = "/c/Program Files/SDCC"
	STVP_ROOT = "/c/Program Files (x86)/STMicroelectronics/st_toolset/stvp"
else
	CC_ROOT = /usr
endif

... and then just tinker, program and run make.

Command
make spl	downloads and prepares SPL libraries
make spl-renew	re-downloads SPL libraries
make	compiles the project (alias for make ihx)
make ihx	compiles to Intel HEX format
make elf	compiles to ELF format (with debug info)
make all	compiles both (ihx and elf)
make clean	deletes build output
make clean-spl-objects	deletes SPL object files (library stays)
make clean-spl	deletes SPL library (forces full SPL rebuild)
make cleanall	deletes everything including SPL libraries
make rebuild	cleans everything and recompiles (elf)
make reflash	cleans everything and flashes again
make flash	uploads ihx to the chip — OpenOCD on Linux, STVP on Windows
make flash-elf	uploads elf to the chip via OpenOCD
make flash-ihex	converts elf to ihex and uploads via OpenOCD
make stm8flash	alternative flash method (uses stm8flash)
make stm8flash-unlock	removes read protection via stm8flash
make openocd	starts OpenOCD for debugging (keeps running, then use make gdb)
make gdb	starts STM8-gdb in TUI mode
make cgdb	starts cgdb with STM8-gdb
make switch-device	interactively switches target device in Makefile
make lib	interactively selects drivers from lib/ and moves them to src/ and inc/
make docs-download	downloads datasheet/reference manual for the current device
make tree	displays the project tree

Dependencies

• GNU Make
• GNU Bash -- on Windows it can be installed together with Git.
• SDCC or SDCC-gas
• STM8 binutils (stm8-gdb, stm8-ld)
• OpenOCD for flash and debug or STVP for flash on Windows.
• (stm8flash for flash2)

On Windows

choco install git make vscode mingw

Three Makefiles

There are three Makefile variants available in the .make directory. This is because the SDCC compiler cannot remove dead code. There are three solutions. The first one is the most optimal, the other two are kept just in case. By default the Makefile is set to the first and most optimal solution sdcc. For more details, see https://chytrosti.marrek.cz/stm8oss.html.

$ ls .make/Makefile*
.make/Makefile-sdcc
.make/Makefile-sdcc-gas
.make/Makefile-sdccrm