WCH CH32V103 build template

This repository is a template for a project built for the WCH CH32V103 RISC-V microcontroller, without using the MounRiver tools. A GCC toolchain is built in a Docker container to make the build simple on all decent platforms; I use it on macOS and have tested it on Linux.

You will need

• Docker
• Patched openocd supporting wlink/WCH-link; either from the MounRiver tools or from source.
• make (probably GNU make?)

Everything else is downloaded into the Docker container.

How to build and flash

• Using Docker:
  • make — full build. Will create the docker container (expect 10-30min) if needed.
  • make wipe — full clean and rebuild.
• Building locally, if you have your own toolchain already:
  • make lall ("local all")
  • make clean lall (equivalent to make wipe)
• To flash:
  • make flash

make flash expects to find a WCH-compatible patched openocd on the system PATH. If yours lives elsewhere, define OPENOCD_DIR on the environment.

What's in here?

The directory tree contains:

• Dockerfile — specification for the Docker image, which will be called riscv-ubuntu.
• Makefile — makefile, orchestrating Docker, Meson, and OpenOCD.
• meson.build — meson build file; this does the actual build.
• meson_cross_riscv.txt — meson cross-compile definition file
• wch-riscv.cfg — OpenOCD configuration for the CH32V103
• ch32v103/ — WCH's support code, Apache 2.0 licensed
  • Core/ — RISC-V core support components
  • Debug/ — a few janky debug helpers WCH threw in
  • Ld/ — linker script
  • Peripheral/ — peripheral drivers
  • Startup/ — startup/CRT code
• mbuild/ — output build directory
• src/ — project source code
  • ch32v10x_it.c and .h — interrupt handlers (this file is not special, you could delete it)
  • main.c — contains main()
  • mcu_config.h — some hardware configuration I factored out of the WCH libs
  • system_ch32v10x.c and .h — clock/power startup code

Making it yours

• Put code under src/ (you can start in main.c if you like)
• Edit meson.build to list the files that need to be built, and select which peripheral libraries you want
  • Consider changing the project name from firmware for more descriptive filenames
• Replace this readme with your own

Changes I made to the WCH support code

• Pull user config values out of system_ch32v10x.c and ch32v10x.h into mcu_config.h.

Other useful resources

Nobody seems to link directly to these except WCH themselves, so I'm putting them here:

• CH32V10x datasheet
• CH32x10x reference manual — beware that this also covers the Cortex-M version

Copying and changing

Intellectual property is bullshit and fake, steal this and don't credit me. You might want to credit WCH for their parts, which have a pesky Apache 2.0 license header on them.