Absolutely silly way to build firmware for microcontrollers

Recently, I needed some firmware for a USB to CAN stick I bought off of aliexpress. But, there was no prebuilt version, so I had to build my own. Fortunatelly, I found nice instructions for it. Unfortunatelly, they were unusable for me because I use nixos and my second distro of choice is fedora.

I didn't feel like I wanted spend time mapping the instructions to either of the distros (as cross-compiling is complicated). Also, first few attempts failed. So I decided to >>just use podman<<. Yeah, it's as silly as it sounds.

Anywho, here's a Dockerfile:

FROM ubuntu:24.04

RUN apt-get update
RUN apt-get install -y cmake gcc-arm-none-eabi git dfu-util usbutils ninja-build
RUN git clone --depth=1 -b stm32g0_support https://github.com/bigtreetech/candleLight_fw src
WORKDIR /src
RUN mkdir build \
	&& cd build \
	&& cmake .. -GNinja -DCMAKE_TOOLCHAIN_FILE=../cmake/gcc-arm-none-eabi-8-2019-q3-update.cmake
WORKDIR /src/build
RUN ninja budgetcan_fw

which you can just plop anywhere and run podman build . --tag silly.

Now I needed a way to run the flashing utility. Since the flashing process is built into the build system, I decided to just run it from the container. This is the magic invocation:

podman run --rm -it --device=/dev/bus/usb/001/002:rwm silly

the --device option value comes from lsusb listing.

Then I could just run ninja budgetcan_fw and my thingamagic was flashed.

Way faster than trying to figure out how to do cross-compilation on nixos (though I'll probably want to go to that rabbit-hole eventually).

sidenote: I really appreciate that everything is USB-C nowadays. It makes doing this stuff on my laptop way easier.