Use RPIOS [pi-gen](https://github.com/RPi-Distro/pi-gen), it's pretty versatile and stupid simple, I could not wrap my head around Yocto and Buildroot. Even set it up in CI so GitHub would build the image and id just get the final tar.gz file as an artifact.
It's all just bash scripts and you can basically strip the entire image down. I had no window manager and no display server I was using DRM to show my UI.
It's all just bash scripts and you can basically strip the entire image down. I had no window manager and no display server I was using DRM to show my UI.