I'm attempting to program my own simple OS. I'll be using the README as a blog page to track resources and outline my experience.
I'm working with a Raspberry Pi 4 and a BeagleBone Black board. Hopefully, I'll be able to get something up and running on both! My typical development environment is Ubuntu on WSL, but if I run into difficulties I may use Windows or hop over to my laptop where I've got PopOS and Fedora.
Learning assembly language with LowLevelLearning
Download the ARM GNU toolchain
Apparently, RealVNC's CEO blogging about building a custom RaspberryPi OS