[deater]

as someone who has written my own OS from scratch (vmwOS) and teach a class on it, I have to agree with a lot of the other comments that x86-based OS projects do end up being exercises in 40-year old PC/x86 retrocomputing.

A few years ago I would have recommended the path I took (writing an OS for the Raspberry Pi) but the Pis have gone off the rails recently. So writing a simple OS for a Pi-1B+ is relatively doable (simple enough, sort of OK documentation, biggest downside is needing USB for the keyboard).

Things led to disaster once everyone wanted to use Pi4 (which was all we could manage to source during the CPU shortage of '23) as the documentation is poor, getting interrupts going became nearly impossible, and the virtual memory/cache/etc setup on the 64-bit cores (at least a few years ago) was not documented well at all.

[shetaye]

If you are still interested in SMP on a 64-bit ARM, we have had some success with virtual memory/cache/peripherals on the Pi Zero 2 W