https://news.ycombinator.com/item?id=20809666

So recently I did a couple of minor patches on the FreeBSD and NetBSD kernels and played with some linux kernel. It was the first time in a a few years, I've been excited about programming.

Unfortunately I'm still completely lost. It seems that there's so much to learn and every kernel update breaks whatever you just finished writing. I see terms in unfamiliar with and often find myself googling basic OS concepts.

Are there any recommendations reading materials to get a better grasp on OS theory and / or the Linux / UNIX kernels and programming for them?