Comment by 0x0203
5 years ago
One of the easiest ways to get into writing your own kernel is to start with the OS Dev wiki [0]. Both the wiki and their forums are a great place for getting your feet wet.
For more general information, there are also a handful of articles and/or blog posts that I've come across when I was getting started that gave a very good introduction to many of the low-level components of how computers work and what the OS needs to do to run them. One of my favorites was Many But Finite [1]. Check out a bunch of his posts about the memory map, the computer boot process [2], cpu rings, etc... Not exhaustive by any means, but good, well-presented info. Many other such sources exist; maybe others will share their favorites.
And if you'd just like to get a more gentle introduction into actual OS code than the monster that is Linux, maybe try looking at some of the BSD's. NetBSD [3] and OpenBSD [4] are remarkably easy to navigate and follow from a code flow perspective, and if you just want to see how things work in a real OS, it's both a good reference and a good place to start.
[0] https://wiki.osdev.org/Main_Page
[1] https://manybutfinite.com/archives
Thank you!