Comment by ModernMech

> just lots of detail.

"Just" is understating it.

It's the kind of project that takes 20 years to accomplish on your own, and everything seems doable from moment to moment because you have to work very slowly, and the stepwise changes aren't hard.

Just get the thing to boot. Just boot into extended mode. Just get graphics running. Just get a userspace. Just implement cooperative multitasking. Every step is "just", but when you take a step back the complexity is enormous, and it becomes hard to explain to anyone how it works in its entirety.

Although it seems easy to the author because that's just how his brain works now -- by then end of it, you and the OS are one and the same, where your brain is essentially a map of the codebase and nothing more, because nothing else can fit.