I tried to read linux kernel and dropped it long back around the year of 2007 or 2008. Whenever I start touching system level code, programming languages becomes alien language for me.
I thought of watching again the OS/computer architecture video courses. Luckily come across xv6 (https://en.wikipedia.org/wiki/Xv6) operating system. This makes/motivating me to give one more attempt to learn the kernel and system level programming.
This one also helps me a lot.
https://github.com/Babtsov/jos/tree/master/lab1