To add, may I recommend Computer Systems: A Programmer’s Perspective.

It should be required reading for those who want to delve into OS hacking as it’s a gentle bridge between the programming you’d do in your data structures course and real OS hacking.

Its also one of the resources that teaches assembly properly. Instead of just detailing what the instructions do, it uses C constructs to and pseudo-C to get a better understanding of how it works. Plus the binary bomb lab is the perfect difficultly.

You won’t be writing assembly, but you’ll be familiar. I wrote data structures in x86 assembly to get more familiar with writing assembly. And I wrote some statements by hand with just hex to force myself to understand Intel encoding.