I needed to add a custom System Request (Sys Req or SysRq) to a linux kernel some time ago. While doing so, I dug deep into how it works and I thought I’d make a quick post about it. Here is a good SuperUser answer about what a SysRq is. You may also know about SysRq via REISUB. This post has three parts: how to raise a SysRq, how SysRq works (looking into kernel code), and how to add your own SysRq.
Operating Systems: Three Easy Pieces by Remzi H. Arpaci-Dusseau & Andrea C. Arpaci-Dusseau (University of Wisconsin-Madison) is an excellent book and used by many universities worldwide. Extremely well written and it’s one of the only textbooks I’ve ever completed from start to end.
It’s also completely free: https://pages.cs.wisc.edu/~remzi/OSTEP/
Ooo nice, thank you for the tip.
I wonder where I could get a physical version. Somewhere other than Amazon that is, they do have it but I’d like to avoid them if at all possible because, well, Amazon. I searched Adlibris which is a Nordic online bookstore but they didn’t have it, unfortunately.
I’m a fan of physical books nowadays. I read e-books for a few years but I felt like I didn’t remember what I read nearly as well as I do if I read an actual paper book, and apparently there’s actually some empirical evidence for this being a wider phenomenon