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.
The BSD book does seem interesting from a historical perspective, BSD is one of Ye Olden UN*X distros after all. Thanks for the recommendations! I think I’ll try to get my hands on a dead trees version of the BSD book.
Oh and did you specifically mean “The Design and Implementation of the 4.4BSD Operating System”? Looks like there’s one for FreeBSD as well
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