i’m currently exploring MINIX and OS development and i need a room to put my thoughts notes whatever the fuck

main resources

books

explains OS design using minix as example - Operating Systems - Design and Implementation
i think this is more generic modern OS introspection but still looks good - Modern Operating Systems

websites

osdev

bootstrapping a minimal kernel - https://wiki.osdev.org/Bare_Bones
setting up a cross compiler - https://wiki.osdev.org/GCC_Cross-Compiler

making an os in rust blog

https://os.phil-opp.com/

OSes to study

MINIX

Microkernel written in C that separates kernel functionality into processes and sends messages between different layers of the OS. — repo: https://github.com/Stichting-MINIX-Research-Foundation/minix

The companion book, Operating Systems - Design and Implementation, is recommended reading.
- If you want to follow along with the book, switch to tag v3.1.0, but the latest release is much easier to rebuild and is compatible with more modern software to use as a base. It definitely beats looking at the source code in the book.
Follow the instructions here to compile: https://wiki.minix3.org/doku.php?id=developersguide:crosscompiling
Patches to apply to MINIX master branch so it compiles with gcc-10+: https://github.com/Stichting-MINIX-Research-Foundation/minix/pull/322
Fork of MINIX that compiles on M1 macOS using Docker: https://github.com/lincdog/minix

Compiling without rebuilding the whole system

I’m pretty sure that this actually doesn’t even work…

alias minix-nbmake=$(git rev-parse --show-toplevel)/../obj.i386/tooldir.xyz/bin/nbmake-i386
alias minix-img=CREATE_IMAGE_ONLY=1 $(git rev-parse --show-toplevel)/releasetools/x86_cdimage.sh
# do this inside of the directory you want to recompile, they usually have a Makefile to recompile
minix-nbmake && minix-nbmake install
# create the image
minix-img

Linux

Monolithic kernel written in C. I think most people know this one — repo: https://github.com/torvalds/linux

A study on the scheduler for Linux 2.6.8.1: https://web.archive.org/web/20070627191326/http://josh.trancesoftware.com/linux/linux_cpu_scheduler.pdf

Serenity

OS with a monolithic kernel written in C++ with a huge monorepo of different utilities. The window system, audio, image rendering, are all seperated into different ‘process servers.’ This description is most likely incorrect and begs for revision. — repo: https://github.com/SerenityOS/serenity

The creator’s YouTube channel, really informative and entertaining for something to watch when bored: https://www.youtube.com/c/AndreasKling/videos
- I recommend sorting by oldest to see base parts being developed
- I also recommend looking for videos with the title of Code Tour but some of the older implementation videos are also interesting

notes

TODO: scheduling

notes for cross compilation with clang / llvm

this assumes that you have a base from the OSdev Bare Bones OS. i just do this because clang is more convenient to use on macOS

CFLAGS for clang: --target=i686-elf -march=i686 -nostdlib -fno-builtin -ffreestanding

clang --target=i686-elf -march=i686 -nostdlib -fno-builtin -ffreestanding -c kernel.c -o kernel.o

remove BLOCK from linker.ld, ALIGN performs basically the same with the LLVM linker. also don’t remove the :s from the file
invoke the LLVM linker like so:
```
ld.lld -T path-to-linker.ld -o output.bin list-of-object-files.o
```
if this needs better explanation, please advise