cowos

Custom OS from scratch in C

Migrated from Rekketstone/cowos

Notes

This only supports 32bit for now, please DO NOT compile with 64bit or it'll fail to boot

compilation of any component

You are required to get your own cross C compiler. This is because normal C compilers for your Linux distro (assuming that you are on Linux) will optimize against your own libs and other things. This OS doesn't exist yet, so this is a big no no in OS development. Another thing is that you want to compile for 32 bit, so you'll need to cross compile anyways...

general c files

i386-elf-gcc -c kernel.c -o kernel.o -std=c99 -ffreestanding -O2 -Wall -Wextra # i386 is the 32 bit version of x86
# also please compile with the -Iinclude flag to include the libraries like string.h in the arch

"compiling" the "boot stub"

i386-elf-as boot.s -o boot.o

linking the "compiled" boot stub w/compiled kernel img

i386-elf-gcc -T linker.ld -o cowos.bin -ffreestanding -O2 -nostdlib boot.o kernel.o

Getting it bootable

You'll need grub and mtools. First move the compiled cowos.bin to isodir/boot. Then run the following command:

grub-mkrescue isodir/ -o cowos.iso

Now you can enjoy running this in qemu lol.

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