i686-os

Toy OS for i686 arch

Usage

make # builds .iso and runs qemu
make clean build # builds .iso
make clean build run_debug # builds .iso and runs qemu with gdb stub

Features

• Multiboot 2 compliant
• Graphics mode (VESA)
• Flat memory model

Hardware requirements

• Should support graphics mode and linear framebuffer

Useful debugging cmds

objdump -D kernel.o -M intel
objdump -s kernel.o -M intel
readelf -W -s kernel.o		// -W tells not to truncate names
g++ -O0
g++ -S -masm=intel -o kernel.asm

Other useful stuff

• QEMU framebuffer address 0xFD000000 (https://wiki.osdev.org/Drawing_In_Protected_Mode)
• Writing to a USB flash drive sudo dd if=myos.iso of=/dev/sdx && sync
• https://gitlab.indel.ch/thirdparty/gcc/commit/5ed3cc7b66af4758f7849ed6f65f4365be8223be documentation for __attribute__((interrupt))

TODO

• Change #define to const where appropriate