Start

In order to compile we will have to use the 32-bit format, Commands:

Compile the source files in 32-bit mode

gcc -m32 -ffreestanding -fno-stack-protector -c init/main.c -o init/main.o gcc -m32 -ffreestanding -fno-stack-protector -c drivers/video/vga.c -o drivers/video/vga.o gcc -m32 -ffreestanding -fno-stack-protector -c drivers/keyboard/kb.c -o drivers/keyboard/kb.o gcc -m32 -ffreestanding -fno-stack-protector -c drivers/shell/shell.c -o drivers/shell/shell.o gcc -m32 -ffreestanding -fno-stack-protector -c lib/string.c -o lib/string.o gcc -m32 -ffreestanding -fno-stack-protector -c sys/syscall/syscall.c -o sys/syscall/syscall.o

Link the object files

ld -m elf_i386 -T linker.ld -o kernel.elf init/main.o drivers/video/vga.o drivers/keyboard/kb.o drivers/shell/shell.o lib/string.o sys/syscall/syscall.o

Optionally, create a raw binary

objcopy -O binary kernel.elf kernel.bin

Copy kernel over to grub

mkdir -p isodir/boot/grub cp kernel.elf isodir/boot/kernel.elf

Make grub.cfg isodir/boot/grub

menuentry "Bunix" { multiboot /boot/kernel.elf }

Create ISO

grub-mkrescue -o bunix.iso isodir

Finally run the ISO

qemu-system-x86_64 -cdrom bunix.iso