Learn to write a simple OS kernel with keyboard/screen support (2014)

mkeykernel

This is a kernel that can read the characters a-z and 0-9 from the keyboard and print them on screen.

See the repo mkernel which is a minimal kernel that prints a string on the screen. mkeykernel just extends this to include keyboard support.

Blog post

Kernel 201 - Let’s write a Kernel with keyboard and screen support

Build commands

nasm -f elf32 kernel.asm -o kasm.o

gcc -m32 -c kernel.c -o kc.o

ld -m elf_i386 -T link.ld -o kernel kasm.o kc.o

If you get the following error message:

kc.o: In function `idt_init':
kernel.c:(.text+0x129): undefined reference to `__stack_chk_fail'

compile with the -fno-stack-protector option:

gcc -fno-stack-protector -m32 -c kernel.c -o bin/kc.o

Test on emulator

qemu-system-i386 -kernel kernel

Get to boot

GRUB requires your kernel executable to be of the pattern kernel-<version> .

So, rename the kernel:

mv kernel kernel-701

Copy it to your boot partition (assuming you are superuser):

cp kernel-701 /boot/kernel-701

Configure your grub/grub2 similar to what is given in _grub_grub2_config folder of mkernel repo .

Reboot.

Voila!