Kernel code, made with Crystal
This is just a proof of concept, it doesn't actually do anything aside from booting.
Run with make run to build a kernel.elf and execute it in QEMU.
You can also do make iso to produce a ISO image that can boot on real hardware.
As a last option, take the kernel.elf produced, put it in your /boot directory
and change grub configuration to offer it as an option in your boot menu. It works.