Simple toy os for x64.

Use cmake to build.

Run with:

qemu-system-x86_64 -no-reboot -display none -serial telnet::4555,server=on -d int \
  -drive if=pflash,format=raw,unit=0,file=OVMF_CODE.fd,readonly=on \
  -drive if=pflash,format=raw,unit=1,file=OVMF_VARS.fd -net none \
  -drive format=raw,file=fat:rw:root

telnet localhost 4555

Project structure:
arch/x86_64/*          bootloader/arch-specific code for x86_64
arch/i386/*            bootloader/arch-specific code for i(3|6)86 (probably broken)
kernel/*               kernel (arch-independent) code
include/*              headers for kernel code