To build

 cd build/x86/
 make


Run with qemu

 qemu -kernel kernel/geekos.exe

or

 qemu -cdrom boot.iso

and to test hard drive recognition create an empty device image,
e.g. `dd if=/dev/zero of=./hda.img bs=512 count=100000` and

 qemu -kernel kernel/geekos.exe -hda hda.img


Make bootable usb-stick

 sudo dd if=boot.iso of=/dev/sdb && sync

and replace `sdb` as needed