- PS/2 answers with ERROR if PS/2 mouse is not connected,
  read_ack should handle error cases correctly. We should
  also probe correctly for the mouse. (0xFE on all commands)
- optimizing the code move the kernel entry 'kernel_main'
  away from it's expected location at 0x8800. How can we pin
  it there? And not use ELF. :-)
- bochs shows us distorted text console output, why?
- printf/puts should they wipe the line to the end as we can see
  old characters (e.g. BIOS messages) behind our own messages?
  Also clear screen is not really a good idea, as we cannot see,
  what was there before
- bootloader has trouble detecting drive geometry of hard disks,
  only the floppy mode works reliably at the moment (in emulators
  and on real machines)