[drv]

Going down the size optimization rabbit hole a little bit (not criticism, I just enjoy this sort of puzzle).

Two bytes shorter:

  call print_str
  ret
  =>
  jmp print_str

Three bytes shorter; this one may be a little too clever, since it depends on the low bit of CR0 being 0 initially:

  mov EAX, CR0
  or EAX, 1
  =>
  mov EAX, CR0
  inc AX