8042(keyboard controller) and keyboard initialization procedure

mov al,0xaa      ;; 8042 self test
call write_64
call real_60
cmp al,0x55
jne fail

mov al,0x60      ;; Enable keyboard interface
call write_64    ;; Enable IRQ1
mov al,0x61
call write_60

mov al,0xff      ;; Reset keyboard and self test
call write_60
call read_60
cmp al,0xfa
jne fail
call read_60
cmp al,0xaa
jne fail

----------------------------------------------------------------------

write_64:
   out 0x64,al
@@:
   in al,0x64
   test al,0x02
   jnz @B
   ret

read_60:
@@:
   in al,0x64
   test al,0x01
   jz @B
   in al,0x60
   ret

write_60:
   out 0x60,al
   in  al,0x64
   test al,0x02
   jnz @B
   ret