Intel Reference Board doesn't work after inserting INT 15h/86h into Flat32.asm

[Toan Le manh]

Hello everyone,

I'm so sorry if this question does not really relate to Coreboot. But I'm
facing a serious problem and trying to get help from you who have excellent
knowledge about BIOS and HW.

I have an Intel Reference Board. I was trying to force BIOS to wait 1
second in SEC phase.
I inserted these assemble code (BIOS wait function) into very first of
ProtectedModeEntryPoint in Flat32.asm file:

MOV     CX, 0FH
  MOV     DX, 4240H
  MOV     AH, 86H
  INT     15H

Then, the board stopped working. Status code showed "00".
Even when I re-flashed its original BIOS, it's still not worked.

Could anyone please help me to figure out what's happen here?
I  appreciate your helps.

Thanks & BRs,
Toan