| ;; $Id$ |
| ;; ----------------------------------------------------------------------- |
| ;; |
| ;; Copyright 1994-2002 H. Peter Anvin - All Rights Reserved |
| ;; |
| ;; This program is free software; you can redistribute it and/or modify |
| ;; it under the terms of the GNU General Public License as published by |
| ;; the Free Software Foundation, Inc., 53 Temple Place Ste 330, |
| ;; Bostom MA 02111-1307, USA; either version 2 of the License, or |
| ;; (at your option) any later version; incorporated herein by reference. |
| ;; |
| ;; ----------------------------------------------------------------------- |
| |
| ;; |
| ;; cpuinit.inc |
| ;; |
| ;; CPU-dependent initialization and related checks. |
| ;; |
| |
| check_escapes: |
| mov ah,02h ; Check keyboard flags |
| int 16h |
| mov [KbdFlags],al ; Save for boot prompt check |
| test al,04h ; Ctrl->skip 386 check |
| jnz skip_checks |
| |
| ; |
| ; Now check that there is sufficient low (DOS) memory |
| ; |
| int 12h |
| cmp ax,(real_mode_seg+0xa00) >> 6 |
| jae enough_ram |
| mov si,err_noram |
| call writestr |
| jmp kaboom |
| enough_ram: |
| skip_checks: |
| |
| ; |
| ; Check if we're 386 (as opposed to 486+); if so we need to blank out |
| ; the WBINVD instruction |
| ; |
| ; We check for 486 by setting EFLAGS.AC |
| ; |
| %if DO_WBINVD |
| pushfd ; Save the good flags |
| pushfd |
| pop eax |
| mov ebx,eax |
| xor eax,(1 << 18) ; AC bit |
| push eax |
| popfd |
| pushfd |
| pop eax |
| popfd ; Restore the original flags |
| xor eax,ebx |
| jnz is_486 |
| ; |
| ; 386 - Looks like we better blot out the WBINVD instruction |
| ; |
| mov byte [try_wbinvd],0c3h ; Near RET |
| is_486: |
| %endif ; DO_WBINVD |
| ; |
| ; Mark A20 type as unknown. This particular word needs to be in BSS, |
| ; so it needs to be initialized. |
| ; |
| mov word [A20Type],0 |
| |
| |