| 1 | ; $Id: bs3-cmn-A20Enable.asm 82968 2020-02-04 10:35:17Z vboxsync $
|
|---|
| 2 | ;; @file
|
|---|
| 3 | ; BS3Kit - Bs3A20Enable.
|
|---|
| 4 | ;
|
|---|
| 5 |
|
|---|
| 6 | ;
|
|---|
| 7 | ; Copyright (C) 2007-2020 Oracle Corporation
|
|---|
| 8 | ;
|
|---|
| 9 | ; This file is part of VirtualBox Open Source Edition (OSE), as
|
|---|
| 10 | ; available from http://www.virtualbox.org. This file is free software;
|
|---|
| 11 | ; you can redistribute it and/or modify it under the terms of the GNU
|
|---|
| 12 | ; General Public License (GPL) as published by the Free Software
|
|---|
| 13 | ; Foundation, in version 2 as it comes in the "COPYING" file of the
|
|---|
| 14 | ; VirtualBox OSE distribution. VirtualBox OSE is distributed in the
|
|---|
| 15 | ; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
|
|---|
| 16 | ;
|
|---|
| 17 | ; The contents of this file may alternatively be used under the terms
|
|---|
| 18 | ; of the Common Development and Distribution License Version 1.0
|
|---|
| 19 | ; (CDDL) only, as it comes in the "COPYING.CDDL" file of the
|
|---|
| 20 | ; VirtualBox OSE distribution, in which case the provisions of the
|
|---|
| 21 | ; CDDL are applicable instead of those of the GPL.
|
|---|
| 22 | ;
|
|---|
| 23 | ; You may elect to license modified versions of this file under the
|
|---|
| 24 | ; terms and conditions of either the GPL or the CDDL or both.
|
|---|
| 25 | ;
|
|---|
| 26 |
|
|---|
| 27 | %include "bs3kit-template-header.mac"
|
|---|
| 28 |
|
|---|
| 29 |
|
|---|
| 30 | BS3_EXTERN_CMN Bs3KbdWait
|
|---|
| 31 | BS3_EXTERN_CMN Bs3KbdRead
|
|---|
| 32 | BS3_EXTERN_CMN Bs3KbdWrite
|
|---|
| 33 |
|
|---|
| 34 |
|
|---|
| 35 | ;;
|
|---|
| 36 | ; Enables the A20 gate.
|
|---|
| 37 | ;
|
|---|
| 38 | ; @uses Nothing.
|
|---|
| 39 | ;
|
|---|
| 40 | BS3_PROC_BEGIN_CMN Bs3A20Enable, BS3_PBC_HYBRID_0_ARGS
|
|---|
| 41 | push xBP
|
|---|
| 42 | mov xBP, xSP
|
|---|
| 43 | BONLY64 sub rsp, 20h
|
|---|
| 44 |
|
|---|
| 45 | call BS3_CMN_NM(Bs3A20EnableViaPortA)
|
|---|
| 46 | ;; @todo real 286 support
|
|---|
| 47 | ; call BS3_CMN_NM(Bs3A20EnableViaKbd)
|
|---|
| 48 |
|
|---|
| 49 | pop xBP
|
|---|
| 50 | BS3_HYBRID_RET
|
|---|
| 51 | BS3_PROC_END_CMN Bs3A20Enable
|
|---|
| 52 |
|
|---|
| 53 |
|
|---|
| 54 | ;;
|
|---|
| 55 | ; Enables the A20 gate via the keyboard controller.
|
|---|
| 56 | ;
|
|---|
| 57 | ; @uses Nothing.
|
|---|
| 58 | ;
|
|---|
| 59 | BS3_PROC_BEGIN_CMN Bs3A20EnableViaKbd, BS3_PBC_HYBRID_0_ARGS
|
|---|
| 60 | push xBP
|
|---|
| 61 | mov xBP, xSP
|
|---|
| 62 | push xAX
|
|---|
| 63 | pushf
|
|---|
| 64 | cli
|
|---|
| 65 | BONLY64 sub rsp, 20h
|
|---|
| 66 |
|
|---|
| 67 | call Bs3KbdWait
|
|---|
| 68 | push 0d0h ; KBD_CCMD_READ_OUTPORT
|
|---|
| 69 | call Bs3KbdRead
|
|---|
| 70 |
|
|---|
| 71 | or al, 002h
|
|---|
| 72 | push xAX
|
|---|
| 73 | push 0d1h ; KBD_CCMD_WRITE_OUTPORT
|
|---|
| 74 | call Bs3KbdWrite
|
|---|
| 75 |
|
|---|
| 76 | add xSP, xCB*3 ; both the above calls
|
|---|
| 77 |
|
|---|
| 78 | mov al, 0ffh ; KBD_CMD_RESET
|
|---|
| 79 | out 64h, al
|
|---|
| 80 | call Bs3KbdWait
|
|---|
| 81 |
|
|---|
| 82 | BONLY64 add rsp, 20h
|
|---|
| 83 | popf
|
|---|
| 84 | pop xAX
|
|---|
| 85 | pop xBP
|
|---|
| 86 | BS3_HYBRID_RET
|
|---|
| 87 | BS3_PROC_END_CMN Bs3A20EnableViaKbd
|
|---|
| 88 |
|
|---|
| 89 |
|
|---|
| 90 | ;;
|
|---|
| 91 | ; Enables the A20 gate via control port A (PS/2 style).
|
|---|
| 92 | ;
|
|---|
| 93 | ; @uses Nothing.
|
|---|
| 94 | ;
|
|---|
| 95 | BS3_PROC_BEGIN_CMN Bs3A20EnableViaPortA, BS3_PBC_HYBRID_0_ARGS
|
|---|
| 96 | push xBP
|
|---|
| 97 | mov xBP, xSP
|
|---|
| 98 | push xAX
|
|---|
| 99 |
|
|---|
| 100 | ; Use Control port A, assuming a PS/2 style system.
|
|---|
| 101 | in al, 092h
|
|---|
| 102 | test al, 02h
|
|---|
| 103 | jnz .done ; avoid trouble writing back the same value.
|
|---|
| 104 | or al, 2 ; enable the A20 gate.
|
|---|
| 105 | out 092h, al
|
|---|
| 106 |
|
|---|
| 107 | .done:
|
|---|
| 108 | pop xAX
|
|---|
| 109 | pop xBP
|
|---|
| 110 | BS3_HYBRID_RET
|
|---|
| 111 | BS3_PROC_END_CMN Bs3A20EnableViaPortA
|
|---|
| 112 |
|
|---|
