[41] | 1 | ; Project name : Assembly Library |
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| 2 | ; Description : DOS Critical Error Handler (24h) replacements. |
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| 3 | |
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[376] | 4 | ; |
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[526] | 5 | ; XTIDE Universal BIOS and Associated Tools |
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| 6 | ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team. |
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[376] | 7 | ; |
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| 8 | ; This program is free software; you can redistribute it and/or modify |
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| 9 | ; it under the terms of the GNU General Public License as published by |
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| 10 | ; the Free Software Foundation; either version 2 of the License, or |
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| 11 | ; (at your option) any later version. |
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[526] | 12 | ; |
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[376] | 13 | ; This program is distributed in the hope that it will be useful, |
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| 14 | ; but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 15 | ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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[526] | 16 | ; GNU General Public License for more details. |
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[376] | 17 | ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html |
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| 18 | ; |
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| 19 | |
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[592] | 20 | ; Note! Only DOS functions 01h - 0Ch, 30h and 59h can be called from a Critical Error Handler. |
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[526] | 21 | |
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[41] | 22 | ; DOS Critical Error Handler return values |
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| 23 | struc CRITICAL_ERROR_ACTION |
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| 24 | .ignoreErrorAndContinueProcessingRequest resb 1 |
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| 25 | .retryOperation resb 1 |
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| 26 | .terminateProgramAsThoughInt21hAH4ChCalled resb 1 |
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[592] | 27 | .failSystemCallInProgress resb 1 ; Needs DOS 3.1+ |
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[41] | 28 | endstruc |
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| 29 | |
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| 30 | |
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| 31 | ; Section containing code |
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| 32 | SECTION .text |
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| 33 | |
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| 34 | ;-------------------------------------------------------------------- |
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| 35 | ; DosCritical_InstallNewHandlerFromCSDX |
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| 36 | ; Parameters: |
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| 37 | ; CS:DX: New Critical Error Handler |
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| 38 | ; Returns: |
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| 39 | ; Nothing |
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| 40 | ; Corrupts registers: |
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| 41 | ; AX |
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| 42 | ;-------------------------------------------------------------------- |
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| 43 | ALIGN JUMP_ALIGN |
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| 44 | DosCritical_InstallNewHandlerFromCSDX: |
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| 45 | push ds |
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| 46 | |
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[593] | 47 | mov al, DOS_CRITICAL_ERROR_HANDLER_24h |
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| 48 | call HookInterruptVectorInALwithHandlerInCSDX |
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[41] | 49 | |
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| 50 | pop ds |
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| 51 | ret |
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| 52 | |
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| 53 | |
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| 54 | ;-------------------------------------------------------------------- |
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| 55 | ; DosCritical_RestoreDosHandler |
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| 56 | ; Parameters: |
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| 57 | ; Nothing |
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| 58 | ; Returns: |
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| 59 | ; Nothing |
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| 60 | ; Corrupts registers: |
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| 61 | ; Nothing |
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| 62 | ;-------------------------------------------------------------------- |
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| 63 | ALIGN JUMP_ALIGN |
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| 64 | DosCritical_RestoreDosHandler: |
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| 65 | push ds |
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| 66 | push dx |
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| 67 | push ax |
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| 68 | |
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| 69 | lds dx, [cs:PSP.fpInt24hCriticalError] |
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| 70 | mov ax, (SET_INTERRUPT_VECTOR<<8) | DOS_CRITICAL_ERROR_HANDLER_24h |
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| 71 | int DOS_INTERRUPT_21h |
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| 72 | |
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| 73 | pop ax |
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| 74 | pop dx |
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| 75 | pop ds |
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| 76 | ret |
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| 77 | |
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| 78 | |
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| 79 | ;-------------------------------------------------------------------- |
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[592] | 80 | ; DosCritical_CustomHandler |
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| 81 | ; Parameters: |
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| 82 | ; Nothing |
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| 83 | ; Returns: |
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| 84 | ; Nothing |
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| 85 | ; Corrupts registers: |
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| 86 | ; Nothing |
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| 87 | ;-------------------------------------------------------------------- |
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| 88 | ALIGN JUMP_ALIGN |
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| 89 | DosCritical_CustomHandler: |
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| 90 | add sp, 6 ; Remove the INT 24h return address and flags from stack |
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| 91 | |
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| 92 | mov ah, GET_EXTENDED_ERROR_INFORMATION ; Requires DOS 3.0+ |
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| 93 | xor bx, bx |
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| 94 | int DOS_INTERRUPT_21h |
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| 95 | mov [cs:bLastCriticalError], al |
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| 96 | |
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| 97 | pop ax |
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| 98 | pop bx |
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| 99 | pop cx |
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| 100 | pop dx |
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| 101 | pop si |
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| 102 | pop di |
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| 103 | pop bp |
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| 104 | pop ds |
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| 105 | pop es |
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| 106 | iret ; Return from the INT 21h call |
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| 107 | |
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| 108 | bLastCriticalError: db 0 |
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| 109 | |
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| 110 | |
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| 111 | ;-------------------------------------------------------------------- |
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[41] | 112 | ; DosCritical_HandlerToIgnoreAllErrors |
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| 113 | ; Parameters: |
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| 114 | ; Nothing |
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| 115 | ; Returns: |
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| 116 | ; AL: CRITICAL_ERROR_ACTION |
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| 117 | ; Corrupts registers: |
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| 118 | ; Nothing |
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[526] | 119 | ;-------------------------------------------------------------------- |
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[41] | 120 | ALIGN JUMP_ALIGN |
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| 121 | DosCritical_HandlerToIgnoreAllErrors: |
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| 122 | mov al, CRITICAL_ERROR_ACTION.ignoreErrorAndContinueProcessingRequest |
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| 123 | iret |
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[592] | 124 | |
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