| 1 | ; Project name : XTIDE Universal BIOS |
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| 2 | ; Description : Functions for swapping drive letters. |
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| 3 | |
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| 4 | ; |
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| 5 | ; XTIDE Universal BIOS and Associated Tools |
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| 6 | ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2012 by XTIDE Universal BIOS Team. |
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| 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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| 12 | ; |
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| 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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| 16 | ; GNU General Public License for more details. |
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| 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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| 20 | ; Section containing code |
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| 21 | SECTION .text |
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| 22 | |
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| 23 | ;-------------------------------------------------------------------- |
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| 24 | ; DriveXlate_ToOrBack |
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| 25 | ; Parameters: |
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| 26 | ; DL: Drive number to be possibly translated |
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| 27 | ; DS: RAMVARS segment |
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| 28 | ; Returns: |
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| 29 | ; DL: Translated drive number |
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| 30 | ; Corrupts registers: |
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| 31 | ; DI |
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| 32 | ;-------------------------------------------------------------------- |
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| 33 | ALIGN JUMP_ALIGN |
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| 34 | DriveXlate_ToOrBack: |
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| 35 | xchg di, ax ; Backup AX |
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| 36 | |
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| 37 | mov ah, 80h ; Assume hard disk |
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| 38 | mov al, [RAMVARS.xlateVars+XLATEVARS.bHDSwap] |
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| 39 | test dl, ah ; Hard disk? |
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| 40 | jnz SHORT .SwapDrive ; If so, jump to swap |
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| 41 | mov al, [RAMVARS.xlateVars+XLATEVARS.bFDSwap] |
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| 42 | cbw |
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| 43 | |
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| 44 | ALIGN JUMP_ALIGN |
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| 45 | .SwapDrive: |
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| 46 | cmp ah, dl ; Swap DL from 00h/80h to xxh? |
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| 47 | je SHORT .SwapToXXhInAL |
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| 48 | cmp al, dl ; Swap DL from xxh to 00h/80h? |
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| 49 | jne SHORT .RestoreAXandReturn |
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| 50 | mov al, ah |
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| 51 | ALIGN JUMP_ALIGN |
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| 52 | .SwapToXXhInAL: |
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| 53 | mov dl, al |
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| 54 | ALIGN JUMP_ALIGN |
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| 55 | .RestoreAXandReturn: |
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| 56 | xchg ax, di ; Restore AX |
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| 57 | ret |
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| 58 | |
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| 59 | |
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| 60 | ;-------------------------------------------------------------------- |
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| 61 | ; Resets drive swapping variables to defaults (no swapping). |
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| 62 | ; |
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| 63 | ; DriveXlate_Reset |
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| 64 | ; Parameters: |
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| 65 | ; DS: RAMVARS segment |
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| 66 | ; Returns: |
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| 67 | ; Nothing |
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| 68 | ; Corrupts registers: |
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| 69 | ; Nothing |
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| 70 | ;-------------------------------------------------------------------- |
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| 71 | DriveXlate_Reset: |
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| 72 | mov WORD [RAMVARS.xlateVars+XLATEVARS.wFDandHDswap], 8000h |
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| 73 | ret |
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| 74 | |
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| 75 | |
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| 76 | ;-------------------------------------------------------------------- |
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| 77 | ; Stores drive to be swapped. |
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| 78 | ; |
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| 79 | ; DriveXlate_SetDriveToSwap |
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| 80 | ; Parameters: |
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| 81 | ; DL: Drive to swap to 00h or 80h |
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| 82 | ; DS: RAMVARS segment |
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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 | DriveXlate_SetDriveToSwap: |
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| 89 | test dl, dl ; Floppy drive? |
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| 90 | js SHORT .SetHardDriveToSwap |
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| 91 | |
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| 92 | ; Set Floppy Drive to swap |
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| 93 | mov [RAMVARS.xlateVars+XLATEVARS.bFDSwap], dl |
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| 94 | ret |
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| 95 | |
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| 96 | .SetHardDriveToSwap: |
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| 97 | mov [RAMVARS.xlateVars+XLATEVARS.bHDSwap], dl |
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| 98 | ret |
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