[99] | 1 | ; Project name : XTIDE Universal BIOS |
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[3] | 2 | ; Description : Functions for accessing DPT data. |
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| 3 | |
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[376] | 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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[3] | 20 | ; Section containing code |
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| 21 | SECTION .text |
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| 22 | |
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[364] | 23 | %ifdef MODULE_ADVANCED_ATA |
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[3] | 24 | ;-------------------------------------------------------------------- |
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[364] | 25 | ; AccessDPT_GetIdeBasePortToBX |
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| 26 | ; Parameters: |
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| 27 | ; DS:DI: Ptr to Disk Parameter Table |
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| 28 | ; Returns: |
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| 29 | ; BX: IDE Base Port Address |
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| 30 | ; Corrupts registers: |
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| 31 | ; Nothing |
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| 32 | ;-------------------------------------------------------------------- |
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| 33 | ALIGN JUMP_ALIGN |
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| 34 | AccessDPT_GetIdeBasePortToBX: |
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| 35 | eMOVZX bx, [di+DPT.bIdevarsOffset] ; CS:BX points to IDEVARS |
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| 36 | mov bx, [cs:bx+IDEVARS.wPort] |
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| 37 | ret |
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| 38 | |
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| 39 | %endif |
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| 40 | |
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| 41 | |
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| 42 | ;-------------------------------------------------------------------- |
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[150] | 43 | ; AccessDPT_GetDriveSelectByteToAL |
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| 44 | ; Parameters: |
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| 45 | ; DS:DI: Ptr to Disk Parameter Table |
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| 46 | ; Returns: |
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| 47 | ; AL: Drive Select Byte |
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| 48 | ; Corrupts registers: |
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| 49 | ; Nothing |
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| 50 | ;-------------------------------------------------------------------- |
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| 51 | ALIGN JUMP_ALIGN |
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| 52 | AccessDPT_GetDriveSelectByteToAL: |
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| 53 | mov al, [di+DPT.wFlags] |
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| 54 | and al, FLG_DRVNHEAD_LBA | FLG_DRVNHEAD_DRV |
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| 55 | or al, MASK_DRVNHEAD_SET ; Bits set to 1 for old drives |
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| 56 | ret |
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| 57 | |
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| 58 | |
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| 59 | ;-------------------------------------------------------------------- |
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| 60 | ; AccessDPT_GetDeviceControlByteToAL |
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| 61 | ; Parameters: |
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| 62 | ; DS:DI: Ptr to Disk Parameter Table |
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| 63 | ; Returns: |
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| 64 | ; AL: Device Control Byte |
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| 65 | ; Corrupts registers: |
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| 66 | ; Nothing |
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| 67 | ;-------------------------------------------------------------------- |
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| 68 | ALIGN JUMP_ALIGN |
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| 69 | AccessDPT_GetDeviceControlByteToAL: |
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| 70 | xor al, al |
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[158] | 71 | test BYTE [di+DPT.bFlagsLow], FLGL_DPT_ENABLE_IRQ |
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[150] | 72 | jnz SHORT .EnableDeviceIrq |
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| 73 | or al, FLG_DEVCONTROL_nIEN ; Disable IRQ |
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| 74 | .EnableDeviceIrq: |
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| 75 | ret |
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| 76 | |
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[227] | 77 | |
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[150] | 78 | ;-------------------------------------------------------------------- |
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[227] | 79 | ; AccessDPT_GetLCHStoAXBLBH |
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[3] | 80 | ; Parameters: |
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| 81 | ; DS:DI: Ptr to Disk Parameter Table |
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| 82 | ; Returns: |
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[227] | 83 | ; AX: Number of L-CHS cylinders |
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| 84 | ; BL: Number of L-CHS heads |
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| 85 | ; BH: Number of L-CHS sectors per track |
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[3] | 86 | ; Corrupts registers: |
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[227] | 87 | ; CX, DX |
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[3] | 88 | ;-------------------------------------------------------------------- |
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[227] | 89 | AccessDPT_GetLCHStoAXBLBH: |
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| 90 | ; Return LBA-assisted CHS if LBA addressing used |
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[173] | 91 | test BYTE [di+DPT.bFlagsLow], FLG_DRVNHEAD_LBA |
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[227] | 92 | jz SHORT .ConvertPchsToLchs |
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[173] | 93 | |
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[227] | 94 | call AccessDPT_GetLbaSectorCountToBXDXAX |
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[358] | 95 | call LbaAssist_ConvertSectorCountFromBXDXAXtoLbaAssistedCHSinDXAXBLBH |
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| 96 | LIMIT_LBA_CYLINDERS_IN_DXAX_TO_LCHS_CYLINDERS |
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[227] | 97 | ret |
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[173] | 98 | |
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[227] | 99 | .ConvertPchsToLchs: |
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| 100 | mov ax, [di+DPT.wPchsCylinders] |
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| 101 | mov bx, [di+DPT.wPchsHeadsAndSectors] |
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[230] | 102 | ; Fall to AccessDPT_ShiftPCHinAXBLtoLCH |
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[227] | 103 | |
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| 104 | |
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| 105 | ;-------------------------------------------------------------------- |
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| 106 | ; AccessDPT_ShiftPCHinAXBLtoLCH |
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[173] | 107 | ; Parameters: |
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[227] | 108 | ; AX: P-CHS cylinders (1...16383) |
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| 109 | ; BL: P-CHS heads (1...16) |
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[173] | 110 | ; Returns: |
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[227] | 111 | ; AX: Number of L-CHS cylinders (1...1024) |
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| 112 | ; BL: Number of L-CHS heads (1...255) |
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[230] | 113 | ; CX: Number of bits shifted (4 at most) |
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[173] | 114 | ; Corrupts registers: |
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| 115 | ; Nothing |
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| 116 | ;-------------------------------------------------------------------- |
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[227] | 117 | AccessDPT_ShiftPCHinAXBLtoLCH: |
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[173] | 118 | xor cx, cx |
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| 119 | .ShiftLoop: |
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[227] | 120 | cmp ax, MAX_LCHS_CYLINDERS ; Need to shift? |
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[231] | 121 | jbe SHORT .Return ; If not, return |
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[173] | 122 | inc cx ; Increment shift count |
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[227] | 123 | shr ax, 1 ; Halve cylinders |
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| 124 | shl bl, 1 ; Double heads |
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[231] | 125 | jnz SHORT .ShiftLoop ; Falls through only on the last (4th) iteration and only if BL was 16 on entry |
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| 126 | dec bl ; DOS doesn't support drives with 256 heads so we limit heads to 255 |
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| 127 | ; We can save a byte here by using DEC BX if we don't care about BH |
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| 128 | .Return: |
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[173] | 129 | ret |
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| 130 | |
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[227] | 131 | |
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[173] | 132 | ;-------------------------------------------------------------------- |
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[230] | 133 | ; AccessDPT_GetLbaSectorCountToBXDXAX |
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| 134 | ; Parameters: |
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| 135 | ; DS:DI: Ptr to Disk Parameter Table |
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| 136 | ; Returns: |
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| 137 | ; BX:DX:AX: 48-bit sector count |
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| 138 | ; Corrupts registers: |
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| 139 | ; Nothing |
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| 140 | ;-------------------------------------------------------------------- |
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| 141 | AccessDPT_GetLbaSectorCountToBXDXAX: |
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| 142 | mov ax, [di+DPT.twLbaSectors] |
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| 143 | mov dx, [di+DPT.twLbaSectors+2] |
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| 144 | mov bx, [di+DPT.twLbaSectors+4] |
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| 145 | ret |
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| 146 | |
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| 147 | |
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| 148 | ;-------------------------------------------------------------------- |
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[3] | 149 | ; Returns pointer to DRVPARAMS for master or slave drive. |
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| 150 | ; |
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| 151 | ; AccessDPT_GetPointerToDRVPARAMStoCSBX |
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| 152 | ; Parameters: |
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| 153 | ; DS:DI: Ptr to Disk Parameter Table |
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| 154 | ; Returns: |
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| 155 | ; CS:BX: Ptr to DRVPARAMS |
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| 156 | ; Corrupts registers: |
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| 157 | ; Nothing |
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| 158 | ;-------------------------------------------------------------------- |
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| 159 | ALIGN JUMP_ALIGN |
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| 160 | AccessDPT_GetPointerToDRVPARAMStoCSBX: |
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[150] | 161 | eMOVZX bx, [di+DPT.bIdevarsOffset] ; CS:BX points to IDEVARS |
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| 162 | add bx, BYTE IDEVARS.drvParamsMaster ; CS:BX points to Master Drive DRVPARAMS |
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[158] | 163 | test BYTE [di+DPT.bFlagsLow], FLGL_DPT_SLAVE |
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[150] | 164 | jz SHORT .ReturnPointerToDRVPARAMS |
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| 165 | add bx, BYTE DRVPARAMS_size ; CS:BX points to Slave Drive DRVPARAMS |
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| 166 | .ReturnPointerToDRVPARAMS: |
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[3] | 167 | ret |
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[200] | 168 | |
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| 169 | ;-------------------------------------------------------------------- |
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| 170 | ; AccessDPT_GetUnshiftedAddressModeToALZF |
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| 171 | ; Parameters: |
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| 172 | ; DS:DI: Ptr to Disk Parameter Table |
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| 173 | ; Returns: |
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[230] | 174 | ; AL: Addressing Mode (L-CHS, P-CHS, LBA28, LBA48) |
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[200] | 175 | ; unshifted (still shifted where it is in bFlagsLow) |
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| 176 | ; ZF: Set based on value in AL |
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| 177 | ; Corrupts registers: |
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| 178 | ; AL |
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| 179 | ;-------------------------------------------------------------------- |
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[230] | 180 | ; |
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| 181 | ; Converted to a macro since only called in two places, and the call/ret overhead |
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[200] | 182 | ; is not worth it for these two instructions (4 bytes total) |
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| 183 | ; |
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| 184 | %macro AccessDPT_GetUnshiftedAddressModeToALZF 0 |
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| 185 | mov al, [di+DPT.bFlagsLow] |
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| 186 | and al, MASKL_DPT_ADDRESSING_MODE |
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| 187 | %endmacro |
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