[165] | 1 | ; Project name : XTIDE Universal BIOS |
---|
| 2 | ; Description : Functions for address translations. |
---|
| 3 | |
---|
[376] | 4 | ; |
---|
| 5 | ; XTIDE Universal BIOS and Associated Tools |
---|
| 6 | ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2012 by XTIDE Universal BIOS Team. |
---|
| 7 | ; |
---|
| 8 | ; This program is free software; you can redistribute it and/or modify |
---|
| 9 | ; it under the terms of the GNU General Public License as published by |
---|
| 10 | ; the Free Software Foundation; either version 2 of the License, or |
---|
| 11 | ; (at your option) any later version. |
---|
| 12 | ; |
---|
| 13 | ; This program is distributed in the hope that it will be useful, |
---|
| 14 | ; but WITHOUT ANY WARRANTY; without even the implied warranty of |
---|
| 15 | ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
---|
| 16 | ; GNU General Public License for more details. |
---|
| 17 | ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html |
---|
| 18 | ; |
---|
| 19 | |
---|
[165] | 20 | ; Section containing code |
---|
| 21 | SECTION .text |
---|
| 22 | |
---|
| 23 | ;--------------------------------------------------------------------- |
---|
| 24 | ; Address_ExtractLCHSparametersFromOldInt13hAddress |
---|
| 25 | ; Parameters: |
---|
| 26 | ; CH: Cylinder number, bits 7...0 |
---|
| 27 | ; CL: Bits 7...6: Cylinder number bits 9 and 8 |
---|
| 28 | ; Bits 5...0: Sector number |
---|
| 29 | ; DH: Head number |
---|
| 30 | ; Returns: |
---|
| 31 | ; BL: Sector number (1...63) |
---|
| 32 | ; BH: Head number (0...255) |
---|
| 33 | ; CX: Cylinder number (0...1023) |
---|
| 34 | ; Corrupts registers: |
---|
| 35 | ; Nothing |
---|
| 36 | ;-------------------------------------------------------------------- |
---|
[191] | 37 | ALIGN JUMP_ALIGN |
---|
[165] | 38 | Address_ExtractLCHSparametersFromOldInt13hAddress: |
---|
| 39 | mov bl, cl ; Copy sector number... |
---|
| 40 | and bl, 3Fh ; ...and limit to 1...63 |
---|
| 41 | sub cl, bl ; Remove from cylinder number high |
---|
| 42 | eROL_IM cl, 2 ; High bits to beginning |
---|
| 43 | mov bh, dh ; Copy Head number |
---|
| 44 | xchg cl, ch ; Cylinder number now in CX |
---|
| 45 | ret |
---|
| 46 | |
---|
| 47 | |
---|
| 48 | ;--------------------------------------------------------------------- |
---|
| 49 | ; Converts LCHS parameters to IDE P-CHS parameters. |
---|
| 50 | ; PCylinder = (LCylinder << n) + (LHead / PHeadCount) |
---|
| 51 | ; PHead = LHead % PHeadCount |
---|
| 52 | ; PSector = LSector |
---|
| 53 | ; |
---|
| 54 | ; Address_ConvertLCHStoPCHS: |
---|
| 55 | ; Parameters: |
---|
| 56 | ; BL: Sector number (1...63) |
---|
| 57 | ; BH: Head number (0...255) |
---|
| 58 | ; CX: Cylinder number (0...1023) |
---|
| 59 | ; DS:DI: Ptr to Disk Parameter Table |
---|
| 60 | ; Returns: |
---|
| 61 | ; BL: Sector number (1...63) |
---|
| 62 | ; BH: Head number (0...15) |
---|
| 63 | ; CX: Cylinder number (0...16382) |
---|
| 64 | ; Corrupts registers: |
---|
| 65 | ; AX, DX |
---|
| 66 | ;-------------------------------------------------------------------- |
---|
| 67 | ALIGN JUMP_ALIGN |
---|
| 68 | ConvertLCHStoPCHS: |
---|
| 69 | ; LHead / PHeadCount and LHead % PHeadCount |
---|
| 70 | eMOVZX ax, bh ; Copy L-CHS Head number to AX |
---|
[227] | 71 | div BYTE [di+DPT.bPchsHeads]; AL = LHead / PHeadCount, AH = LHead % PHeadCount |
---|
[165] | 72 | mov bh, ah ; Copy P-CHS Head number to BH |
---|
| 73 | xor ah, ah ; AX = LHead / PHeadCount |
---|
| 74 | |
---|
| 75 | ; (LCylinder << n) + (LHead / PHeadCount) |
---|
| 76 | mov dx, cx ; Copy L-CHS Cylinder number to DX |
---|
| 77 | mov cl, [di+DPT.bFlagsLow] ; Load shift count |
---|
| 78 | and cl, MASKL_DPT_CHS_SHIFT_COUNT |
---|
| 79 | shl dx, cl ; DX = LCylinder << n |
---|
| 80 | add ax, dx ; AX = P-CHS Cylinder number |
---|
| 81 | xchg cx, ax ; Move P-CHS Cylinder number to CX |
---|
| 82 | DoNotConvertLCHS: |
---|
| 83 | ret |
---|
| 84 | |
---|
[191] | 85 | ;-------------------------------------------------------------------- |
---|
| 86 | ; Address_OldInt13hAddressToIdeAddress |
---|
| 87 | ; Parameters: |
---|
| 88 | ; CH: Cylinder number, bits 7...0 |
---|
| 89 | ; CL: Bits 7...6: Cylinder number bits 9 and 8 |
---|
| 90 | ; Bits 5...0: Starting sector number (1...63) |
---|
| 91 | ; DH: Starting head number (0...255) |
---|
| 92 | ; DS:DI: Ptr to DPT |
---|
| 93 | ; Returns: |
---|
| 94 | ; BL: LBA Low Register / Sector Number Register (LBA 7...0) |
---|
| 95 | ; CL: LBA Mid Register / Low Cylinder Register (LBA 15...8) |
---|
| 96 | ; CH: LBA High Register / High Cylinder Register (LBA 23...16) |
---|
| 97 | ; BH: Drive and Head Register (LBA 27...24) |
---|
| 98 | ; Corrupts registers: |
---|
| 99 | ; AX, DX |
---|
| 100 | ;-------------------------------------------------------------------- |
---|
| 101 | ALIGN JUMP_ALIGN |
---|
| 102 | Address_OldInt13hAddressToIdeAddress: |
---|
[194] | 103 | call Address_ExtractLCHSparametersFromOldInt13hAddress |
---|
[230] | 104 | |
---|
[200] | 105 | AccessDPT_GetUnshiftedAddressModeToALZF |
---|
[230] | 106 | |
---|
| 107 | ;;; 0: ADDR_DPT_LCHS |
---|
| 108 | jz DoNotConvertLCHS |
---|
| 109 | |
---|
[194] | 110 | ;;; 1: ADDR_DPT_PCHS |
---|
[230] | 111 | ; |
---|
[194] | 112 | ; Since we are only checking for zero, we can do our math in the high order bits, |
---|
| 113 | ; in this case effectively subtracting 1 from the address mode. |
---|
| 114 | ; |
---|
| 115 | sub al,(1<<ADDRESSING_MODE_FIELD_POSITION) |
---|
[230] | 116 | jz ConvertLCHStoPCHS |
---|
[194] | 117 | |
---|
[230] | 118 | ;;; 2: ADDR_DPT_LBA28 and 3: ADDR_DPT_LBA48 |
---|
| 119 | ; Fall through to ConvertLCHStoLBARegisterValues |
---|
| 120 | |
---|
[165] | 121 | ;--------------------------------------------------------------------- |
---|
| 122 | ; Converts LCHS parameters to 28-bit LBA address. |
---|
| 123 | ; Only 24-bits are used since LHCS to LBA28 conversion has 8.4GB limit. |
---|
| 124 | ; LBA = ((cylToSeek*headsPerCyl+headToSeek)*sectPerTrack)+sectToSeek-1 |
---|
| 125 | ; |
---|
| 126 | ; Returned address is in same registers that |
---|
| 127 | ; Address_DoNotConvertLCHS and Address_ConvertLCHStoPCHS returns. |
---|
| 128 | ; |
---|
| 129 | ; ConvertLCHStoLBARegisterValues: |
---|
| 130 | ; Parameters: |
---|
| 131 | ; BL: Sector number (1...63) |
---|
| 132 | ; BH: Head number (0...255) |
---|
| 133 | ; CX: Cylinder number (0...1023) |
---|
| 134 | ; DS:DI: Ptr to Disk Parameter Table |
---|
| 135 | ; Returns: |
---|
| 136 | ; BL: LBA Low Register / Sector Number Register (LBA 7...0) |
---|
| 137 | ; CL: LBA Mid Register / Low Cylinder Register (LBA 15...8) |
---|
| 138 | ; CH: LBA High Register / High Cylinder Register (LBA 23...16) |
---|
| 139 | ; BH: Drive and Head Register (LBA 27...24) |
---|
| 140 | ; Corrupts registers: |
---|
| 141 | ; AX, DX |
---|
| 142 | ;-------------------------------------------------------------------- |
---|
| 143 | ALIGN JUMP_ALIGN |
---|
| 144 | ConvertLCHStoLBARegisterValues: |
---|
| 145 | ; cylToSeek*headsPerCyl (18-bit result) |
---|
[294] | 146 | mov ax, LBA_ASSIST_SPT ; Load Sectors per Track |
---|
| 147 | xchg cx, ax ; Cylinder number to AX, Sectors per Track to CX |
---|
[230] | 148 | |
---|
[294] | 149 | %ifdef USE_386 |
---|
| 150 | movzx dx, [di+DPT.bLbaHeads] |
---|
| 151 | %else |
---|
| 152 | cwd |
---|
| 153 | mov dl, [di+DPT.bLbaHeads] |
---|
| 154 | %endif |
---|
[165] | 155 | mul dx ; DX:AX = cylToSeek*headsPerCyl |
---|
| 156 | |
---|
| 157 | ; +=headToSeek (18-bit result) |
---|
| 158 | add al, bh ; Add Head number to DX:AX |
---|
| 159 | adc ah, dh ; DH = Zero after previous multiplication |
---|
| 160 | adc dl, dh |
---|
| 161 | |
---|
| 162 | ; *=sectPerTrack (18-bit by 6-bit multiplication with 24-bit result) |
---|
| 163 | xchg ax, dx ; Hiword to AX, loword to DX |
---|
| 164 | mul cl ; AX = hiword * Sectors per Track |
---|
| 165 | mov bh, al ; Backup hiword * Sectors per Track |
---|
| 166 | xchg ax, dx ; Loword back to AX |
---|
| 167 | mul cx ; DX:AX = loword * Sectors per Track |
---|
| 168 | add dl, bh ; DX:AX = (cylToSeek*headsPerCyl+headToSeek)*sectPerTrack |
---|
| 169 | |
---|
| 170 | ; +=sectToSeek-1 (24-bit result) |
---|
| 171 | xor bh, bh ; Sector number now in BX |
---|
| 172 | dec bx ; sectToSeek-=1 |
---|
| 173 | add ax, bx ; Add to loword |
---|
| 174 | adc dl, bh ; Add possible carry to byte2, BH=zero |
---|
| 175 | |
---|
| 176 | ; Copy DX:AX to proper return registers |
---|
| 177 | xchg bx, ax ; BL = Sector Number Register (LBA 7...0) |
---|
| 178 | mov cl, bh ; Low Cylinder Register (LBA 15...8) |
---|
| 179 | mov ch, dl ; High Cylinder Register (LBA 23...16) |
---|
| 180 | mov bh, dh ; Drive and Head Register (LBA 27...24) |
---|
| 181 | ret |
---|