[41] | 1 | ; Project name : Assembly Library |
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| 2 | ; Description : Functions for memory access. |
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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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[41] | 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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[46] | 24 | ; OPTIMIZE_STRING_OPERATION |
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[41] | 25 | ; Parameters |
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[46] | 26 | ; %1: Repeat instruction |
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| 27 | ; %2: String instruction without size (for example MOVS and not MOVSB or MOVSW) |
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| 28 | ; CX: Number of BYTEs to operate |
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| 29 | ; DS:SI: Ptr to source data |
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| 30 | ; ES:DI: Ptr to destination |
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[41] | 31 | ; Returns: |
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[46] | 32 | ; SI, DI: Updated by number of bytes operated |
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| 33 | ; Corrupts registers: |
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[41] | 34 | ; Nothing |
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[46] | 35 | ;-------------------------------------------------------------------- |
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| 36 | %macro OPTIMIZE_STRING_OPERATION 2 |
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| 37 | push cx |
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| 38 | |
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| 39 | shr cx, 1 ; Operate with WORDs for performance |
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[103] | 40 | jz %%HandleRemainingByte |
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[46] | 41 | %1 %2w |
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| 42 | %%HandleRemainingByte: |
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| 43 | jnc SHORT %%OperationCompleted |
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| 44 | %2b |
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| 45 | |
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| 46 | ALIGN JUMP_ALIGN |
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| 47 | %%OperationCompleted: |
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| 48 | pop cx |
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| 49 | %endmacro |
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| 50 | |
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| 51 | |
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| 52 | ;-------------------------------------------------------------------- |
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| 53 | ; Memory_CopyCXbytesFromDSSItoESDI |
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| 54 | ; Parameters |
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| 55 | ; CX: Number of bytes to copy |
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| 56 | ; DS:SI: Ptr to source data |
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| 57 | ; ES:DI: Ptr to destination buffer |
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| 58 | ; Returns: |
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| 59 | ; SI, DI: Updated by number of bytes copied |
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[41] | 60 | ; Corrupts registers: |
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[46] | 61 | ; Nothing |
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[41] | 62 | ;-------------------------------------------------------------------- |
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[131] | 63 | %ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS |
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[41] | 64 | ALIGN JUMP_ALIGN |
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[46] | 65 | Memory_CopyCXbytesFromDSSItoESDI: |
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| 66 | OPTIMIZE_STRING_OPERATION rep, movs |
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| 67 | ret |
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[131] | 68 | %endif |
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[41] | 69 | |
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[46] | 70 | |
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[41] | 71 | ;-------------------------------------------------------------------- |
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[46] | 72 | ; Memory_ZeroSSBPwithSizeInCX |
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[41] | 73 | ; Parameters |
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[46] | 74 | ; CX: Number of bytes to zero |
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[41] | 75 | ; SS:BP: Ptr to buffer to zero |
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| 76 | ; Returns: |
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| 77 | ; Nothing |
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| 78 | ; Corrupts registers: |
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| 79 | ; Nothing |
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| 80 | ;-------------------------------------------------------------------- |
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| 81 | ALIGN JUMP_ALIGN |
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[46] | 82 | Memory_ZeroSSBPwithSizeInCX: |
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[50] | 83 | push es |
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| 84 | push di |
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[41] | 85 | push ax |
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[105] | 86 | call Registers_CopySSBPtoESDI |
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[46] | 87 | call Memory_ZeroESDIwithSizeInCX |
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[41] | 88 | pop ax |
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[50] | 89 | pop di |
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| 90 | pop es |
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[41] | 91 | ret |
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| 92 | |
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| 93 | ;-------------------------------------------------------------------- |
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[46] | 94 | ; Memory_ZeroESDIwithSizeInCX |
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[41] | 95 | ; Parameters |
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[46] | 96 | ; CX: Number of bytes to zero |
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| 97 | ; ES:DI: Ptr to destination buffer |
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[41] | 98 | ; Returns: |
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[50] | 99 | ; DI: Updated by number of BYTEs stored |
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[41] | 100 | ; Corrupts registers: |
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| 101 | ; AX |
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| 102 | ;-------------------------------------------------------------------- |
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| 103 | ALIGN JUMP_ALIGN |
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[46] | 104 | Memory_ZeroESDIwithSizeInCX: |
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[41] | 105 | xor ax, ax |
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[46] | 106 | ; Fall to Memory_StoreCXbytesFromAccumToESDI |
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[41] | 107 | |
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| 108 | ;-------------------------------------------------------------------- |
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[46] | 109 | ; Memory_StoreCXbytesFromAccumToESDI |
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[41] | 110 | ; Parameters |
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| 111 | ; AX: Word to use to fill buffer |
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[46] | 112 | ; CX: Number of BYTEs to store |
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| 113 | ; ES:DI: Ptr to destination buffer |
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[41] | 114 | ; Returns: |
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[50] | 115 | ; DI: Updated by number of BYTEs stored |
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[41] | 116 | ; Corrupts registers: |
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| 117 | ; Nothing |
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| 118 | ;-------------------------------------------------------------------- |
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| 119 | ALIGN JUMP_ALIGN |
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[46] | 120 | Memory_StoreCXbytesFromAccumToESDI: |
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| 121 | OPTIMIZE_STRING_OPERATION rep, stos |
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[41] | 122 | ret |
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| 123 | |
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| 124 | |
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| 125 | ;-------------------------------------------------------------------- |
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| 126 | ; Memory_ReserveCXbytesFromStackToDSSI |
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| 127 | ; Parameters |
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| 128 | ; CX: Number of bytes to reserve |
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| 129 | ; Returns: |
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| 130 | ; DS:SI: Ptr to reserved buffer |
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| 131 | ; Corrupts registers: |
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| 132 | ; AX |
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| 133 | ;-------------------------------------------------------------------- |
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[194] | 134 | %ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS |
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[41] | 135 | ALIGN JUMP_ALIGN |
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| 136 | Memory_ReserveCXbytesFromStackToDSSI: |
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| 137 | pop ax |
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| 138 | push ss |
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| 139 | pop ds |
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| 140 | sub sp, cx |
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| 141 | mov si, sp |
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| 142 | jmp ax |
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[194] | 143 | %endif |
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