[41] | 1 | ; File name : Memory.asm |
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| 2 | ; Project name : Assembly Library |
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| 3 | ; Created date : 14.7.2010 |
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| 4 | ; Last update : 15.9.2010 |
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| 5 | ; Author : Tomi Tilli |
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| 6 | ; Description : Functions for memory access. |
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| 7 | |
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| 8 | ; Section containing code |
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| 9 | SECTION .text |
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| 10 | |
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| 11 | ;-------------------------------------------------------------------- |
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| 12 | ; Memory_ZeroDSSIbyWordsInCX |
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| 13 | ; Parameters |
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| 14 | ; CX: Number of words to zero |
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| 15 | ; DS:SI: Ptr to buffer to zero |
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| 16 | ; Returns: |
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| 17 | ; Nothing |
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| 18 | ; Corrupts registers: |
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| 19 | ; AX |
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| 20 | ;-------------------------------------------------------------------- |
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| 21 | ALIGN JUMP_ALIGN |
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| 22 | Memory_ZeroDSSIbyWordsInCX: |
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| 23 | call Memory_ExchangeDSSIwithESDI |
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| 24 | call Memory_ZeroESDIbyWordsInCX |
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| 25 | jmp SHORT Memory_ExchangeDSSIwithESDI |
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| 26 | |
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| 27 | ;-------------------------------------------------------------------- |
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| 28 | ; Memory_ZeroSSBPbyWordsInCX |
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| 29 | ; Parameters |
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| 30 | ; CX: Number of words to zero |
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| 31 | ; SS:BP: Ptr to buffer to zero |
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| 32 | ; Returns: |
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| 33 | ; Nothing |
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| 34 | ; Corrupts registers: |
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| 35 | ; Nothing |
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| 36 | ;-------------------------------------------------------------------- |
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| 37 | ALIGN JUMP_ALIGN |
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| 38 | Memory_ZeroSSBPbyWordsInCX: |
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| 39 | push es |
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| 40 | push di |
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| 41 | push ax |
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| 42 | |
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| 43 | push ss |
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| 44 | pop es |
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| 45 | mov di, bp |
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| 46 | call Memory_ZeroESDIbyWordsInCX |
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| 47 | |
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| 48 | pop ax |
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| 49 | pop di |
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| 50 | pop es |
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| 51 | ret |
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| 52 | |
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| 53 | ;-------------------------------------------------------------------- |
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| 54 | ; Memory_ZeroESDIbyWordsInCX |
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| 55 | ; Parameters |
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| 56 | ; CX: Number of words to zero |
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| 57 | ; ES:DI: Ptr to buffer to zero |
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| 58 | ; Returns: |
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| 59 | ; Nothing |
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| 60 | ; Corrupts registers: |
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| 61 | ; AX |
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| 62 | ;-------------------------------------------------------------------- |
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| 63 | ALIGN JUMP_ALIGN |
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| 64 | Memory_ZeroESDIbyWordsInCX: |
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| 65 | xor ax, ax |
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| 66 | ; Fall to Memory_FillESDIwithAXbyCXtimes |
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| 67 | |
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| 68 | ;-------------------------------------------------------------------- |
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| 69 | ; Memory_FillESDIwithAXbyCXtimes |
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| 70 | ; Parameters |
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| 71 | ; AX: Word to use to fill buffer |
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| 72 | ; CX: Number of words to fill |
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| 73 | ; ES:DI: Ptr to buffer to fill |
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| 74 | ; Returns: |
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| 75 | ; Nothing |
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| 76 | ; Corrupts registers: |
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| 77 | ; Nothing |
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| 78 | ;-------------------------------------------------------------------- |
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| 79 | ALIGN JUMP_ALIGN |
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| 80 | Memory_FillESDIwithAXbyCXtimes: |
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| 81 | cld |
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| 82 | push di |
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| 83 | push cx |
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| 84 | rep stosw |
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| 85 | pop cx |
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| 86 | pop di |
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| 87 | ret |
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| 88 | |
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| 89 | |
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| 90 | ;-------------------------------------------------------------------- |
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| 91 | ; Memory_ExchangeDSSIwithESDI |
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| 92 | ; Parameters |
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| 93 | ; Nothing |
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| 94 | ; Returns: |
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| 95 | ; DS:SI and ES:DI are exchanged. |
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| 96 | ; Corrupts registers: |
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| 97 | ; Nothing |
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| 98 | ;-------------------------------------------------------------------- |
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| 99 | ALIGN JUMP_ALIGN |
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| 100 | Memory_ExchangeDSSIwithESDI: |
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| 101 | xchg si, di |
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| 102 | push ds |
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| 103 | push es |
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| 104 | pop ds |
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| 105 | pop es |
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| 106 | ret |
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| 107 | |
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| 108 | |
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| 109 | ;-------------------------------------------------------------------- |
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| 110 | ; Memory_CopySSBPtoDSSI |
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| 111 | ; Memory_CopySSBPtoESDI |
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| 112 | ; Parameters |
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| 113 | ; Nothing |
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| 114 | ; Returns: |
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| 115 | ; DS:SI: Same as SS:BP |
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| 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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| 120 | Memory_CopySSBPtoDSSI: |
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| 121 | push ss |
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| 122 | pop ds |
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| 123 | mov si, bp |
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| 124 | ret |
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| 125 | |
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| 126 | ALIGN JUMP_ALIGN |
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| 127 | Memory_CopySSBPtoESDI: |
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| 128 | push ss |
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| 129 | pop es |
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| 130 | mov di, bp |
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| 131 | ret |
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| 132 | |
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| 133 | |
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| 134 | ;-------------------------------------------------------------------- |
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| 135 | ; Memory_SetZFifNullPointerInDSSI |
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| 136 | ; Parameters |
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| 137 | ; DS:SI: Far pointer |
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| 138 | ; Returns: |
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| 139 | ; ZF: Set if NULL pointer in DS:SI |
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| 140 | ; Corrupts registers: |
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| 141 | ; Nothing |
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| 142 | ;-------------------------------------------------------------------- |
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| 143 | ALIGN JUMP_ALIGN |
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| 144 | Memory_SetZFifNullPointerInDSSI: |
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| 145 | push ax |
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| 146 | mov ax, ds |
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| 147 | or ax, si |
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| 148 | pop ax |
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| 149 | ret |
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| 150 | |
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| 151 | |
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| 152 | ;-------------------------------------------------------------------- |
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| 153 | ; Memory_ReserveCXbytesFromStackToDSSI |
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| 154 | ; Parameters |
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| 155 | ; CX: Number of bytes to reserve |
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| 156 | ; Returns: |
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| 157 | ; DS:SI: Ptr to reserved buffer |
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| 158 | ; Corrupts registers: |
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| 159 | ; AX |
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| 160 | ;-------------------------------------------------------------------- |
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| 161 | ALIGN JUMP_ALIGN |
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| 162 | Memory_ReserveCXbytesFromStackToDSSI: |
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| 163 | pop ax |
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| 164 | push ss |
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| 165 | pop ds |
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| 166 | sub sp, cx |
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| 167 | mov si, sp |
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| 168 | jmp ax |
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