[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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[46] | 4 | ; Last update : 1.10.2010 |
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[41] | 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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[46] | 12 | ; OPTIMIZE_STRING_OPERATION |
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[41] | 13 | ; Parameters |
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[46] | 14 | ; %1: Repeat instruction |
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| 15 | ; %2: String instruction without size (for example MOVS and not MOVSB or MOVSW) |
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| 16 | ; CX: Number of BYTEs to operate |
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| 17 | ; DS:SI: Ptr to source data |
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| 18 | ; ES:DI: Ptr to destination |
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[41] | 19 | ; Returns: |
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[46] | 20 | ; SI, DI: Updated by number of bytes operated |
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| 21 | ; Corrupts registers: |
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[41] | 22 | ; Nothing |
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[46] | 23 | ;-------------------------------------------------------------------- |
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| 24 | %macro OPTIMIZE_STRING_OPERATION 2 |
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| 25 | push cx |
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| 26 | |
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| 27 | shr cx, 1 ; Operate with WORDs for performance |
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| 28 | jcxz %%HandleRemainingByte |
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| 29 | %1 %2w |
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| 30 | %%HandleRemainingByte: |
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| 31 | jnc SHORT %%OperationCompleted |
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| 32 | %2b |
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| 33 | |
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| 34 | ALIGN JUMP_ALIGN |
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| 35 | %%OperationCompleted: |
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| 36 | pop cx |
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| 37 | %endmacro |
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| 38 | |
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| 39 | |
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| 40 | ;-------------------------------------------------------------------- |
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| 41 | ; Memory_CopyCXbytesFromDSSItoESDI |
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| 42 | ; Parameters |
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| 43 | ; CX: Number of bytes to copy |
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| 44 | ; DS:SI: Ptr to source data |
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| 45 | ; ES:DI: Ptr to destination buffer |
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| 46 | ; Returns: |
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| 47 | ; SI, DI: Updated by number of bytes copied |
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[41] | 48 | ; Corrupts registers: |
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[46] | 49 | ; Nothing |
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[41] | 50 | ;-------------------------------------------------------------------- |
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| 51 | ALIGN JUMP_ALIGN |
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[46] | 52 | Memory_CopyCXbytesFromDSSItoESDI: |
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| 53 | OPTIMIZE_STRING_OPERATION rep, movs |
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| 54 | ret |
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[41] | 55 | |
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[46] | 56 | |
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[41] | 57 | ;-------------------------------------------------------------------- |
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[46] | 58 | ; Memory_ZeroSSBPwithSizeInCX |
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[41] | 59 | ; Parameters |
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[46] | 60 | ; CX: Number of bytes to zero |
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[41] | 61 | ; SS:BP: Ptr to buffer to zero |
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| 62 | ; Returns: |
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| 63 | ; Nothing |
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| 64 | ; Corrupts registers: |
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| 65 | ; Nothing |
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| 66 | ;-------------------------------------------------------------------- |
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| 67 | ALIGN JUMP_ALIGN |
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[46] | 68 | Memory_ZeroSSBPwithSizeInCX: |
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[41] | 69 | push ax |
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| 70 | |
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[46] | 71 | call Memory_ExchangeSSBPwithESDI |
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| 72 | call Memory_ZeroESDIwithSizeInCX |
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| 73 | call Memory_ExchangeSSBPwithESDI |
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[41] | 74 | |
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| 75 | pop ax |
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| 76 | ret |
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| 77 | |
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| 78 | ;-------------------------------------------------------------------- |
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[46] | 79 | ; Memory_ZeroESDIwithSizeInCX |
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[41] | 80 | ; Parameters |
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[46] | 81 | ; CX: Number of bytes to zero |
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| 82 | ; ES:DI: Ptr to destination buffer |
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[41] | 83 | ; Returns: |
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| 84 | ; Nothing |
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| 85 | ; Corrupts registers: |
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| 86 | ; AX |
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| 87 | ;-------------------------------------------------------------------- |
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| 88 | ALIGN JUMP_ALIGN |
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[46] | 89 | Memory_ZeroESDIwithSizeInCX: |
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[41] | 90 | xor ax, ax |
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[46] | 91 | ; Fall to Memory_StoreCXbytesFromAccumToESDI |
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[41] | 92 | |
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| 93 | ;-------------------------------------------------------------------- |
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[46] | 94 | ; Memory_StoreCXbytesFromAccumToESDI |
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[41] | 95 | ; Parameters |
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| 96 | ; AX: Word to use to fill buffer |
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[46] | 97 | ; CX: Number of BYTEs to store |
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| 98 | ; ES:DI: Ptr to destination buffer |
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[41] | 99 | ; Returns: |
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| 100 | ; Nothing |
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| 101 | ; Corrupts registers: |
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| 102 | ; Nothing |
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| 103 | ;-------------------------------------------------------------------- |
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| 104 | ALIGN JUMP_ALIGN |
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[46] | 105 | Memory_StoreCXbytesFromAccumToESDI: |
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| 106 | OPTIMIZE_STRING_OPERATION rep, stos |
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| 107 | sub di, cx |
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[41] | 108 | ret |
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| 109 | |
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| 110 | |
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| 111 | ;-------------------------------------------------------------------- |
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[46] | 112 | ; Memory_ExchangeSSBPwithESDI |
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[41] | 113 | ; Memory_ExchangeDSSIwithESDI |
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| 114 | ; Parameters |
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| 115 | ; Nothing |
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| 116 | ; Returns: |
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[46] | 117 | ; SS:BP/DS:SI and ES:DI are exchanged. |
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[41] | 118 | ; Corrupts registers: |
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| 119 | ; Nothing |
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| 120 | ;-------------------------------------------------------------------- |
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| 121 | ALIGN JUMP_ALIGN |
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[46] | 122 | Memory_ExchangeSSBPwithESDI: |
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| 123 | xchg bp, di |
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| 124 | push ss |
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| 125 | push es |
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| 126 | pop ss |
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| 127 | pop es |
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| 128 | ret |
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| 129 | |
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| 130 | ALIGN JUMP_ALIGN |
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[41] | 131 | Memory_ExchangeDSSIwithESDI: |
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| 132 | xchg si, di |
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| 133 | push ds |
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| 134 | push es |
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| 135 | pop ds |
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| 136 | pop es |
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| 137 | ret |
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| 138 | |
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| 139 | |
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| 140 | ;-------------------------------------------------------------------- |
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| 141 | ; Memory_CopySSBPtoESDI |
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| 142 | ; Parameters |
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| 143 | ; Nothing |
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| 144 | ; Returns: |
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[46] | 145 | ; ES:DI: Same as SS:BP |
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[41] | 146 | ; Corrupts registers: |
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| 147 | ; Nothing |
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| 148 | ;-------------------------------------------------------------------- |
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| 149 | ALIGN JUMP_ALIGN |
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| 150 | Memory_CopySSBPtoESDI: |
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| 151 | push ss |
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| 152 | pop es |
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| 153 | mov di, bp |
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| 154 | ret |
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| 155 | |
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| 156 | |
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| 157 | ;-------------------------------------------------------------------- |
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| 158 | ; Memory_SetZFifNullPointerInDSSI |
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| 159 | ; Parameters |
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| 160 | ; DS:SI: Far pointer |
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| 161 | ; Returns: |
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| 162 | ; ZF: Set if NULL pointer in DS:SI |
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| 163 | ; Corrupts registers: |
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| 164 | ; Nothing |
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| 165 | ;-------------------------------------------------------------------- |
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| 166 | ALIGN JUMP_ALIGN |
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| 167 | Memory_SetZFifNullPointerInDSSI: |
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| 168 | push ax |
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| 169 | mov ax, ds |
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| 170 | or ax, si |
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| 171 | pop ax |
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| 172 | ret |
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| 173 | |
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| 174 | |
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| 175 | ;-------------------------------------------------------------------- |
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| 176 | ; Memory_ReserveCXbytesFromStackToDSSI |
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| 177 | ; Parameters |
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| 178 | ; CX: Number of bytes to reserve |
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| 179 | ; Returns: |
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| 180 | ; DS:SI: Ptr to reserved buffer |
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| 181 | ; Corrupts registers: |
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| 182 | ; AX |
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| 183 | ;-------------------------------------------------------------------- |
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| 184 | ALIGN JUMP_ALIGN |
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| 185 | Memory_ReserveCXbytesFromStackToDSSI: |
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| 186 | pop ax |
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| 187 | push ss |
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| 188 | pop ds |
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| 189 | sub sp, cx |
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| 190 | mov si, sp |
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| 191 | jmp ax |
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