[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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| 4 | ; Section containing code |
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| 5 | SECTION .text |
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| 6 | |
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| 7 | ;-------------------------------------------------------------------- |
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[46] | 8 | ; OPTIMIZE_STRING_OPERATION |
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[41] | 9 | ; Parameters |
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[46] | 10 | ; %1: Repeat instruction |
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| 11 | ; %2: String instruction without size (for example MOVS and not MOVSB or MOVSW) |
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| 12 | ; CX: Number of BYTEs to operate |
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| 13 | ; DS:SI: Ptr to source data |
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| 14 | ; ES:DI: Ptr to destination |
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[41] | 15 | ; Returns: |
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[46] | 16 | ; SI, DI: Updated by number of bytes operated |
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| 17 | ; Corrupts registers: |
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[41] | 18 | ; Nothing |
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[46] | 19 | ;-------------------------------------------------------------------- |
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| 20 | %macro OPTIMIZE_STRING_OPERATION 2 |
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| 21 | push cx |
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| 22 | |
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| 23 | shr cx, 1 ; Operate with WORDs for performance |
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[103] | 24 | jz %%HandleRemainingByte |
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[46] | 25 | %1 %2w |
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| 26 | %%HandleRemainingByte: |
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| 27 | jnc SHORT %%OperationCompleted |
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| 28 | %2b |
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| 29 | |
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| 30 | ALIGN JUMP_ALIGN |
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| 31 | %%OperationCompleted: |
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| 32 | pop cx |
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| 33 | %endmacro |
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| 34 | |
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| 35 | |
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| 36 | ;-------------------------------------------------------------------- |
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| 37 | ; Memory_CopyCXbytesFromDSSItoESDI |
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| 38 | ; Parameters |
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| 39 | ; CX: Number of bytes to copy |
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| 40 | ; DS:SI: Ptr to source data |
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| 41 | ; ES:DI: Ptr to destination buffer |
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| 42 | ; Returns: |
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| 43 | ; SI, DI: Updated by number of bytes copied |
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[41] | 44 | ; Corrupts registers: |
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[46] | 45 | ; Nothing |
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[41] | 46 | ;-------------------------------------------------------------------- |
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[131] | 47 | %ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS |
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[41] | 48 | ALIGN JUMP_ALIGN |
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[46] | 49 | Memory_CopyCXbytesFromDSSItoESDI: |
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| 50 | OPTIMIZE_STRING_OPERATION rep, movs |
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| 51 | ret |
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[131] | 52 | %endif |
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[41] | 53 | |
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[46] | 54 | |
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[41] | 55 | ;-------------------------------------------------------------------- |
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[46] | 56 | ; Memory_ZeroSSBPwithSizeInCX |
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[41] | 57 | ; Parameters |
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[46] | 58 | ; CX: Number of bytes to zero |
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[41] | 59 | ; SS:BP: Ptr to buffer to zero |
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| 60 | ; Returns: |
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| 61 | ; Nothing |
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| 62 | ; Corrupts registers: |
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| 63 | ; Nothing |
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| 64 | ;-------------------------------------------------------------------- |
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| 65 | ALIGN JUMP_ALIGN |
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[46] | 66 | Memory_ZeroSSBPwithSizeInCX: |
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[50] | 67 | push es |
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| 68 | push di |
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[41] | 69 | push ax |
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[105] | 70 | call Registers_CopySSBPtoESDI |
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[46] | 71 | call Memory_ZeroESDIwithSizeInCX |
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[41] | 72 | pop ax |
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[50] | 73 | pop di |
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| 74 | pop es |
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[41] | 75 | ret |
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| 76 | |
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| 77 | ;-------------------------------------------------------------------- |
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[46] | 78 | ; Memory_ZeroESDIwithSizeInCX |
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[41] | 79 | ; Parameters |
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[46] | 80 | ; CX: Number of bytes to zero |
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| 81 | ; ES:DI: Ptr to destination buffer |
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[41] | 82 | ; Returns: |
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[50] | 83 | ; DI: Updated by number of BYTEs stored |
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[41] | 84 | ; Corrupts registers: |
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| 85 | ; AX |
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| 86 | ;-------------------------------------------------------------------- |
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| 87 | ALIGN JUMP_ALIGN |
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[46] | 88 | Memory_ZeroESDIwithSizeInCX: |
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[41] | 89 | xor ax, ax |
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[46] | 90 | ; Fall to Memory_StoreCXbytesFromAccumToESDI |
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[41] | 91 | |
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| 92 | ;-------------------------------------------------------------------- |
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[46] | 93 | ; Memory_StoreCXbytesFromAccumToESDI |
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[41] | 94 | ; Parameters |
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| 95 | ; AX: Word to use to fill buffer |
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[46] | 96 | ; CX: Number of BYTEs to store |
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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 | ; Nothing |
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| 102 | ;-------------------------------------------------------------------- |
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| 103 | ALIGN JUMP_ALIGN |
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[46] | 104 | Memory_StoreCXbytesFromAccumToESDI: |
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| 105 | OPTIMIZE_STRING_OPERATION rep, stos |
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[41] | 106 | ret |
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| 107 | |
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| 108 | |
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| 109 | ;-------------------------------------------------------------------- |
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| 110 | ; Memory_ReserveCXbytesFromStackToDSSI |
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| 111 | ; Parameters |
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| 112 | ; CX: Number of bytes to reserve |
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| 113 | ; Returns: |
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| 114 | ; DS:SI: Ptr to reserved buffer |
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| 115 | ; Corrupts registers: |
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| 116 | ; AX |
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| 117 | ;-------------------------------------------------------------------- |
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[194] | 118 | %ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS |
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[41] | 119 | ALIGN JUMP_ALIGN |
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| 120 | Memory_ReserveCXbytesFromStackToDSSI: |
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| 121 | pop ax |
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| 122 | push ss |
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| 123 | pop ds |
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| 124 | sub sp, cx |
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| 125 | mov si, sp |
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| 126 | jmp ax |
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[194] | 127 | %endif |
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