[150] | 1 | ; Project name : XTIDE Universal BIOS |
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[3] | 2 | ; Description : Functions for finding Disk Parameter Table. |
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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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| 8 | ; Finds pointer to first unused Disk Parameter Table. |
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| 9 | ; |
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[150] | 10 | ; FindDPT_ForNewDriveToDSDI |
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[3] | 11 | ; Parameters: |
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| 12 | ; DS: RAMVARS segment |
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| 13 | ; Returns: |
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| 14 | ; DS:DI: Ptr to first unused DPT |
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| 15 | ; Corrupts registers: |
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[258] | 16 | ; DX |
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[150] | 17 | ;-------------------------------------------------------------------- |
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| 18 | ALIGN JUMP_ALIGN |
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| 19 | FindDPT_ForNewDriveToDSDI: |
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[258] | 20 | mov ax, [RAMVARS.wDrvCntAndFirst] |
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| 21 | add al, ah |
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| 22 | %ifdef MODULE_SERIAL_FLOPPY |
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| 23 | add al, [RAMVARS.xlateVars+XLATEVARS.bFlopCreateCnt] |
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| 24 | %endif |
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[259] | 25 | xchg ax, dx |
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| 26 | ; fall-through to FindDPT_ForDriveNumber |
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[150] | 27 | |
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| 28 | ;-------------------------------------------------------------------- |
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| 29 | ; Finds Disk Parameter Table for drive number. |
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| 30 | ; IDE Base Port address will be stored to RAMVARS if correct DPT is found. |
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| 31 | ; |
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| 32 | ; FindDPT_ForDriveNumber |
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| 33 | ; Parameters: |
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| 34 | ; DL: Drive number |
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| 35 | ; DS: RAMVARS segment |
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| 36 | ; Returns: |
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| 37 | ; DS:DI: Ptr to DPT |
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| 38 | ; Corrupts registers: |
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[3] | 39 | ; Nothing |
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| 40 | ;-------------------------------------------------------------------- |
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| 41 | ALIGN JUMP_ALIGN |
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[150] | 42 | FindDPT_ForDriveNumber: |
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| 43 | push dx |
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[161] | 44 | xchg di, ax ; Save the contents of AX in DI |
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[3] | 45 | |
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[258] | 46 | %ifdef MODULE_SERIAL_FLOPPY |
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| 47 | mov ax, [RAMVARS.wDrvCntAndFirst] |
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| 48 | |
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| 49 | test dl, dl |
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| 50 | js .harddisk |
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| 51 | |
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| 52 | call RamVars_UnpackFlopCntAndFirstToAL |
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| 53 | add dl, ah ; add in end of hard disk DPT list, floppies start immediately after |
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| 54 | .harddisk: |
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| 55 | sub dl, al ; subtract off beginning of either hard disk or floppy list (as appropriate) |
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| 56 | %else |
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| 57 | sub dl, [RAMVARS.bFirstDrv] ; subtract off beginning of hard disk list |
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| 58 | %endif |
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| 59 | |
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[150] | 60 | mov al, LARGEST_DPT_SIZE |
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[258] | 61 | |
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[150] | 62 | mul dl |
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| 63 | add ax, BYTE RAMVARS_size |
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[3] | 64 | |
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[258] | 65 | xchg di, ax ; Restore AX and put result in DI |
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[150] | 66 | pop dx |
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[259] | 67 | |
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[150] | 68 | ret |
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| 69 | |
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[3] | 70 | ;-------------------------------------------------------------------- |
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[259] | 71 | ; Consolidator for checking the result from RamVars_IsDriveHandledByThisBIOS |
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| 72 | ; and then if it is our drive, getting the DPT with FindDPT_ForDriveNumber |
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| 73 | ; |
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| 74 | ; RamVars_IsDriveHandledByThisBIOS_And_FindDPT_ForDriveNumber |
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| 75 | ; Parameters: |
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| 76 | ; DL: Drive number |
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| 77 | ; DS: RAMVARS segment |
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| 78 | ; Returns: |
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| 79 | ; DS:DI: Ptr to DPT, if it is our drive |
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| 80 | ; CF: Set if not our drive, clear if it is our drive |
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| 81 | ; Corrupts registers: |
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| 82 | ; Nothing |
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| 83 | ;-------------------------------------------------------------------- |
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| 84 | ALIGN JUMP_ALIGN |
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| 85 | RamVars_IsDriveHandledByThisBIOS_And_FindDPT_ForDriveNumber: |
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| 86 | call RamVars_IsDriveHandledByThisBIOS |
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| 87 | jnc FindDPT_ForDriveNumber |
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| 88 | ret |
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| 89 | |
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| 90 | |
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| 91 | ;-------------------------------------------------------------------- |
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[3] | 92 | ; Finds Disk Parameter Table for |
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| 93 | ; Master or Slave drive at wanted port. |
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| 94 | ; |
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[150] | 95 | ; FindDPT_ToDSDIForIdeMasterAtPortDX |
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| 96 | ; FindDPT_ToDSDIForIdeSlaveAtPortDX |
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[3] | 97 | ; Parameters: |
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| 98 | ; DX: IDE Base Port address |
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| 99 | ; DS: RAMVARS segment |
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| 100 | ; Returns: |
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| 101 | ; DL: Drive number (if DPT found) |
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| 102 | ; DS:DI: Ptr to DPT |
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| 103 | ; CF: Set if wanted DPT found |
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| 104 | ; Cleared if DPT not found |
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| 105 | ; Corrupts registers: |
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[150] | 106 | ; SI |
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[200] | 107 | ; |
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| 108 | ; Converted to macros since there is only once call site for each of these |
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| 109 | ; |
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[3] | 110 | ;-------------------------------------------------------------------- |
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[200] | 111 | |
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| 112 | %macro FindDPT_ToDSDIForIdeMasterAtPortDX 0 |
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[152] | 113 | mov si, IterateToMasterAtPortCallback |
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[200] | 114 | call IterateAllDPTs |
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| 115 | %endmacro |
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[3] | 116 | |
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[200] | 117 | %macro FindDPT_ToDSDIForIdeSlaveAtPortDX 0 |
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[152] | 118 | mov si, IterateToSlaveAtPortCallback |
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[200] | 119 | call IterateAllDPTs |
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| 120 | %endmacro |
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[3] | 121 | |
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[200] | 122 | |
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[3] | 123 | ;-------------------------------------------------------------------- |
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| 124 | ; Iteration callback for finding DPT using |
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| 125 | ; IDE base port for Master or Slave drive. |
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| 126 | ; |
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[152] | 127 | ; IterateToSlaveAtPortCallback |
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| 128 | ; IterateToMasterAtPortCallback |
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[3] | 129 | ; Parameters: |
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| 130 | ; DX: IDE Base Port address |
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| 131 | ; DS:DI: Ptr to DPT to examine |
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| 132 | ; Returns: |
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| 133 | ; CF: Set if wanted DPT found |
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| 134 | ; Cleared if wrong DPT |
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| 135 | ; Corrupts registers: |
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| 136 | ; Nothing |
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| 137 | ;-------------------------------------------------------------------- |
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| 138 | ALIGN JUMP_ALIGN |
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[152] | 139 | IterateToSlaveAtPortCallback: |
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[158] | 140 | test BYTE [di+DPT.bFlagsLow], FLGL_DPT_SLAVE ; Clears CF |
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[150] | 141 | jnz SHORT CompareBasePortAddress |
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| 142 | ret ; Wrong DPT |
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[3] | 143 | |
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| 144 | ALIGN JUMP_ALIGN |
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[152] | 145 | IterateToMasterAtPortCallback: |
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[158] | 146 | test BYTE [di+DPT.bFlagsLow], FLGL_DPT_SLAVE |
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[150] | 147 | jnz SHORT ReturnWrongDPT ; Return if slave drive |
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[3] | 148 | |
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[150] | 149 | CompareBasePortAddress: |
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[3] | 150 | push bx |
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[150] | 151 | eMOVZX bx, BYTE [di+DPT.bIdevarsOffset] ; CS:BX now points to IDEVARS |
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| 152 | cmp dx, [cs:bx+IDEVARS.wPort] ; Wanted port? |
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[3] | 153 | pop bx |
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[150] | 154 | jne SHORT ReturnWrongDPT |
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[200] | 155 | |
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| 156 | ReturnRightDPT: |
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[150] | 157 | stc ; Set CF since wanted DPT |
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[3] | 158 | ret |
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[152] | 159 | |
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| 160 | |
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| 161 | ;-------------------------------------------------------------------- |
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[233] | 162 | ; IterateToDptWithFlagsHighInBL |
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[152] | 163 | ; Parameters: |
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| 164 | ; DS:DI: Ptr to DPT to examine |
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[233] | 165 | ; BL: Bit(s) to test in DPT.bFlagsHigh |
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[152] | 166 | ; Returns: |
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| 167 | ; CF: Set if wanted DPT found |
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| 168 | ; Cleared if wrong DPT |
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| 169 | ; Corrupts registers: |
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| 170 | ; Nothing |
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| 171 | ;-------------------------------------------------------------------- |
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| 172 | ALIGN JUMP_ALIGN |
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[233] | 173 | IterateToDptWithFlagsHighInBL: |
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| 174 | test BYTE [di+DPT.bFlagsHigh], bl ; Clears CF (but we need the clc |
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| 175 | ; below anyway for callers above) |
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[200] | 176 | jnz SHORT ReturnRightDPT |
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| 177 | |
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[150] | 178 | ReturnWrongDPT: |
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[152] | 179 | clc ; Clear CF since wrong DPT |
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[3] | 180 | ret |
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| 181 | |
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| 182 | ;-------------------------------------------------------------------- |
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[233] | 183 | ; FindDPT_ToDSDIforSerialDevice |
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[161] | 184 | ; Parameters: |
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| 185 | ; DS: RAMVARS segment |
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| 186 | ; Returns: |
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| 187 | ; DS:DI: Ptr to DPT |
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| 188 | ; CF: Set if wanted DPT found |
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| 189 | ; Cleared if DPT not found |
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| 190 | ; Corrupts registers: |
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[203] | 191 | ; SI |
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[161] | 192 | ;-------------------------------------------------------------------- |
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[233] | 193 | ALIGN JUMP_ALIGN |
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| 194 | FindDPT_ToDSDIforSerialDevice: |
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| 195 | mov bl, FLGH_DPT_SERIAL_DEVICE |
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| 196 | ; fall-through |
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| 197 | |
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| 198 | ;-------------------------------------------------------------------- |
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| 199 | ; FindDPT_ToDSDIforFlagsHigh |
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| 200 | ; Parameters: |
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| 201 | ; DS: RAMVARS segment |
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| 202 | ; BL: Bit(s) to test in DPT.bFlagsHigh |
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| 203 | ; Returns: |
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| 204 | ; DS:DI: Ptr to DPT |
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| 205 | ; CF: Set if wanted DPT found |
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| 206 | ; Cleared if DPT not found |
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| 207 | ; Corrupts registers: |
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| 208 | ; SI |
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| 209 | ;-------------------------------------------------------------------- |
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[161] | 210 | ALIGN JUMP_ALIGN |
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[233] | 211 | FindDPT_ToDSDIforFlagsHighInBL: |
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| 212 | mov si, IterateToDptWithFlagsHighInBL |
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[161] | 213 | ; Fall to IterateAllDPTs |
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| 214 | |
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| 215 | ;-------------------------------------------------------------------- |
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[3] | 216 | ; Iterates all Disk Parameter Tables. |
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| 217 | ; |
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[150] | 218 | ; IterateAllDPTs |
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[3] | 219 | ; Parameters: |
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[152] | 220 | ; AX,BX,DX: Parameters to callback function |
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| 221 | ; CS:SI: Ptr to callback function |
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| 222 | ; DS: RAMVARS segment |
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[3] | 223 | ; Returns: |
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[152] | 224 | ; DS:DI: Ptr to wanted DPT (if found) |
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[258] | 225 | ; If not found, points to first empty DPT |
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[152] | 226 | ; CF: Set if wanted DPT found |
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[200] | 227 | ; Cleared if DPT not found, or no DPTs present |
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[3] | 228 | ; Corrupts registers: |
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[150] | 229 | ; Nothing unless corrupted by callback function |
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[3] | 230 | ;-------------------------------------------------------------------- |
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| 231 | ALIGN JUMP_ALIGN |
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[150] | 232 | IterateAllDPTs: |
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[3] | 233 | push cx |
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[258] | 234 | |
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| 235 | mov di, RAMVARS_size ; Point DS:DI to first DPT |
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| 236 | |
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[259] | 237 | mov cl, [RAMVARS.bDrvCnt] |
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| 238 | xor ch, ch ; Clears CF |
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[258] | 239 | |
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[259] | 240 | jcxz .AllDptsIterated ; Return if no drives, CF will be clear from xor above |
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| 241 | |
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[3] | 242 | ALIGN JUMP_ALIGN |
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| 243 | .LoopWhileDPTsLeft: |
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| 244 | call si ; Is wanted DPT? |
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[150] | 245 | jc SHORT .AllDptsIterated ; If so, return |
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[259] | 246 | add di, BYTE LARGEST_DPT_SIZE ; Point to next DPT, clears CF |
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[258] | 247 | loop .LoopWhileDPTsLeft |
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[259] | 248 | |
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| 249 | ; fall-through: DPT was not found, CF is already clear from ADD di inside the loop |
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[258] | 250 | |
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[3] | 251 | ALIGN JUMP_ALIGN |
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[150] | 252 | .AllDptsIterated: |
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[3] | 253 | pop cx |
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| 254 | ret |
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[259] | 255 | |
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