| 1 | ; Project name : XTIDE Universal BIOS |
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| 2 | ; Description : Int 13h function AH=2h, Read Disk Sectors. |
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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 | ; Int 13h function AH=2h, Read Disk Sectors. |
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| 9 | ; |
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| 10 | ; AH2h_HandlerForReadDiskSectors |
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| 11 | ; Parameters: |
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| 12 | ; AL, CX, DH, ES: Same as in INTPACK |
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| 13 | ; DL: Translated Drive number |
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| 14 | ; DS:DI: Ptr to DPT (in RAMVARS segment) |
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| 15 | ; SS:BP: Ptr to INTPACK |
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| 16 | ; Parameters on INTPACK in SS:BP: |
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| 17 | ; AL: Number of sectors to read (1...255) |
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| 18 | ; CH: Cylinder number, bits 7...0 |
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| 19 | ; CL: Bits 7...6: Cylinder number bits 9 and 8 |
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| 20 | ; Bits 5...0: Starting sector number (1...63) |
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| 21 | ; DH: Starting head number (0...255) |
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| 22 | ; ES:BX: Pointer to buffer recieving data |
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| 23 | ; Returns with INTPACK in SS:BP: |
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| 24 | ; AH: Int 13h/40h floppy return status |
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| 25 | ; AL: Burst error length if AH returns 11h, undefined otherwise |
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| 26 | ; CF: 0 if successfull, 1 if error |
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| 27 | ;-------------------------------------------------------------------- |
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| 28 | ALIGN JUMP_ALIGN |
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| 29 | AH2h_HandlerForReadDiskSectors: |
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| 30 | test al, al ; Invalid sector count? |
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| 31 | jz SHORT AH2h_ZeroCntErr ; If so, return with error |
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| 32 | |
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| 33 | ; Select sector or block mode command |
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| 34 | mov ah, HCMD_READ_SECT ; Load sector mode command |
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| 35 | cmp BYTE [di+DPT.bSetBlock], 1 ; Block mode enabled? |
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| 36 | eCMOVA ah, HCMD_READ_MUL ; Load block mode command |
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| 37 | |
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| 38 | ; Transfer data |
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| 39 | call HCommand_OutputCountAndLCHSandCommand |
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| 40 | jc SHORT .ReturnWithErrorCodeInAH |
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| 41 | mov bx, [bp+INTPACK.bx] |
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| 42 | call HPIO_ReadBlock ; Read data from IDE-controller |
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| 43 | .ReturnWithErrorCodeInAH: |
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| 44 | jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH |
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| 45 | |
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| 46 | ; Invalid sector count (also for AH=3h and AH=4h) |
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| 47 | AH2h_ZeroCntErr: |
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| 48 | mov ah, RET_HD_INVALID ; Invalid value passed |
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| 49 | jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH |
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