| 1 | ; Project name : XTIDE Universal BIOS
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| 2 | ; Description : Int 13h function AH=8h, Read Disk Drive Parameters.
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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=8h, Read Disk Drive Parameters.
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| 9 | ;
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| 10 | ; AH8h_HandlerForReadDiskDriveParameters
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| 11 | ; Parameters:
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| 12 | ; DL: Translated Drive number
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| 13 | ; DS:DI: Ptr to DPT (in RAMVARS segment)
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| 14 | ; SS:BP: Ptr to IDEPACK
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| 15 | ; Returns with INTPACK:
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| 16 | ; CH: Maximum cylinder number, bits 7...0
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| 17 | ; CL: Bits 7...6: Cylinder number bits 9...8
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| 18 | ; Bits 5...0: Maximum sector number (1...63)
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| 19 | ; DH: Maximum head number (0...255)
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| 20 | ; DL: Number of drives
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| 21 | ; AH: Int 13h/40h floppy return status
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| 22 | ; CF: 0 if successfull, 1 if error
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| 23 | ;--------------------------------------------------------------------
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| 24 | ALIGN JUMP_ALIGN
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| 25 | AH8h_HandlerForReadDiskDriveParameters:
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| 26 | call RamVars_IsDriveHandledByThisBIOS
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| 27 | jnc SHORT .GetDriveParametersForForeignHardDiskInDL
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| 28 | call AH8h_GetDriveParameters
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| 29 | jmp SHORT .ReturnAfterStoringValuesToIntpack
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| 30 |
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| 31 | .GetDriveParametersForForeignHardDiskInDL:
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| 32 | call Int13h_CallPreviousInt13hHandler
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| 33 | jc SHORT .ReturnErrorFromPreviousInt13hHandler
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| 34 | call RamVars_GetCountOfKnownDrivesToDL
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| 35 | .ReturnAfterStoringValuesToIntpack:
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| 36 | mov [bp+IDEPACK.intpack+INTPACK.cx], cx
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| 37 | mov [bp+IDEPACK.intpack+INTPACK.dx], dx
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| 38 | xor ah, ah
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| 39 | .ReturnErrorFromPreviousInt13hHandler:
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| 40 | jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH
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| 41 |
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| 42 |
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| 43 | ;--------------------------------------------------------------------
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| 44 | ; Returns L-CHS parameters for drive and total hard disk count.
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| 45 | ;
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| 46 | ; AH8h_GetDriveParameters
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| 47 | ; Parameters:
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| 48 | ; DS:DI: Ptr to DPT (in RAMVARS segment)
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| 49 | ; Returns:
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| 50 | ; CH: Maximum cylinder number, bits 7...0
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| 51 | ; CL: Bits 7...6: Cylinder number bits 9...8
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| 52 | ; Bits 5...0: Maximum sector number (1...63)
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| 53 | ; DH: Maximum head number (0...255)
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| 54 | ; DL: Number of drives
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| 55 | ; Corrupts registers:
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| 56 | ; AX, BX
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| 57 | ;--------------------------------------------------------------------
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| 58 | ALIGN JUMP_ALIGN
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| 59 | AH8h_GetDriveParameters:
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| 60 | call AccessDPT_GetLCHSfromPCHS ; AX=sectors, BX=cylinders, DX=heads
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| 61 | ; Fall to .PackReturnValues
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| 62 |
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| 63 | ;--------------------------------------------------------------------
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| 64 | ; Packs L-CHS values to INT 13h, AH=08h return values.
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| 65 | ;
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| 66 | ; .PackReturnValues
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| 67 | ; Parameters:
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| 68 | ; AX: Number of L-CHS sectors per track (1...63)
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| 69 | ; BX: Number of L-CHS cylinders available (1...1024)
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| 70 | ; DX: Number of L-CHS heads (1...256)
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| 71 | ; DS: RAMVARS segment
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| 72 | ; Returns:
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| 73 | ; CH: Maximum cylinder number, bits 7...0
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| 74 | ; CL: Bits 7...6: Cylinder number bits 9...8
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| 75 | ; Bits 5...0: Maximum sector number (1...63)
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| 76 | ; DH: Maximum head number (0...255)
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| 77 | ; DL: Number of drives
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| 78 | ; Corrupts registers:
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| 79 | ; AX, BX
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| 80 | ;--------------------------------------------------------------------
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| 81 | .PackReturnValues:
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| 82 | dec bx ; Cylinder count to last cylinder
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| 83 | dec dx ; Head count to max head number
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| 84 | mov dh, dl ; Max head number to DH
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| 85 | mov ch, bl ; Cylinder bits 7...0 to CH
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| 86 | mov cl, bh ; Cylinder bits 9...8 to CL
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| 87 | eROR_IM cl, 2 ; Cylinder bits 9...8 to CL bits 7...6
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| 88 | or cl, al ; Sectors per track to CL bits 5...0
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| 89 | jmp RamVars_GetCountOfKnownDrivesToDL
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