| 1 | ; Project name : XTIDE Universal BIOS
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| 2 | ; Description : Int 13h function AH=15h, Read Disk Drive Size.
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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=15h, Read Disk Drive Size.
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| 9 | ;
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| 10 | ; AH15h_HandlerForReadDiskDriveSize
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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 | ; If successful:
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| 17 | ; AH: Hard Disk: 3 (Hard disk accessible)
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| 18 | ; Floppy: 1 (Floppy disk, without change detection)
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| 19 | ; CX:DX: Total number of sectors
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| 20 | ; CF: 0
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| 21 | ; If failed:
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| 22 | ; AH: 0 (Drive not present)
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| 23 | ; CX:DX: 0
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| 24 | ; CF: 1
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| 25 | ;--------------------------------------------------------------------
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| 26 | ALIGN JUMP_ALIGN
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| 27 | AH15h_HandlerForReadDiskDriveSize:
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| 28 | %ifdef MODULE_SERIAL_FLOPPY
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| 29 | mov cl, 1 ; 1 = floppy disk, no change detection
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| 30 |
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| 31 | test dl,dl ; DO NOT store the sector count if this is a
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| 32 | jns .FloppyDrive ; floppy disk, some OS's depend on this not
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| 33 | ; happening for floppies in order to boot.
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| 34 | %endif
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| 35 |
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| 36 | call AH15h_GetSectorCountToBXDXAX
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| 37 | mov [bp+IDEPACK.intpack+INTPACK.cx], dx ; HIWORD to CX
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| 38 | xchg [bp+IDEPACK.intpack+INTPACK.dx], ax ; LOWORD to DX, AL gets drive number
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| 39 |
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| 40 | xor ah, ah
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| 41 | %ifdef MODULE_SERIAL_FLOPPY
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| 42 | mov cl, 3 ; 3 = Hard Disk Accessible
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| 43 | .FloppyDrive:
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| 44 |
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| 45 | call Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH_ALHasDriveNumber ; Store success to BDA and CF
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| 46 | mov [bp+IDEPACK.intpack+INTPACK.ah], cl
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| 47 | %else
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| 48 | call Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH ; Store success to BDA and CF
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| 49 | mov BYTE [bp+IDEPACK.intpack+INTPACK.ah], 3
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| 50 | %endif
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| 51 |
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| 52 | jmp Int13h_ReturnFromHandlerWithoutStoringErrorCode
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| 53 |
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| 54 |
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| 55 | ;--------------------------------------------------------------------
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| 56 | ; AH15h_GetSectorCountFromForeignDriveToDXAX:
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| 57 | ; AH15h_GetSectorCountToBXDXAX:
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| 58 | ; Parameters:
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| 59 | ; DL: Drive number (AH15h_GetSectorCountFromForeignDriveToDXAX only)
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| 60 | ; DS: RAMVARS segment
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| 61 | ; DS:DI: Ptr to DPT (AH15h_GetSectorCountToDXAX only)
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| 62 | ; Returns:
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| 63 | ; DX:AX: Total sector count
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| 64 | ; BX: Zero
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| 65 | ; Corrupts registers:
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| 66 | ; CX
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| 67 | ;--------------------------------------------------------------------
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| 68 | AH15h_GetSectorCountFromForeignDriveToDXAX:
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| 69 | mov ah, GET_DRIVE_PARAMETERS
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| 70 | call Int13h_CallPreviousInt13hHandler
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| 71 | jmp SHORT ConvertAH08hReturnValuesToSectorCount
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| 72 |
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| 73 | AH15h_GetSectorCountToBXDXAX:
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| 74 | call AH8h_GetDriveParameters
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| 75 | ; Fall to ConvertAH08hReturnValuesToSectorCount
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| 76 |
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| 77 | ConvertAH08hReturnValuesToSectorCount:
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| 78 | call Address_ExtractLCHSparametersFromOldInt13hAddress
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| 79 | mov al, bh ; AL = Max head number
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| 80 | inc cx ; Max cylinder number to cylinder count
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| 81 | inc ax ; Max head number to head count (AH=8h returns max 254 so no overflow to AH)
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| 82 | mul bl ; AX = Head count * Sectors per track
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| 83 | mul cx ; DX:AX = Total sector count for AH=0xh transfer functions
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| 84 | xor bx, bx
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| 85 | ret
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