| 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 succesfull: |
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| 17 | ; AH: 3 (Hard disk accessible) |
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| 18 | ; CX:DX: Total number of sectors |
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| 19 | ; CF: 0 |
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| 20 | ; If failed: |
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| 21 | ; AH: 0 (Drive not present) |
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| 22 | ; CX:DX: 0 |
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| 23 | ; CF: 1 |
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| 24 | ;-------------------------------------------------------------------- |
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| 25 | ALIGN JUMP_ALIGN |
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| 26 | AH15h_HandlerForReadDiskDriveSize: |
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| 27 | call AH15h_GetSectorCountToDXAX |
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| 28 | mov [bp+IDEPACK.intpack+INTPACK.cx], dx ; HIWORD to CX |
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| 29 | mov [bp+IDEPACK.intpack+INTPACK.dx], ax ; LOWORD to DX |
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| 30 | |
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| 31 | xor ah, ah |
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| 32 | call Int13h_SetErrorCodeToIntpackInSSBPfromAH ; Store success to BDA and CF |
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| 33 | mov BYTE [bp+IDEPACK.intpack+INTPACK.ah], 3 ; Type code = Hard disk |
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| 34 | jmp Int13h_ReturnFromHandlerWithoutStoringErrorCode |
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| 35 | |
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| 36 | |
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| 37 | ;-------------------------------------------------------------------- |
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| 38 | ; AH15h_GetSectorCountFromForeignDriveToDXAX: |
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| 39 | ; AH15h_GetSectorCountToDXAX: |
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| 40 | ; Parameters: |
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| 41 | ; DL: Drive number |
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| 42 | ; DS: RAMVARS segment |
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| 43 | ; DS:DI: Ptr to DPT (AH15h_GetSectorCount only) |
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| 44 | ; Returns: |
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| 45 | ; DX:AX: Total sector count |
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| 46 | ; BX: Zero |
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| 47 | ; Corrupts registers: |
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| 48 | ; CX |
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| 49 | ;-------------------------------------------------------------------- |
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| 50 | AH15h_GetSectorCountFromForeignDriveToDXAX: |
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| 51 | mov ah, GET_DRIVE_PARAMETERS |
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| 52 | call Int13h_CallPreviousInt13hHandler |
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| 53 | jmp SHORT ConvertAH08hReturnValuesToSectorCount |
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| 54 | |
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| 55 | ALIGN JUMP_ALIGN |
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| 56 | AH15h_GetSectorCountToDXAX: |
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| 57 | call AH8h_GetDriveParameters |
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| 58 | ; Fall to ConvertAH08hReturnValuesToSectorCount |
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| 59 | |
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| 60 | ConvertAH08hReturnValuesToSectorCount: |
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| 61 | call Address_ExtractLCHSparametersFromOldInt13hAddress |
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| 62 | xor ax, ax ; Zero AX |
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| 63 | inc cx ; Max cylinder number to cylinder count |
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| 64 | xchg al, bh ; AX=Max head number, BX=Sectors per track |
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| 65 | inc ax ; AX=Head count |
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| 66 | mul bx ; AX=Head count * Sectors per track |
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| 67 | mul cx ; DX:AX = Total sector count |
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| 68 | xor bx, bx ; Zero BX for 48-bit sector count (and clear CF) |
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| 69 | ret |
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