| 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 | ;
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| 5 | ; XTIDE Universal BIOS and Associated Tools
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| 6 | ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team.
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| 7 | ;
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| 8 | ; This program is free software; you can redistribute it and/or modify
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| 9 | ; it under the terms of the GNU General Public License as published by
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| 10 | ; the Free Software Foundation; either version 2 of the License, or
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| 11 | ; (at your option) any later version.
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| 12 | ;
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| 13 | ; This program is distributed in the hope that it will be useful,
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| 14 | ; but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 15 | ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 16 | ; GNU General Public License for more details.
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| 17 | ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
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| 18 | ;
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| 19 |
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| 20 | ; Section containing code
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| 21 | SECTION .text
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| 22 |
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| 23 | ;--------------------------------------------------------------------
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| 24 | ; Int 13h function AH=15h, Read Disk Drive Size.
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| 25 | ;
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| 26 | ; It is unclear what is the total number of sectors to return.
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| 27 | ; Award BIOS from 1997 returns full capacity instead of L-CHS limit
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| 28 | ; like we do. I think it makes more sense if this function returns
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| 29 | ; L-CHS limit.
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| 30 | ;
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| 31 | ; AH15h_HandlerForReadDiskDriveSize
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| 32 | ; Parameters:
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| 33 | ; DL: Translated Drive number
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| 34 | ; DS:DI: Ptr to DPT (in RAMVARS segment)
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| 35 | ; SS:BP: Ptr to IDEPACK
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| 36 | ; Returns with INTPACK:
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| 37 | ; If successful:
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| 38 | ; AH: Hard Disk: 3 (Hard disk accessible)
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| 39 | ; Floppy: 1 (Floppy disk, without change detection)
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| 40 | ; CX:DX: Total number of sectors
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| 41 | ; CF: 0
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| 42 | ; If failed:
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| 43 | ; AH: 0 (Drive not present)
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| 44 | ; CX:DX: 0
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| 45 | ; CF: 1
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| 46 | ;--------------------------------------------------------------------
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| 47 | AH15h_HandlerForReadDiskDriveSize:
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| 48 | %ifdef MODULE_SERIAL_FLOPPY
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| 49 | mov cl, 1 ; 1 = floppy disk, no change detection
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| 50 |
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| 51 | test dl,dl ; DO NOT store the sector count if this is a
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| 52 | jns .FloppyDrive ; floppy disk, some OS's depend on this not
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| 53 | ; happening for floppies in order to boot.
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| 54 | %endif
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| 55 |
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| 56 | call AH15h_GetSectorCountToBXDXAX
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| 57 | mov [bp+IDEPACK.intpack+INTPACK.cx], dx ; HIWORD to CX
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| 58 | xchg [bp+IDEPACK.intpack+INTPACK.dx], ax ; LOWORD to DX, AL gets drive number
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| 59 |
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| 60 | xor ah, ah
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| 61 | %ifdef MODULE_SERIAL_FLOPPY
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| 62 | mov cl, 3 ; 3 = Hard Disk Accessible
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| 63 | .FloppyDrive:
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| 64 |
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| 65 | call Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH_ALHasDriveNumber ; Store success to BDA and CF
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| 66 | mov [bp+IDEPACK.intpack+INTPACK.ah], cl
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| 67 | %else
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| 68 | call Int13h_SetErrorCodeToBdaAndToIntpackInSSBPfromAH ; Store success to BDA and CF
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| 69 | mov BYTE [bp+IDEPACK.intpack+INTPACK.ah], 3
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| 70 | %endif
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| 71 |
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| 72 | jmp Int13h_ReturnFromHandlerWithoutStoringErrorCode
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| 73 |
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| 74 |
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| 75 | ;--------------------------------------------------------------------
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| 76 | ; AH15h_GetSectorCountFromForeignDriveToDXAX:
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| 77 | ; AH15h_GetSectorCountToBXDXAX:
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| 78 | ; Parameters:
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| 79 | ; DL: Drive number (AH15h_GetSectorCountFromForeignDriveToDXAX only)
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| 80 | ; DS: RAMVARS segment
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| 81 | ; DS:DI: Ptr to DPT (AH15h_GetSectorCountToDXAX only)
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| 82 | ; Returns:
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| 83 | ; DX:AX: Total sector count
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| 84 | ; BX: Zero
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| 85 | ; Corrupts registers:
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| 86 | ; CX
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| 87 | ;--------------------------------------------------------------------
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| 88 | %ifdef MODULE_BOOT_MENU
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| 89 | AH15h_GetSectorCountFromForeignDriveToDXAX:
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| 90 | mov ah, GET_DRIVE_PARAMETERS
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| 91 | call Int13h_CallPreviousInt13hHandler
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| 92 | jmp SHORT ConvertAH08hReturnValuesToSectorCount
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| 93 | %endif
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| 94 |
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| 95 | AH15h_GetSectorCountToBXDXAX:
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| 96 | call AH8h_GetDriveParameters
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| 97 | ; Fall to ConvertAH08hReturnValuesToSectorCount
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| 98 |
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| 99 | ConvertAH08hReturnValuesToSectorCount:
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| 100 | call Address_ExtractLCHSparametersFromOldInt13hAddress
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| 101 | mov al, bh ; AL = Max head number
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| 102 | inc cx ; Max cylinder number to cylinder count
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| 103 | inc ax ; Max head number to head count (AH=8h returns max 254 so no overflow to AH)
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| 104 | mul bl ; AX = Head count * Sectors per track
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| 105 | mul cx ; DX:AX = Total sector count for AH=0xh transfer functions
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| 106 | xor bx, bx
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| 107 | ret
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