| 1 | ; Project name : XTIDE Universal BIOS
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| 2 | ; Description : Int 13h function AH=48h, Get Extended 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=48h, Get Extended Drive Parameters.
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| 9 | ;
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| 10 | ; AH48h_GetExtendedDriveParameters
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| 11 | ; Parameters:
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| 12 | ; SI: 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 IDEPACK
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| 16 | ; Parameters on INTPACK:
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| 17 | ; DS:SI: Ptr to Extended Drive Information Table to fill
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| 18 | ; Returns with INTPACK:
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| 19 | ; AH: Int 13h return status
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| 20 | ; DS:SI: Ptr to Extended Drive Information Table
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| 21 | ; CF: 0 if successful, 1 if error
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| 22 | ;--------------------------------------------------------------------
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| 23 | AH48h_HandlerForGetExtendedDriveParameters:
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| 24 | call AccessDPT_GetPointerToDRVPARAMStoCSBX
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| 25 | push bx
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| 26 | call AccessDPT_GetLbaSectorCountToBXDXAX
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| 27 | pop di ; CS:DI now points to DRVPARAMS
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| 28 |
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| 29 | ; Point DS:SI to Extended Drive Information Table to fill
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| 30 | mov ds, [bp+IDEPACK.intpack+INTPACK.ds]
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| 31 | mov cx, MINIMUM_EDRIVEINFO_SIZE
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| 32 | cmp [si+EDRIVE_INFO.wSize], cx
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| 33 | jb SHORT Prepare_ReturnFromInt13hWithInvalidFunctionError
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| 34 | je SHORT .SkipEddConfigurationParameters
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| 35 |
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| 36 | ; We do not support EDD Configuration Parameters so set to FFFF:FFFFh
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| 37 | mov cx, -1 ; FFFFh
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| 38 | mov [si+EDRIVE_INFO.fpEDDparams], cx
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| 39 | mov [si+EDRIVE_INFO.fpEDDparams+2], cx
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| 40 | mov cx, EDRIVE_INFO_size
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| 41 |
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| 42 | ; Fill Extended Drive Information Table in DS:SI
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| 43 | .SkipEddConfigurationParameters:
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| 44 | mov [si+EDRIVE_INFO.wSize], cx
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| 45 | mov WORD [si+EDRIVE_INFO.wFlags], FLG_DMA_BOUNDARY_ERRORS_HANDLED_BY_BIOS
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| 46 |
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| 47 | push ds ; Move CS to DS to avoid segment overrides
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| 48 | push cs
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| 49 | pop ds
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| 50 |
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| 51 | ; Limit LBA if necessary
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| 52 | test BYTE [di+DRVPARAMS.wFlags], FLG_DRVPARAMS_USERLBA
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| 53 | jz SHORT .StoreTotalSectorsFromBXDXAX
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| 54 | test bx, bx
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| 55 | jnz SHORT .LimitTotalSectors
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| 56 | cmp dx, [di+DRVPARAMS.dwMaximumLBA+2]
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| 57 | jb SHORT .StoreTotalSectorsFromBXDXAX ; Real size less than max
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| 58 | ja SHORT .LimitTotalSectors
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| 59 | cmp ax, [di+DRVPARAMS.dwMaximumLBA]
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| 60 | jbe SHORT .StoreTotalSectorsFromBXDXAX ; Real size less than max
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| 61 |
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| 62 | .LimitTotalSectors:
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| 63 | xor bx, bx
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| 64 | mov ax, [di+DRVPARAMS.dwMaximumLBA]
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| 65 | mov dx, [di+DRVPARAMS.dwMaximumLBA+2]
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| 66 |
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| 67 | .StoreTotalSectorsFromBXDXAX:
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| 68 | pop ds ; Restore DS from the change above
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| 69 | mov [si+EDRIVE_INFO.qwTotalSectors], ax
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| 70 | xor ax, ax ; Return with success
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| 71 | mov [si+EDRIVE_INFO.qwTotalSectors+2], dx
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| 72 | mov [si+EDRIVE_INFO.qwTotalSectors+4], bx
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| 73 | mov [si+EDRIVE_INFO.qwTotalSectors+6], ax ; Always zero
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| 74 | mov WORD [si+EDRIVE_INFO.wSectorSize], 512
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| 75 |
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| 76 | .ReturnWithError:
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| 77 | jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH
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