| 1 | ; Project name : XTIDE Universal BIOS
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| 2 | ; Description : Functions for creating Disk Parameter Table.
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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 | ; Creates new Disk Parameter Table for detected hard disk.
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| 9 | ; Drive is then fully accessible using any BIOS function.
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| 10 | ;
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| 11 | ; CreateDPT_FromAtaInformation
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| 12 | ; Parameters:
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| 13 | ; BH: Drive Select byte for Drive and Head Register
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| 14 | ; ES:SI: Ptr to 512-byte ATA information read from the drive
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| 15 | ; CS:BP: Ptr to IDEVARS for the controller
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| 16 | ; DS: RAMVARS segment
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| 17 | ; ES: BDA Segment
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| 18 | ; Returns:
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| 19 | ; DL: Drive number for new drive
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| 20 | ; DS:DI: Ptr to Disk Parameter Table (if succesfull)
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| 21 | ; CF: Cleared if DPT created successfully
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| 22 | ; Set if any error
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| 23 | ; Corrupts registers:
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| 24 | ; AX, BX, CX, DH
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| 25 | ;--------------------------------------------------------------------
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| 26 | CreateDPT_FromAtaInformation:
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| 27 | call FindDPT_ForNewDrive ; Get new DPT to DS:DI
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| 28 | ; Fall to .InitializeDPT
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| 29 |
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| 30 | ;--------------------------------------------------------------------
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| 31 | ; .InitializeDPT
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| 32 | ; Parameters:
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| 33 | ; BH: Drive Select byte for Drive and Head Register
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| 34 | ; DS:DI: Ptr to Disk Parameter Table
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| 35 | ; CS:BP: Ptr to IDEVARS for the controller
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| 36 | ; Returns:
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| 37 | ; AX: Zero
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| 38 | ; Corrupts registers:
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| 39 | ; Nothing
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| 40 | ;--------------------------------------------------------------------
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| 41 | .InitializeDPT:
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| 42 | xor ax, ax
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| 43 | mov BYTE [di+DPT.bSize], DPT_size
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| 44 | mov [di+DPT.wDrvNumAndFlags], ax
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| 45 | mov BYTE [di+DPT.bReset], MASK_RESET_ALL
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| 46 | mov [di+DPT.bIdeOff], bp
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| 47 | mov [di+DPT.bDrvSel], bh
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| 48 | ; Fall to .StoreDriveControlByte
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| 49 |
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| 50 | ;--------------------------------------------------------------------
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| 51 | ; .StoreDriveControlByte
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| 52 | ; Parameters:
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| 53 | ; AX: Zero
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| 54 | ; BH: Drive Select byte for Drive and Head Register
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| 55 | ; DS:DI: Ptr to Disk Parameter Table
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| 56 | ; ES:SI: Ptr to 512-byte ATA information read from the drive
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| 57 | ; CS:BP: Ptr to IDEVARS for the controller
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| 58 | ; Returns:
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| 59 | ; Nothing
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| 60 | ; Corrupts registers:
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| 61 | ; AX
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| 62 | ;--------------------------------------------------------------------
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| 63 | .StoreDriveControlByte:
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| 64 | cmp BYTE [cs:bp+IDEVARS.bIRQ], al ; Interrupts enabled?
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| 65 | jne SHORT .CheckHeadCount
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| 66 | or al, FLG_IDE_CTRL_nIEN ; Disable interrupts
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| 67 | .CheckHeadCount:
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| 68 | cmp BYTE [es:si+ATA1.wHeadCnt], 8 ; 1...8 heads?
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| 69 | jbe SHORT .StoreDrvCtrlByteToDPT
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| 70 | or al, FLG_IDE_CTRL_O8H ; Over 8 heads (pre-ATA)
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| 71 | .StoreDrvCtrlByteToDPT:
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| 72 | mov [di+DPT.bDrvCtrl], al
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| 73 | ; Fall to .StorePCHS
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| 74 |
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| 75 | ;--------------------------------------------------------------------
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| 76 | ; .StorePCHS
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| 77 | ; Parameters:
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| 78 | ; AH: Zero
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| 79 | ; BH: Drive Select byte for Drive and Head Register
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| 80 | ; DS:DI: Ptr to Disk Parameter Table
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| 81 | ; ES:SI: Ptr to 512-byte ATA information read from the drive
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| 82 | ; CS:BP: Ptr to IDEVARS for the controller
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| 83 | ; Returns:
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| 84 | ; AX: P-CHS cylinders
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| 85 | ; BL: P-CHS heads
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| 86 | ; BH: P-CHS sectors
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| 87 | ; Corrupts registers:
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| 88 | ; Nothing
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| 89 | ;--------------------------------------------------------------------
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| 90 | .StorePCHS:
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| 91 | mov al, FLG_DRVPARAMS_USERCHS ; User specified CHS?
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| 92 | call AccessDPT_TestIdeVarsFlagsForMasterOrSlaveDrive
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| 93 | jnz SHORT .GetUserSpecifiedPCHS
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| 94 | call AtaID_GetPCHS ; Get from ATA information
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| 95 | jmp SHORT .StorePCHStoDPT
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| 96 |
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| 97 | .GetUserSpecifiedPCHS:
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| 98 | call AccessDPT_GetPointerToDRVPARAMStoCSBX
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| 99 | mov ax, [cs:bx+DRVPARAMS.wCylinders]
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| 100 | mov bx, [cs:bx+DRVPARAMS.wHeadsAndSectors]
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| 101 | or BYTE [di+DPT.bFlags], FLG_DPT_USERCHS
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| 102 |
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| 103 | .StorePCHStoDPT:
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| 104 | mov [di+DPT.wPCyls], ax
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| 105 | mov [di+DPT.wHeadsAndSectors], bx
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| 106 | ; Fall to .StoreLCHS
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| 107 |
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| 108 | ;--------------------------------------------------------------------
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| 109 | ; .StoreLCHS
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| 110 | ; Parameters:
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| 111 | ; AX: P-CHS cylinders
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| 112 | ; BL: P-CHS heads
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| 113 | ; DS:DI: Ptr to Disk Parameter Table
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| 114 | ; ES:SI: Ptr to 512-byte ATA information read from the drive
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| 115 | ; Returns:
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| 116 | ; Nothing
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| 117 | ; Corrupts registers:
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| 118 | ; AX, BX, CX
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| 119 | ;--------------------------------------------------------------------
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| 120 | .StoreLCHS:
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| 121 | xor bh, bh ; BX = P-CHS Heads (1...16)
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| 122 | xor cx, cx
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| 123 | .ShiftLoop:
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| 124 | cmp ax, 1024 ; Need to shift?
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| 125 | jbe SHORT .LimitHeadsTo255 ; If not, return
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| 126 | inc cx ; Increment shift count
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| 127 | shr ax, 1 ; Halve cylinders
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| 128 | shl bx, 1 ; Double heads
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| 129 | jmp SHORT .ShiftLoop
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| 130 |
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| 131 | .LimitHeadsTo255:
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| 132 | test bh, bh ; 256 heads?
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| 133 | jz SHORT .StoreLCHStoDPT ; If less, no correction needed
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| 134 | dec bx ; Limit to 255 heads since DOS does not support 256 heads
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| 135 | .StoreLCHStoDPT:
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| 136 | mov [di+DPT.bShLtoP], cl
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| 137 | mov [di+DPT.wLHeads], bx
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| 138 | ; Fall to .StoreAddressing
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| 139 |
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| 140 | ;--------------------------------------------------------------------
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| 141 | ; .StoreAddressing
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| 142 | ; Parameters:
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| 143 | ; DS:DI: Ptr to Disk Parameter Table
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| 144 | ; ES:SI: Ptr to 512-byte ATA information read from the drive
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| 145 | ; Returns:
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| 146 | ; Nothing
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| 147 | ; Corrupts registers:
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| 148 | ; Nothing
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| 149 | ;--------------------------------------------------------------------
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| 150 | .StoreAddressing:
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| 151 | cmp WORD [di+DPT.wPCyls], 1024 ; L-CHS possible? (no translation needed)
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| 152 | jbe SHORT .StoreBlockMode ; If so, nothing needs to be changed
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| 153 | test BYTE [di+DPT.bFlags], FLG_DPT_USERCHS
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| 154 | jnz SHORT .StorePCHSaddressing ; Use user defined P-CHS
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| 155 | test WORD [es:si+ATA1.wCaps], A2_wCaps_LBA
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| 156 | jz SHORT .StorePCHSaddressing ; Use P-CHS since LBA not supported
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| 157 | test WORD [es:si+ATA6.wSetSup83], A6_wSetSup83_LBA48
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| 158 | jz SHORT .StoreLBA28addressing ; Use LBA-28 since LBA-48 not supported
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| 159 | or BYTE [di+DPT.bFlags], ADDR_DPT_LBA48<<1
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| 160 | .StoreLBA28addressing:
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| 161 | or BYTE [di+DPT.bFlags], ADDR_DPT_LBA28<<1
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| 162 | or BYTE [di+DPT.bDrvSel], FLG_IDE_DRVHD_LBA
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| 163 | jmp SHORT .StoreBlockMode
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| 164 | .StorePCHSaddressing:
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| 165 | or BYTE [di+DPT.bFlags], ADDR_DPT_PCHS<<1
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| 166 | ; Fall to .StoreBlockMode
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| 167 |
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| 168 | ;--------------------------------------------------------------------
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| 169 | ; .StoreBlockMode
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| 170 | ; Parameters:
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| 171 | ; DS:DI: Ptr to Disk Parameter Table
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| 172 | ; ES:SI: Ptr to 512-byte ATA information read from the drive
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| 173 | ; Returns:
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| 174 | ; Nothing
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| 175 | ; Corrupts registers:
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| 176 | ; AX
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| 177 | ;--------------------------------------------------------------------
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| 178 | .StoreBlockMode:
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| 179 | mov al, 1 ; Minimum block size is 1 sector
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| 180 | mov ah, [es:si+ATA1.bBlckSize] ; Load max block size in sectors
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| 181 | mov [di+DPT.wSetAndMaxBlock], ax
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| 182 | ; Fall to .StoreEBIOSSupport
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| 183 |
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| 184 | ;--------------------------------------------------------------------
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| 185 | ; .StoreEBIOSSupport
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| 186 | ; Parameters:
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| 187 | ; DS:DI: Ptr to Disk Parameter Table
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| 188 | ; ES:SI: Ptr to 512-byte ATA information read from the drive
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| 189 | ; Returns:
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| 190 | ; Nothing
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| 191 | ; Corrupts registers:
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| 192 | ; AX, BX, DX
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| 193 | ;--------------------------------------------------------------------
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| 194 | .StoreEBIOSSupport:
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| 195 | test BYTE [cs:ROMVARS.wFlags], FLG_ROMVARS_FULLMODE
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| 196 | jz SHORT .StoreDriveNumberAndUpdateDriveCount ; No EBIOS support since small DPTs needed
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| 197 |
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| 198 | mov bl, [di+DPT.bFlags]
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| 199 | and bx, BYTE MASK_DPT_ADDR ; Addressing mode
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| 200 | jmp [cs:bx+.rgwAddrJmp] ; Jump to handle addressing mode
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| 201 | .rgwAddrJmp:
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| 202 | dw .StoreDriveNumberAndUpdateDriveCount ; ADDR_DPT_LCHS
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| 203 | dw .StoreDriveNumberAndUpdateDriveCount ; ADDR_DPT_PCHS
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| 204 | dw .SupportForLBA28 ; ADDR_DPT_LBA28
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| 205 | dw .SupportForLBA48 ; ADDR_DPT_LBA48
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| 206 |
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| 207 | .SupportForLBA28:
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| 208 | sub BYTE [di+DPT.bSize], 2 ; Only 4 bytes for sector count
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| 209 | .SupportForLBA48:
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| 210 | add BYTE [di+DPT.bSize], EBDPT_size - DPT_size
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| 211 | or BYTE [di+DPT.bFlags], FLG_DPT_EBIOS
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| 212 | call AtaID_GetTotalSectorCount
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| 213 | mov [di+EBDPT.twCapacity], ax
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| 214 | mov [di+EBDPT.twCapacity+2], dx
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| 215 | mov [di+EBDPT.twCapacity+4], bx
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| 216 | ; Fall to .StoreDriveNumberAndUpdateDriveCount
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| 217 |
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| 218 | ;--------------------------------------------------------------------
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| 219 | ; .StoreDriveNumberAndUpdateDriveCount
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| 220 | ; Parameters:
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| 221 | ; DS:DI: Ptr to Disk Parameter Table
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| 222 | ; ES:SI: Ptr to 512-byte ATA information read from the drive
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| 223 | ; ES: BDA Segment
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| 224 | ; Returns:
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| 225 | ; DL: Drive number for new drive
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| 226 | ; CF: Cleared if DPT parameters stored successfully
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| 227 | ; Set if any error
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| 228 | ; Corrupts registers:
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| 229 | ; Nothing
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| 230 | ;--------------------------------------------------------------------
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| 231 | .StoreDriveNumberAndUpdateDriveCount:
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| 232 | ; Make sure that more drives can be accepted
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| 233 | mov dl, [es:BDA.bHDCount] ; Load number of hard disks
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| 234 | test dl, 80h ; Hard disks at maximum?
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| 235 | stc ; Assume error
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| 236 | jnz SHORT .TooManyDrives ; If so, return
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| 237 |
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| 238 | ; Store drive number to DPT
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| 239 | or dl, 80h ; Set bit 7 since hard disk
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| 240 | mov [di+DPT.bDrvNum], dl ; Store drive number
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| 241 |
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| 242 | ; Update BDA and RAMVARS
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| 243 | inc BYTE [es:BDA.bHDCount] ; Increment drive count to BDA
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| 244 | call RamVars_IncrementHardDiskCount
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| 245 | clc
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| 246 | .TooManyDrives:
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| 247 | ret
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