source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CreateDPT.asm@ 174

Last change on this file since 174 was 173, checked in by aitotat@…, 13 years ago

Changes to XTIDE Universal BIOS:

  • L-CHS parameters are now generated differently for LBA enabled drives.
  • Booting to EBIOS partitions now seems to work (at least on one drive).
File size: 6.9 KB
RevLine 
[99]1; Project name : XTIDE Universal BIOS
[3]2; Description : Functions for creating Disk Parameter Table.
3
4; Section containing code
5SECTION .text
6
7;--------------------------------------------------------------------
8; Creates new Disk Parameter Table for detected hard disk.
9; Drive is then fully accessible using any BIOS function.
10;
11; CreateDPT_FromAtaInformation
12; Parameters:
13; BH: Drive Select byte for Drive and Head Register
14; ES:SI: Ptr to 512-byte ATA information read from the drive
15; CS:BP: Ptr to IDEVARS for the controller
16; DS: RAMVARS segment
17; ES: BDA Segment
18; Returns:
19; DL: Drive number for new drive
20; DS:DI: Ptr to Disk Parameter Table (if succesfull)
21; CF: Cleared if DPT created successfully
22; Set if any error
23; Corrupts registers:
[99]24; AX, BX, CX, DH
[3]25;--------------------------------------------------------------------
26CreateDPT_FromAtaInformation:
[150]27 call FindDPT_ForNewDriveToDSDI
[99]28 ; Fall to .InitializeDPT
[3]29
30;--------------------------------------------------------------------
[99]31; .InitializeDPT
[3]32; Parameters:
33; BH: Drive Select byte for Drive and Head Register
34; DS:DI: Ptr to Disk Parameter Table
35; CS:BP: Ptr to IDEVARS for the controller
36; Returns:
[150]37; Nothing
[3]38; Corrupts registers:
[150]39; AX
[3]40;--------------------------------------------------------------------
[99]41.InitializeDPT:
[150]42 mov [di+DPT.bIdevarsOffset], bp ; IDEVARS must start in first 256 bytes of ROM
43 ; Fall to .StoreDriveSelectAndDriveControlByte
[3]44
45;--------------------------------------------------------------------
[150]46; .StoreDriveSelectAndDriveControlByte
[3]47; Parameters:
48; BH: Drive Select byte for Drive and Head Register
49; DS:DI: Ptr to Disk Parameter Table
50; ES:SI: Ptr to 512-byte ATA information read from the drive
51; CS:BP: Ptr to IDEVARS for the controller
52; Returns:
[99]53; Nothing
[3]54; Corrupts registers:
55; AX
56;--------------------------------------------------------------------
[150]57.StoreDriveSelectAndDriveControlByte:
58 mov al, bh
59 and ax, BYTE FLG_DRVNHEAD_DRV ; AL now has Master/Slave bit
60 cmp [cs:bp+IDEVARS.bIRQ], ah ; Interrupts enabled?
61 jz SHORT .StoreFlags ; If not, do not set interrupt flag
[158]62 or al, FLGL_DPT_ENABLE_IRQ
[150]63.StoreFlags:
64 mov [di+DPT.wFlags], ax
[173]65 ; Fall to .StoreAddressing
[3]66
67;--------------------------------------------------------------------
[173]68; .StoreAddressing
[3]69; Parameters:
70; DS:DI: Ptr to Disk Parameter Table
71; ES:SI: Ptr to 512-byte ATA information read from the drive
72; CS:BP: Ptr to IDEVARS for the controller
73; Returns:
[173]74; DX:AX or AX: Number of cylinders
75; BH: Number of sectors per track
76; BL: Number of heads
[3]77; Corrupts registers:
[173]78; CX, (DX)
[3]79;--------------------------------------------------------------------
[173]80.StoreAddressing:
81 ; Check if CHS defined in ROMVARS
[99]82 mov al, FLG_DRVPARAMS_USERCHS ; User specified CHS?
[3]83 call AccessDPT_TestIdeVarsFlagsForMasterOrSlaveDrive
[173]84 jnz SHORT .StoreUserDefinedCHSaddressing
85
86 ; Check if LBA supported
[169]87 call AtaID_GetPCHStoAXBLBHfromAtaInfoInESSI
[173]88 test BYTE [es:si+ATA1.wCaps+1], A1_wCaps_LBA>>8
89 jz SHORT .StoreCHSaddressing
[3]90
[173]91 ; Check if 48-bit LBA supported
92 test BYTE [es:si+ATA6.wSetSup83+1], A6_wSetSup83_LBA48>>8
93 jz SHORT .StoreLBA28addressing
94 or BYTE [di+DPT.bFlagsLow], ADDRESSING_MODE_LBA48<<ADDRESSING_MODE_FIELD_POSITION
95.StoreLBA28addressing:
96 or BYTE [di+DPT.bFlagsLow], ADDRESSING_MODE_LBA28<<ADDRESSING_MODE_FIELD_POSITION
97 call AtaID_GetTotalSectorCountToBXDXAXfromAtaInfoInESSI
98 call AtaID_GetLbaAssistedCHStoDXAXBLBH
99 jmp SHORT .StoreChsFromDXAXBX
100
101 ; Check if P-CHS to L-CHS translation required
102.StoreUserDefinedCHSaddressing:
[3]103 call AccessDPT_GetPointerToDRVPARAMStoCSBX
104 mov ax, [cs:bx+DRVPARAMS.wCylinders]
[99]105 mov bx, [cs:bx+DRVPARAMS.wHeadsAndSectors]
[173]106.StoreCHSaddressing:
107 cmp ax, MAX_LCHS_CYLINDERS
108 jbe SHORT .StoreChsFromAXBX ; No translation required
[3]109
[173]110 ; We need to get number of bits to shift for translation
111 push bx
112 push ax
113 eMOVZX dx, bl ; Heads now in DX
114 xchg bx, ax ; Sectors now in BX
115 call AccessDPT_ShiftPCHinBXDXtoLCH
116 or cl, ADDRESSING_MODE_PCHS<<ADDRESSING_MODE_FIELD_POSITION
117 or [di+DPT.bFlagsLow], cl ; Store bits to shift
118 pop ax
119 pop bx
120 ; Fall to .StoreChsFromAXBX
[3]121
122;--------------------------------------------------------------------
[173]123; .StoreChsFromAXBX
124; .StoreChsFromDXAXBX
[3]125; Parameters:
[173]126; DX:AX or AX: Number of cylinders
127; BH: Number of sectors per track
128; BL: Number of heads
[3]129; DS:DI: Ptr to Disk Parameter Table
130; ES:SI: Ptr to 512-byte ATA information read from the drive
[160]131; CS:BP: Ptr to IDEVARS for the controller
[3]132; Returns:
[99]133; Nothing
[3]134; Corrupts registers:
[173]135; DX
[3]136;--------------------------------------------------------------------
[173]137.StoreChsFromAXBX:
138 xor dx, dx
139.StoreChsFromDXAXBX:
140 mov [di+DPT.dwCylinders], ax
141 mov [di+DPT.dwCylinders+2], dx
142 mov [di+DPT.wHeadsAndSectors], bx
[99]143 ; Fall to .StoreBlockMode
[3]144
145;--------------------------------------------------------------------
[99]146; .StoreBlockMode
[3]147; Parameters:
148; DS:DI: Ptr to Disk Parameter Table
149; ES:SI: Ptr to 512-byte ATA information read from the drive
[160]150; CS:BP: Ptr to IDEVARS for the controller
[3]151; Returns:
[99]152; Nothing
[3]153; Corrupts registers:
[150]154; Nothing
[3]155;--------------------------------------------------------------------
[99]156.StoreBlockMode:
[150]157 cmp BYTE [es:si+ATA1.bBlckSize], 1 ; Max block size in sectors
158 jbe SHORT .BlockModeTransfersNotSupported
[158]159 or BYTE [di+DPT.bFlagsHigh], FLGH_DPT_BLOCK_MODE_SUPPORTED
[150]160.BlockModeTransfersNotSupported:
161 ; Fall to .StoreDeviceSpecificParameters
[3]162
163;--------------------------------------------------------------------
[150]164; .StoreDeviceSpecificParameters
[3]165; Parameters:
166; DS:DI: Ptr to Disk Parameter Table
167; ES:SI: Ptr to 512-byte ATA information read from the drive
[160]168; CS:BP: Ptr to IDEVARS for the controller
[3]169; Returns:
[99]170; Nothing
[3]171; Corrupts registers:
[150]172; AX, BX, CX, DX
[3]173;--------------------------------------------------------------------
[150]174.StoreDeviceSpecificParameters:
175 call Device_FinalizeDPT
[99]176 ; Fall to .StoreDriveNumberAndUpdateDriveCount
[3]177
178;--------------------------------------------------------------------
[99]179; .StoreDriveNumberAndUpdateDriveCount
[3]180; Parameters:
181; DS:DI: Ptr to Disk Parameter Table
182; ES:SI: Ptr to 512-byte ATA information read from the drive
[160]183; CS:BP: Ptr to IDEVARS for the controller
[3]184; ES: BDA Segment
185; Returns:
186; DL: Drive number for new drive
[162]187; CF: Always cleared
[3]188; Corrupts registers:
189; Nothing
190;--------------------------------------------------------------------
[99]191.StoreDriveNumberAndUpdateDriveCount:
[150]192 mov dl, [es:BDA.bHDCount]
193 or dl, 80h ; Set bit 7 since hard disk
[3]194
[150]195 inc BYTE [RAMVARS.bDrvCnt] ; Increment drive count to RAMVARS
196 inc BYTE [es:BDA.bHDCount] ; Increment drive count to BDA
[3]197
[150]198 cmp BYTE [RAMVARS.bFirstDrv], 0 ; First drive set?
199 ja SHORT .AllDone ; If so, return
200 mov [RAMVARS.bFirstDrv], dl ; Store first drive number
[162]201 clc
[150]202.AllDone:
[3]203 ret
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