source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CreateDPT.asm@ 187

Last change on this file since 187 was 181, checked in by krille_n_@…, 13 years ago

Changes to all parts of the project:

  • Size optimizations.
  • Added a define (EXCLUDE_FROM_XTIDECFG) to exclude unused library code from XTIDECFG.
  • Tried to minimize time spent with interrupts disabled.
  • Some minor attempts to improve speed (reordering instructions etc).
  • Tried to improve readability, did some cleanup and fixed some errors in comments.
File size: 7.1 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
[175]65
66%ifdef MODULE_SERIAL
67 cmp byte [cs:bp+IDEVARS.bDevice], DEVICE_SERIAL_PORT
[181]68 jnz .StoreAddressing
[175]69 or byte [di+DPT.bFlagsHigh], FLGH_DPT_SERIAL_DEVICE
[181]70%endif
[173]71 ; Fall to .StoreAddressing
[3]72
73;--------------------------------------------------------------------
[173]74; .StoreAddressing
[3]75; Parameters:
76; DS:DI: Ptr to Disk Parameter Table
77; ES:SI: Ptr to 512-byte ATA information read from the drive
78; CS:BP: Ptr to IDEVARS for the controller
79; Returns:
[173]80; DX:AX or AX: Number of cylinders
81; BH: Number of sectors per track
82; BL: Number of heads
[3]83; Corrupts registers:
[173]84; CX, (DX)
[3]85;--------------------------------------------------------------------
[173]86.StoreAddressing:
87 ; Check if CHS defined in ROMVARS
[99]88 mov al, FLG_DRVPARAMS_USERCHS ; User specified CHS?
[3]89 call AccessDPT_TestIdeVarsFlagsForMasterOrSlaveDrive
[173]90 jnz SHORT .StoreUserDefinedCHSaddressing
91
92 ; Check if LBA supported
[169]93 call AtaID_GetPCHStoAXBLBHfromAtaInfoInESSI
[173]94 test BYTE [es:si+ATA1.wCaps+1], A1_wCaps_LBA>>8
95 jz SHORT .StoreCHSaddressing
[3]96
[173]97 ; Check if 48-bit LBA supported
98 test BYTE [es:si+ATA6.wSetSup83+1], A6_wSetSup83_LBA48>>8
99 jz SHORT .StoreLBA28addressing
100 or BYTE [di+DPT.bFlagsLow], ADDRESSING_MODE_LBA48<<ADDRESSING_MODE_FIELD_POSITION
101.StoreLBA28addressing:
102 or BYTE [di+DPT.bFlagsLow], ADDRESSING_MODE_LBA28<<ADDRESSING_MODE_FIELD_POSITION
103 call AtaID_GetTotalSectorCountToBXDXAXfromAtaInfoInESSI
104 call AtaID_GetLbaAssistedCHStoDXAXBLBH
105 jmp SHORT .StoreChsFromDXAXBX
106
107 ; Check if P-CHS to L-CHS translation required
108.StoreUserDefinedCHSaddressing:
[3]109 call AccessDPT_GetPointerToDRVPARAMStoCSBX
110 mov ax, [cs:bx+DRVPARAMS.wCylinders]
[99]111 mov bx, [cs:bx+DRVPARAMS.wHeadsAndSectors]
[173]112.StoreCHSaddressing:
113 cmp ax, MAX_LCHS_CYLINDERS
114 jbe SHORT .StoreChsFromAXBX ; No translation required
[3]115
[173]116 ; We need to get number of bits to shift for translation
117 push ax
118 eMOVZX dx, bl ; Heads now in DX
[181]119 xchg bx, ax ; Cylinders now in BX
120 call AccessDPT_ShiftPCHinBXDXtoLCH ; Leaves AX untouched
121 xchg bx, ax ; Restore HeadsAndSectors to BX
[173]122 or cl, ADDRESSING_MODE_PCHS<<ADDRESSING_MODE_FIELD_POSITION
123 or [di+DPT.bFlagsLow], cl ; Store bits to shift
124 pop ax
125 ; Fall to .StoreChsFromAXBX
[3]126
127;--------------------------------------------------------------------
[173]128; .StoreChsFromAXBX
129; .StoreChsFromDXAXBX
[3]130; Parameters:
[173]131; DX:AX or AX: Number of cylinders
132; BH: Number of sectors per track
133; BL: Number of heads
[3]134; DS:DI: Ptr to Disk Parameter Table
135; ES:SI: Ptr to 512-byte ATA information read from the drive
[160]136; CS:BP: Ptr to IDEVARS for the controller
[3]137; Returns:
[99]138; Nothing
[3]139; Corrupts registers:
[173]140; DX
[3]141;--------------------------------------------------------------------
[173]142.StoreChsFromAXBX:
143 xor dx, dx
144.StoreChsFromDXAXBX:
145 mov [di+DPT.dwCylinders], ax
146 mov [di+DPT.dwCylinders+2], dx
147 mov [di+DPT.wHeadsAndSectors], bx
[99]148 ; Fall to .StoreBlockMode
[3]149
150;--------------------------------------------------------------------
[99]151; .StoreBlockMode
[3]152; Parameters:
153; DS:DI: Ptr to Disk Parameter Table
154; ES:SI: Ptr to 512-byte ATA information read from the drive
[160]155; CS:BP: Ptr to IDEVARS for the controller
[3]156; Returns:
[99]157; Nothing
[3]158; Corrupts registers:
[150]159; Nothing
[3]160;--------------------------------------------------------------------
[99]161.StoreBlockMode:
[150]162 cmp BYTE [es:si+ATA1.bBlckSize], 1 ; Max block size in sectors
163 jbe SHORT .BlockModeTransfersNotSupported
[158]164 or BYTE [di+DPT.bFlagsHigh], FLGH_DPT_BLOCK_MODE_SUPPORTED
[150]165.BlockModeTransfersNotSupported:
166 ; Fall to .StoreDeviceSpecificParameters
[3]167
168;--------------------------------------------------------------------
[150]169; .StoreDeviceSpecificParameters
[3]170; Parameters:
171; DS:DI: Ptr to Disk Parameter Table
172; ES:SI: Ptr to 512-byte ATA information read from the drive
[160]173; CS:BP: Ptr to IDEVARS for the controller
[3]174; Returns:
[99]175; Nothing
[3]176; Corrupts registers:
[150]177; AX, BX, CX, DX
[3]178;--------------------------------------------------------------------
[150]179.StoreDeviceSpecificParameters:
180 call Device_FinalizeDPT
[99]181 ; Fall to .StoreDriveNumberAndUpdateDriveCount
[3]182
183;--------------------------------------------------------------------
[99]184; .StoreDriveNumberAndUpdateDriveCount
[3]185; Parameters:
186; DS:DI: Ptr to Disk Parameter Table
187; ES:SI: Ptr to 512-byte ATA information read from the drive
[160]188; CS:BP: Ptr to IDEVARS for the controller
[3]189; ES: BDA Segment
190; Returns:
191; DL: Drive number for new drive
[162]192; CF: Always cleared
[3]193; Corrupts registers:
194; Nothing
195;--------------------------------------------------------------------
[99]196.StoreDriveNumberAndUpdateDriveCount:
[150]197 mov dl, [es:BDA.bHDCount]
198 or dl, 80h ; Set bit 7 since hard disk
[3]199
[150]200 inc BYTE [RAMVARS.bDrvCnt] ; Increment drive count to RAMVARS
201 inc BYTE [es:BDA.bHDCount] ; Increment drive count to BDA
[3]202
[150]203 cmp BYTE [RAMVARS.bFirstDrv], 0 ; First drive set?
204 ja SHORT .AllDone ; If so, return
205 mov [RAMVARS.bFirstDrv], dl ; Store first drive number
[162]206 clc
[150]207.AllDone:
[3]208 ret
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