source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CreateDPT.asm@ 542

Last change on this file since 542 was 542, checked in by aitotat@…, 12 years ago

Changes to XTIDE Universal BIOS:

  • Fixed a bug that allowed EBIOS functions for user defined CHS.
  • Simplified user defined CHS and LBA setup a little.
File size: 9.8 KB
Line 
1; Project name : XTIDE Universal BIOS
2; Description : Functions for creating Disk Parameter Table.
3
4;
5; XTIDE Universal BIOS and Associated Tools
6; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team.
7;
8; This program is free software; you can redistribute it and/or modify
9; it under the terms of the GNU General Public License as published by
10; the Free Software Foundation; either version 2 of the License, or
11; (at your option) any later version.
12;
13; This program is distributed in the hope that it will be useful,
14; but WITHOUT ANY WARRANTY; without even the implied warranty of
15; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16; GNU General Public License for more details.
17; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
18;
19
20; Section containing code
21SECTION .text
22
23;--------------------------------------------------------------------
24; Creates new Disk Parameter Table for detected hard disk.
25; Drive is then fully accessible using any BIOS function.
26;
27; CreateDPT_FromAtaInformation
28; Parameters:
29; BH: Drive Select byte for Drive and Head Register
30; DX: Autodetected port (for devices that support autodetection)
31; ES:SI: Ptr to 512-byte ATA information read from the drive
32; CS:BP: Ptr to IDEVARS for the controller
33; DS: RAMVARS segment
34; ES: BDA Segment
35; Returns:
36; DS:DI: Ptr to Disk Parameter Table (if successful)
37; CF: Cleared if DPT created successfully
38; Set if any error
39; Corrupts registers:
40; AX, BX, CX, DX
41;--------------------------------------------------------------------
42CreateDPT_FromAtaInformation:
43 call FindDPT_ForNewDriveToDSDI
44 ; Fall to .InitializeDPT
45
46;--------------------------------------------------------------------
47; .InitializeDPT
48; Parameters:
49; BH: Drive Select byte for Drive and Head Register
50; DX: Autodetected port (for devices that support autodetection)
51; DS:DI: Ptr to Disk Parameter Table
52; CS:BP: Ptr to IDEVARS for the controller
53; Returns:
54; Nothing
55; Corrupts registers:
56; AX
57;--------------------------------------------------------------------
58.InitializeDPT:
59 call CreateDPT_StoreIdevarsOffsetAndBasePortFromCSBPtoDPTinDSDI
60 ; Fall to .StoreDriveSelectAndDriveControlByte
61
62;--------------------------------------------------------------------
63; .StoreDriveSelectAndDriveControlByte
64; Parameters:
65; BH: Drive Select byte for Drive and Head Register
66; DS:DI: Ptr to Disk Parameter Table
67; ES:SI: Ptr to 512-byte ATA information read from the drive
68; CS:BP: Ptr to IDEVARS for the controller
69; Returns:
70; Nothing
71; Corrupts registers:
72; AX
73;--------------------------------------------------------------------
74.StoreDriveSelectAndDriveControlByte:
75 mov al, bh
76 and ax, BYTE FLG_DRVNHEAD_DRV ; AL now has Master/Slave bit
77%ifdef MODULE_IRQ
78 cmp [cs:bp+IDEVARS.bIRQ], ah ; Interrupts enabled?
79 jz SHORT .StoreFlags ; If not, do not set interrupt flag
80 or al, FLGL_DPT_ENABLE_IRQ
81.StoreFlags:
82%endif
83 mov [di+DPT.wFlags], ax
84 ; Fall to .StoreCHSparametersAndAddressingMode
85
86;--------------------------------------------------------------------
87; .StoreCHSparametersAndAddressingMode
88; Parameters:
89; DS:DI: Ptr to Disk Parameter Table
90; ES:SI: Ptr to 512-byte ATA information read from the drive
91; CS:BP: Ptr to IDEVARS for the controller
92; Returns:
93; Nothing
94; Corrupts registers:
95; AX, BX, CX, DX
96;--------------------------------------------------------------------
97.StoreCHSparametersAndAddressingMode:
98 ; Apply any user limited values to ATA ID
99 call AtaID_ModifyESSIforUserDefinedLimitsAndReturnTranslateModeInDX
100
101 ; Translate P-CHS to L-CHS
102 call AtaGeometry_GetLCHStoAXBLBHfromAtaInfoInESSIandTranslateModeInDX
103 mov [di+DPT.wLchsCylinders], ax
104 mov [di+DPT.wLchsHeadsAndSectors], bx
105 mov al, dl
106 eSHL_IM al, TRANSLATEMODE_FIELD_POSITION
107 or cl, al
108
109 ; Store P-CHS and flags
110 call AtaGeometry_GetPCHStoAXBLBHfromAtaInfoInESSI
111 dec dx ; Set ZF if TRANSLATEMODE_LARGE, SF if TRANSLATEMODE_NORMAL
112 js SHORT .NothingToChange
113 jz SHORT .LimitHeadsForLargeAddressingMode
114
115 or cl, FLGL_DPT_LBA ; Set LBA bit for Assisted LBA
116 jmp SHORT .NothingToChange
117.LimitHeadsForLargeAddressingMode:
118 MIN_U bl, 15 ; Cannot have 16 P-Heads in LARGE addressing mode
119.NothingToChange:
120 or [di+DPT.bFlagsLow], cl ; Shift count and addressing mode
121 mov [di+DPT.wPchsHeadsAndSectors], bx
122
123%ifdef MODULE_EBIOS
124 test cl, FLGL_DPT_LBA
125 jz SHORT .NoLbaSoNoEBIOS
126
127 ; Store P-Cylinders but only if we have 15,482,880 or less sectors since
128 ; we only need P-Cylinders so we can return it from AH=48h
129 call AtaGeometry_GetLbaSectorCountToBXDXAXfromAtaInfoInESSI
130 sub ax, MAX_SECTOR_COUNT_TO_RETURN_PCHS & 0FFFFh
131 sbb dx, MAX_SECTOR_COUNT_TO_RETURN_PCHS >> 16
132 sbb bx, BYTE 0
133 ja SHORT .StoreNumberOfLbaSectors
134
135 ; Since we might have altered the default P-CHS parameters to be
136 ; presented to the drive (AH=09h), we need to calculate new
137 ; P-Cylinders. It could be read from the ATA ID after
138 ; COMMAND_INITIALIZE_DEVICE_PARAMETERS but that is too much trouble.
139 ; P-Cyls = MIN(16383*16*63, LBA sector count) / (P-Heads * P-Sectors per track)
140 call AtaGeometry_GetLbaSectorCountToBXDXAXfromAtaInfoInESSI
141 xchg cx, ax ; Sector count to DX:CX
142 mov al, [di+DPT.bPchsHeads]
143 mul BYTE [di+DPT.bPchsSectorsPerTrack]
144 xchg cx, ax
145 div cx ; AX = new P-Cylinders
146 mov [di+DPT.wPchsCylinders], ax
147
148 ; Store CHS sector count as total sector count
149 mul cx
150 xor bx, bx
151 xor cx, cx ; Clear LBA48 flag
152 jmp SHORT .StoreTotalSectorsFromBXDXAXandLBA48flagFromCL
153 ; Fall to .StoreNumberOfLbaSectors
154
155;--------------------------------------------------------------------
156; .StoreNumberOfLbaSectors
157; Parameters:
158; DS:DI: Ptr to Disk Parameter Table
159; ES:SI: Ptr to 512-byte ATA information read from the drive
160; CS:BP: Ptr to IDEVARS for the controller
161; Returns:
162; Nothing
163; Corrupts registers:
164; AX, BX, CX, DX
165;--------------------------------------------------------------------
166.StoreNumberOfLbaSectors:
167 ; Store LBA 28/48 total sector count
168 call AtaGeometry_GetLbaSectorCountToBXDXAXfromAtaInfoInESSI
169.StoreTotalSectorsFromBXDXAXandLBA48flagFromCL:
170 or [di+DPT.bFlagsLow], cl
171 mov [di+DPT.twLbaSectors], ax
172 mov [di+DPT.twLbaSectors+2], dx
173 mov [di+DPT.twLbaSectors+4], bx
174.NoLbaSoNoEBIOS:
175%endif ; MODULE_EBIOS
176 ; Fall to .StoreBlockMode
177
178;--------------------------------------------------------------------
179; .StoreBlockMode
180; Parameters:
181; DS:DI: Ptr to Disk Parameter Table
182; ES:SI: Ptr to 512-byte ATA information read from the drive
183; CS:BP: Ptr to IDEVARS for the controller
184; Returns:
185; Nothing
186; Corrupts registers:
187; Nothing
188;--------------------------------------------------------------------
189.StoreBlockMode:
190 cmp BYTE [es:si+ATA1.bBlckSize], 1 ; Max block size in sectors
191 jbe SHORT .BlockModeTransfersNotSupported
192 or BYTE [di+DPT.bFlagsHigh], FLGH_DPT_BLOCK_MODE_SUPPORTED
193.BlockModeTransfersNotSupported:
194 ; Fall to .StoreDeviceSpecificParameters
195
196;--------------------------------------------------------------------
197; .StoreDeviceSpecificParameters
198; Parameters:
199; DS:DI: Ptr to Disk Parameter Table
200; ES:SI: Ptr to 512-byte ATA information read from the drive
201; CS:BP: Ptr to IDEVARS for the controller
202; Returns:
203; Nothing
204; Corrupts registers:
205; AX, BX, CX, DX
206;--------------------------------------------------------------------
207.StoreDeviceSpecificParameters:
208 call Device_FinalizeDPT
209
210;----------------------------------------------------------------------
211; Update drive counts (hard and floppy)
212;----------------------------------------------------------------------
213
214%ifdef MODULE_SERIAL_FLOPPY
215;
216; These two instructions serve two purposes:
217; 1. If the drive is a floppy drive (CF set), then we effectively increment the counter.
218; 2. If this is a hard disk, and there have been any floppy drives previously added, then the hard disk is
219; effectively discarded. This is more of a safety check then code that should ever normally be hit (see below).
220; Since the floppy DPT's come after the hard disk DPT's, without expensive (code size) code to relocate a DPT,
221; this was necessary. Now, this situation shouldn't happen in normal operation, for a couple of reasons:
222; A. xtidecfg always puts configured serial ports at the end of the IDEVARS list
223; B. the auto serial code is always executed last
224; C. the serial server always returns floppy drives last
225;
226 adc byte [RAMVARS.xlateVars+XLATEVARS.bFlopCreateCnt], 0
227 jnz .AllDone
228%else
229;
230; Even without floppy support enabled, we shouldn't try to mount a floppy image as a hard disk, which
231; could lead to unpredictable results since no MBR will be present, etc. The server doesn't know that
232; floppies are supported, so it is important to still fail here if a floppy is seen during the drive scan.
233;
234 jc .AllDone
235%endif
236
237 inc BYTE [RAMVARS.bDrvCnt] ; Increment drive count to RAMVARS
238
239.AllDone:
240 clc
241 ret
242
243
244;--------------------------------------------------------------------
245; CreateDPT_StoreIdevarsOffsetAndBasePortFromCSBPtoDPTinDSDI
246; Parameters:
247; DX: Autodetected port (for devices that support autodetection)
248; DS:DI: Ptr to Disk Parameter Table
249; CS:BP: Ptr to IDEVARS for the controller
250; Returns:
251; Nothing
252; Corrupts registers:
253; AX
254;--------------------------------------------------------------------
255CreateDPT_StoreIdevarsOffsetAndBasePortFromCSBPtoDPTinDSDI:
256 mov [di+DPT.bIdevarsOffset], bp ; IDEVARS must start in first 256 bytes of ROM
257
258%ifdef MODULE_8BIT_IDE_ADVANCED
259 call DetectDrives_DoesIdevarsInCSBPbelongToXTCF
260 jne SHORT .DeviceUsesPortSpecifiedInIDEVARS
261 mov [di+DPT.wBasePort], dx
262 ret
263.DeviceUsesPortSpecifiedInIDEVARS:
264%endif ; MODULE_8BIT_IDE_ADVANCED
265
266 mov ax, [cs:bp+IDEVARS.wBasePort]
267 mov [di+DPT.wBasePort], ax
268 ret
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