source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CreateDPT.asm@ 543

Last change on this file since 543 was 543, checked in by aitotat@…, 12 years ago

Changes to XTIDE Universal BIOS:

  • Compatible DPTs can no longer have more than 1024 cylinders.
File size: 10.0 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
147 ; We could remove wPchsCylinders from DPT if we calculate it on AH=48h
148 ; but that would require extra code so we save ROM space instead.
149 mov [di+DPT.wPchsCylinders], ax
150
151 ; Store CHS sector count as total sector count. We must not use
152 ; LBA sector count if it is 15,482,880 or less.
153 mul cx
154 xor bx, bx
155 jmp SHORT .StoreTotalSectorsFromBXDXAX
156 ; Fall to .StoreNumberOfLbaSectors
157
158;--------------------------------------------------------------------
159; .StoreNumberOfLbaSectors
160; Parameters:
161; DS:DI: Ptr to Disk Parameter Table
162; ES:SI: Ptr to 512-byte ATA information read from the drive
163; CS:BP: Ptr to IDEVARS for the controller
164; Returns:
165; Nothing
166; Corrupts registers:
167; AX, BX, CX, DX
168;--------------------------------------------------------------------
169.StoreNumberOfLbaSectors:
170 ; Store LBA 28/48 total sector count
171 call AtaGeometry_GetLbaSectorCountToBXDXAXfromAtaInfoInESSI
172 or [di+DPT.bFlagsLow], cl ; LBA48 flag
173.StoreTotalSectorsFromBXDXAX:
174 mov [di+DPT.twLbaSectors], ax
175 mov [di+DPT.twLbaSectors+2], dx
176 mov [di+DPT.twLbaSectors+4], bx
177.NoLbaSoNoEBIOS:
178%endif ; MODULE_EBIOS
179 ; Fall to .StoreBlockMode
180
181;--------------------------------------------------------------------
182; .StoreBlockMode
183; Parameters:
184; DS:DI: Ptr to Disk Parameter Table
185; ES:SI: Ptr to 512-byte ATA information read from the drive
186; CS:BP: Ptr to IDEVARS for the controller
187; Returns:
188; Nothing
189; Corrupts registers:
190; Nothing
191;--------------------------------------------------------------------
192.StoreBlockMode:
193 cmp BYTE [es:si+ATA1.bBlckSize], 1 ; Max block size in sectors
194 jbe SHORT .BlockModeTransfersNotSupported
195 or BYTE [di+DPT.bFlagsHigh], FLGH_DPT_BLOCK_MODE_SUPPORTED
196.BlockModeTransfersNotSupported:
197 ; Fall to .StoreDeviceSpecificParameters
198
199;--------------------------------------------------------------------
200; .StoreDeviceSpecificParameters
201; Parameters:
202; DS:DI: Ptr to Disk Parameter Table
203; ES:SI: Ptr to 512-byte ATA information read from the drive
204; CS:BP: Ptr to IDEVARS for the controller
205; Returns:
206; Nothing
207; Corrupts registers:
208; AX, BX, CX, DX
209;--------------------------------------------------------------------
210.StoreDeviceSpecificParameters:
211 call Device_FinalizeDPT
212
213;----------------------------------------------------------------------
214; Update drive counts (hard and floppy)
215;----------------------------------------------------------------------
216
217%ifdef MODULE_SERIAL_FLOPPY
218;
219; These two instructions serve two purposes:
220; 1. If the drive is a floppy drive (CF set), then we effectively increment the counter.
221; 2. If this is a hard disk, and there have been any floppy drives previously added, then the hard disk is
222; effectively discarded. This is more of a safety check then code that should ever normally be hit (see below).
223; Since the floppy DPT's come after the hard disk DPT's, without expensive (code size) code to relocate a DPT,
224; this was necessary. Now, this situation shouldn't happen in normal operation, for a couple of reasons:
225; A. xtidecfg always puts configured serial ports at the end of the IDEVARS list
226; B. the auto serial code is always executed last
227; C. the serial server always returns floppy drives last
228;
229 adc byte [RAMVARS.xlateVars+XLATEVARS.bFlopCreateCnt], 0
230 jnz .AllDone
231%else
232;
233; Even without floppy support enabled, we shouldn't try to mount a floppy image as a hard disk, which
234; could lead to unpredictable results since no MBR will be present, etc. The server doesn't know that
235; floppies are supported, so it is important to still fail here if a floppy is seen during the drive scan.
236;
237 jc .AllDone
238%endif
239
240 inc BYTE [RAMVARS.bDrvCnt] ; Increment drive count to RAMVARS
241
242.AllDone:
243 clc
244 ret
245
246
247;--------------------------------------------------------------------
248; CreateDPT_StoreIdevarsOffsetAndBasePortFromCSBPtoDPTinDSDI
249; Parameters:
250; DX: Autodetected port (for devices that support autodetection)
251; DS:DI: Ptr to Disk Parameter Table
252; CS:BP: Ptr to IDEVARS for the controller
253; Returns:
254; Nothing
255; Corrupts registers:
256; AX
257;--------------------------------------------------------------------
258CreateDPT_StoreIdevarsOffsetAndBasePortFromCSBPtoDPTinDSDI:
259 mov [di+DPT.bIdevarsOffset], bp ; IDEVARS must start in first 256 bytes of ROM
260
261%ifdef MODULE_8BIT_IDE_ADVANCED
262 call DetectDrives_DoesIdevarsInCSBPbelongToXTCF
263 jne SHORT .DeviceUsesPortSpecifiedInIDEVARS
264 mov [di+DPT.wBasePort], dx
265 ret
266.DeviceUsesPortSpecifiedInIDEVARS:
267%endif ; MODULE_8BIT_IDE_ADVANCED
268
269 mov ax, [cs:bp+IDEVARS.wBasePort]
270 mov [di+DPT.wBasePort], ax
271 ret
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