source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CreateDPT.asm@ 544

Last change on this file since 544 was 544, checked in by aitotat@…, 12 years ago

Changes to XTIDE Universal BIOS:

  • Comparing BX:DX:AX against 15,482,880 sectors now works correctly.
  • P-Cylinders are now stored to Compatible DPTs if EBIOS functions are disabled by CHS adressing mode.
File size: 10.2 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%ifdef CREATE_COMPATIBLE_DPT
125 ; Store P-Cylinders here for Compatible DPTs when FLGL_DPT_LBA is not set
126 ; or when drive has over 15,482,880 sectors
127 mov [di+DPT.wPchsCylinders], ax
128%endif
129 test cl, FLGL_DPT_LBA
130 jz SHORT .NoLbaSoNoEBIOS
131
132 ; Store P-Cylinders but only if we have 15,482,880 or less sectors since
133 ; we only need P-Cylinders so we can return it from AH=48h
134 call AtaGeometry_GetLbaSectorCountToBXDXAXfromAtaInfoInESSI
135 sub ax, (MAX_SECTOR_COUNT_TO_RETURN_PCHS+1) & 0FFFFh
136 sbb dx, (MAX_SECTOR_COUNT_TO_RETURN_PCHS+1) >> 16
137 sbb bx, BYTE 0
138 jnc SHORT .StoreNumberOfLbaSectors
139
140 ; Since we might have altered the default P-CHS parameters to be
141 ; presented to the drive (AH=09h), we need to calculate new
142 ; P-Cylinders. It could be read from the ATA ID after
143 ; COMMAND_INITIALIZE_DEVICE_PARAMETERS but that is too much trouble.
144 ; P-Cyls = MIN(16383*16*63, LBA sector count) / (P-Heads * P-Sectors per track)
145 call AtaGeometry_GetLbaSectorCountToBXDXAXfromAtaInfoInESSI
146 xchg cx, ax ; Sector count to DX:CX
147 mov al, [di+DPT.bPchsHeads]
148 mul BYTE [di+DPT.bPchsSectorsPerTrack]
149 xchg cx, ax
150 div cx ; AX = new P-Cylinders
151
152 ; We could remove wPchsCylinders from DPT if we calculate it on AH=48h
153 ; (and for compatible DPTs) but that would require extra code so we save ROM space instead.
154 mov [di+DPT.wPchsCylinders], ax
155
156 ; Store CHS sector count as total sector count. We must not use
157 ; LBA sector count if it is 15,482,880 or less.
158 mul cx
159 xor bx, bx
160 jmp SHORT .StoreTotalSectorsFromBXDXAX
161 ; Fall to .StoreNumberOfLbaSectors
162
163;--------------------------------------------------------------------
164; .StoreNumberOfLbaSectors
165; Parameters:
166; DS:DI: Ptr to Disk Parameter Table
167; ES:SI: Ptr to 512-byte ATA information read from the drive
168; CS:BP: Ptr to IDEVARS for the controller
169; Returns:
170; Nothing
171; Corrupts registers:
172; AX, BX, CX, DX
173;--------------------------------------------------------------------
174.StoreNumberOfLbaSectors:
175 ; Store LBA 28/48 total sector count
176 call AtaGeometry_GetLbaSectorCountToBXDXAXfromAtaInfoInESSI
177 or [di+DPT.bFlagsLow], cl ; LBA48 flag
178.StoreTotalSectorsFromBXDXAX:
179 mov [di+DPT.twLbaSectors], ax
180 mov [di+DPT.twLbaSectors+2], dx
181 mov [di+DPT.twLbaSectors+4], bx
182.NoLbaSoNoEBIOS:
183%endif ; MODULE_EBIOS
184 ; Fall to .StoreBlockMode
185
186;--------------------------------------------------------------------
187; .StoreBlockMode
188; Parameters:
189; DS:DI: Ptr to Disk Parameter Table
190; ES:SI: Ptr to 512-byte ATA information read from the drive
191; CS:BP: Ptr to IDEVARS for the controller
192; Returns:
193; Nothing
194; Corrupts registers:
195; Nothing
196;--------------------------------------------------------------------
197.StoreBlockMode:
198 cmp BYTE [es:si+ATA1.bBlckSize], 1 ; Max block size in sectors
199 jbe SHORT .BlockModeTransfersNotSupported
200 or BYTE [di+DPT.bFlagsHigh], FLGH_DPT_BLOCK_MODE_SUPPORTED
201.BlockModeTransfersNotSupported:
202 ; Fall to .StoreDeviceSpecificParameters
203
204;--------------------------------------------------------------------
205; .StoreDeviceSpecificParameters
206; Parameters:
207; DS:DI: Ptr to Disk Parameter Table
208; ES:SI: Ptr to 512-byte ATA information read from the drive
209; CS:BP: Ptr to IDEVARS for the controller
210; Returns:
211; Nothing
212; Corrupts registers:
213; AX, BX, CX, DX
214;--------------------------------------------------------------------
215.StoreDeviceSpecificParameters:
216 call Device_FinalizeDPT
217
218;----------------------------------------------------------------------
219; Update drive counts (hard and floppy)
220;----------------------------------------------------------------------
221
222%ifdef MODULE_SERIAL_FLOPPY
223;
224; These two instructions serve two purposes:
225; 1. If the drive is a floppy drive (CF set), then we effectively increment the counter.
226; 2. If this is a hard disk, and there have been any floppy drives previously added, then the hard disk is
227; effectively discarded. This is more of a safety check then code that should ever normally be hit (see below).
228; Since the floppy DPT's come after the hard disk DPT's, without expensive (code size) code to relocate a DPT,
229; this was necessary. Now, this situation shouldn't happen in normal operation, for a couple of reasons:
230; A. xtidecfg always puts configured serial ports at the end of the IDEVARS list
231; B. the auto serial code is always executed last
232; C. the serial server always returns floppy drives last
233;
234 adc byte [RAMVARS.xlateVars+XLATEVARS.bFlopCreateCnt], 0
235 jnz .AllDone
236%else
237;
238; Even without floppy support enabled, we shouldn't try to mount a floppy image as a hard disk, which
239; could lead to unpredictable results since no MBR will be present, etc. The server doesn't know that
240; floppies are supported, so it is important to still fail here if a floppy is seen during the drive scan.
241;
242 jc .AllDone
243%endif
244
245 inc BYTE [RAMVARS.bDrvCnt] ; Increment drive count to RAMVARS
246
247.AllDone:
248 clc
249 ret
250
251
252;--------------------------------------------------------------------
253; CreateDPT_StoreIdevarsOffsetAndBasePortFromCSBPtoDPTinDSDI
254; Parameters:
255; DX: Autodetected port (for devices that support autodetection)
256; DS:DI: Ptr to Disk Parameter Table
257; CS:BP: Ptr to IDEVARS for the controller
258; Returns:
259; Nothing
260; Corrupts registers:
261; AX
262;--------------------------------------------------------------------
263CreateDPT_StoreIdevarsOffsetAndBasePortFromCSBPtoDPTinDSDI:
264 mov [di+DPT.bIdevarsOffset], bp ; IDEVARS must start in first 256 bytes of ROM
265
266%ifdef MODULE_8BIT_IDE_ADVANCED
267 call DetectDrives_DoesIdevarsInCSBPbelongToXTCF
268 jne SHORT .DeviceUsesPortSpecifiedInIDEVARS
269 mov [di+DPT.wBasePort], dx
270 ret
271.DeviceUsesPortSpecifiedInIDEVARS:
272%endif ; MODULE_8BIT_IDE_ADVANCED
273
274 mov ax, [cs:bp+IDEVARS.wBasePort]
275 mov [di+DPT.wBasePort], ax
276 ret
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