source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CreateDPT.asm@ 557

Last change on this file since 557 was 550, checked in by aitotat@…, 12 years ago

Changes to XTIDE Universal BIOS:

  • CREATE_COMPATIBLE_DPT is now MODULE_COMPATIBLE_TABLES.
  • DPTs pointed by INT 41h and INT 46h are now swapped when swapping drives 81h and 80h.
  • Block mode commands are no longer used when block size is set to 1 with AH=24h.
File size: 9.6 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_GetLCHStoAXBLBHfromAtaInfoInESSIwithTranslateModeInDX
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 dl ; Set ZF if TRANSLATEMODE_LARGE, SF if TRANSLATEMODE_NORMAL
112 js SHORT .NothingToChange
113 jz SHORT .LimitHeadsForLargeAddressingMode
114
115 ; Set LBA bit for Assisted LBA
116 or cl, FLGL_DPT_LBA
117 jmp SHORT .NothingToChange
118
119.LimitHeadsForLargeAddressingMode:
120 ; We cannot have 16 P-Heads heads in Revised ECHS mode (8193 or more cylinders)
121 ; but 16 heads are allowed when there are 8192 or less cylinders (ECHS).
122 ; Both of these are LARGE modes so do not confuse with NORMAL mode.
123 call AtaGeometry_IsDriveSmallEnoughForECHS
124 jc SHORT .NothingToChange
125 dec bx ; Adjust 16 P-Heads to 15
126
127.NothingToChange:
128 or [di+DPT.bFlagsLow], cl ; Shift count and addressing mode
129 mov [di+DPT.wPchsHeadsAndSectors], bx
130%ifdef MODULE_COMPATIBLE_TABLES OR MODULE_EBIOS
131 ; Store P-Cylinders here for Compatible DPTs when FLGL_DPT_LBA is not set
132 ; or when drive has over 15,482,880 sectors
133 mov [di+DPT.wPchsCylinders], ax
134%endif
135
136%ifdef MODULE_EBIOS
137 test cl, FLGL_DPT_LBA
138 jz SHORT .NoLbaSoNoEBIOS
139
140 ; Store P-Cylinders but only if we have 15,482,880 or less sectors since
141 ; we only need P-Cylinders so we can return it from AH=48h
142 call AtaGeometry_GetLbaSectorCountToBXDXAXfromAtaInfoInESSI
143 sub ax, (MAX_SECTOR_COUNT_TO_RETURN_PCHS+1) & 0FFFFh
144 sbb dx, (MAX_SECTOR_COUNT_TO_RETURN_PCHS+1) >> 16
145 sbb bx, BYTE 0
146 jnc SHORT .StoreNumberOfLbaSectors
147
148 ; Since we might have altered the default P-CHS parameters to be
149 ; presented to the drive (AH=09h), we need to calculate new
150 ; P-Cylinders. It could be read from the ATA ID after
151 ; COMMAND_INITIALIZE_DEVICE_PARAMETERS but that is too much trouble.
152 ; P-Cyls = MIN(16383*16*63, LBA sector count) / (P-Heads * P-Sectors per track)
153 call AtaGeometry_GetLbaSectorCountToBXDXAXfromAtaInfoInESSI
154 xchg cx, ax ; Sector count to DX:CX
155 mov al, [di+DPT.bPchsHeads]
156 mul BYTE [di+DPT.bPchsSectorsPerTrack]
157 xchg cx, ax
158 div cx ; AX = new P-Cylinders
159
160 ; We could remove wPchsCylinders from DPT if we calculate it on AH=48h
161 ; (and for compatible DPTs) but that would require extra code so we save ROM space instead.
162 mov [di+DPT.wPchsCylinders], ax
163
164 ; Store CHS sector count as total sector count. We must not use
165 ; LBA sector count if it is 15,482,880 or less.
166 mul cx
167 xor bx, bx
168 jmp SHORT .StoreTotalSectorsFromBXDXAX
169 ; Fall to .StoreNumberOfLbaSectors
170
171;--------------------------------------------------------------------
172; .StoreNumberOfLbaSectors
173; Parameters:
174; DS:DI: Ptr to Disk Parameter Table
175; ES:SI: Ptr to 512-byte ATA information read from the drive
176; CS:BP: Ptr to IDEVARS for the controller
177; Returns:
178; Nothing
179; Corrupts registers:
180; AX, BX, CX, DX
181;--------------------------------------------------------------------
182.StoreNumberOfLbaSectors:
183 ; Store LBA 28/48 total sector count
184 call AtaGeometry_GetLbaSectorCountToBXDXAXfromAtaInfoInESSI
185 or [di+DPT.bFlagsLow], cl ; LBA48 flag
186.StoreTotalSectorsFromBXDXAX:
187 mov [di+DPT.twLbaSectors], ax
188 mov [di+DPT.twLbaSectors+2], dx
189 mov [di+DPT.twLbaSectors+4], bx
190.NoLbaSoNoEBIOS:
191%endif ; MODULE_EBIOS
192 ; Fall to .StoreDeviceSpecificParameters
193
194;--------------------------------------------------------------------
195; .StoreDeviceSpecificParameters
196; Parameters:
197; DS:DI: Ptr to Disk Parameter Table
198; ES:SI: Ptr to 512-byte ATA information read from the drive
199; CS:BP: Ptr to IDEVARS for the controller
200; Returns:
201; Nothing
202; Corrupts registers:
203; AX, BX, CX, DX
204;--------------------------------------------------------------------
205.StoreDeviceSpecificParameters:
206 call Device_FinalizeDPT
207
208;----------------------------------------------------------------------
209; Update drive counts (hard and floppy)
210;----------------------------------------------------------------------
211
212%ifdef MODULE_SERIAL_FLOPPY
213;
214; These two instructions serve two purposes:
215; 1. If the drive is a floppy drive (CF set), then we effectively increment the counter.
216; 2. If this is a hard disk, and there have been any floppy drives previously added, then the hard disk is
217; effectively discarded. This is more of a safety check then code that should ever normally be hit (see below).
218; Since the floppy DPT's come after the hard disk DPT's, without expensive (code size) code to relocate a DPT,
219; this was necessary. Now, this situation shouldn't happen in normal operation, for a couple of reasons:
220; A. xtidecfg always puts configured serial ports at the end of the IDEVARS list
221; B. the auto serial code is always executed last
222; C. the serial server always returns floppy drives last
223;
224 adc byte [RAMVARS.xlateVars+XLATEVARS.bFlopCreateCnt], 0
225 jnz .AllDone
226%else
227;
228; Even without floppy support enabled, we shouldn't try to mount a floppy image as a hard disk, which
229; could lead to unpredictable results since no MBR will be present, etc. The server doesn't know that
230; floppies are supported, so it is important to still fail here if a floppy is seen during the drive scan.
231;
232 jc .AllDone
233%endif
234
235 inc BYTE [RAMVARS.bDrvCnt] ; Increment drive count to RAMVARS
236
237.AllDone:
238 clc
239 ret
240
241
242;--------------------------------------------------------------------
243; CreateDPT_StoreIdevarsOffsetAndBasePortFromCSBPtoDPTinDSDI
244; Parameters:
245; DX: Autodetected port (for devices that support autodetection)
246; DS:DI: Ptr to Disk Parameter Table
247; CS:BP: Ptr to IDEVARS for the controller
248; Returns:
249; Nothing
250; Corrupts registers:
251; AX
252;--------------------------------------------------------------------
253CreateDPT_StoreIdevarsOffsetAndBasePortFromCSBPtoDPTinDSDI:
254 mov [di+DPT.bIdevarsOffset], bp ; IDEVARS must start in first 256 bytes of ROM
255 mov ax, [cs:bp+IDEVARS.wBasePort]
256 mov [di+DPT.wBasePort], ax
257 ret
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