source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/CreateDPT.asm@ 420

Last change on this file since 420 was 411, checked in by aitotat@…, 13 years ago

Changes to XTIDE Universal BIOS:

  • Moved some IRQ and LBA48 code to related modules.
File size: 10.8 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, 2011-2012 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; ES:SI: Ptr to 512-byte ATA information read from the drive
31; CS:BP: Ptr to IDEVARS for the controller
32; DS: RAMVARS segment
33; ES: BDA Segment
34; Returns:
35; DL: Drive number for new drive
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, DH
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; DS:DI: Ptr to Disk Parameter Table
51; CS:BP: Ptr to IDEVARS for the controller
52; Returns:
53; Nothing
54; Corrupts registers:
55; AX
56;--------------------------------------------------------------------
57.InitializeDPT:
58 mov [di+DPT.bIdevarsOffset], bp ; IDEVARS must start in first 256 bytes of ROM
59 ; Fall to .StoreDriveSelectAndDriveControlByte
60
61;--------------------------------------------------------------------
62; .StoreDriveSelectAndDriveControlByte
63; Parameters:
64; BH: Drive Select byte for Drive and Head Register
65; DS:DI: Ptr to Disk Parameter Table
66; ES:SI: Ptr to 512-byte ATA information read from the drive
67; CS:BP: Ptr to IDEVARS for the controller
68; Returns:
69; Nothing
70; Corrupts registers:
71; AX
72;--------------------------------------------------------------------
73.StoreDriveSelectAndDriveControlByte:
74 mov al, bh
75 and ax, BYTE FLG_DRVNHEAD_DRV ; AL now has Master/Slave bit
76%ifdef MODULE_IRQ
77 cmp [cs:bp+IDEVARS.bIRQ], ah ; Interrupts enabled?
78 jz SHORT .StoreFlags ; If not, do not set interrupt flag
79 or al, FLGL_DPT_ENABLE_IRQ
80.StoreFlags:
81%endif
82 mov [di+DPT.wFlags], ax
83 ; Fall to .StoreAddressing
84
85;--------------------------------------------------------------------
86; .StoreAddressing
87; Parameters:
88; DS:DI: Ptr to Disk Parameter Table
89; ES:SI: Ptr to 512-byte ATA information read from the drive
90; CS:BP: Ptr to IDEVARS for the controller
91; Returns:
92; Nothing
93; Corrupts registers:
94; AX, BX, CX, DX
95;--------------------------------------------------------------------
96.StoreAddressing:
97 ; Check if CHS defined in ROMVARS
98 call AccessDPT_GetPointerToDRVPARAMStoCSBX
99 test byte [cs:bx+DRVPARAMS.wFlags], FLG_DRVPARAMS_USERCHS ; User specified CHS?
100 jnz SHORT .StoreUserDefinedPCHS
101
102 ; Check if LBA supported
103 call AtaID_GetPCHStoAXBLBHfromAtaInfoInESSI
104 test BYTE [es:si+ATA1.wCaps+1], A1_wCaps_LBA>>8
105 jz SHORT .StoreCHSfromAXBHBL ; Small old drive with CHS addressing only
106
107 ; Store LBA 28/48 addressing and total sector count
108 call AtaID_GetTotalSectorCountToBXDXAXfromAtaInfoInESSI
109 call StoreLbaAddressingAndTotalSectorCountFromBXDXAX
110
111 ; Replace sector count with user defined if necessary
112 call AccessDPT_GetPointerToDRVPARAMStoCSBX
113 test BYTE [cs:bx+DRVPARAMS.wFlags], FLG_DRVPARAMS_USERLBA
114 jz SHORT .KeepTotalSectorsFromAtaID
115 mov ax, [cs:bx+DRVPARAMS.dwMaximumLBA]
116 mov dx, [cs:bx+DRVPARAMS.dwMaximumLBA+2]
117 xor bx, bx
118
119 ; Compare user defined and ATA-ID sector count and select smaller
120 cmp bx, [di+DPT.twLbaSectors+4]
121 jb SHORT .StoreUserDefinedSectorCountToDPT
122 cmp dx, [di+DPT.twLbaSectors+2]
123 jb SHORT .StoreUserDefinedSectorCountToDPT
124 ja SHORT .KeepTotalSectorsFromAtaID
125 cmp ax, [di+DPT.twLbaSectors]
126 jae SHORT .KeepTotalSectorsFromAtaID
127.StoreUserDefinedSectorCountToDPT:
128 call StoreLbaAddressingAndTotalSectorCountFromBXDXAX
129
130 ; Calculate L-CHS for old INT 13h
131.KeepTotalSectorsFromAtaID:
132 mov bx, [di+DPT.twLbaSectors+4] ; Restore BX
133 call LbaAssist_ConvertSectorCountFromBXDXAXtoLbaAssistedCHSinDXAXBLBH
134 mov [di+DPT.bLbaHeads], bl
135 jmp SHORT .StoreBlockMode
136
137;--------------------------------------------------------------------
138; .StoreUserDefinedPCHS
139; Parameters:
140; DS:DI: Ptr to Disk Parameter Table
141; ES:SI: Ptr to 512-byte ATA information read from the drive
142; CS:BP: Ptr to IDEVARS for the controller
143; Returns:
144; AX: Number of P-CHS cylinders
145; BH: Number of P-CHS sectors per track
146; BL: Number of P-CHS heads
147; Corrupts registers:
148; Nothing
149;--------------------------------------------------------------------
150.StoreUserDefinedPCHS:
151 call AccessDPT_GetPointerToDRVPARAMStoCSBX
152 mov ax, [cs:bx+DRVPARAMS.wCylinders]
153 mov bx, [cs:bx+DRVPARAMS.wHeadsAndSectors]
154 ; Fall to .StoreCHSfromAXBHBL
155
156;--------------------------------------------------------------------
157; .StoreCHSfromAXBHBL
158; Parameters:
159; AX: Number of P-CHS cylinders
160; BH: Number of P-CHS sectors per track
161; BL: Number of P-CHS heads
162; DS:DI: Ptr to Disk Parameter Table
163; ES:SI: Ptr to 512-byte ATA information read from the drive
164; CS:BP: Ptr to IDEVARS for the controller
165; Returns:
166; AX: Number of P-CHS cylinders
167; BH: Number of P-CHS sectors per track
168; BL: Number of P-CHS heads
169; Corrupts registers:
170; CX
171;--------------------------------------------------------------------
172.StoreCHSfromAXBHBL:
173 push ax
174 push bx
175 call AccessDPT_ShiftPCHinAXBLtoLCH ; Get number of bits to shift
176 pop bx
177 pop ax
178 jcxz .StorePCHSfromAXDX ; Small drive so use L-CHS addressing
179
180 ; Store P-CHS addressing mode and number of bits to shift in L-CHS to P-CHS translation
181 or cl, ADDRESSING_MODE_PCHS<<ADDRESSING_MODE_FIELD_POSITION
182 or [di+DPT.bFlagsLow], cl
183 ; Fall to .StoreChsFromAXBLBH
184
185;--------------------------------------------------------------------
186; .StoreChsFromAXBLBH
187; Parameters:
188; AX: Number of P-CHS cylinders
189; BH: Number of P-CHS sectors per track
190; BL: Number of P-CHS heads
191; DS:DI: Ptr to Disk Parameter Table
192; ES:SI: Ptr to 512-byte ATA information read from the drive
193; CS:BP: Ptr to IDEVARS for the controller
194; Returns:
195; Nothing
196; Corrupts registers:
197; Nothing
198;--------------------------------------------------------------------
199.StorePCHSfromAXDX:
200 mov [di+DPT.wPchsCylinders], ax
201 mov [di+DPT.wPchsHeadsAndSectors], bx
202 ; Fall to .StoreBlockMode
203
204;--------------------------------------------------------------------
205; .StoreBlockMode
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; Nothing
214;--------------------------------------------------------------------
215.StoreBlockMode:
216 cmp BYTE [es:si+ATA1.bBlckSize], 1 ; Max block size in sectors
217 jbe SHORT .BlockModeTransfersNotSupported
218 or BYTE [di+DPT.bFlagsHigh], FLGH_DPT_BLOCK_MODE_SUPPORTED
219.BlockModeTransfersNotSupported:
220 ; Fall to .StoreDeviceSpecificParameters
221
222;--------------------------------------------------------------------
223; .StoreDeviceSpecificParameters
224; Parameters:
225; DS:DI: Ptr to Disk Parameter Table
226; ES:SI: Ptr to 512-byte ATA information read from the drive
227; CS:BP: Ptr to IDEVARS for the controller
228; Returns:
229; Nothing
230; Corrupts registers:
231; AX, BX, CX, DX
232;--------------------------------------------------------------------
233.StoreDeviceSpecificParameters:
234 call Device_FinalizeDPT
235
236;----------------------------------------------------------------------
237; Update drive counts (hard and floppy)
238;----------------------------------------------------------------------
239
240%ifdef MODULE_SERIAL_FLOPPY
241;
242; These two instructions serve two purposes:
243; 1. If the drive is a floppy drive (CF set), then we effectively increment the counter.
244; 2. If this is a hard disk, and there have been any floppy drives previously added, then the hard disk is
245; effectively discarded. This is more of a safety check then code that should ever normally be hit (see below).
246; Since the floppy DPT's come after the hard disk DPT's, without expensive (code size) code to relocate a DPT,
247; this was necessary. Now, this situation shouldn't happen in normal operation, for a couple of reasons:
248; A. xtidecfg always puts configured serial ports at the end of the IDEVARS list
249; B. the auto serial code is always executed last
250; C. the serial server always returns floppy drives last
251;
252 adc byte [RAMVARS.xlateVars+XLATEVARS.bFlopCreateCnt], 0
253 jnz .AllDone
254%else
255;
256; Even without floppy support enabled, we shouldn't try to mount a floppy image as a hard disk, which
257; could lead to unpredictable results since no MBR will be present, etc. The server doesn't know that
258; floppies are supported, so it is important to still fail here if a floppy is seen during the drive scan.
259;
260 jc .AllDone
261%endif
262
263 inc BYTE [RAMVARS.bDrvCnt] ; Increment drive count to RAMVARS
264
265.AllDone:
266 clc
267 ret
268
269
270;--------------------------------------------------------------------
271; StoreLbaAddressingAndTotalSectorCountFromBXDXAX
272; Parameters:
273; BX:DX:AX: Total Sector Count
274; DS:DI: Ptr to Disk Parameter Table
275; Returns:
276; Nothing
277; Corrupts registers:
278; CX
279;--------------------------------------------------------------------
280StoreLbaAddressingAndTotalSectorCountFromBXDXAX:
281 mov [di+DPT.twLbaSectors], ax
282 mov [di+DPT.twLbaSectors+2], dx
283 mov [di+DPT.twLbaSectors+4], bx
284
285%ifdef MODULE_EBIOS
286 and BYTE [di+DPT.bFlagsLow], ~MASKL_DPT_ADDRESSING_MODE
287 test bx, bx
288 jnz SHORT .SetLba48AddressingToDPT ; Must be LBA48
289
290 ; Drives can report at most 0FFF FFFFh LBA28 sectors according to ATA specification.
291 ; That is (2^28)-1 so we can simply check if DH is zero or not.
292 test dh, dh
293 jz SHORT .SetLba28AddressingToDPT
294.SetLba48AddressingToDPT:
295 or BYTE [di+DPT.bFlagsLow], ADDRESSING_MODE_LBA48<<ADDRESSING_MODE_FIELD_POSITION
296.SetLba28AddressingToDPT:
297%endif
298 or BYTE [di+DPT.bFlagsLow], ADDRESSING_MODE_LBA28<<ADDRESSING_MODE_FIELD_POSITION
299 ret
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