source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/FindDPT.asm@ 562

Last change on this file since 562 was 526, checked in by krille_n_@…, 11 years ago

Changes:

  • Update of the copyright notices to include the year 2013.
File size: 9.5 KB
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[150]1; Project name : XTIDE Universal BIOS
[3]2; Description : Functions for finding Disk Parameter Table.
3
[376]4;
[526]5; XTIDE Universal BIOS and Associated Tools
6; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team.
[376]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.
[526]12;
[376]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
[526]16; GNU General Public License for more details.
[376]17; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
[526]18;
[376]19
[3]20; Section containing code
21SECTION .text
22
23;--------------------------------------------------------------------
[262]24; Checks if drive is handled by this BIOS, and return DPT pointer.
[3]25;
[294]26; FindDPT_ForDriveNumberInDL
[3]27; Parameters:
[262]28; DL: Drive number
[3]29; DS: RAMVARS segment
30; Returns:
[262]31; CF: Cleared if drive is handled by this BIOS
32; Set if drive belongs to some other BIOS
33; DI: DPT Pointer if drive is handled by this BIOS
34; Zero if drive belongs to some other BIOS
[3]35; Corrupts registers:
[262]36; Nothing
[150]37;--------------------------------------------------------------------
38ALIGN JUMP_ALIGN
[294]39FindDPT_ForDriveNumberInDL:
[262]40 xchg di, ax ; Save the contents of AX in DI
41
[294]42;
[262]43; Check Our Hard Disks
44;
[433]45 mov ax, [RAMVARS.wFirstDrvAndCount] ; Drive count to AH, First number to AL
[262]46 add ah, al ; One past last drive to AH
47
[258]48%ifdef MODULE_SERIAL_FLOPPY
[262]49 cmp dl, ah ; Above last supported?
50 jae SHORT .HardDiskNotHandledByThisBIOS
[294]51
[262]52 cmp dl, al ; Below first supported?
53 jae SHORT .CalcDPTForDriveNumber
54
[294]55ALIGN JUMP_ALIGN
56.HardDiskNotHandledByThisBIOS:
[262]57;
58; Check Our Floppy Disks
[294]59;
[262]60 call RamVars_UnpackFlopCntAndFirstToAL
61 js SHORT .DiskIsNotHandledByThisBIOS
[294]62
[277]63 cbw ; Always 0h (no floppy drive covered above)
64 adc ah, al ; Add in first drive number and number of drives
65
[262]66 cmp ah, dl ; Check second drive if two, first drive if only one
67 jz SHORT .CalcDPTForDriveNumber
68 cmp al, dl ; Check first drive in all cases, redundant but OK to repeat
[294]69 jnz SHORT .DiskIsNotHandledByThisBIOS
[262]70%else
[294]71 cmp dl, ah ; Above last supported?
[262]72 jae SHORT .DiskIsNotHandledByThisBIOS
[294]73
[262]74 cmp dl, al ; Below first supported?
[294]75 jb SHORT .DiskIsNotHandledByThisBIOS
[258]76%endif
[262]77 ; fall-through to CalcDPTForDriveNumber
[150]78
79;--------------------------------------------------------------------
80; Finds Disk Parameter Table for drive number.
[294]81; Not intended to be called except by FindDPT_ForDriveNumberInDL
[150]82;
[262]83; CalcDPTForDriveNumber
[150]84; Parameters:
85; DL: Drive number
86; DS: RAMVARS segment
[294]87; DI: Saved copy of AX from entry at FindDPT_ForDriveNumberInDL
[150]88; Returns:
89; DS:DI: Ptr to DPT
[262]90; CF: Clear
[150]91; Corrupts registers:
[3]92; Nothing
93;--------------------------------------------------------------------
94ALIGN JUMP_ALIGN
[262]95.CalcDPTForDriveNumber:
[150]96 push dx
[3]97
[258]98%ifdef MODULE_SERIAL_FLOPPY
[433]99 mov ax, [RAMVARS.wFirstDrvAndCount]
[294]100
[258]101 test dl, dl
102 js .harddisk
103
104 call RamVars_UnpackFlopCntAndFirstToAL
105 add dl, ah ; add in end of hard disk DPT list, floppies start immediately after
[294]106
107ALIGN JUMP_ALIGN
[258]108.harddisk:
109 sub dl, al ; subtract off beginning of either hard disk or floppy list (as appropriate)
110%else
111 sub dl, [RAMVARS.bFirstDrv] ; subtract off beginning of hard disk list
112%endif
[262]113
[294]114.CalcDPTForNewDrive:
[150]115 mov al, LARGEST_DPT_SIZE
[294]116
[150]117 mul dl
[522]118 add ax, RAMVARS_size ; Clears CF (will not overflow)
[3]119
[150]120 pop dx
[262]121
122 xchg di, ax ; Restore AX from entry at FindDPT_ForDriveNumber, put DPT pointer in DI
[150]123 ret
124
[294]125ALIGN JUMP_ALIGN
126.DiskIsNotHandledByThisBIOS:
[259]127;
[262]128; Drive not found...
129;
130 xor ax, ax ; Clear DPT pointer
[294]131 stc ; Is not supported by our BIOS
132
[262]133 xchg di, ax ; Restore AX from save at top
[259]134 ret
135
[271]136
[259]137;--------------------------------------------------------------------
[521]138; FindDPT_MasterOrSingleForIdevarsOffsetInDL
[271]139; Parameters:
140; DL: Offset to IDEVARS to search for
141; DS: RAMVARS segment
142; Returns:
143; DS:DI: Ptr to first DPT with same IDEVARS as in DL
144; CF: Clear if wanted DPT found
145; Set if DPT not found, or no DPTs present
146; Corrupts registers:
147; SI
148;--------------------------------------------------------------------
[521]149FindDPT_MasterOrSingleForIdevarsOffsetInDL:
[271]150 mov si, IterateFindFirstDPTforIdevars ; iteration routine (see below)
151 jmp SHORT FindDPT_IterateAllDPTs ; look for the first drive on this controller, if any
152
153;--------------------------------------------------------------------
[521]154; FindDPT_SlaveForIdevarsOffsetInDL
155; Parameters:
156; DL: Offset to IDEVARS to search for
157; DS: RAMVARS segment
158; Returns:
159; DS:DI: Ptr to second DPT with same IDEVARS as in DL
160; CF: Clear if wanted DPT found
161; Set if DPT not found, or no DPTs present
162; Corrupts registers:
163; SI
164;--------------------------------------------------------------------
165FindDPT_SlaveForIdevarsOffsetInDL:
166 mov si, IterateFindSecondDPTforIdevars ; iteration routine (see below)
167 jmp SHORT FindDPT_IterateAllDPTs ; look for the second drive on this controller, if any
168
169;--------------------------------------------------------------------
170; Iteration routines for FindDPT_MasterOrSingleForIdevarsOffsetInDL and
171; FindDPT_SlaveForIdevarsOffsetInDL, for use with IterateAllDPTs
[294]172;
[271]173; Returns when DPT is found on the controller with Idevars offset in DL
174;
[521]175; IterateFindSecondDPTforIdevars
[271]176; IterateFindFirstDPTforIdevars
177; DL: Offset to IDEVARS to search from DPTs
[524]178; SI: Offset to this callback function
[271]179; DS:DI: Ptr to DPT to examine
180; Returns:
181; CF: Clear if wanted DPT found
182; Set if wrong DPT
183;--------------------------------------------------------------------
[521]184IterateFindSecondDPTforIdevars:
185 call IterateFindFirstDPTforIdevars
[524]186 jc SHORT .WrongController
187 mov si, IterateFindFirstDPTforIdevars
188.WrongController:
189 stc
190 ret
[521]191
[294]192IterateFindFirstDPTforIdevars:
[271]193 cmp dl, [di+DPT.bIdevarsOffset] ; Clears CF if matched
194 je .done
195 stc ; Set CF for not found
[294]196.done:
[271]197 ret
198
199
200;--------------------------------------------------------------------
[262]201; Finds pointer to first unused Disk Parameter Table.
202; Should only be used before DetectDrives is complete (not valid after this time).
[3]203;
[262]204; FindDPT_ForNewDriveToDSDI
[3]205; Parameters:
206; DS: RAMVARS segment
207; Returns:
[262]208; DS:DI: Ptr to first unused DPT
[3]209; Corrupts registers:
[262]210; AX
[3]211;--------------------------------------------------------------------
[262]212ALIGN JUMP_ALIGN
213FindDPT_ForNewDriveToDSDI:
214 push dx
[294]215
[262]216%ifdef MODULE_SERIAL_FLOPPY
217 mov dx, [RAMVARS.wDrvCntAndFlopCnt]
218 add dl, dh
219%else
220 mov dl, [RAMVARS.bDrvCnt]
221%endif
[294]222
[262]223 jmp short FindDPT_ForDriveNumberInDL.CalcDPTForNewDrive
[3]224
[152]225;--------------------------------------------------------------------
[233]226; IterateToDptWithFlagsHighInBL
[152]227; Parameters:
228; DS:DI: Ptr to DPT to examine
[294]229; BL: Bit(s) to test in DPT.bFlagsHigh
[152]230; Returns:
[262]231; CF: Clear if wanted DPT found
232; Set if wrong DPT
[152]233; Corrupts registers:
234; Nothing
235;--------------------------------------------------------------------
236ALIGN JUMP_ALIGN
[294]237IterateToDptWithFlagsHighInBL:
238 test [di+DPT.bFlagsHigh], bl ; Clears CF
[262]239 jnz SHORT .ReturnRightDPT
240 stc
[294]241.ReturnRightDPT:
[3]242 ret
243
244;--------------------------------------------------------------------
[233]245; FindDPT_ToDSDIforSerialDevice
[161]246; Parameters:
247; DS: RAMVARS segment
248; Returns:
249; DS:DI: Ptr to DPT
250; CF: Set if wanted DPT found
251; Cleared if DPT not found
252; Corrupts registers:
[203]253; SI
[161]254;--------------------------------------------------------------------
[265]255%ifdef MODULE_SERIAL
[294]256ALIGN JUMP_ALIGN
257FindDPT_ToDSDIforSerialDevice:
[233]258 mov bl, FLGH_DPT_SERIAL_DEVICE
259; fall-through
[265]260%endif
[294]261
[233]262;--------------------------------------------------------------------
263; FindDPT_ToDSDIforFlagsHigh
264; Parameters:
265; DS: RAMVARS segment
266; BL: Bit(s) to test in DPT.bFlagsHigh
267; Returns:
268; DS:DI: Ptr to DPT
269; CF: Set if wanted DPT found
270; Cleared if DPT not found
271; Corrupts registers:
272; SI
273;--------------------------------------------------------------------
[526]274%ifdef MODULE_IRQ
[161]275ALIGN JUMP_ALIGN
[526]276FindDPT_ToDSDIforFlagsHighInBL:
[489]277%endif
[233]278 mov si, IterateToDptWithFlagsHighInBL
[161]279 ; Fall to IterateAllDPTs
280
281;--------------------------------------------------------------------
[3]282; Iterates all Disk Parameter Tables.
283;
[271]284; FindDPT_IterateAllDPTs
[3]285; Parameters:
[152]286; AX,BX,DX: Parameters to callback function
287; CS:SI: Ptr to callback function
[262]288; Callback routine should return CF=clear if found
[152]289; DS: RAMVARS segment
[3]290; Returns:
[152]291; DS:DI: Ptr to wanted DPT (if found)
[258]292; If not found, points to first empty DPT
[262]293; CF: Clear if wanted DPT found
294; Set if DPT not found, or no DPTs present
[3]295; Corrupts registers:
[150]296; Nothing unless corrupted by callback function
[3]297;--------------------------------------------------------------------
298ALIGN JUMP_ALIGN
[271]299FindDPT_IterateAllDPTs:
[3]300 push cx
[258]301
302 mov di, RAMVARS_size ; Point DS:DI to first DPT
[294]303 eMOVZX cx, [RAMVARS.bDrvCnt]
[262]304 jcxz .NotFound ; Return if no drives
[294]305
[3]306ALIGN JUMP_ALIGN
307.LoopWhileDPTsLeft:
308 call si ; Is wanted DPT?
[262]309 jnc SHORT .Found ; If so, return
310 add di, BYTE LARGEST_DPT_SIZE ; Point to next DPT
[258]311 loop .LoopWhileDPTsLeft
[262]312
[3]313ALIGN JUMP_ALIGN
[262]314.NotFound:
315 stc
316
317ALIGN JUMP_ALIGN
318.Found:
[3]319 pop cx
320 ret
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