source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH0h_HReset.asm@ 389

Last change on this file since 389 was 376, checked in by gregli@…, 12 years ago

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1; Project name : XTIDE Universal BIOS
2; Description : Int 13h function AH=0h, Disk Controller Reset.
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; Int 13h function AH=0h, Disk Controller Reset.
25;
26; Note: We handle all AH=0h calls, even for drives handled by other
27; BIOSes!
28;
29; AH0h_HandlerForDiskControllerReset
30; Parameters:
31; DL: Translated Drive number (ignored so all drives are reset)
32; If bit 7 is set all hard disks and floppy disks reset.
33; DS:DI: Ptr to DPT (or Null if foreign drive)
34; SS:BP: Ptr to IDEPACK
35; Returns with INTPACK:
36; AH: Int 13h return status (from drive requested in DL)
37; CF: 0 if successful, 1 if error
38;--------------------------------------------------------------------
39AH0h_HandlerForDiskControllerReset:
40 eMOVZX bx, dl ; Copy requested drive to BL, zero BH to assume no errors
41 call ResetFloppyDrivesWithInt40h
42
43%ifdef MODULE_SERIAL_FLOPPY
44;
45; "Reset" emulated serial floppy drives, if any. There is nothing to actually do for this reset,
46; but record the proper error return code if one of these floppy drives is the drive requested.
47;
48 call RamVars_UnpackFlopCntAndFirstToAL
49 cbw ; Clears AH (there are flop drives) or ffh (there are not)
50 ; Either AH has success code (flop drives are present)
51 ; or it doesn't matter because we won't match drive ffh
52
53 cwd ; clears DX (there are flop drives) or ffffh (there are not)
54
55 adc dl, al ; second drive (CF set) if present
56 ; If no drive is present, this will result in ffh which
57 ; won't match a drive
58 call BackupErrorCodeFromTheRequestedDriveToBH
59 mov dl, al ; We may end up doing the first drive twice (if there is
60 call BackupErrorCodeFromTheRequestedDriveToBH ; only one drive), but doing it again is not harmful.
61%endif
62
63 test bl, bl ; If we were called with a floppy disk, then we are done,
64 jns SHORT .SkipHardDiskReset ; don't do hard disks.
65
66 call ResetForeignHardDisks
67
68 ; Resetting our hard disks will modify dl and bl to be idevars offset based instead of drive number based,
69 ; such that this call must be the last in the list of reset routines called.
70 ;
71 ; This needs to happen after ResetForeignHardDisks, as that call may have set the error code for 80h,
72 ; and we need to override that value if we are xlate'd into 80h with one of our drives.
73 ;
74 call ResetHardDisksHandledByOurBIOS
75
76.SkipHardDiskReset:
77 mov ah, bh
78 jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH
79
80
81;--------------------------------------------------------------------
82; ResetFloppyDrivesWithInt40h
83; Parameters:
84; BL: Requested drive (DL when entering AH=00h)
85; Returns:
86; BH: Error code from requested drive (if available)
87; Corrupts registers:
88; AX, DL, DI
89;--------------------------------------------------------------------
90ResetFloppyDrivesWithInt40h:
91 call GetDriveNumberForForeignHardDiskHandlerToDL
92 and dl, 7Fh ; Clear hard disk bit
93 xor ah, ah ; Disk Controller Reset
94 int BIOS_DISKETTE_INTERRUPT_40h
95 jmp SHORT BackupErrorCodeFromTheRequestedDriveToBH
96
97
98;--------------------------------------------------------------------
99; ResetForeignHardDisks
100; Parameters:
101; BL: Requested drive (DL when entering AH=00h)
102; DS: RAMVARS segment
103; Returns:
104; BH: Error code from requested drive (if available)
105; Corrupts registers:
106; AX, DL, DI
107;--------------------------------------------------------------------
108ResetForeignHardDisks:
109 call GetDriveNumberForForeignHardDiskHandlerToDL
110 xor ah, ah ; Disk Controller Reset
111 call Int13h_CallPreviousInt13hHandler
112;;; fall-through to BackupErrorCodeFromTheRequestedDriveToBH
113
114
115;--------------------------------------------------------------------
116; BackupErrorCodeFromTheRequestedDriveToBH
117; Parameters:
118; AH: Error code from the last resetted drive
119; DL: Drive last resetted
120; BL: Requested drive (DL when entering AH=00h)
121; Returns:
122; BH: Backuped error code
123; Corrupts registers:
124; Nothing
125;--------------------------------------------------------------------
126BackupErrorCodeFromTheRequestedDriveToBH:
127 cmp dl, bl ; Requested drive?
128 eCMOVE bh, ah
129 ret
130
131
132;--------------------------------------------------------------------
133; GetDriveNumberForForeignHardDiskHandlerToDL
134; Parameters:
135; BL: Requested drive (DL when entering AH=00h)
136; DS: RAMVARS segment
137; Returns:
138; DS:DI: Ptr to DPT if our drive (or Null if foreign drive)
139; DL: BL if foreign drive
140; 80h if our drive
141;--------------------------------------------------------------------
142GetDriveNumberForForeignHardDiskHandlerToDL:
143 mov dl, bl
144 test di, di
145 jz SHORT .Return
146 mov dl, 80h ; First possible Hard Disk should be safe value
147.Return:
148 ret
149
150AH0h_ResetAllOurHardDisksAtTheEndOfDriveInitialization equ ResetHardDisksHandledByOurBIOS.ErrorCodeNotUsed
151
152;--------------------------------------------------------------------
153; ResetHardDisksHandledByOurBIOS
154; Parameters:
155; DS:DI: Ptr to DPT for requested drive
156; If DPT pointer is not available, or error result in BH won't be used anyway,
157; enter through .ErrorCodeNotUsed.
158; SS:BP: Ptr to IDEPACK
159; Returns:
160; BH: Error code from requested drive (if available)
161; Corrupts registers:
162; AX, BX, CX, DX, SI, DI
163;--------------------------------------------------------------------
164ResetHardDisksHandledByOurBIOS:
165 xor bl, bl ; Assume Null IdevarsOffset for now, assuming foreign drive
166 test di, di
167 jz .ErrorCodeNotUsed
168 mov bl, [di+DPT.bIdevarsOffset] ; replace drive number with Idevars pointer for cmp with dl
169
170.ErrorCodeNotUsed: ; BH will be garbage on exit if this entry point is used,
171 ; but reset of all drives will still happen
172
173 mov dl, ROMVARS.ideVars0 ; starting Idevars offset
174
175 ; Get count of ALL Idevars structures, not just the ones that are configured. This may seem odd,
176 ; but it catches the .ideVarsSerialAuto structure, which would not be scanned if the count from
177 ; RamVars_GetIdeControllerCountToCX was used. Unused controllers won't make a difference, since no DPT
178 ; will point to them. Performance isn't an issue, as this is a reset operation.
179 ;
180 mov cx, (ROMVARS.ideVarsEnd - ROMVARS.ideVarsBegin) / IDEVARS_size
181
182.loop:
183 call FindDPT_ForIdevarsOffsetInDL ; look for the first drive on this controller, if any
184 jc .notFound
185
186 call AHDh_ResetDrive ; reset master and slave on that controller
187 call BackupErrorCodeFromTheRequestedDriveToBH ; save error code if same controller as drive from entry
188
189.notFound:
190 add dl, IDEVARS_size ; move Idevars pointer forward
191 loop .loop
192
193.done:
194 ret
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