source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Inc/RamVars.inc @ 522

Last change on this file since 522 was 522, checked in by aitotat@…, 11 years ago

Changes to XTIDE Universal BIOS:

  • INT 13h stack is now at the beginning of RAMVARS.
  • RELOCATE_INT13H_STACK is now allowed only for AT builds. This saves few bytes from interrupt table when lite mode is used.
File size: 4.5 KB
Line 
1; Project name  :   XTIDE Universal BIOS
2; Description   :   RAMVARS struct containing BIOS variables stored in RAM.
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%ifndef RAMVARS_INC
21%define RAMVARS_INC
22
23; Segment when RAMVARS is stored to top of interrupt vectors.
24%ifndef USE_AT
25    LITE_MODE_RAMVARS_SEGMENT   EQU     30h
26%endif
27
28
29%ifdef MODULE_SERIAL_FLOPPY OR MODULE_DRIVEXLATE
30    %define NEED_XLATEVARS
31%endif
32
33
34; RAM Variables.
35; Variables should be kept to minimum since they might be located
36; at the top of interrupt vectors.
37struc RAMVARS
38%ifdef RELOCATE_INT13H_STACK
39                        resb    256 ; Size of our stack
40    .rgbTopOfStack:
41    .fpInt13hEntryStack resb    4
42    .dwStackChangeDSDI:
43    .wStackChangeDI     resb    2
44    .wStackChangeDS     resb    2
45%endif
46    .wDrvDetectSignature:           ; Signature when BIOS is in drive detection mode
47    .fpOldI13h          resb    4   ; Far pointer to old INT 13h handler
48    .wSignature         resb    2   ; Sign for finding stolen 1...64 kiB
49    .bTimeoutTicksLeft  resb    1
50    .bLastTimeoutUpdate resb    1
51
52    .wFirstDrvAndCount:
53    .bFirstDrv          resb    1   ; Number of first drive for this BIOS
54    .wDrvCntAndFlopCnt:             ; Both the hard disk and floppy counts in one word
55                                    ; (yes, misaligned, but it is only used this way during initialization)
56    .bDrvCnt            resb    1   ; Number of drives handled by this BIOS
57
58    ; Variables for drive number translation
59%ifdef NEED_XLATEVARS
60    .xlateVars          resb    XLATEVARS_size
61%endif
62endstruc
63
64; Note!!! .wDrvDetectSignature and .wSignature are intentionally in different locations.
65RAMVARS_RAM_SIGNATURE           EQU "Xu"    ; RAMVARS signature for .wSignature
66RAMVARS_DRV_DETECT_SIGNATURE    EQU 5A5Ah   ; Signature when BIOS is in drive detection mode
67
68
69%ifdef NEED_XLATEVARS
70; Variables for translating drive numbers.
71    struc XLATEVARS
72    %ifdef MODULE_SERIAL_FLOPPY
73        .bFlopCreateCnt:
74        .bFlopCntAndFirst   resb    1   ; Normally, packed starting floppy drive number (high order 7 bits)
75                                        ; and number of drives (low order bit, max 2 drives supported).
76                                        ; During initialization, until the end of DetectDrives_FromAllIDEControllers,
77                                        ; this byte contains the raw number of floppy drives seen
78                                        ; (using .bFlopCreateCnt)
79    %else
80                            resb    1   ; alignment
81    %endif
82
83    %ifdef MODULE_DRIVEXLATE
84        .bXlatedDrv         resb    1   ; Drive number after translation
85        .wFDandHDswap:
86        .bFDSwap            resb    1   ; Floppy Drive to swap to 00h and vice versa
87        .bHDSwap            resb    1   ; Hard Drive to swap to 80h and vice versa
88    %else
89                            resb    1   ; alignment
90    %endif
91    endstruc
92%endif
93
94%ifdef MODULE_SERIAL_FLOPPY
95  %ifndef CHECK_FOR_UNUSED_ENTRYPOINTS
96    %if RAMVARS.xlateVars != RAMVARS.bDrvCnt+1 || XLATEVARS.bFlopCreateCnt != 0
97        %error "bFlopCreateCnt needs to be the first thing in XLATEVARS, and .xlateVars needs to come immediately after .bDrvCnt.  In at least one place, we read .wDrvCntAndFlopCnt to get both counts in one fetch"
98    %endif
99  %endif
100%endif
101
102
103
104;
105; IDEPACK NOTE: The first six bytes of this structure are directly put on the
106; wire for MODULE_SERIAL, please do not change the order or insert other members.
107;
108struc IDEPACK   ; PIOVARS and MEMPIOVARS overwrite the first 7 bytes
109    .bFeatures              resb    1
110    .bDrvAndHead            resb    1   ; LBA28 27...24
111
112    .wSectorCountAndLbaLow:
113    .bSectorCount           resb    1
114    .bSectorNumber:
115    .bLbaLow                resb    1   ; LBA 7...0
116
117    .wCylinder:
118    .wLbaMiddleAndHigh:
119    .bLbaMiddle             resb    1   ; LBA 15...8
120    .bLbaHigh               resb    1   ; LBA 23...16
121
122    .bCommand               resb    1
123    .bDeviceControl         resb    1   ; Offset 7 shared with PIOVARS and MEMPIOVARS
124                            resb    1   ; Used by PIOVARS and MEMPIOVARS
125
126%ifdef MODULE_EBIOS
127    ; Parameters for 48-bit LBA
128    .bLbaLowExt             resb    1   ; LBA48 31...24
129    .wLbaMiddleAndHighExt:
130    .bLbaMiddleExt          resb    1   ; LBA48 39...32
131    .bLbaHighExt            resb    1   ; LBA48 47...40
132%endif
133
134    .intpack                resb    INTPACK_size
135endstruc
136
137SIZE_OF_IDEPACK_WITHOUT_INTPACK     EQU (IDEPACK_size - INTPACK_size)
138
139
140%endif ; RAMVARS_INC
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