source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Inc/BootVars.inc @ 545

Last change on this file since 545 was 545, checked in by aitotat@…, 11 years ago

Changes to XTIDE Universal BIOS:

  • Integrated XT-CFv3 support by James Pearce.
  • XT-CFv2 memory mapped I/O and DMA modes are no longer supported (but PIO mode is).
File size: 6.1 KB
Line 
1; Project name  :   XTIDE Universal BIOS
2; Description   :   Defines for BOOTVARS struct used by boot menu
3;                   and drive initialization.
4
5;
6; XTIDE Universal BIOS and Associated Tools
7; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team.
8;
9; This program is free software; you can redistribute it and/or modify
10; it under the terms of the GNU General Public License as published by
11; the Free Software Foundation; either version 2 of the License, or
12; (at your option) any later version.
13;
14; This program is distributed in the hope that it will be useful,
15; but WITHOUT ANY WARRANTY; without even the implied warranty of
16; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17; GNU General Public License for more details.
18; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
19;
20
21%ifndef BOOTVARS_INC
22%define BOOTVARS_INC
23
24; Default drives
25DEFAULT_FLOPPY_DRIVE_LETTER             EQU 'A'
26DEFAULT_HARD_DRIVE_LETTER               EQU 'C'
27
28; Number of times to retry booting before accepting error
29BOOT_READ_RETRY_TIMES       EQU     3
30
31
32
33; Pre-boot variables. These do not exist after successful boot to OS.
34; Segment is always 0000h, same as BDA segment
35struc BOOTVARS
36                        resb    7C00h
37    .rgbAtaInfo:                        ; 7C00h, ATA Information for drive detection
38    .rgbBootSect        resb    512     ; 7C00h, Boot sector
39                        resb    256     ; Boot Menu stack
40    .rgbMnuStack:
41    .dwPostStack        resb    4       ; POST stack pointer when entering INT 19h
42%ifdef MODULE_HOTKEYS
43    .hotkeyVars             resb    HOTKEYVARS_size
44%endif
45    .rgDrvDetectInfo:                   ; Array containing DRVDETECTINFO structs
46endstruc
47
48
49%ifdef MODULE_HOTKEYS
50
51struc HOTKEYVARS
52    .wTimeWhenDisplayed resb    2       ; System time (ticks) when Hotkey bar was first displayed
53    .wFddAndHddLetters:
54    .bFddLetter         resb    1       ; Floppy Drive letter hotkey (upper case)
55    .bHddLetter         resb    1       ; Hard Drive letter hotkey (upper case). Must be after .bFddLetter!
56    .bFlags             resb    1       ; Must be just after .bHddLetter!  (dependency in Hotkeybar.asm)
57    .bScancode          resb    1       ; Function hotkey scancode, must be just after .bFlags!
58endstruc
59
60%ifndef CHECK_FOR_UNUSED_ENTRYPOINTS
61%if HOTKEYVARS.bFddLetter+1 != HOTKEYVARS.bHddLetter || HOTKEYVARS.bHddLetter+1 != HOTKEYVARS.bFlags || HOTKEYVARS.bFlags+1 != HOTKEYVARS.bScancode
62%error "HOTKEYVARS: bytes need to come in the order .bFddLetter, then .bHddLetter, then .bFlags, then .bScancode"
63%endif
64%endif
65
66; Bit defines for HOTKEYVARS.bFlags
67FLG_HOTKEY_HD_FIRST         EQU     (1<<0)  ; First try to boot from HDD, then FDD
68
69%endif ; MODULE_HOTKEYS
70
71struc DRVDETECTINFO
72    .StartOfDrvDetectInfo:
73    .szDrvName              resb    MAX_HARD_DISK_NAME_LENGTH
74                            resb    2   ; Zero word (ensures string terminates)
75    .wInitErrorFlags        resb    2   ; Errors during initialization
76
77    ; DRVDETECTINFO's size must be an even multiple of DPT's size
78    .EndOfDriveDetectInfo:  resb    LARGEST_DPT_SIZE - (.EndOfDriveDetectInfo % LARGEST_DPT_SIZE)
79endstruc
80
81; Boot Menu Information Table. These are generated for all XTIDE Universal
82; BIOS drives. Available only until boot is successful.
83MAX_HARD_DISK_NAME_LENGTH           EQU     30      ; Bytes reserved for drive name
84DPT_DRVDETECTINFO_SIZE_MULTIPLIER   EQU     DRVDETECTINFO_size / LARGEST_DPT_SIZE
85
86
87%ifndef CHECK_FOR_UNUSED_ENTRYPOINTS
88
89%if MAX_HARD_DISK_NAME_LENGTH % 2 <> 0
90    %error "MAX_HARD_DISK_NAME_LENGTH needs to be a multiple of 2, memory is moved with word operations."
91%endif
92
93%if DRVDETECTINFO_size % LARGEST_DPT_SIZE <> 0
94    %error "DRVDETECTINFO's size must be an even multiple of DPT's size.  Add or remove padding at the bottom of DRVDETECTINFO to bring the two sizes into alignment.  As DRVDETECTINFO is only used at boot time, with plenty of memory to consume, it is OK to waste some space here."
95%endif
96
97%if DRVDETECTINFO.szDrvName <> 0
98    %error "DRVDETECTINFO.szDrvName is assumed to be the first member of struc DRVDETECTINFO, in BootMenuPrint_RefreshItem"
99%endif
100
101%endif
102
103
104;--------------------------------------------------------------------
105; Stores POST stack pointer to BOOTVARS.
106;
107; STORE_POST_STACK_POINTER
108;   Parameters:
109;       ES:     BDA and Interrupt Vector segment (zero)
110;   Returns:
111;       Nothing
112;   Corrupts registers:
113;       Nothing
114;--------------------------------------------------------------------
115%macro STORE_POST_STACK_POINTER 0
116    mov     [es:BOOTVARS.dwPostStack], sp
117    mov     [es:BOOTVARS.dwPostStack+2], ss
118%endmacro
119
120
121;--------------------------------------------------------------------
122; Initializes stack for boot menu usage.
123; POST stack is not large enough when DPTs are stored to 30:0h.
124;
125; Note regarding LOAD_BDA_SEGMENT_TO: If you force the use of SP
126; then you also have to unconditionally enable the CLI/STI pair.
127; The reason for this is that only some buggy 808x CPU:s need the
128; CLI/STI instruction pair when changing stacks. Other CPU:s disable
129; interrupts automatically when SS is modified for the duration of
130; the immediately following instruction to give time to change SP.
131;
132; SWITCH_TO_BOOT_MENU_STACK
133;   Parameters:
134;       Nothing
135;   Returns:
136;       SS:SP:  Pointer to top of Boot Menu stack
137;   Corrupts registers:
138;       Nothing
139;--------------------------------------------------------------------
140%macro SWITCH_TO_BOOT_MENU_STACK 0
141%ifndef USE_186
142    cli                                 ; Disable interrupts
143%endif
144    LOAD_BDA_SEGMENT_TO ss, sp
145    mov     sp, BOOTVARS.rgbMnuStack    ; Load offset to stack
146%ifndef USE_186
147    sti                                 ; Enable interrupts
148%endif
149%endmacro
150
151
152;--------------------------------------------------------------------
153; Restores SS and SP to initial boot loader values.
154;
155; Note! Must return with AX=0 and CF preserved.
156; See Int19hMenu_JumpToBootSector_or_RomBoot.
157;
158; SWITCH_BACK_TO_POST_STACK
159;   Parameters:
160;       AX:     BDA and Interrupt Vector segment (zero)
161;   Returns:
162;       SS:SP:  Ptr to POST stack
163;   Corrupts registers:
164;       Nothing (not even FLAGS)
165;--------------------------------------------------------------------
166%macro SWITCH_BACK_TO_POST_STACK 0
167%ifndef USE_386
168    cli
169    mov     ss, ax
170    mov     sp, [ss:BOOTVARS.dwPostStack]
171    mov     ss, [ss:BOOTVARS.dwPostStack+2]
172    sti
173%else
174    mov     ss, ax
175    lss     sp, [ss:BOOTVARS.dwPostStack]
176%endif
177%endmacro
178
179
180%endif ; BOOTVARS_INC
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