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1; -*- fundamental -*- (asm-mode sucks)
2; -----------------------------------------------------------------------
3;
4;   Copyright 1994-2009 H. Peter Anvin - All Rights Reserved
5;   Copyright 2009-2011 Intel Corporation; author: H. Peter Anvin
6;
7;   This program is free software; you can redistribute it and/or modify
8;   it under the terms of the GNU General Public License as published by
9;   the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
10;   Boston MA 02110-1301, USA; either version 2 of the License, or
11;   (at your option) any later version; incorporated herein by reference.
12;
13; -----------------------------------------------------------------------
14
15;
16; diskfs.inc
17;
18; Common code for conventional disk-based filesystems
19;
20
21;
22; Some semi-configurable constants... change on your own risk.
23;
24NULLFILE	equ 0			; Null character == empty filename
25NULLOFFSET	equ 0			; Position in which to look
26retry_count	equ 16			; How patient are we with the disk?
27%assign HIGHMEM_SLOP 0			; Avoid this much memory near the top
28LDLINUX_MAGIC	equ 0x3eb202fe		; A random number to identify ourselves with
29
30; This indicates the general format of the last few bytes in the boot sector
31BS_MAGIC_VER	equ 0x1b << 9
32
33MIN_SECTOR_SHIFT	equ 9
34MIN_SECTOR_SIZE		equ (1 << MIN_SECTOR_SHIFT)
35
36; ---------------------------------------------------------------------------
37;   BEGIN CODE
38; ---------------------------------------------------------------------------
39
40;
41; Memory below this point is reserved for the BIOS and the MBR
42;
43		section .earlybss
44		global trackbuf:data hidden
45trackbufsize	equ 8192
46trackbuf	resb trackbufsize	; Track buffer goes here
47		; ends at 2800h
48
49;
50; Common bootstrap code for disk-based derivatives
51;
52%include "diskstart.inc"
53
54;
55; Now, everything is "up and running"... patch kaboom for more
56; verbosity and using the full screen system
57;
58		; E9 = JMP NEAR
59		mov di,kaboom.patch
60		mov al,0e9h
61		stosb
62		mov ax,kaboom2-2
63		sub ax,di
64		stosw
65
66;
67; If we get to this point ldlinux.c32 failed to run. There's nothing
68; left to do but inform that user that something went wrong.
69;
70enter_command:
71auto_boot:
72		jmp kaboom
73
74		section .bss16
75		alignb 4
76ThisKbdTo	resd 1			; Temporary holder for KbdTimeout
77ThisTotalTo	resd 1			; Temporary holder for TotalTimeout
78KernelExtPtr	resw 1			; During search, final null pointer
79FuncFlag	resb 1			; Escape sequences received from keyboard
80KernelType	resb 1			; Kernel type, from vkernel, if known
81		global KernelName
82KernelName	resb FILENAME_MAX	; Mangled name for kernel
83
84		section .text16
85;
86; COM32 vestigial data structure
87;
88%include "com32.inc"
89
90;
91; Common local boot code
92;
93%include "localboot.inc"
94
95;
96; kaboom2: once everything is loaded, replace the part of kaboom
97;	   starting with "kaboom.patch" with this part
98
99kaboom2:
100		mov si,err_bootfailed
101		pm_call pm_writestr
102		cmp byte [kaboom.again+1],18h	; INT 18h version?
103		je .int18
104		pm_call pm_getchar
105		pm_call syslinux_force_text_mode
106		int 19h			; And try once more to boot...
107.norge:		jmp short .norge	; If int 19h returned; this is the end
108.int18:
109		pm_call syslinux_force_text_mode
110		int 18h
111.noreg:		jmp short .noreg	; Nynorsk
112
113; -----------------------------------------------------------------------------
114;  Common modules
115; -----------------------------------------------------------------------------
116
117%include "common.inc"		; Universal modules
118
119; -----------------------------------------------------------------------------
120;  Begin data section
121; -----------------------------------------------------------------------------
122
123		section .data16
124		global copyright_str
125copyright_str   db ' Copyright (C) 1994-'
126		asciidec YEAR
127		db ' H. Peter Anvin et al', CR, LF, 0
128err_bootfailed	db CR, LF, 'Boot failed: please change disks and press '
129		db 'a key to continue.', CR, LF, 0
130
131;
132; Misc initialized (data) variables
133;
134%ifdef debug				; This code for debugging only
135debug_magic	dw 0D00Dh		; Debug code sentinel
136%endif
137