bootsect.h revision 1.2 
1/*	$OpenBSD: bootsect.h,v 1.2 1997/02/24 14:32:46 niklas Exp $	*/
2/*	$NetBSD: bootsect.h,v 1.7 1995/07/24 06:36:23 leo Exp $	*/
3
4/*
5 * Written by Paul Popelka (paulp@uts.amdahl.com)
6 *
7 * You can do anything you want with this software, just don't say you wrote
8 * it, and don't remove this notice.
9 *
10 * This software is provided "as is".
11 *
12 * The author supplies this software to be publicly redistributed on the
13 * understanding that the author is not responsible for the correct
14 * functioning of this software in any circumstances and is not liable for
15 * any damages caused by this software.
16 *
17 * October 1992
18 */
19
20/*
21 * Format of a boot sector.  This is the first sector on a DOS floppy disk
22 * or the fist sector of a partition on a hard disk.  But, it is not the
23 * first sector of a partitioned hard disk.
24 */
25struct bootsector33 {
26	u_int8_t	bsJump[3];		/* jump inst E9xxxx or EBxx90 */
27	int8_t		bsOemName[8];		/* OEM name and version */
28	int8_t		bsBPB[19];		/* BIOS parameter block */
29	int8_t		bsDriveNumber;		/* drive number (0x80) */
30	int8_t		bsBootCode[479];	/* pad so struct is 512b */
31	u_int16_t	bsBootSectSig;
32#define	BOOTSIG	0xaa55
33};
34
35struct bootsector50 {
36	u_int8_t	bsJump[3];		/* jump inst E9xxxx or EBxx90 */
37	int8_t		bsOemName[8];		/* OEM name and version */
38	int8_t		bsBPB[25];		/* BIOS parameter block */
39	int8_t		bsDriveNumber;		/* drive number (0x80) */
40	int8_t		bsReserved1;		/* reserved */
41	int8_t		bsBootSignature;	/* ext. boot signature (0x29) */
42#define	EXBOOTSIG	0x29
43	int8_t		bsVolumeID[4];		/* volume ID number */
44	int8_t		bsVolumeLabel[11];	/* volume label */
45	int8_t		bsFileSysType[8];	/* fs type (FAT12 or FAT16) */
46	int8_t		bsBootCode[448];	/* pad so structure is 512b */
47	u_int16_t	bsBootSectSig;
48#define	BOOTSIG	0xaa55
49};
50#ifdef	atari
51/*
52 * The boot sector on a gemdos fs is a little bit different from the msdos fs
53 * format. Currently there is no need to declare a seperate structure, the
54 * bootsector33 struct will do.
55 */
56#if 0
57struct bootsec_atari {
58	u_int8_t	bsBranch[2];		/* branch inst if auto-boot	*/
59	int8_t		bsFiller[6];		/* anything or nothing		*/
60	int8_t		bsSerial[3];		/* serial no. for mediachange	*/
61	int8_t		bsBPB[19];		/* BIOS parameter block		*/
62	int8_t		bsBootCode[482];	/* pad so struct is 512b	*/
63};
64#endif
65#endif /* atari */
66
67union bootsector {
68	struct bootsector33 bs33;
69	struct bootsector50 bs50;
70};
71
72/*
73 * Shorthand for fields in the bpb.
74 */
75#define	bsBytesPerSec	bsBPB.bpbBytesPerSec
76#define	bsSectPerClust	bsBPB.bpbSectPerClust
77#define	bsResSectors	bsBPB.bpbResSectors
78#define	bsFATS		bsBPB.bpbFATS
79#define	bsRootDirEnts	bsBPB.bpbRootDirEnts
80#define	bsSectors	bsBPB.bpbSectors
81#define	bsMedia		bsBPB.bpbMedia
82#define	bsFATsecs	bsBPB.bpbFATsecs
83#define	bsSectPerTrack	bsBPB.bpbSectPerTrack
84#define	bsHeads		bsBPB.bpbHeads
85#define	bsHiddenSecs	bsBPB.bpbHiddenSecs
86#define	bsHugeSectors	bsBPB.bpbHugeSectors
87