1 /* $FreeBSD: src/sys/msdosfs/bpb.h,v 1.7.2.1 2000/10/27 09:45:07 bde Exp $ */
2 /* $NetBSD: bpb.h,v 1.7 1997/11/17 15:36:24 ws Exp $ */
5 * Written by Paul Popelka (paulp@uts.amdahl.com)
7 * You can do anything you want with this software, just don't say you wrote
8 * it, and don't remove this notice.
10 * This software is provided "as is".
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.
20 #ifndef _VFS_MSDOSFS_BPB_H_
21 #define _VFS_MSDOSFS_BPB_H_
24 * BIOS Parameter Block (BPB) for DOS 3.3
27 u_int16_t bpbBytesPerSec; /* bytes per sector */
28 u_int8_t bpbSecPerClust; /* sectors per cluster */
29 u_int16_t bpbResSectors; /* number of reserved sectors */
30 u_int8_t bpbFATs; /* number of FATs */
31 u_int16_t bpbRootDirEnts; /* number of root directory entries */
32 u_int16_t bpbSectors; /* total number of sectors */
33 u_int8_t bpbMedia; /* media descriptor */
34 u_int16_t bpbFATsecs; /* number of sectors per FAT */
35 u_int16_t bpbSecPerTrack; /* sectors per track */
36 u_int16_t bpbHeads; /* number of heads */
37 u_int16_t bpbHiddenSecs; /* number of hidden sectors */
41 * BPB for DOS 5.0 The difference is bpbHiddenSecs is a short for DOS 3.3,
42 * and bpbHugeSectors is not in the 3.3 bpb.
45 u_int16_t bpbBytesPerSec; /* bytes per sector */
46 u_int8_t bpbSecPerClust; /* sectors per cluster */
47 u_int16_t bpbResSectors; /* number of reserved sectors */
48 u_int8_t bpbFATs; /* number of FATs */
49 u_int16_t bpbRootDirEnts; /* number of root directory entries */
50 u_int16_t bpbSectors; /* total number of sectors */
51 u_int8_t bpbMedia; /* media descriptor */
52 u_int16_t bpbFATsecs; /* number of sectors per FAT */
53 u_int16_t bpbSecPerTrack; /* sectors per track */
54 u_int16_t bpbHeads; /* number of heads */
55 u_int32_t bpbHiddenSecs; /* # of hidden sectors */
56 u_int32_t bpbHugeSectors; /* # of sectors if bpbSectors == 0 */
60 * BPB for DOS 7.10 (FAT32). This one has a few extensions to bpb50.
63 u_int16_t bpbBytesPerSec; /* bytes per sector */
64 u_int8_t bpbSecPerClust; /* sectors per cluster */
65 u_int16_t bpbResSectors; /* number of reserved sectors */
66 u_int8_t bpbFATs; /* number of FATs */
67 u_int16_t bpbRootDirEnts; /* number of root directory entries */
68 u_int16_t bpbSectors; /* total number of sectors */
69 u_int8_t bpbMedia; /* media descriptor */
70 u_int16_t bpbFATsecs; /* number of sectors per FAT */
71 u_int16_t bpbSecPerTrack; /* sectors per track */
72 u_int16_t bpbHeads; /* number of heads */
73 u_int32_t bpbHiddenSecs; /* # of hidden sectors */
74 u_int32_t bpbHugeSectors; /* # of sectors if bpbSectors == 0 */
75 u_int32_t bpbBigFATsecs; /* like bpbFATsecs for FAT32 */
76 u_int16_t bpbExtFlags; /* extended flags: */
77 #define FATNUM 0xf /* mask for numbering active FAT */
78 #define FATMIRROR 0x80 /* FAT is mirrored (like it always was) */
79 u_int16_t bpbFSVers; /* filesystem version */
80 #define FSVERS 0 /* currently only 0 is understood */
81 u_int32_t bpbRootClust; /* start cluster for root directory */
82 u_int16_t bpbFSInfo; /* filesystem info structure sector */
83 u_int16_t bpbBackup; /* backup boot sector */
84 u_int8_t bpbReserved[12]; /* reserved for future expansion */
89 * BPB for gemdos filesystems. Atari leaves the obsolete stuff undefined.
90 * Currently there is no need for a separate BPB structure.
94 u_int16_t bpbBytesPerSec; /* bytes per sector */
95 u_int8_t bpbSecPerClust; /* sectors per cluster */
96 u_int16_t bpbResSectors; /* number of reserved sectors */
97 u_int8_t bpbFATs; /* number of FATs */
98 u_int16_t bpbRootDirEnts; /* number of root directory entries */
99 u_int16_t bpbSectors; /* total number of sectors */
100 u_int8_t bpbUseless1; /* meaningless on gemdos fs */
101 u_int16_t bpbFATsecs; /* number of sectors per FAT */
102 u_int16_t bpbUseless2; /* meaningless for harddisk fs */
103 u_int16_t bpbUseless3; /* meaningless for harddisk fs */
104 u_int16_t bpbHiddenSecs; /* the TOS-BIOS ignores this */
110 * The following structures represent how the bpb's look on disk. shorts
111 * and longs are just character arrays of the appropriate length. This is
112 * because the compiler forces shorts and longs to align on word or
113 * halfword boundaries.
115 * XXX The little-endian code here assumes that the processor can access
116 * 16-bit and 32-bit quantities on byte boundaries. If this is not true,
117 * use the macros for the big-endian case.
120 #include <machine/endian.h>
123 #define UNLALIGNED_ACCESS
126 #if (BYTE_ORDER == LITTLE_ENDIAN) && defined(UNALIGNED_ACCESS)
127 #define getushort(x) *((u_int16_t *)(x))
128 #define getulong(x) *((u_int32_t *)(x))
129 #define putushort(p, v) (*((u_int16_t *)(p)) = (v))
130 #define putulong(p, v) (*((u_int32_t *)(p)) = (v))
132 #define getushort(x) (((u_int8_t *)(x))[0] + (((u_int8_t *)(x))[1] << 8))
133 #define getulong(x) (((u_int8_t *)(x))[0] + (((u_int8_t *)(x))[1] << 8) \
134 + (((u_int8_t *)(x))[2] << 16) \
135 + (((u_int8_t *)(x))[3] << 24))
136 #define putushort(p, v) (((u_int8_t *)(p))[0] = (v), \
137 ((u_int8_t *)(p))[1] = (v) >> 8)
138 #define putulong(p, v) (((u_int8_t *)(p))[0] = (v), \
139 ((u_int8_t *)(p))[1] = (v) >> 8, \
140 ((u_int8_t *)(p))[2] = (v) >> 16,\
141 ((u_int8_t *)(p))[3] = (v) >> 24)
145 * BIOS Parameter Block (BPB) for DOS 3.3
148 int8_t bpbBytesPerSec[2]; /* bytes per sector */
149 int8_t bpbSecPerClust; /* sectors per cluster */
150 int8_t bpbResSectors[2]; /* number of reserved sectors */
151 int8_t bpbFATs; /* number of FATs */
152 int8_t bpbRootDirEnts[2]; /* number of root directory entries */
153 int8_t bpbSectors[2]; /* total number of sectors */
154 int8_t bpbMedia; /* media descriptor */
155 int8_t bpbFATsecs[2]; /* number of sectors per FAT */
156 int8_t bpbSecPerTrack[2]; /* sectors per track */
157 int8_t bpbHeads[2]; /* number of heads */
158 int8_t bpbHiddenSecs[2]; /* number of hidden sectors */
162 * BPB for DOS 5.0 The difference is bpbHiddenSecs is a short for DOS 3.3,
163 * and bpbHugeSectors is not in the 3.3 bpb.
166 int8_t bpbBytesPerSec[2]; /* bytes per sector */
167 int8_t bpbSecPerClust; /* sectors per cluster */
168 int8_t bpbResSectors[2]; /* number of reserved sectors */
169 int8_t bpbFATs; /* number of FATs */
170 int8_t bpbRootDirEnts[2]; /* number of root directory entries */
171 int8_t bpbSectors[2]; /* total number of sectors */
172 int8_t bpbMedia; /* media descriptor */
173 int8_t bpbFATsecs[2]; /* number of sectors per FAT */
174 int8_t bpbSecPerTrack[2]; /* sectors per track */
175 int8_t bpbHeads[2]; /* number of heads */
176 int8_t bpbHiddenSecs[4]; /* number of hidden sectors */
177 int8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */
181 * BPB for DOS 7.10 (FAT32). This one has a few extensions to bpb50.
184 u_int8_t bpbBytesPerSec[2]; /* bytes per sector */
185 u_int8_t bpbSecPerClust; /* sectors per cluster */
186 u_int8_t bpbResSectors[2]; /* number of reserved sectors */
187 u_int8_t bpbFATs; /* number of FATs */
188 u_int8_t bpbRootDirEnts[2]; /* number of root directory entries */
189 u_int8_t bpbSectors[2]; /* total number of sectors */
190 u_int8_t bpbMedia; /* media descriptor */
191 u_int8_t bpbFATsecs[2]; /* number of sectors per FAT */
192 u_int8_t bpbSecPerTrack[2]; /* sectors per track */
193 u_int8_t bpbHeads[2]; /* number of heads */
194 u_int8_t bpbHiddenSecs[4]; /* # of hidden sectors */
195 u_int8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */
196 u_int8_t bpbBigFATsecs[4]; /* like bpbFATsecs for FAT32 */
197 u_int8_t bpbExtFlags[2]; /* extended flags: */
198 u_int8_t bpbFSVers[2]; /* filesystem version */
199 u_int8_t bpbRootClust[4]; /* start cluster for root directory */
200 u_int8_t bpbFSInfo[2]; /* filesystem info structure sector */
201 u_int8_t bpbBackup[2]; /* backup boot sector */
202 u_int8_t bpbReserved[12]; /* reserved for future expansion */
206 * FAT32 FSInfo block.
210 u_int8_t fsifill1[480];
212 u_int8_t fsinfree[4];
213 u_int8_t fsinxtfree[4];
214 u_int8_t fsifill2[12];
216 u_int8_t fsifill3[508];
220 #endif /* !_VFS_MSDOSFS_BPB_H_ */