master
1/* $NetBSD: bpb.h,v 1.8 2016/01/22 22:53:36 dholland Exp $ */
2
3/*
4 * Written by Paul Popelka (paulp@uts.amdahl.com)
5 *
6 * You can do anything you want with this software, just don't say you wrote
7 * it, and don't remove this notice.
8 *
9 * This software is provided "as is".
10 *
11 * The author supplies this software to be publicly redistributed on the
12 * understanding that the author is not responsible for the correct
13 * functioning of this software in any circumstances and is not liable for
14 * any damages caused by this software.
15 *
16 * October 1992
17 */
18
19#ifndef _MSDOSFS_BPB_H_
20#define _MSDOSFS_BPB_H_
21
22/*
23 * BIOS Parameter Block (BPB) for DOS 3.3
24 */
25struct bpb33 {
26 uint16_t bpbBytesPerSec; /* bytes per sector */
27 uint8_t bpbSecPerClust; /* sectors per cluster */
28 uint16_t bpbResSectors; /* number of reserved sectors */
29 uint8_t bpbFATs; /* number of FATs */
30 uint16_t bpbRootDirEnts; /* number of root directory entries */
31 uint16_t bpbSectors; /* total number of sectors */
32 uint8_t bpbMedia; /* media descriptor */
33 uint16_t bpbFATsecs; /* number of sectors per FAT */
34 uint16_t bpbSecPerTrack; /* sectors per track */
35 uint16_t bpbHeads; /* number of heads */
36 uint16_t bpbHiddenSecs; /* number of hidden sectors */
37};
38
39/*
40 * BPB for DOS 5.0 The difference is bpbHiddenSecs is a short for DOS 3.3,
41 * and bpbHugeSectors is not in the 3.3 bpb.
42 */
43struct bpb50 {
44 uint16_t bpbBytesPerSec; /* bytes per sector */
45 uint8_t bpbSecPerClust; /* sectors per cluster */
46 uint16_t bpbResSectors; /* number of reserved sectors */
47 uint8_t bpbFATs; /* number of FATs */
48 uint16_t bpbRootDirEnts; /* number of root directory entries */
49 uint16_t bpbSectors; /* total number of sectors */
50 uint8_t bpbMedia; /* media descriptor */
51 uint16_t bpbFATsecs; /* number of sectors per FAT */
52 uint16_t bpbSecPerTrack; /* sectors per track */
53 uint16_t bpbHeads; /* number of heads */
54 uint32_t bpbHiddenSecs; /* # of hidden sectors */
55 uint32_t bpbHugeSectors; /* # of sectors if bpbSectors == 0 */
56};
57
58/*
59 * BPB for DOS 7.10 (FAT32). This one has a few extensions to bpb50.
60 */
61struct bpb710 {
62 uint16_t bpbBytesPerSec; /* bytes per sector */
63 uint8_t bpbSecPerClust; /* sectors per cluster */
64 uint16_t bpbResSectors; /* number of reserved sectors */
65 uint8_t bpbFATs; /* number of FATs */
66 uint16_t bpbRootDirEnts; /* number of root directory entries */
67 uint16_t bpbSectors; /* total number of sectors */
68 uint8_t bpbMedia; /* media descriptor */
69 uint16_t bpbFATsecs; /* number of sectors per FAT */
70 uint16_t bpbSecPerTrack; /* sectors per track */
71 uint16_t bpbHeads; /* number of heads */
72 uint32_t bpbHiddenSecs; /* # of hidden sectors */
73 uint32_t bpbHugeSectors; /* # of sectors if bpbSectors == 0 */
74 uint32_t bpbBigFATsecs; /* like bpbFATsecs for FAT32 */
75 uint16_t bpbExtFlags; /* extended flags: */
76#define FATNUM 0xf /* mask for numbering active FAT */
77#define FATMIRROR 0x80 /* FAT is mirrored (like it always was) */
78 uint16_t bpbFSVers; /* filesystem version */
79#define FSVERS 0 /* currently only 0 is understood */
80 uint32_t bpbRootClust; /* start cluster for root directory */
81 uint16_t bpbFSInfo; /* filesystem info structure sector */
82 uint16_t bpbBackup; /* backup boot sector */
83 uint8_t bpbReserved[12]; /* Reserved for future expansion */
84};
85
86#ifdef atari
87/*
88 * BPB for GEMDOS filesystems. Atari leaves the obsolete stuff undefined.
89 * Currently there is no need for a separate BPB structure.
90 */
91#if 0
92struct bpb_a {
93 uint16_t bpbBytesPerSec; /* bytes per sector */
94 uint8_t bpbSecPerClust; /* sectors per cluster */
95 uint16_t bpbResSectors; /* number of reserved sectors */
96 uint8_t bpbFATs; /* number of FATs */
97 uint16_t bpbRootDirEnts; /* number of root directory entries */
98 uint16_t bpbSectors; /* total number of sectors */
99 uint8_t bpbUseless1; /* meaningless on GEMDOS FS */
100 uint16_t bpbFATsecs; /* number of sectors per FAT */
101 uint16_t bpbUseless2; /* meaningless for harddisk fs */
102 uint16_t bpbUseless3; /* meaningless for harddisk fs */
103 uint16_t bpbHiddenSecs; /* the TOS-BIOS ignores this */
104};
105#endif
106#endif /* atari */
107
108/*
109 * The following structures represent how the bpb's look on disk. shorts
110 * and longs are just character arrays of the appropriate length. This is
111 * because the compiler forces shorts and longs to align on word or
112 * halfword boundaries.
113 */
114
115#include <sys/endian.h>
116
117#define getushort(p) le16dec(p)
118#define getulong(p) le32dec(p)
119#define putushort(p, v) le16enc((p), (v))
120#define putulong(p, v) le32enc((p), (v))
121
122/*
123 * BIOS Parameter Block (BPB) for DOS 3.3
124 */
125struct byte_bpb33 {
126 int8_t bpbBytesPerSec[2]; /* bytes per sector */
127 int8_t bpbSecPerClust; /* sectors per cluster */
128 int8_t bpbResSectors[2]; /* number of reserved sectors */
129 int8_t bpbFATs; /* number of FATs */
130 int8_t bpbRootDirEnts[2]; /* number of root directory entries */
131 int8_t bpbSectors[2]; /* total number of sectors */
132 int8_t bpbMedia; /* media descriptor */
133 int8_t bpbFATsecs[2]; /* number of sectors per FAT */
134 int8_t bpbSecPerTrack[2]; /* sectors per track */
135 int8_t bpbHeads[2]; /* number of heads */
136 int8_t bpbHiddenSecs[2]; /* number of hidden sectors */
137};
138
139/*
140 * BPB for DOS 5.0 The difference is bpbHiddenSecs is a short for DOS 3.3,
141 * and bpbHugeSectors is not in the 3.3 bpb.
142 */
143struct byte_bpb50 {
144 int8_t bpbBytesPerSec[2]; /* bytes per sector */
145 int8_t bpbSecPerClust; /* sectors per cluster */
146 int8_t bpbResSectors[2]; /* number of reserved sectors */
147 int8_t bpbFATs; /* number of FATs */
148 int8_t bpbRootDirEnts[2]; /* number of root directory entries */
149 int8_t bpbSectors[2]; /* total number of sectors */
150 int8_t bpbMedia; /* media descriptor */
151 int8_t bpbFATsecs[2]; /* number of sectors per FAT */
152 int8_t bpbSecPerTrack[2]; /* sectors per track */
153 int8_t bpbHeads[2]; /* number of heads */
154 int8_t bpbHiddenSecs[4]; /* number of hidden sectors */
155 int8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */
156};
157
158/*
159 * BPB for DOS 7.10 (FAT32). This one has a few extensions to bpb50.
160 */
161struct byte_bpb710 {
162 uint8_t bpbBytesPerSec[2]; /* bytes per sector */
163 uint8_t bpbSecPerClust; /* sectors per cluster */
164 uint8_t bpbResSectors[2]; /* number of reserved sectors */
165 uint8_t bpbFATs; /* number of FATs */
166 uint8_t bpbRootDirEnts[2]; /* number of root directory entries */
167 uint8_t bpbSectors[2]; /* total number of sectors */
168 uint8_t bpbMedia; /* media descriptor */
169 uint8_t bpbFATsecs[2]; /* number of sectors per FAT */
170 uint8_t bpbSecPerTrack[2]; /* sectors per track */
171 uint8_t bpbHeads[2]; /* number of heads */
172 uint8_t bpbHiddenSecs[4]; /* # of hidden sectors */
173 uint8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */
174 uint8_t bpbBigFATsecs[4]; /* like bpbFATsecs for FAT32 */
175 uint8_t bpbExtFlags[2]; /* extended flags: */
176 uint8_t bpbFSVers[2]; /* filesystem version */
177 uint8_t bpbRootClust[4]; /* start cluster for root directory */
178 uint8_t bpbFSInfo[2]; /* filesystem info structure sector */
179 uint8_t bpbBackup[2]; /* backup boot sector */
180 uint8_t bpbReserved[12]; /* Reserved for future expansion */
181};
182
183/*
184 * FAT32 FSInfo block.
185 */
186struct fsinfo {
187 uint8_t fsisig1[4];
188 uint8_t fsifill1[480];
189 uint8_t fsisig2[4];
190 uint8_t fsinfree[4];
191 uint8_t fsinxtfree[4];
192 uint8_t fsifill2[12];
193 uint8_t fsisig3[4];
194 uint8_t fsifill3[508];
195 uint8_t fsisig4[4];
196};
197#endif /* _MSDOSFS_BPB_H_ */