Annotation of src/sys/fs/msdosfs/bpb.h, Revision 1.8
1.8 ! dholland 1: /* $NetBSD: bpb.h,v 1.7 2012/11/04 17:57:59 jakllsch Exp $ */
1.1 jdolecek 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:
1.4 christos 19: #ifndef _MSDOSFS_BPB_H_
20: #define _MSDOSFS_BPB_H_
21:
1.1 jdolecek 22: /*
23: * BIOS Parameter Block (BPB) for DOS 3.3
24: */
25: struct bpb33 {
1.8 ! dholland 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 */
1.1 jdolecek 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: */
43: struct bpb50 {
1.8 ! dholland 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 */
1.1 jdolecek 56: };
57:
58: /*
59: * BPB for DOS 7.10 (FAT32). This one has a few extensions to bpb50.
60: */
61: struct bpb710 {
1.8 ! dholland 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: */
1.1 jdolecek 76: #define FATNUM 0xf /* mask for numbering active FAT */
77: #define FATMIRROR 0x80 /* FAT is mirrored (like it always was) */
1.8 ! dholland 78: uint16_t bpbFSVers; /* filesystem version */
1.1 jdolecek 79: #define FSVERS 0 /* currently only 0 is understood */
1.8 ! dholland 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 */
1.1 jdolecek 84: };
85:
86: #ifdef atari
87: /*
1.7 jakllsch 88: * BPB for GEMDOS filesystems. Atari leaves the obsolete stuff undefined.
1.1 jdolecek 89: * Currently there is no need for a separate BPB structure.
90: */
91: #if 0
92: struct bpb_a {
1.8 ! dholland 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 */
1.1 jdolecek 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.
1.6 cbiere 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))
1.1 jdolecek 121:
122: /*
123: * BIOS Parameter Block (BPB) for DOS 3.3
124: */
125: struct 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: */
143: struct 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: */
161: struct byte_bpb710 {
1.8 ! dholland 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 */
1.1 jdolecek 181: };
182:
183: /*
184: * FAT32 FSInfo block.
185: */
186: struct fsinfo {
1.8 ! dholland 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];
1.1 jdolecek 196: };
1.4 christos 197: #endif /* _MSDOSFS_BPB_H_ */
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