Dr Andrew Scott G7VAV

My photo
 
June 2025
Mo Tu We Th Fr Sa Su
26 27 28 29 30 31 1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30 1 2 3 4 5 6


msdos_fs.h
001: #ifndef _LINUX_MSDOS_FS_H
002: #define _LINUX_MSDOS_FS_H
003: 
004: #include <linux/types.h>
005: #include <linux/magic.h>
006: #include <asm/byteorder.h>
007: 
008: /*
009:  * The MS-DOS filesystem constants/structures
010:  */
011: 
012: #define SECTOR_SIZE     512             /* sector size (bytes) */
013: #define SECTOR_BITS     9               /* log2(SECTOR_SIZE) */
014: #define MSDOS_DPB       (MSDOS_DPS)     /* dir entries per block */
015: #define MSDOS_DPB_BITS  4               /* log2(MSDOS_DPB) */
016: #define MSDOS_DPS       (SECTOR_SIZE / sizeof(struct msdos_dir_entry))
017: #define MSDOS_DPS_BITS  4               /* log2(MSDOS_DPS) */
018: #define MSDOS_LONGNAME  256             /* maximum name length */
019: #define CF_LE_W(v)      le16_to_cpu(v)
020: #define CF_LE_L(v)      le32_to_cpu(v)
021: #define CT_LE_W(v)      cpu_to_le16(v)
022: #define CT_LE_L(v)      cpu_to_le32(v)
023: 
024: 
025: #define MSDOS_ROOT_INO  1       /* == MINIX_ROOT_INO */
026: #define MSDOS_DIR_BITS  5       /* log2(sizeof(struct msdos_dir_entry)) */
027: 
028: /* directory limit */
029: #define FAT_MAX_DIR_ENTRIES     (65536)
030: #define FAT_MAX_DIR_SIZE        (FAT_MAX_DIR_ENTRIES << MSDOS_DIR_BITS)
031: 
032: #define ATTR_NONE       0       /* no attribute bits */
033: #define ATTR_RO         1       /* read-only */
034: #define ATTR_HIDDEN     2       /* hidden */
035: #define ATTR_SYS        4       /* system */
036: #define ATTR_VOLUME     8       /* volume label */
037: #define ATTR_DIR        16      /* directory */
038: #define ATTR_ARCH       32      /* archived */
039: 
040: /* attribute bits that are copied "as is" */
041: #define ATTR_UNUSED     (ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN)
042: /* bits that are used by the Windows 95/Windows NT extended FAT */
043: #define ATTR_EXT        (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
044: 
045: #define CASE_LOWER_BASE 8       /* base is lower case */
046: #define CASE_LOWER_EXT  16      /* extension is lower case */
047: 
048: #define DELETED_FLAG    0xe5    /* marks file as deleted when in name[0] */
049: #define IS_FREE(n)      (!*(n) || *(n) == DELETED_FLAG)
050: 
051: #define FAT_LFN_LEN     255     /* maximum long name length */
052: #define MSDOS_NAME      11      /* maximum name length */
053: #define MSDOS_SLOTS     21      /* max # of slots for short and long names */
054: #define MSDOS_DOT       ".          "   /* ".", padded to MSDOS_NAME chars */
055: #define MSDOS_DOTDOT    "..         "   /* "..", padded to MSDOS_NAME chars */
056: 
057: #define FAT_FIRST_ENT(s, x)     ((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \
058:         MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x))
059: 
060: /* start of data cluster's entry (number of reserved clusters) */
061: #define FAT_START_ENT   2
062: 
063: /* maximum number of clusters */
064: #define MAX_FAT12       0xFF4
065: #define MAX_FAT16       0xFFF4
066: #define MAX_FAT32       0x0FFFFFF6
067: #define MAX_FAT(s)      (MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \
068:         MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12)
069: 
070: /* bad cluster mark */
071: #define BAD_FAT12       0xFF7
072: #define BAD_FAT16       0xFFF7
073: #define BAD_FAT32       0x0FFFFFF7
074: 
075: /* standard EOF */
076: #define EOF_FAT12       0xFFF
077: #define EOF_FAT16       0xFFFF
078: #define EOF_FAT32       0x0FFFFFFF
079: 
080: #define FAT_ENT_FREE    (0)
081: #define FAT_ENT_BAD     (BAD_FAT32)
082: #define FAT_ENT_EOF     (EOF_FAT32)
083: 
084: #define FAT_FSINFO_SIG1 0x41615252
085: #define FAT_FSINFO_SIG2 0x61417272
086: #define IS_FSINFO(x)    (le32_to_cpu((x)->signature1) == FAT_FSINFO_SIG1 \
087:                          && le32_to_cpu((x)->signature2) == FAT_FSINFO_SIG2)
088: 
089: struct __fat_dirent {
090:         long            d_ino;
091:         __kernel_off_t  d_off;
092:         unsigned short  d_reclen;
093:         char            d_name[256]; /* We must not include limits.h! */
094: };
095: 
096: /*
097:  * ioctl commands
098:  */
099: #define VFAT_IOCTL_READDIR_BOTH         _IOR('r', 1, struct __fat_dirent[2])
100: #define VFAT_IOCTL_READDIR_SHORT        _IOR('r', 2, struct __fat_dirent[2])
101: /* <linux/videotext.h> has used 0x72 ('r') in collision, so skip a few */
102: #define FAT_IOCTL_GET_ATTRIBUTES        _IOR('r', 0x10, __u32)
103: #define FAT_IOCTL_SET_ATTRIBUTES        _IOW('r', 0x11, __u32)
104: 
105: struct fat_boot_sector {
106:         __u8    ignored[3];     /* Boot strap short or near jump */
107:         __u8    system_id[8];   /* Name - can be used to special case
108:                                    partition manager volumes */
109:         __u8    sector_size[2]; /* bytes per logical sector */
110:         __u8    sec_per_clus;   /* sectors/cluster */
111:         __le16  reserved;       /* reserved sectors */
112:         __u8    fats;           /* number of FATs */
113:         __u8    dir_entries[2]; /* root directory entries */
114:         __u8    sectors[2];     /* number of sectors */
115:         __u8    media;          /* media code */
116:         __le16  fat_length;     /* sectors/FAT */
117:         __le16  secs_track;     /* sectors per track */
118:         __le16  heads;          /* number of heads */
119:         __le32  hidden;         /* hidden sectors (unused) */
120:         __le32  total_sect;     /* number of sectors (if sectors == 0) */
121: 
122:         /* The following fields are only used by FAT32 */
123:         __le32  fat32_length;   /* sectors/FAT */
124:         __le16  flags;          /* bit 8: fat mirroring, low 4: active fat */
125:         __u8    version[2];     /* major, minor filesystem version */
126:         __le32  root_cluster;   /* first cluster in root directory */
127:         __le16  info_sector;    /* filesystem info sector */
128:         __le16  backup_boot;    /* backup boot sector */
129:         __le16  reserved2[6];   /* Unused */
130: };
131: 
132: struct fat_boot_fsinfo {
133:         __le32   signature1;    /* 0x41615252L */
134:         __le32   reserved1[120];        /* Nothing as far as I can tell */
135:         __le32   signature2;    /* 0x61417272L */
136:         __le32   free_clusters; /* Free cluster count.  -1 if unknown */
137:         __le32   next_cluster;  /* Most recently allocated cluster */
138:         __le32   reserved2[4];
139: };
140: 
141: struct msdos_dir_entry {
142:         __u8    name[MSDOS_NAME];/* name and extension */
143:         __u8    attr;           /* attribute bits */
144:         __u8    lcase;          /* Case for base and extension */
145:         __u8    ctime_cs;       /* Creation time, centiseconds (0-199) */
146:         __le16  ctime;          /* Creation time */
147:         __le16  cdate;          /* Creation date */
148:         __le16  adate;          /* Last access date */
149:         __le16  starthi;        /* High 16 bits of cluster in FAT32 */
150:         __le16  time,date,start;/* time, date and first cluster */
151:         __le32  size;           /* file size (in bytes) */
152: };
153: 
154: /* Up to 13 characters of the name */
155: struct msdos_dir_slot {
156:         __u8    id;             /* sequence number for slot */
157:         __u8    name0_4[10];    /* first 5 characters in name */
158:         __u8    attr;           /* attribute byte */
159:         __u8    reserved;       /* always 0 */
160:         __u8    alias_checksum; /* checksum for 8.3 alias */
161:         __u8    name5_10[12];   /* 6 more characters in name */
162:         __le16   start;         /* starting cluster number, 0 in long slots */
163:         __u8    name11_12[4];   /* last 2 characters in name */
164: };
165: 
166: #endif /* !_LINUX_MSDOS_FS_H */
167: 


for client (none)
© Andrew Scott 2006 - 2025,
All Rights Reserved
http://www.andrew-scott.uk/
Andrew Scott
http://www.andrew-scott.co.uk/