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NEWFS_MSDOS(8)            BSD System Manager's Manual           NEWFS_MSDOS(8)

     newfs_msdos -- construct a new MS-DOS (FAT) file system

     newfs_msdos [-N] [-B boot] [-F FAT-type] [-I volid] [-O OEM]
                 [-S sector-size] [-a FAT-size] [-b block-size]
                 [-c cluster-size] [-e dirents] [-f format] [-h heads]
                 [-i info] [-k backup] [-m media] [-n FATs] [-o hidden]
                 [-r reserved] [-s total] [-u track-size] [-v volume-name]
                 special [disktype]

     The newfs_msdos utility creates a FAT12, FAT16, or FAT32 file system on
     device special, using disktab(5) entry disktype to determine geometry, if

     The options are as follow:

     -N      Don't create a file system: just print out parameters.

     -B boot
             Get bootstrap from file.

     -F FAT-type
             FAT type (one of 12, 16, or 32).

     -I volid
             Volume ID.

     -O OEM  OEM string (up to 8 characters).  The default is "BSD  4.4".

     -S sector-size
             Number of bytes per sector.  Acceptable values are powers of 2 in
             the range 128 through 32768.

     -a FAT-size
             Number of sectors per FAT.

     -b block-size
             File system block size (bytes per cluster).  This should resolve
             to an acceptable number of sectors per cluster (see below).

     -c cluster-size
             Sectors per cluster.  Acceptable values are powers of 2 in the
             range 1 through 128.

     -e dirents
             Number of root directory entries (FAT12 and FAT16 only).

     -f format
             Specify a standard (floppy disk) format.  The eight standard for-
             mats are (capacities in kilobytes): 160, 180, 320, 360, 640, 720,
             1200, 1232, 1440, 2880.

     -h heads
             Number of drive heads.

     -i info
             Location of the file system info sector (FAT32 only).  A value of
             0xffff signifies no info sector.

     -k backup
             Location of the backup boot sector (FAT32 only).  A value of
             0xffff signifies no backup sector.

     -m media
             Media descriptor (acceptable range 0xf0 to 0xff).

     -n FATs
             Number of FATs.  Acceptable values are 1 to 16 inclusive.  The
             default is 2.

     -o hidden
             Number of hidden sectors.

     -r reserved
             Number of reserved sectors.

     -s total
             File system size.

     -u track-size
             Number of sectors per track.

     -v volume-name
             Volume name (filesystem name), up to 11 characters.  The name
             should consist of only those characters permitted in regular DOS
             (8+3) filenames.

     FAT file system parameters occupy a "Boot Sector BPB (BIOS Parameter
     Block)" in the first of the "reserved" sectors which precede the actual
     file system.  For reference purposes, this structure is presented below.

     struct bsbpb {
         u_int16_t   bps;            /* [-S] bytes per sector */
         u_int8_t    spc;            /* [-c] sectors per cluster */
         u_int16_t   res;            /* [-r] reserved sectors */
         u_int8_t    nft;            /* [-n] number of FATs */
         u_int16_t   rde;            /* [-e] root directory entries */
         u_int16_t   sec;            /* [-s] total sectors */
         u_int8_t    mid;            /* [-m] media descriptor */
         u_int16_t   spf;            /* [-a] sectors per FAT */
         u_int16_t   spt;            /* [-u] sectors per track */
         u_int16_t   hds;            /* [-h] drive heads */
         u_int32_t   hid;            /* [-o] hidden sectors */
         u_int32_t   bsec;           /* [-s] big total sectors */
     /* FAT32 extensions */
     struct bsxbpb {
         u_int32_t   bspf;           /* [-a] big sectors per FAT */
         u_int16_t   xflg;           /* control flags */
         u_int16_t   vers;           /* file system version */
         u_int32_t   rdcl;           /* root directory start cluster */
         u_int16_t   infs;           /* [-i] file system info sector */
         u_int16_t   bkbs;           /* [-k] backup boot sector */

          newfs_msdos /dev/disk0s1

     Create a file system, using default parameters, on /dev/disk0s1.

          newfs_msdos -f 1440 -v foo fd0

     Create a standard 1.44M file system, with volume name "foo", on /dev/fd0.

     fdisk(8), mount(8)

     Exit status is 0 on success and 1 on error.

     The newfs_msdos command appeared in FreeBSD 3.0.

     Robert Nordier <rnordierATFreeBSD.org>.

BSD                              July 6, 1998                              BSD