November 25, 2006 NEWFS_MSDOS 8

### NAME

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

### SYNOPSIS

newfs_msdos [-N] [-B boot] [-F FAT-type] [-I volid] [-L label] [-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] special [disktype]

### DESCRIPTION

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

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.

-L label
  Volume label (up to 11 characters). The label should consist of only those characters permitted in regular DOS (8+3) filenames. The default is "```NO_NAME`.

-O OEM
  OEM string (up to 8 characters). The default is "```NetBSD`.

-S sector-size
  Number of bytes per sector. Acceptable values are powers of 2 in the range 512 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 standard formats 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.

If newfs_msdos receives a ```SIGINFO` signal (see the status argument for stty(1)), a line will be written to the standard error output indicating the name of the device currently being formatted, the sector number being written, and the total number of sectors to be written.

### NOTES

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 */
    };

`

### EXAMPLES

  `

      newfs_msdos /dev/rwd1a

  `

Create a file system, using default parameters, on ```/dev/rwd1a`.

  `

      newfs_msdos -f 1440 -L foo /dev/rfd0a

  `

Create a standard 1.44M file system, with volume label foo, on ```/dev/rfd0a`.

### DIAGNOSTICS

Exit status is 0 on success and 1 on error.

### SEE ALSO

disktab(5), disklabel(8), fdisk(8), newfs(8)

### HISTORY

The newfs_msdos command first appeared in NetBSD1.3.

### AUTHORS

Robert Nordier <rnordier@FreeBSD.org>
.