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 NetBSD 1.3.

AUTHORS
Robert Nordier <rnordier@FreeBSD.org>.