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 Do not create a file system: just print out parame

ters.

-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.

-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 stan

dard 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 on

ly). 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 in

clusive. 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.

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 pre

sented 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 en

tries */
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

*/

};

EXIT STATUS

Exit status is 0 on success and 1 on error.

EXAMPLES

newfs_msdos /dev/ad0s1

Create a file system, using default parameters, on

/dev/ad0s1.

newfs_msdos -f 1440 -L foo fd0

Create a standard 1.44M file system, with volume label foo,

on /dev/fd0.

SEE ALSO

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

HISTORY

The newfs_msdos utility first appeared in FreeBSD 3.0.

AUTHORS

Robert Nordier <rnordier@FreeBSD.org>.

BSD July 6, 1998

BSD