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NEWFS_MSDOS(8) BSD System Manager’s Manual 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] [−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]

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.

−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 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.

−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.

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/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.

SEE ALSO

fdisk(8), mount(8)

DIAGNOSTICS

Exit status is 0 on success and 1 on error.

HISTORY

The newfs_msdos command appeared in FreeBSD 3.0.

AUTHORS

Robert Nordier <rnordier [AT] FreeBSD.org>.

BSD July 6, 1998 BSD