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] [-@ offset] [-B boot] [-C create-size] [-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 or file named 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.

     -@ offset
	     Build the filesystem at the specified offset in bytes in the device or file.  A suffix s, k, m, g (lower or upper case) appended to
	     the offset specifies that the number is in sectors, kilobytes, megabytes or gigabytes, respectively.

     -B boot
	     Get bootstrap from file.

     -C create-size
	     Create the image file with the specified size.  A suffix character appended to the size is interpreted as for the -@ option.  The
	     file is created by truncating any existing file with the same name, seeking just before the required size and writing a single 0
	     byte.  As a consequence, the space occupied on disk may be smaller than the size specified as a parameter.

     -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.  If the block or cluster size are not specified,
	     the code uses a cluster between 512 bytes and 32K depending on the filesystem size.

     -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 indicat-
     ing the name of the device currently being formatted, the sector number being written, and the total number of sectors to be written.

NOTES

     If some parameters (e.g. size, number of sectors, etc.) are not specified through options or disktype, the program tries to generate them
     automatically.  In particular, the size is determined as the device or file size minus the offset specified with the -@ option.  When the
     geometry is not available, it is assumed to be 63 sectors, 255 heads.  The size is then rounded to become a multiple of the track size and
     avoid complaints by some filesystem code.

     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.  Create a 30MB image file, with the FAT partition starting 63 sec-
     tors within the image file:

	   newfs_msdos -C 30M -@63s ./somefile

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>.

BSD
								  March 26, 2009							       BSD