newfs_msdos8
Construct a new ms-dos (fat) file system
Usage
newfs_msdos [-N]
[-a
FAT-size]
[-B
boot]
[-b
block-size]
[-c
cluster-size]
[-e
dirents]
[-F
FAT-type]
[-f
format]
[-h
heads]
[-I
volid]
[-i
info]
[-k
backup]
[-L
label]
[-m
media]
[-n
FATs]
[-O
OEM]
[-o
hidden]
[-r
reserved]
[-S
sector-size]
[-s
total]
[-u
track-size]
special
[disktype]
Overview
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 special file should be a raw device, for example /dev/rsd0i; if a relative path like sd0i is specified, the corresponding raw device is used.
The options are as follows:
-
-a FAT-size -
Number of sectors per FAT.
-
-B boot -
Get bootstrap from file.
-
-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 FAT-type -
FAT type (one of 12, 16, or 32).
-
-f format -
Specify a standard (floppy disk) format. The eight standard formats are (capacities in kilobytes): 160, 180, 320, 360, 720, 1200, 1440, 2880.
-
-h heads -
Number of drive heads.
-
-I volid -
Volume ID.
-
-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.
-
-L label -
Volume label (up to 11 characters). The label should consist of only those characters permitted in regular DOS (8+3) filenames.
-
-m media -
Media descriptor (acceptable range 0xf0 to 0xff).
-
-N -
Don't create a file system: just print out parameters.
-
-n FATs -
Number of FATs. Acceptable values are 1 to 16 inclusive. The default is 2.
-
-O OEM -
OEM string (up to 8 characters). The default is "BSD 4.4".
-
-o hidden -
Number of hidden sectors.
-
-r reserved -
Number of reserved sectors.
-
-S sector-size -
Number of bytes per sector. Acceptable values are powers of 2 in the range 512 through 32768.
-
-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 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
Create a file system, using default parameters, on /dev/rwd0i.
newfs_msdos /dev/rwd0i
Create a standard 1.44M file system, with volume label "foo", on /dev/rfd0c.
newfs_msdos -f 1440 -L foo fd0c
Diagnostics
Exit status is 0 on success and 1 on error.
Releases
61 releases since OpenBSD 2.1; the text changed 14 times.
-B since OpenBSD 2.7;
-F since OpenBSD 2.7;
-I since OpenBSD 2.7;
-N since OpenBSD 2.7;
-O since OpenBSD 2.7;
-S since OpenBSD 2.7;
-a since OpenBSD 2.7;
-b since OpenBSD 2.7;
-c since OpenBSD 2.7;
-e since OpenBSD 2.7;
-f since OpenBSD 2.7;
-h since OpenBSD 2.7;
-i since OpenBSD 2.7;
-k since OpenBSD 2.7;
-m since OpenBSD 2.7;
-n since OpenBSD 2.7;
-o since OpenBSD 2.7;
-r since OpenBSD 2.7;
-u since OpenBSD 2.7.