.TH MKFS 8
.UC
.SH NAME
mkfs \- construct a file system
.SH SYNTAX
.B /etc/mkfs
special proto [m] [n]
.br
.B /etc/mkfs
special size  [m] [n]
.SH DESCRIPTION
.I Mkfs
constructs a file system
by writing on the special file
.I special
according to the directions
found in
the prototype file
.IR proto .
The prototype file
contains tokens separated by spaces or
new lines.
The first token is the name of a file
to be copied onto block zero as
the bootstrap program,
see \fIboot\fP\|(8).
The second token is a number specifying the
size of the created file system.
Typically it will be the number of logical blocks on the device
(not necessarily the same as physical blocks),
perhaps diminished
by space for swapping.
The next token is the number of inodes
in the i-list.
The next set of tokens comprise the specification
for the root file.
File specifications consist of tokens
giving the mode,
the user id,
the group id,
and the initial contents of the file.
The syntax of the contents field
depends on the mode.
.PP
The mode token for a file is a 6 character string.
The first character
specifies the type of the file.
(The characters
.B \-bcd
specify regular, block special,
character special and directory files
respectively.)
The second character of the type
is either
.B u
or
.B \-
to specify set-user-id mode or not.
The third is
.B g
or
.B \-
for the set-group-id mode.
The rest of the mode
is a three digit octal number giving the
owner, group, and other read, write, execute
permissions, see \fIchmod\fP\|(1).
.PP
Two decimal number
tokens come after the mode; they specify the
user and group ID's of the owner of the file.
.PP
If the file is a regular file,
the next token is a pathname
whence the contents and size are copied.
.PP
If the file is a block or character special file,
two decimal number tokens
follow which give the major and minor device numbers.
.PP
If the file is a directory,
.I mkfs
makes the entries
.BR . ""
and
.B  ..
and then
reads a list of names and
(recursively)
file specifications for the entries
in the directory.
The scan is terminated with 
.BR $ .
.PP
If the prototype file cannot be opened and
its name consists of a string of digits,
.I mkfs
builds a file system with an empty directory in it.
.I Mkfs
always constructs a lost+found directory.
The size of the file system, in logical blocks, is the value
of
.I proto
interpreted as a decimal number.
The number of inodes is calculated
as a function of the filsystem size.
The boot program is left uninitialized.
.PP
The optional flags \fIm\fP and \fIn\fP determine the block interleaving
of the freelist that will be constructed,
where \fIm\fP is the distance between successive 1024-byte blocks,
and \fIn\fP is the number of blocks before the pattern repeats,
typically one cylinder.
The optimal values for
these parameters vary with the speed and geometry of the disk,
as well as the speed of the processor.
.PP
A sample prototype specification follows:
.PP
.nf
.in +5
/usr/src/sys/mdec/rkuboot
2436 55
d\-\-777 3 1
usr	d\-\-777 3 1
	sh	\-\-\-755 3 1 /bin/sh
	ken	d\-\-755 6 1
		$
	b0	b\-\-644 3 1 0 0
	c0	c\-\-644 3 1 0 0
	$
$
.in -5
.fi
.SH FILES
.ta 2.5i
/usr/src/sys/mdec/*uboot	bootstrap binaries
.SH "SEE ALSO"
dir(5), filsys(5), boot(8)
.SH BUGS
There should be some way to specify links.