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CONFIG(1)		  BSD General Commands Manual		     CONFIG(1)

NAME
     config -- build kernel compilation	directories

SYNOPSIS
     config [-Ppv] [-b builddir] [-s srcdir] [config-file]
     config -x [kernel-file]
     config -L [-v] [-s	srcdir]	[config-file]

DESCRIPTION
     In	its first synopsis form, config	creates	a kernel build directory from
     the machine description file config-file, which describes the system to
     configure.	 Refer to section KERNEL BUILD CONFIGURATION for the details
     of	that use of config.

     In	its second synopsis form, config takes the binary kernel kernel-file
     as	its single argument (aside from	the mandatory -x flag),	then extracts
     the embedded configuration	file (if any) and writes it to standard	out-
     put.  If kernel-file is not given,	/netbsd	is used.  Configuration	data
     will be available if the given kernel was compiled	with either
     INCLUDE_CONFIG_FILE or INCLUDE_JUST_CONFIG	options.

     In	its third synopsis form, config	is a tool for the kernel developer and
     generates a "lint"	configuration file to be used during regression	test-
     ing.  Refer to section LINT CONFIGURATION for the details of that use of
     config.

     config accepts the	following parameters:

     -b	builddir
	     Use builddir as the kernel	build directory, instead of computing
	     and creating one automatically.

     -L	     Generate a	lint configuration.  See section LINT CONFIGURATION
	     for details.

     -P	     Pack locators to save space in the	resulting kernel binary.  The
	     amount of space saved that	way is so small	that this option
	     should be considered historical, and of no	actual use.

     -p	     Generate a	build directory	suited for kernel profiling.  However,
	     this options should be avoided in favor of	the relevant options
	     inside the	configuration file as described	in section KERNEL
	     BUILD CONFIGURATION.

     -s	srcdir
	     Point to the top of the kernel source tree.  It must be an	abso-
	     lute path when config is used to prepare a	kernel build direc-
	     tory, but can be relative when it is used in combination with the
	     -L	flag.

     -v	     Increase verbosity	by enabling some more warnings.

     -x	     Extract the configuration embedded	in a kernel binary.

   KERNEL BUILD	CONFIGURATION
     There are several different ways to run the config	program.  The tradi-
     tional way	is to run config from the conf subdirectory of the machine-
     specific directory	of the system source (usually /sys/arch/MACHINE/conf,
     where MACHINE is one of vax, hp300, and so	forth),	and to specify as the
     config-file the name of a machine description file	located	in that	direc-
     tory.  config will	by default create files	in the directory
     ../compile/SYSTEMNAME, where SYSTEMNAME is	the last path component	of
     config-file.  config will assume that the top-level kernel	source direc-
     tory is located four directories above the	build directory.

     Another way is to create the build	directory yourself, place the machine
     description file in the build directory with the name CONFIG, and run
     config from within	the build directory without specifying a config-file.
     config will then by default create	files in the current directory.	 If
     you run config this way, you must specify the location of the top-level
     kernel source directory using the -s option or by using the "source" di-
     rective at	the beginning of the machine description file.

     Finally, you can specify the build	directory for config and run it	from
     anywhere.	You can	specify	a build	directory with the -b option or	by us-
     ing the "build" directive at the beginning	of the machine description
     file.  You	must specify the location of the top-level kernel source di-
     rectory if	you specify a build directory.

     If	config-file is a binary	kernel,	config will try	to extract the config-
     uration file embedded into	it, which will be present if that kernel was
     built either with INCLUDE_CONFIG_FILE or INCLUDE_JUST_CONFIG options.
     This work mode requires you to manually specify a build directory with
     the -b option, which implies the need to provide a	source tree too.

     If	the -p option is supplied, .PROF is appended to	the default compila-
     tion directory name, and config acts as if	the lines "makeoptions
     PROF="-pg"" and "options GPROF" appeared in the machine description file.
     This will build a system that includes profiling code; see	kgmon(8) and
     gprof(1).	The -p flag is expected	to be used for "one-shot" profiles of
     existing systems; for regular profiling, it is probably wiser to create a
     separate machine description file containing the makeoptions line.

     The old undocumented -g flag is no	longer supported.  Instead, use
     "makeoptions DEBUG="-g"" and (typically) "options KGDB".

     The output	of config consists of a	number of files, principally ioconf.c,
     a description of I/O devices that may be attached to the system; and a
     Makefile, used by make(1) in building the kernel.

     After running config, it is wise to run "make depend" in the directory
     where the new makefile was	created.  config prints	a reminder of this
     when it completes.

     If	config stops due to errors, the	problems reported should be corrected
     and config	should be run again.  config attempts to avoid changing	the
     compilation directory if there are	configuration errors, but this code is
     not well-tested, and some problems	(such as running out of	disk space)
     are unrecoverable.

   LINT	CONFIGURATION
     A so-called "lint"	configuration should include everything	from the ker-
     nel that can possibly be selected.	 The rationale is to provide a way to
     reach all the code	a user might select, in	order to make sure all options
     and drivers compile without error for a given source tree.

     When used with the	-L flag, config	takes the regular configuration	file
     config-file and prints on the standard output a configuration file	that
     includes config-file, selects all options and file-systems	the user can
     possibly select, and defines an instance of every possible	attachment as
     described by the kernel option definition files used by config-file.

     The resulting configuration file is meant as a way	to select all possible
     features in order to test that each of them compiles.  It is not meant to
     result in a kernel	binary that can	run on any hardware.

     Unlike the	first synopsis form, the provided srcdir is relative to	the
     current working directory.	 In the	first synopsis form, it	is relative to
     the build directory.

SEE ALSO
     The SYNOPSIS portion of each device in section 4.

     options(4), config(5), config(9)

HISTORY
     The config	command	appeared in 4.1BSD.  It	was completely revised in
     4.4BSD.  The -x option appeared in	NetBSD 2.0.  The -L option appeared in
     NetBSD 5.0.

BSD			       September 9, 2007			   BSD

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | HISTORY

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