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BUILD(7)	     BSD Miscellaneous Information Manual	      BUILD(7)

     build -- information on how to build the system

     The sources for the FreeBSD system	and its	applications are contained in
     three different directories, normally /usr/src, /usr/doc, and /usr/ports.
     Directory /usr/src	contains the "base system" sources, which is loosely
     defined as	the things required to rebuild the system to a useful state.
     Directory /usr/doc	contains the source for	the system documentation, ex-
     cluding the manual	pages.	Directory /usr/ports contains a	tree that pro-
     vides a consistent	interface for building and installing third party ap-
     plications.  For more information about the ports build process, see

     The make(1) command is used in each of these directories to build and in-
     stall the things in that directory.  Issuing the make(1) command in any
     directory or subdirectory of those	directories has	the same effect	as is-
     suing the same command in all subdirectories of that directory.  With no
     target specified, the things in that directory are	just built.

     A source tree is allowed to be read-only.	As described in	make(1), ob-
     jects are usually built in	a separate object directory hierarchy speci-
     fied by the environment variable MAKEOBJDIRPREFIX,	or under /usr/obj if
     variable MAKEOBJDIRPREFIX is not set.  For	a given	source directory, its
     canonical object directory	would be ${MAKEOBJDIRPREFIX}${.CURDIR} if
     make(1) variable MAKEOBJDIRPREFIX is set, or /usr/obj${.CURDIR} if	this
     variable is not set.  Cross-builds	set the	object directory as described
     in	the documentation for the buildworld target below.

     The build may be controlled by defining make(1) variables described in
     the ENVIRONMENT section below, and	by the variables documented in

     The following list	provides the names and actions for the targets sup-
     ported by the build system:

     clean	  Remove any files created during the build process.

     cleandepend  Remove the file ${.OBJDIR}/${DEPENDFILE} generated by	a
		  prior	"make depend" step.

     cleandir	  Remove the canonical object directory	if it exists, or per-
		  form actions equivalent to "make clean cleandepend" if it
		  does not.  This target will also remove an obj link in
		  ${.CURDIR} if	that exists.

		  It is	advisable to run "make cleandir" twice:	the first in-
		  vocation will	remove the canonical object directory and the
		  second one will clean	up ${.CURDIR}.

     depend	  Generate a list of build dependencies	in file

     install	  Install the results of the build to the appropriate location
		  in the installation directory	hierarchy specified in vari-
		  able DESTDIR.

     obj	  Create the canonical object directory	associated with	the
		  current directory.

     objlink	  Create a symbolic link to the	canonical object directory in

     tags	  Generate a tags file using the program specified in the
		  make(1) variable CTAGS.  The build system supports ctags(1)
		  and GNU Global.

     The other supported targets under directory /usr/src are:

     buildenv	      Spawn an interactive shell with environment variables
		      set up for cross-building	the system.  The target	archi-
		      tecture needs to be specified with make(1) variables

		      This target is only useful after a complete cross-
		      toolchain	including the compiler,	linker,	assembler,
		      headers and libraries has	been built; see	the toolchain
		      target below.

     buildworld	      Build everything but the kernel, configure files in etc,
		      and release.  The	actual build location prefix used is
		      ${MAKEOBJDIRPREFIX}${.CURDIR} for	native builds, and
		      ${MAKEOBJDIRPREFIX}/${TARGET}${.CURDIR} for cross	builds
		      and native builds	with variable CROSS_BUILD_TESTING set.

     cleanworld	      Attempt to clean up targets built	by a preceding
		      buildworld step.

     distributeworld  Distribute everything compiled by	a preceding buildworld
		      step.  Files are placed in the directory hierarchy spec-
		      ified by make(1) variable	DISTDIR.  This target is used
		      while building a release;	see release(7).

     installworld     Install everything built by a preceding buildworld step
		      into the directory hierarchy pointed to by make(1) vari-
		      able DESTDIR.

		      If installing onto an NFS	file system and	running
		      make(1) with the -j option, make sure that rpc.lockd(8)
		      is running on both client	and server.  See rc.conf(5) on
		      how to make it start at boot time.

     toolchain	      Create the build toolchain needed	to build the rest of
		      the system.  For cross-architecture builds, this step
		      creates a	cross-toolchain.

     universe	      Execute a	buildworld and buildkernel for all kernels in-
		      cluding LINT, for	each architecture supported by the
		      build system.  This command takes	a long time.

     update	      Get updated sources as configured	in make.conf(5).

     Kernel specific build targets in /usr/src are:

     buildkernel      Rebuild the kernel and the kernel	modules.

     installkernel    Install the kernel and the kernel	modules	to directory
		      ${DESTDIR}/boot/kernel, renaming any pre-existing	direc-
		      tory with	this name to kernel.old	if it contained	the
		      currently	running	kernel.	 The target directory under
		      ${DESTDIR} may be	modified using the INSTKERNNAME	and
		      KODIR make(1) variables.

     kernel	      Equivalent to buildkernel	followed by installkernel

		      Rebuild the tools	needed for kernel compilation.	Use
		      this if you did not do a buildworld first.

     reinstallkernel  Reinstall	the kernel and the kernel modules, overwriting
		      the contents of the target directory.  As	with the
		      installkernel target, the	target directory can be	speci-
		      fied using the make(1) variable INSTKERNNAME.

     Convenience targets for cleaning up the install destination directory de-
     noted by variable DESTDIR include:

     check-old	      Print a list of old files	and directories	in the system.

     delete-old	      Delete obsolete base system files	and directories	inter-
		      actively.	 When -DBATCH_DELETE_OLD_FILES is specified at
		      the command line,	the delete operation will be non-in-
		      teractive.  The variables	DESTDIR, TARGET_ARCH and
		      TARGET should be set as with "make installworld".

     delete-old-libs  Delete obsolete base system libraries interactively.
		      This target should only be used if no 3rd	party software
		      uses these libraries.  When -DBATCH_DELETE_OLD_FILES is
		      specified	at the command line, the delete	operation will
		      be non-interactive.  The variables DESTDIR, TARGET_ARCH
		      and TARGET should	be set as with "make installworld".

     Variables that influence all builds include:

     DESTDIR	       The directory hierarchy prefix where built objects will
		       be installed.  If not set, DESTDIR defaults to the
		       empty string.

     MAKEOBJDIRPREFIX  Defines the prefix for directory	names in the tree of
		       built objects.  Defaults	to /usr/obj if not defined.
		       This variable should only be set	in the environment and
		       not via /etc/make.conf or the command line.

     NO_WERROR	       If defined, compiler warnings will not cause the	build
		       to halt,	even if	the makefile says otherwise.

     Additionally, builds in /usr/src are influenced by	the following make(1)

     LOCAL_DIRS	      If set, this variable supplies a list of additional di-
		      rectories	to build, relative to the root of the source

     SUBDIR_OVERRIDE  Override the default list	of sub-directories and only
		      build the	sub-directory named in this variable.  This
		      variable is useful when debugging	failed builds.

			    make some-target SUBDIR_OVERRIDE=foo/bar

     TARGET	      The target hardware platform.  This is analogous to the
		      "uname -m" output.  This is necessary to cross-build
		      some target architectures.  For example, cross-building
		      for PC98 machines	requires TARGET_ARCH=i386 and
		      TARGET=pc98.  If not set,	TARGET defaults	to the current
		      hardware platform.

     TARGET_ARCH      The target machine processor architecture.  This is
		      analogous	to the "uname -p" output.  Set this to cross-
		      build for	a different architecture.  If not set,
		      TARGET_ARCH defaults to the current machine architec-

     Builds under directory /usr/doc are influenced by the following make(1)

     DOC_LANG  If set, restricts the documentation build to the	language sub-
	       directories specified as	its content.  The default action is to
	       build documentation for all languages.


     For an "approved" method of updating your system from the latest sources,
     please see	the COMMON ITEMS section in src/UPDATING.

     The following sequence of commands	can be used to cross-build the system
     for the sparc64 architecture on an	i386 host:

	   cd /usr/src
	   make	TARGET_ARCH=sparc64 buildworld
	   make	TARGET_ARCH=sparc64 DESTDIR=/clients/sparc64 installworld

     cc(1), install(1),	make(1), make.conf(5), src.conf(5), ports(7),
     release(7), config(8), mergemaster(8), reboot(8), shutdown(8)

     Mike W. Meyer <>.

BSD				October	1, 2006				   BSD


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