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

     build -- information on how to build the system

     The source	for the	FreeBSD	system and applications	are contained in three
     different directories, normally /usr/src, /usr/doc, and /usr/ports.
     /usr/src contains the "base system" sources, which	is loosely defined as
     the things	required to rebuild the	system to a useful state.  /usr/doc
     contains the source for the system	documentation, excluding the manual
     pages.  /usr/ports	is a tree that provides	a consistent interface for
     building and installing third party applications.

     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.  The fol-
     lowing list provides the names and	actions	for other targets:

     clean	 Removes any files created during the build process.

     install	 Installs the results of the build for this directory.

     update	 Gets updated sources as configured in /etc/make.conf.

     The other /usr/src	make targets are:

     buildworld	 Rebuild everything but	the kernel, configure files in /etc,
		 and release.

		 Install everything built by buildworld.

     world	 buildworld + installworld.

		 Rebuild the kernel and	the kernel modules.

		 Install the kernel and	the kernel modules.

		 Reinstall the kernel and the kernel modules.

     For more information about	the ports build	process, see ports(7).

     TARGET_ARCH  The target machine processor architecture.  This is analo-
		  gous to the "uname -p" output.  Set this to cross-build for
		  a different architecture.

     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.

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

     DESTDIR	  The directory	hierarchy where	the resulting binaries will be


     The "approved" method of updating your system from	the latest sources is:

	   make	buildworld
	   make	buildkernel KERNCONF=FOO
	   make	installkernel KERNCONF=FOO
	   <Reboot the new kernel in single user mode>
	   make	installworld

     "FOO" must	be replaced with the name of the kernel	configuration file
     from which	the kernel should be built.  Alternatively, the	KERNCONF vari-
     able in /etc/make.conf can	be set to the name of the kernel to build; in
     this case the KERNCONF=FOO	part of	the buildkernel	and installkernel com-
     mands can be omitted.

     After running these commands a system reboot is required, otherwise many
     programs which have been rebuilt (such as ps(1), top(1), etc.) may	not
     work with the old kernel which is still running.  While not strictly nec-
     essary much of the	time for upgrades from very recent sources, the	reboot
     into single user mode is critically important for upgrading from older
     kernels, or when you know "weird things" have happened with the kernel.

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

	   cd /usr/src
	   make	TARGET_ARCH=alpha buildworld
	   make	TARGET_ARCH=alpha DESTDIR=/clients/axp installworld

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

     Mike W. Meyer <>.

BSD				March 15, 2002				   BSD


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