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28.Dd June 4, 2024
29.Dt BUILD 7
30.Os
31.Sh NAME
32.Nm build
33.Nd general instructions on how to build the
34.Fx
35system
36.Sh DESCRIPTION
37The sources for the
38.Fx
39system and its applications are contained in three different directories,
40normally
41.Pa /usr/src ,
42.Pa /usr/doc ,
43and
44.Pa /usr/ports .
45These directories may be initially empty or non-existent until updated with
46Git
47.Po installed from packages with
48.Xr pkg 7
49or from
50.Xr ports 7 Pc .
51Directory
52.Pa /usr/src
53contains the
54.Dq "base system"
55sources, which is loosely defined as the things required to rebuild
56the system to a useful state.
57Directory
58.Pa /usr/doc
59contains the source for the system documentation, excluding the manual
60pages.
61Directory
62.Pa /usr/ports
63contains a tree that provides a consistent interface for building and
64installing third party applications.
65For more information about the ports build process, see
66.Xr ports 7 .
67.Pp
68The
69.Xr make 1
70command is used in each of these directories to build and install the
71things in that directory.
72Issuing the
73.Xr make 1
74command in any directory issues the
75.Xr make 1
76command recursively in all subdirectories.
77With no target specified, the items in the directories are built
78and no further action is taken.
79.Pp
80A source tree is allowed to be read-only.
81As described in
82.Xr make 1 ,
83objects are usually built in a separate object directory hierarchy
84specified by the environment variable
85.Va MAKEOBJDIRPREFIX ,
86or under
87.Pa /usr/obj
88if variable
89.Va MAKEOBJDIRPREFIX
90is not set.
91The canonical object directory is described in the documentation for the
92.Cm buildworld
93target below.
94.Pp
95The build may be controlled by defining
96.Xr make 1
97variables described in the
98.Sx ENVIRONMENT
99section below, and by the variables documented in
100.Xr make.conf 5 .
101.Pp
102The default components included in the build are specified in the file
103.Pa /etc/src.conf
104in the source tree.
105To override the default file, include the SRCCONF option in the make steps,
106pointing to a custom src.conf file.
107For more information see
108.Xr src.conf 5 .
109.Pp
110The following list provides the names and actions for the targets
111supported by the build system:
112.Bl -tag -width ".Cm cleandepend"
113.It Cm analyze
114Run Clang static analyzer against all objects and present output on stdout.
115.It Cm check
116Run tests for a given subdirectory.
117The default directory used is
118.Pa ${.OBJDIR} ,
119but the check directory can be changed with
120.Pa ${CHECKDIR} .
121.It Cm checkworld
122Run the
123.Fx
124test suite on installed world.
125.It Cm clean
126Remove any files created during the build process.
127.It Cm cleandepend
128Remove the
129.Pa ${.OBJDIR}/${DEPENDFILE}*
130files generated by prior
131.Dq Li "make"
132and
133.Dq Li "make depend"
134steps.
135.It Cm cleandir
136Remove the canonical object directory if it exists, or perform
137actions equivalent to
138.Dq Li "make clean cleandepend"
139if it does not.
140This target will also remove an
141.Pa obj
142link in
143.Pa ${.CURDIR}
144if that exists.
145.Pp
146It is advisable to run
147.Dq Li "make cleandir"
148twice: the first invocation will remove the canonical object directory
149and the second one will clean up
150.Pa ${.CURDIR} .
151.It Cm depend
152Generate a list of build dependencies in file
153.Pa ${.OBJDIR}/${DEPENDFILE} .
154Per-object dependencies are generated at build time and stored in
155.Pa ${.OBJDIR}/${DEPENDFILE}.${OBJ} .
156.It Cm install
157Install the results of the build to the appropriate location in the
158installation directory hierarchy specified in variable
159.Va DESTDIR .
160.It Cm obj
161Create the canonical object directory associated with the current
162directory.
163.It Cm objlink
164Create a symbolic link to the canonical object directory in
165.Pa ${.CURDIR} .
166.It Cm tags
167Generate a tags file using the program specified in the
168.Xr make 1
169variable
170.Va CTAGS .
171The build system supports
172.Xr ctags 1
173and
174.Nm "GNU Global" .
175.El
176.Pp
177The other supported targets under directory
178.Pa /usr/src
179are:
180.Bl -tag -width ".Cm distributeworld"
181.It Cm buildenv
182Spawn an interactive shell with environment variables set up for
183building the system or individual components.
184For cross-building the target architecture needs to be specified with
185.Xr make 1
186variables
187.Va TARGET_ARCH
188and
189.Va TARGET .
190.Pp
191This target is only useful after a complete toolchain (including
192the compiler, linker, assembler, headers and libraries) has been
193built; see the
194.Cm toolchain
195target below.
196.It Cm buildworld
197Build everything but the kernel, configure files in
198.Pa etc ,
199and
200.Pa release .
201The object directory can be changed from the default
202.Pa /usr/obj
203by setting the
204.Pa MAKEOBJDIRPREFIX
205.Xr make 1
206variable.
207The actual build location prefix used
208depends on the
209.Va WITH_UNIFIED_OBJDIR
210option from
211.Xr src.conf 5 .
212If enabled it is
213.Pa ${MAKEOBJDIRPREFIX}${.CURDIR}/${TARGET}.${TARGET_ARCH}
214for all builds.
215If disabled it is
216.Pa ${MAKEOBJDIRPREFIX}${.CURDIR}
217for native builds, and
218.Pa ${MAKEOBJDIRPREFIX}/${TARGET}.${TARGET_ARCH}${.CURDIR}
219for cross builds and native builds with variable
220.Va CROSS_BUILD_TESTING
221set.
222.It Cm cleankernel
223Attempts to clean up targets built by a preceding
224.Cm buildkernel ,
225or similar step, built from the same source directory and
226.Va KERNCONF .
227.It Cm cleanworld
228Attempt to clean up targets built by a preceding
229.Cm buildworld ,
230or similar step, built from this source directory.
231.It Cm cleanuniverse
232When
233.Va WITH_UNIFIED_OBJDIR
234is enabled, attempt to clean up targets built by a preceding
235.Cm buildworld ,
236.Cm universe ,
237or similar step, for any architecture built from this source directory.
238.It Cm distributeworld
239Distribute everything compiled by a preceding
240.Cm buildworld
241step.
242Files are placed in the directory hierarchy specified by
243.Xr make 1
244variable
245.Va DISTDIR .
246This target is used while building a release; see
247.Xr release 7 .
248.It Cm native-xtools
249This target builds a cross-toolchain for the given
250.Sy TARGET
251and
252.Sy TARGET_ARCH ,
253as well as a select list of static userland tools for the host system.
254This is intended to be used in a jail where QEMU is used to improve
255performance by avoiding emulating binaries that do not need to be emulated.
256.Sy TARGET
257and
258.Sy TARGET_ARCH
259should be defined.
260.It Cm native-xtools-install
261Installs the results to
262.Pa ${DESTDIR}/${NXTP}
263where
264.Va NXTP
265defaults to
266.Pa nxb-bin .
267.Sy TARGET
268and
269.Sy TARGET_ARCH
270must be defined.
271.It Cm packageworld
272Archive the results of
273.Cm distributeworld ,
274placing the results in
275.Va DISTDIR .
276This target is used while building a release; see
277.Xr release 7 .
278.It Cm installworld
279Install everything built by a preceding
280.Cm buildworld
281step into the directory hierarchy pointed to by
282.Xr make 1
283variable
284.Va DESTDIR .
285.Pp
286If installing onto an NFS file system and running
287.Xr make 1
288with the
289.Fl j
290option, make sure that
291.Xr rpc.lockd 8
292is running on both client and server.
293See
294.Xr rc.conf 5
295on how to make it start at boot time.
296.It Cm toolchain
297Create the build toolchain needed to build the rest of the system.
298For cross-architecture builds, this step creates a cross-toolchain.
299.It Cm universe
300For each architecture,
301execute a
302.Cm buildworld
303followed by a
304.Cm buildkernel
305for all kernels for that architecture,
306including
307.Pa LINT .
308This command takes a long time.
309.It Cm kernels
310Like
311.Cm universe
312with
313.Va WITHOUT_WORLDS
314defined so only the kernels for each architecture are built.
315.It Cm worlds
316Like
317.Cm universe
318with
319.Va WITHOUT_KERNELS
320defined so only the worlds for each architecture are built.
321.It Cm targets
322Print a list of supported
323.Va TARGET
324/
325.Va TARGET_ARCH
326pairs for world and kernel targets.
327.It Cm tinderbox
328Execute the same targets as
329.Cm universe .
330In addition print a summary of all failed targets at the end and
331exit with an error if there were any.
332.It Cm toolchains
333Create a build toolchain for each architecture supported by the build system.
334.It Cm xdev
335Builds and installs a cross-toolchain and sysroot for the given
336.Sy TARGET
337and
338.Sy TARGET_ARCH .
339The sysroot contains target library and headers.
340The target is an alias for
341.Cm xdev-build
342and
343.Cm xdev-install .
344The location of the files installed can be controlled with
345.Va DESTDIR .
346The target location in
347.Va DESTDIR
348is
349.Pa ${DESTDIR}/${XDTP}
350where
351.Va XDTP
352defaults to
353.Pa /usr/${XDDIR}
354and
355.Va XDDIR
356defaults to
357.Pa ${TARGET_ARCH}-freebsd .
358.It Cm xdev-build
359Builds for the
360.Cm xdev
361target.
362.It Cm xdev-install
363Installs the files for the
364.Cm xdev
365target.
366.It Cm xdev-links
367Installs autoconf-style symlinks to
368.Pa ${DESTDIR}/usr/bin
369pointing into the xdev toolchain in
370.Pa ${DESTDIR}/${XDTP} .
371.El
372.Pp
373Kernel specific build targets in
374.Pa /usr/src
375are:
376.Bl -tag -width ".Cm distributekernel"
377.It Cm buildkernel
378Rebuild the kernel and the kernel modules.
379The object directory can be changed from the default
380.Pa /usr/obj
381by setting the
382.Pa MAKEOBJDIRPREFIX
383.Xr make 1
384variable.
385.It Cm installkernel
386Install the kernel and the kernel modules to directory
387.Pa ${DESTDIR}/boot/kernel ,
388renaming any pre-existing directory with this name to
389.Pa kernel.old
390if it contained the currently running kernel.
391The target directory under
392.Pa ${DESTDIR}
393may be modified using the
394.Va INSTKERNNAME
395and
396.Va KODIR
397.Xr make 1
398variables.
399.It Cm distributekernel
400Install the kernel to the directory
401.Pa ${DISTDIR}/kernel/boot/kernel .
402This target is used while building a release; see
403.Xr release 7 .
404.It Cm packages
405Create a
406.Xr pkg 7
407repository containing packages that can be used to create or upgrade an
408installation of the base system.
409The output repository is placed in the object directory, under
410.Pa repo/${PKG_ABI}
411where
412.Va PKG_ABI
413is the
414.Xr pkg 7
415ABI for the build target, for example,
416.Pa /usr/obj/${SRCDIR}/repo/FreeBSD:15:amd64 .
417.It Cm packagekernel
418Archive the results of
419.Cm distributekernel ,
420placing the results in
421.Va DISTDIR .
422This target is used while building a release; see
423.Xr release 7 .
424.It Cm kernel
425Equivalent to
426.Cm buildkernel
427followed by
428.Cm installkernel
429.It Cm kernel-toolchain
430Rebuild the tools needed for kernel compilation.
431Use this if you did not do a
432.Cm buildworld
433first.
434.It Cm reinstallkernel
435Reinstall the kernel and the kernel modules, overwriting the contents
436of the target directory.
437As with the
438.Cm installkernel
439target, the target directory can be specified using the
440.Xr make 1
441variable
442.Va INSTKERNNAME .
443.El
444.Pp
445Convenience targets for cleaning up the install destination directory
446denoted by variable
447.Va DESTDIR
448include:
449.Bl -tag -width ".Cm delete-old-libs"
450.It Cm check-old
451Print a list of old files and directories in the system.
452.It Cm delete-old
453Delete obsolete base system files and directories interactively.
454When
455.Li -DBATCH_DELETE_OLD_FILES
456is specified at the command line, the delete operation will be
457non-interactive.
458The variables
459.Va DESTDIR ,
460.Va TARGET_ARCH
461and
462.Va TARGET
463should be set as with
464.Dq Li "make installworld" .
465.It Cm delete-old-libs
466Delete obsolete base system libraries interactively.
467This target should only be used if no third party software uses these
468libraries.
469When
470.Li -DBATCH_DELETE_OLD_FILES
471is specified at the command line, the delete operation will be
472non-interactive.
473The variables
474.Va DESTDIR ,
475.Va TARGET_ARCH
476and
477.Va TARGET
478should be set as with
479.Dq Li "make installworld" .
480.El
481.Sh ENVIRONMENT
482Variables that influence all builds include:
483.Bl -tag -width ".Va MAKEOBJDIRPREFIX"
484.It Va DEBUG_FLAGS
485Defines a set of debugging flags that will be used to build all userland
486binaries under
487.Pa /usr/src .
488When
489.Va DEBUG_FLAGS
490is defined, the
491.Cm install
492and
493.Cm installworld
494targets install binaries from the current
495.Va MAKEOBJDIRPREFIX
496without stripping,
497so that debugging information is retained in the installed binaries.
498.It Va DESTDIR
499The directory hierarchy prefix where built objects will be installed.
500If not set,
501.Va DESTDIR
502defaults to the empty string.
503.It Va MAKEOBJDIRPREFIX
504Defines the prefix for directory names in the tree of built objects.
505Defaults to
506.Pa /usr/obj
507if not defined.
508This variable should only be set in the environment or
509.Pa /etc/src-env.conf
510and not via
511.Pa /etc/make.conf
512or
513.Pa /etc/src.conf
514or the command line.
515.It Va WITHOUT_WERROR
516If defined, compiler warnings will not cause the build to halt,
517even if the makefile says otherwise.
518.It Va WITH_CTF
519If defined, the build process will run the DTrace CTF conversion
520tools on built objects.
521.El
522.Pp
523Additionally, builds in
524.Pa /usr/src
525are influenced by the following
526.Xr make 1
527variables:
528.Bl -tag -width ".Va LOCAL_MODULES_DIR"
529.It Va CROSS_TOOLCHAIN
530Requests use of an external toolchain to build either the world or kernel.
531This value of this variable can either be the full path to a file,
532or the base name of a file in
533.Pa ${LOCALBASE}/share/toolchains .
534The file should be a make file which sets variables to request an external
535toolchain such as
536.Va XCC .
537.Pp
538External toolchains are available in ports for both LLVM and GCC/binutils.
539For external toolchains available in ports,
540.Va CROSS_TOOLCHAIN
541should be set to the name of the package.
542LLVM toolchain packages use the name llvm<major version>.
543GCC toolchains provide separate packages for each architecture and use the
544name ${MACHINE_ARCH}-gcc<major version>.
545.It Va KERNCONF
546Overrides which kernel to build and install for the various kernel
547make targets.
548It defaults to
549.Cm GENERIC .
550.It Va KERNCONFDIR
551Overrides the directory in which
552.Va KERNCONF
553and any files included by
554.Va KERNCONF
555should be found.
556Defaults to
557.Pa sys/${ARCH}/conf .
558.It Va KERNFAST
559If set, the build target
560.Cm buildkernel
561defaults to setting
562.Va NO_KERNELCLEAN ,
563.Va NO_KERNELCONFIG ,
564and
565.Va NO_KERNELOBJ .
566When set to a value other than
567.Cm 1
568then
569.Va KERNCONF
570is set to the value of
571.Va KERNFAST .
572.It Va LOCAL_DIRS
573If set, this variable supplies a list of additional directories relative to
574the root of the source tree to build as part of the
575.Cm everything
576target.
577The directories are built in parallel with each other,
578and with the base system directories.
579Insert a
580.Va .WAIT
581directive at the beginning of the
582.Va LOCAL_DIRS
583list to ensure all base system directories are built first.
584.Va .WAIT
585may also be used as needed elsewhere within the list.
586.It Va LOCAL_ITOOLS
587If set, this variable supplies a list of additional tools that are used by the
588.Cm installworld
589and
590.Cm distributeworld
591targets.
592.It Va LOCAL_LIB_DIRS
593If set, this variable supplies a list of additional directories relative to
594the root of the source tree to build as part of the
595.Cm libraries
596target.
597The directories are built in parallel with each other,
598and with the base system libraries.
599Insert a
600.Va .WAIT
601directive at the beginning of the
602.Va LOCAL_DIRS
603list to ensure all base system libraries are built first.
604.Va .WAIT
605may also be used as needed elsewhere within the list.
606.It Va LOCAL_MTREE
607If set, this variable supplies a list of additional mtrees relative to the
608root of the source tree to use as part of the
609.Cm hierarchy
610target.
611.It Va LOCAL_LEGACY_DIRS
612If set, this variable supplies a list of additional directories relative to
613the root of the source tree to build as part of the
614.Cm legacy
615target.
616.It Va LOCAL_BSTOOL_DIRS
617If set, this variable supplies a list of additional directories relative to
618the root of the source tree to build as part of the
619.Cm bootstrap-tools
620target.
621.It Va LOCAL_TOOL_DIRS
622If set, this variable supplies a list of additional directories relative to
623the root of the source tree to build as part of the
624.Cm build-tools
625target.
626.It Va LOCAL_XTOOL_DIRS
627If set, this variable supplies a list of additional directories relative to
628the root of the source tree to build as part of the
629.Cm cross-tools
630target.
631.It Va PORTS_MODULES
632A list of ports with kernel modules that should be built and installed
633as part of the
634.Cm buildkernel
635and
636.Cm installkernel
637process.
638.Bd -literal -offset indent
639make PORTS_MODULES=emulators/virtualbox-ose-kmod kernel
640.Ed
641.It Va LOCAL_MODULES
642A list of external kernel modules that should be built and installed
643as part of the
644.Cm buildkernel
645and
646.Cm installkernel
647process.
648Defaults to the list of sub-directories of
649.Va LOCAL_MODULES_DIR .
650.It Va LOCAL_MODULES_DIR
651The directory in which to search for the kernel modules specified by
652.Va LOCAL_MODULES .
653Each kernel module should consist of a directory containing a makefile.
654Defaults to
655.Pa ${LOCALBASE}/sys/modules .
656.It Va SRCCONF
657Specify a file to override the default
658.Pa /etc/src.conf .
659The src.conf file controls the components to build.
660See
661.Xr src.conf 5
662.It Va STRIPBIN
663Command to use at install time when stripping binaries.
664Be sure to add any additional tools required to run
665.Va STRIPBIN
666to the
667.Va LOCAL_ITOOLS
668.Xr make 1
669variable before running the
670.Cm distributeworld
671or
672.Cm installworld
673targets.
674See
675.Xr install 1
676for more details.
677.It Va SUBDIR_OVERRIDE
678Override the default list of sub-directories and only build the
679sub-directory named in this variable.
680If combined with
681.Cm buildworld
682then all libraries and includes, and some of the build tools will still build
683as well.
684Specifying
685.Cm -DNO_LIBS ,
686and
687.Cm -DWORLDFAST
688will only build the specified directory as was done historically.
689When combined with
690.Cm buildworld
691it is necessary to override
692.Va LOCAL_LIB_DIRS
693with any custom directories containing libraries.
694This allows building a subset of the system in the same way as
695.Cm buildworld
696does using its sysroot handling.
697This variable can also be useful when debugging failed builds.
698.Bd -literal -offset indent
699make some-target SUBDIR_OVERRIDE=foo/bar
700.Ed
701.It Va SYSDIR
702Specify the location of the kernel source to override the default
703.Pa /usr/src/sys .
704The kernel source is located in the
705.Pa sys
706subdirectory of the source tree checked out from the
707.Pa src.git
708repository.
709.It Va TARGET
710The target hardware platform.
711This is analogous to the
712.Dq Nm uname Fl m
713output.
714This is necessary to cross-build some target architectures.
715For example, cross-building for ARM64 machines requires
716.Va TARGET_ARCH Ns = Ns Li aarch64
717and
718.Va TARGET Ns = Ns Li arm64 .
719If not set,
720.Va TARGET
721defaults to the current hardware platform, unless
722.Va TARGET_ARCH
723is also set, in which case it defaults to the appropriate
724value for that architecture.
725.It Va TARGET_ARCH
726The target machine processor architecture.
727This is analogous to the
728.Dq Nm uname Fl p
729output.
730Set this to cross-build for a different architecture.
731If not set,
732.Va TARGET_ARCH
733defaults to the current machine architecture, unless
734.Va TARGET
735is also set, in which case it defaults to the appropriate
736value for that platform.
737Typically, one only needs to set
738.Va TARGET .
739.El
740.Pp
741Builds under directory
742.Pa /usr/src
743are also influenced by defining one or more of the following symbols,
744using the
745.Fl D
746option of
747.Xr make 1 :
748.Bl -tag -width ".Va LOADER_DEFAULT_INTERP"
749.It Va LOADER_DEFAULT_INTERP
750Defines what interpreter the default loader program will have.
751Valid values include
752.Dq 4th ,
753.Dq lua ,
754and
755.Dq simp .
756This creates the default link for
757.Pa /boot/loader
758to the loader with that interpreter.
759It also determines what interpreter is compiled into
760.Pa userboot .
761.It Va NO_CLEANDIR
762If set, the build targets that clean parts of the object tree use the
763equivalent of
764.Dq make clean
765instead of
766.Dq make cleandir .
767.It Va NO_CLEAN
768If set, no object tree files are cleaned at all.
769This is the default when
770.Va WITH_META_MODE
771is used with
772.Xr filemon 4
773loaded.
774See
775.Xr src.conf 5
776for more details.
777Setting
778.Va NO_CLEAN
779implies
780.Va NO_KERNELCLEAN ,
781so when
782.Va NO_CLEAN
783is set no kernel objects are cleaned either.
784.It Va NO_CTF
785If set, the build process does not run the DTrace CTF conversion tools
786on built objects.
787.It Va NO_SHARE
788If set, the build does not descend into the
789.Pa /usr/src/share
790subdirectory (i.e., manual pages, locale data files, timezone data files and
791other
792.Pa /usr/src/share
793files will not be rebuild from their sources).
794.It Va NO_KERNELCLEAN
795If set, the build process does not run
796.Dq make clean
797as part of the
798.Cm buildkernel
799target.
800.It Va NO_KERNELCONFIG
801If set, the build process does not run
802.Xr config 8
803as part of the
804.Cm buildkernel
805target.
806.It Va NO_KERNELOBJ
807If set, the build process does not run
808.Dq make obj
809as part of the
810.Cm buildkernel
811target.
812.It Va NO_LIBS
813If set, the libraries phase will be skipped.
814.It Va NO_OBJWALK
815If set, no object directories will be created.
816This should only be used if object directories were created in a
817previous build and no new directories are connected.
818.It Va UNIVERSE_TOOLCHAIN
819Requests use of the toolchain built as part of the
820.Cm universe
821target as an external toolchain.
822.It Va WORLDFAST
823If set, the build target
824.Cm buildworld
825defaults to setting
826.Va NO_CLEAN ,
827.Va NO_OBJWALK ,
828and will skip most bootstrap phases.
829It will only bootstrap libraries and build all of userland.
830This option should be used only when it is known that none of the bootstrap
831needs changed and that no new directories have been connected to the build.
832.El
833.Pp
834Builds under directory
835.Pa /usr/doc
836are influenced by the following
837.Xr make 1
838variables:
839.Bl -tag -width ".Va DOC_LANG"
840.It Va DOC_LANG
841If set, restricts the documentation build to the language subdirectories
842specified as its content.
843The default action is to build documentation for all languages.
844.El
845.Pp
846Builds using the
847.Cm universe
848and related targets are influenced by the following
849.Xr make 1
850variables:
851.Bl -tag -width ".Va USE_GCC_TOOLCHAINS"
852.It Va JFLAG
853Pass the value of this variable to each
854.Xr make 1
855invocation used to build worlds and kernels.
856This can be used to enable multiple jobs within a single architecture's build
857while still building each architecture serially.
858.It Va MAKE_JUST_KERNELS
859Only build kernels for each supported architecture.
860.It Va MAKE_JUST_WORLDS
861Only build worlds for each supported architecture.
862.It Va WITHOUT_WORLDS
863Only build kernels for each supported architecture.
864.It Va WITHOUT_KERNELS
865Only build worlds for each supported architecture.
866.It Va UNIVERSE_TARGET
867Execute the specified
868.Xr make 1
869target for each supported architecture instead of the default action of
870building a world and one or more kernels.
871This variable implies
872.Va WITHOUT_KERNELS .
873.It Va USE_GCC_TOOLCHAINS
874Use external GCC toolchains to build the requested targets.
875If the required toolchain package for a supported architecture is not installed,
876the build for that architecture is skipped.
877.It Va TARGETS
878Only build the listed targets instead of each supported architecture.
879.It Va EXTRA_TARGETS
880In addition to the supported architectures, build the semi-supported
881architectures.
882A semi-supported architecture has build support in the
883.Fx
884tree, but receives significantly less testing and is generally for
885fringe uses that do not have a wide appeal.
886.El
887.Sh FILES
888.Bl -tag -width ".Pa /usr/share/examples/etc/make.conf" -compact
889.It Pa /usr/doc/Makefile
890.It Pa /usr/doc/share/mk/doc.project.mk
891.It Pa /usr/ports/Mk/bsd.port.mk
892.It Pa /usr/ports/Mk/bsd.sites.mk
893.It Pa /usr/share/examples/etc/make.conf
894.It Pa /usr/src/Makefile
895.It Pa /usr/src/Makefile.inc1
896.El
897.Sh EXAMPLES
898For an
899.Dq approved
900method of updating your system from the latest sources, please see the
901.Sx COMMON ITEMS
902section in
903.Pa src/UPDATING .
904.Pp
905The following sequence of commands can be used to cross-build the system for
906the arm64 (aarch64) architecture on a different host architecture, such as
907amd64:
908.Bd -literal -offset indent
909cd /usr/src
910make TARGET=arm64 buildworld buildkernel
911make TARGET=arm64 DESTDIR=/clients/arm64 installworld installkernel
912.Ed
913.Sh SEE ALSO
914.Xr cc 1 ,
915.Xr install 1 ,
916.Xr make 1 ,
917.Xr make.conf 5 ,
918.Xr src.conf 5 ,
919.Xr arch 7 ,
920.Xr development 7 ,
921.Xr pkg 7 ,
922.Xr ports 7 ,
923.Xr release 7 ,
924.Xr tests 7 ,
925.Xr config 8 ,
926.Xr etcupdate 8 ,
927.Xr reboot 8 ,
928.Xr shutdown 8
929.Sh HISTORY
930The
931.Nm
932manpage first appeared in
933.Fx 4.3 .
934.Sh AUTHORS
935.An Mike W. Meyer Aq Mt mwm@mired.org
936