BUILDING revision 1.48
1BUILDING(8)             NetBSD System Manager's Manual             BUILDING(8)
2
3NAME
4     BUILDING - Procedure for building NetBSD from source code.
5
6STATUS
7     This document is a work-in-progress.  As such, the information described
8     here may not match the reality of the build system as of this writing.
9     Once this document is completely in sync with reality, this paragraph
10     will be removed.
11
12     Discrepancies between this documentation and the current reality of
13     implementation are noted specially, as with the note below:
14
15     Note: This document applies only to platforms which use the new toolchain
16     as indicated by the default setting of TOOLCHAIN_MISSING in <bsd.own.mk>.
17     Platforms which have not yet been switched to the new toolchain should
18     continue building traditionally, using the notes specified in the file
19     UPDATING.
20
21REQUIREMENTS
22     NetBSD is designed to be buildable on most POSIX-compliant host systems.
23     The basic build procedure is the same whether compiling natively (on the
24     same NetBSD architecture) or cross compiling (on another architecture or
25     OS).
26
27     This source tree contains a special subtree, ``tools'', which uses the
28     host system to create a build toolchain for the target architecture.  The
29     host system must have at least C and C++ compilers in order to create the
30     toolchain (make is not required); all other tools are created as part of
31     the NetBSD build process.
32
33           Note: A couple of host toolchain components are not yet available
34           in the tools directory.  Also, some tools use non-POSIX, non-ANSI C
35           extensions and need to be standardized.  As a result, cross-compil-
36           ing from systems other than NetBSD is not currently supported.
37
38FILES
39   Source tree layout
40     doc/BUILDING.mdoc
41                    This document (in -mdoc troff format; the original copy).
42
43     BUILDING       This document (in plaintext).
44
45     tools/compat/README
46                    Special notes for cross-hosting a NetBSD build on non-
47                    NetBSD platforms.
48
49     Makefile       The main Makefile for NetBSD; should only be run for
50                    native builds with an appropriately up-to-date version of
51                    NetBSD make(1).  (For building from out-of-date systems or
52                    on a non-native host, see the build.sh shell script.)
53
54     UPDATING       Special notes for updating from an earlier revision of
55                    NetBSD.  It is important to read this file before every
56                    build of an updated source tree.
57
58     build.sh       Bourne-compatible shell script used for building the host
59                    build tools and the NetBSD system from scratch.  Can be
60                    used for both native and cross builds, and should be used
61                    instead of make(1) for any source tree that is updated and
62                    recompiled regularly.
63
64     crypto/dist/, dist/, gnu/dist/
65                    Sources imported verbatim from third parties, without man-
66                    gling the existing build structure.  Other source trees in
67                    bin through usr.sbin use the NetBSD make(1) ``reachover''
68                    Makefile semantics when building these programs for a
69                    native host.
70
71     distrib/, etc/
72                    Sources for items used when making a full release snap-
73                    shot, such as files installed in DESTDIR/etc on the desti-
74                    nation system, boot media, and release notes.
75
76     regress/       Regression test harness.  Can be cross-compiled, but only
77                    run natively.
78
79     sys/           NetBSD kernel sources.
80
81     tools/         ``Reachover'' build structure for the host build tools.
82                    This has a special method of determining out-of-date sta-
83                    tus.
84
85     bin/ ... usr.sbin/
86                    Sources to the NetBSD userland (non-kernel) programs.  If
87                    any of these directories are missing, they will be skipped
88                    during the build.
89
90   Build tree layout
91     The NetBSD build tree is described in hier(7), and the release layout is
92     described in release(7).
93
94CONFIGURATION
95   Environment variables
96     Several environment variables control the behaviour of NetBSD builds.
97
98     MACHINE           Machine type.
99
100     MACHINE_ARCH      Machine architecture.
101
102     MAKE              Path name to invoke make(1) as.
103
104     MAKEFLAGS         Flags to invoke make(1) with.
105
106     MAKEOBJDIR        Directory to use as the .OBJDIR for the current direc-
107                       tory.  Used only if MAKEOBJDIRPREFIX is not defined.
108                       MAKEOBJDIR can only be provided in the environment or
109                       via the -O flag of build.sh.
110
111     MAKEOBJDIRPREFIX  Top level directory of the object directory tree.  If
112                       this is defined, ${MAKEOBJDIRPREFIX}/${.CURDIR} is used
113                       as the .OBJDIR for the current directory.  The current
114                       directory may be read only.  MAKEOBJDIRPREFIX can only
115                       be provided in the environment or via the -M flag of
116                       build.sh.
117
118   "make" variables
119     Several variables control the behavior of NetBSD builds.  Unless other-
120     wise specified, these variables may be set in either the process environ-
121     ment or the make(1) configuration file specified by MAKECONF.
122
123     BUILDID     Identifier for the build.  The identifier will be appended to
124                 object directory names, and can be consulted in the make(1)
125                 configuration file in order to set additional build parame-
126                 ters, such as compiler flags.
127
128     DESTDIR     Directory to contain the built NetBSD system.  If set, spe-
129                 cial options are passed to the compilation tools to prevent
130                 their default use of the host system's /usr/include,
131                 /usr/lib, and so forth.  This pathname should not end with a
132                 slash (/) character (for installation into the system's root
133                 directory, set DESTDIR to an empty string).  The directory
134                 must reside on a file system which supports long file names
135                 and hard links.
136
137                 Default: Empty string if USETOOLS is ``yes''; unset other-
138                 wise.
139
140                 Note: build.sh will provide a default of destdir.MACHINE (in
141                 the top-level .OBJDIR) unless run in `expert' mode
142
143     MAKECONF    The name of the make(1) configuration file.  Only settable in
144                 the process environment.
145
146                 Default: ``/etc/mk.conf''
147
148     MAKEVERBOSE
149                 Level of verbosity of status messages.  Supported values:
150
151                 0    No descriptive messages are shown.
152
153                 1    Descriptive messages are shown.
154
155                 2    Descriptive messages (prefixed with a `#') and command
156                      output is not suppressed.
157
158                 Default: 2
159
160     MKCATPAGES  Can be set to ``yes'' or ``no''.  Indicates whether prefor-
161                 matted plaintext manual pages will be created during a build.
162
163                 Default: ``yes''
164
165     MKCRYPTO    Can be set to ``yes'' or ``no''.  Indicates whether crypto-
166                 graphic code will be included in a build; provided for the
167                 benefit of countries that do not allow strong cryptography.
168                 Will not affect use of the standard low-security password
169                 encryption system, crypt(3).
170
171                 Default: ``yes''
172
173     MKDOC       Can be set to ``yes'' or ``no''.  Indicates whether system
174                 documentation destined for DESTDIR/usr/share/doc will be
175                 installed during a build.
176
177                 Default: ``yes''
178
179     MKHOSTOBJ   Can be set to ``yes'' or ``no''.  If set to ``yes'', then for
180                 programs intended to be run on the compile host, the name,
181                 release, and architecture of the host operating system will
182                 be suffixed to the name of the object directory created by
183                 ``make obj''.  (This allows multiple host systems to compile
184                 NetBSD for a single target.)  If set to ``no'', then programs
185                 built to be run on the compile host will use the same object
186                 directory names as programs built to be run on the target.
187
188                 Default: ``no''
189
190     MKINFO      Can be set to ``yes'' or ``no''.  Indicates whether GNU Info
191                 files, used for the documentation for most of the compilation
192                 tools, will be created and installed during a build.
193
194                 Default: ``yes''
195
196     MKLINT      Can be set to ``yes'' or ``no''.  Indicates whether lint(1)
197                 will be run against portions of the NetBSD source code during
198                 the build, and whether lint libraries will be installed into
199                 DESTDIR/usr/libdata/lint.
200
201                 Default: ``yes''
202
203     MKMAN       Can be set to ``yes'' or ``no''.  Indicates whether manual
204                 pages will be installed during a build.
205
206                 Default: ``yes''
207
208     MKNLS       Can be set to ``yes'' or ``no''.  Indicates whether Native
209                 Language System locale zone files will be compiled and
210                 installed during a build.
211
212                 Default: ``yes''
213
214     MKOBJ       Can be set to ``yes'' or ``no''.  Indicates whether object
215                 directories will be created when running ``make obj''.  If
216                 set to ``no'', then all built files will be located inside
217                 the regular source tree.
218
219                 Default: ``yes''
220
221     MKPIC       Can be set to ``yes'' or ``no''.  Indicates whether shared
222                 objects and libraries will be created and installed during a
223                 build.  If set to ``no'', the entire built system will be
224                 statically linked.
225
226                 Default: Platform dependent.  As of this writing, all plat-
227                 forms except sh3 default to ``yes''.
228
229     MKPICINSTALL
230                 Can be set to ``yes'' or ``no''.  Indicates whether the ar(1)
231                 format libraries (lib*_pic.a), used to generate shared
232                 libraries, are installed during a build.
233
234                 Default: ``yes''
235
236     MKPROFILE   Can be set to ``yes'' or ``no''.  Indicates whether profiled
237                 libraries (lib*_p.a) will be built and installed during a
238                 build.
239
240                 Default: ``yes''; however, some platforms turn off MKPROFILE
241                 by default at times due to toolchain problems with profiled
242                 code.
243
244     MKSHARE     Can be set to ``yes'' or ``no''.  Indicates whether files
245                 destined to reside in DESTDIR/usr/share will be built and
246                 installed during a build.  If set to ``no'', then all of
247                 MKCATPAGES, MKDOC, MKINFO, MKMAN, and MKNLS will be set to
248                 ``no'' unconditionally.
249
250                 Default: ``yes''
251
252     MKUNPRIVED  Can be set to ``yes'' or ``no''.  Indicates whether an
253                 unprivileged install will occur.  The user, group, permis-
254                 sions, and file flags, will not be set on the installed item;
255                 instead the information will be appended to a file called
256                 METALOG in DESTDIR.  The contents of METALOG is used during
257                 the generation of the distribution tar files to ensure that
258                 the appropriate file ownership is stored.
259
260                 Default: ``no''
261
262     MKUPDATE    Can be set to ``yes'' or ``no''.  Indicates whether all
263                 install operations intended to write to DESTDIR will compare
264                 file timestamps before installing, and skip the install phase
265                 if the destination files are up-to-date.  This also has
266                 implications on full builds (see next subsection).
267
268                 Default: ``no''
269
270     TOOLDIR     Directory to hold the host tools, once built.  This directory
271                 should be unique to a given host system and NetBSD source
272                 tree.  (However, multiple targets may share the same TOOLDIR;
273                 the target-dependent files have unique names.)  If unset, a
274                 default based on the uname(1) information of the host plat-
275                 form will be created in the .OBJDIR of src.
276
277                 Default: Unset.
278
279     USETOOLS    Indicates whether the tools specified by TOOLDIR should be
280                 used as part of a build in progress.  Must be set to ``yes''
281                 if cross-compiling.
282
283                 yes    Use the tools from TOOLDIR.
284
285                 no     Do not use the tools from TOOLDIR, but refuse to build
286                        native compilation tool components that are version-
287                        specific for that tool.
288
289                 never  Do not use the tools from TOOLDIR, even when building
290                        native tool components.  This is similar to the tradi-
291                        tional NetBSD build method, but does not verify that
292                        the compilation tools in use are up-to-date enough in
293                        order to build the tree successfully.  This may cause
294                        build or runtime problems when building the whole
295                        NetBSD source tree.
296
297                 Default: ``yes'' if building all or part of a whole NetBSD
298                 source tree (detected automatically); ``no'' otherwise (to
299                 preserve traditional semantics of the <bsd.*.mk> make(1)
300                 include files).
301
302   "make" variables for full builds
303     These variables only affect the top level ``Makefile'' and do not affect
304     manually building subtrees of the NetBSD source code.
305
306     INSTALLWORLDDIR  Location for the ``make installworld'' target to install
307                      to.
308
309                      Default: ``/''
310
311     MKOBJDIRS        Can be set to ``yes'' or ``no''.  Indicates whether
312                      object directories will be created automatically (via a
313                      ``make obj'' pass) at the start of a build.
314
315                      Default: ``no''
316
317     MKUPDATE         Can be set to ``yes'' or ``no''.  If set, then in addi-
318                      tion to the effects described for MKUPDATE=yes above,
319                      this implies the effects of NOCLEANDIR (i.e., ``make
320                      cleandir'' is avoided).
321
322                      Default: ``no''
323
324     NBUILDJOBS       Now obsolete.  Use the make(1) option -j, instead (see
325                      below)
326
327                      Default: Unset.
328
329     NOCLEANDIR       If set, avoids the ``make cleandir'' phase of a full
330                      build.  This has the effect of allowing only changed
331                      files in a source tree to be recompiled.  This can speed
332                      up builds when updating only a few files in the tree.
333
334                      Default: Unset.
335
336     NODISTRIBDIRS    If set, avoids the ``make distrib-dirs'' phase of a full
337                      build.  This skips running mtree(8) on DESTDIR, useful
338                      on systems where building as an unprivileged user, or
339                      where it is known that the system-wide mtree files have
340                      not changed.
341
342                      Default: Unset.
343
344     NOINCLUDES       If set, avoids the ``make includes'' phase of a full
345                      build.  This has the effect of preventing make(1) from
346                      thinking that some programs are out-of-date simply
347                      because the system include files have changed.  However,
348                      this option should not be used when updating the entire
349                      NetBSD source tree arbitrarily; it is suggested to use
350                      MKUPDATE=yes in that case.
351
352                      Default: Unset.
353
354     RELEASEDIR       If set, specifies the directory to which a release(7)
355                      layout will be written at the end of a ``make release''.
356
357                      Default: Unset.
358
359                      Note: build.sh will provide a default of releasedir (in
360                      the top-level .OBJDIR) unless run in `expert' mode
361
362BUILDING
363   "make" command line options
364     This is only a summary of options available to make(1); only the options
365     used most frequently with NetBSD builds are listed here.
366
367     -j njob    Run up to njob make(1) subjobs in parallel.  Makefiles should
368                use .WAIT or have explicit dependancies as necessary to
369                enforce build ordering.  If you see build failures with -j,
370                please save complete build logs so the failures can be ana-
371                lyzed.
372
373     -m dir     Specify the default directory for searching for system Make-
374                file segments, mainly the <bsd.*.mk> files.  When building any
375                full NetBSD source tree, this should be set to the
376                ``share/mk'' directory in the source tree.  (This is set auto-
377                matically when building from the top level.)
378
379     -n         Display the commands that would have been executed, but do not
380                actually execute them.  This will still cause recursion to
381                take place.
382
383     -V var     Print make(1)'s idea of the value of var.  Does not build any
384                targets.
385
386     var=value  Set the variable var to value, overriding any setting speci-
387                fied by the process environment, the MAKECONF configuration
388                file, or the system Makefile segments.
389
390   "make" targets
391     These default targets may be built by running make(1) in any subtree of
392     the NetBSD source code.  It is recommended that none of these be used
393     from the top level Makefile; as a specific exception, ``make obj'' and
394     ``make cleandir'' are useful in that context.
395
396     all        Build programs, libraries, and preformatted documentation.
397
398     clean      Remove program and library object code files.
399
400     cleandir   Same as clean, but also remove preformatted documentation,
401                dependency files generated by ``make depend'', and any other
402                files known to be created at build time.  ``make distclean''
403                may be used as a synonym, for familiarity with a similar well-
404                known convention.
405
406     depend     Create dependency files (.depend) containing more detailed
407                information about the dependencies of source code on header
408                files.  Allows programs to be recompiled automatically when a
409                dependency changes.
410
411     dependall  Does a ``make depend'' immediately followed by a ``make all''.
412                This improves cache locality of the build since both passes
413                read the source files in their entirety.
414
415     includes   Build and install system header files.  Typically needed
416                before any system libraries or programs can be built.
417
418     install    Install programs, libraries, and documentation into DESTDIR.
419                Few files will be installed to DESTDIR/dev, DESTDIR/etc,
420                DESTDIR/root or DESTDIR/var in order to prevent user supplied
421                configuration data from being overwritten.
422
423     lint       Run lint(1) against the C source code, where appropriate, and
424                generate system-installed lint libraries.
425
426     obj        Create object directories to be used for built files, instead
427                of building directly in the source tree.
428
429     tags       Create ctags(1) searchable function lists usable by the ex(1)
430                and vi(1) text editors.
431
432   "make" targets for the top level
433     Additional make(1) targets are usable specifically from the top source
434     level to facilitate building the entire NetBSD source tree.
435
436     build         Build the entire NetBSD system.  This orders portions of
437                   the source tree such that prerequisites will be built in
438                   the proper order.
439
440     distribution  Do a ``make build'', and then install a full distribution
441                   into DESTDIR, including files in DESTDIR/dev, DESTDIR/etc,
442                   DESTDIR/root and DESTDIR/var.
443
444     buildworld    As per ``make distribution'', except that it ensures that
445                   DESTDIR is not the root directory.
446
447     installworld  Install the distribution from DESTDIR to INSTALLWORLDDIR
448                   (which defaults to the root directory).  Ensures that
449                   INSTALLWORLDDIR is the not root directory if cross compil-
450                   ing.
451
452                   Note: It is highly recommended that you upgrade your kernel
453                   and reboot before performing this operation.
454
455     sets          Create distribution sets from DESTDIR into
456                   RELEASEDIR/MACHINE/binary/sets.  Should be run after ``make
457                   distribution'' (as ``make build'' does not install all of
458                   the required files).
459
460     sourcesets    Create source sets of the source tree into
461                   RELEASEDIR/source/sets.
462
463     release       Do a ``make distribution'', build kernels, distribution
464                   media, and install sets (this as per ``make sets''), and
465                   then package the system into a standard release layout as
466                   described by release(7).  This requires that RELEASEDIR be
467                   set (see above).
468
469     regression-tests
470                   Can only be run after building the regression tests in the
471                   directory ``regress''.  Runs the compiled regression tests
472                   on the local host.
473
474   The "build.sh" script
475     This script file is a Bourne shell script designed to build the entire
476     NetBSD system on any host with a Bourne shell in /bin/sh, including many
477     that are not POSIX compliant.  Note that if a host system's /bin/sh is
478     unusually old and broken, the Korn Shell (/bin/ksh), if available, may be
479     a usable alternative.
480
481     All cross-compile builds, and most native builds, of the entire system
482     should make use of build.sh rather than just running ``make''.  This way,
483     the make(1) program will be bootstrapped properly, in case the host sys-
484     tem has an older or incompatible ``make'' program.
485
486     When compiling the entire system via build.sh, many make(1) variables are
487     set for you in order to help encapsulate the build process.  In the list
488     of options below, variables that are automatically set by build.sh are
489     noted where applicable.
490
491     The following operations are supported by build.sh:
492
493     build         Build the system as per ``make build''.  This option
494                   implies the obj and tools operations.
495
496     distribution  Build a full distribution as per ``make distribution''.
497                   This option implies the build operation.
498
499     release       Build a full release as per ``make release''.  This option
500                   implies the distribution operation.
501
502     makewrapper   Create the nbmake-MACHINE wrapper.  This operation is auto-
503                   matically performed for any of the other operations.
504
505     obj           Perform ``make obj''.
506
507     tools         Build and install the host tools from src/tools.
508
509     install=idir  Install the contents of DESTDIR to idir, using ``make
510                   installworld''.
511
512     kernel=kconf  Build a new kernel.  The kconf argument is the name of a
513                   configuration file suitable for use by config(8).  If kconf
514                   does not contain any `/' characters, the configuration file
515                   is expected to be found in the KERNCONFDIR directory, which
516                   is typically sys/arch/MACHINE/conf.  The new kernel will be
517                   built in a subdirectory of KERNOBJDIR, which is typically
518                   sys/arch/MACHINE/compile or an associated object directory.
519                   In order to ensure that the kernel is built using up-to-
520                   date tools, it is strongly recommended that the tools be
521                   rebuilt (using the tools operation).
522
523     releasekernel=kconf
524                   Install a gzip(1)ed copy of the kernel built by
525                   kernel=kconf into RELEASEDIR/MACHINE/binary/kernel, usually
526                   as netbsd-kconf.gz, although the ``netbsd'' prefix is
527                   determined from the ``config'' directives in kconf.
528
529     sets          Perform ``make sets''.
530
531     sourcesets    Perform ``make sourcesets''.
532
533     The following command line options alter the behaviour of the above oper-
534     ations: The following command line options alter the behaviour of the
535     build.sh operations described above:
536
537     -a arch   Set the value of MACHINE_ARCH to arch.
538
539     -B buildid
540               Set the value of BUILDID to buildid.  This will also append the
541               build idenfitier to the name of the ``make'' wrapper script so
542               that the resulting name is of the form
543               ``nbmake-MACHINE-BUILDID''.
544
545     -D dest   Set the value of DESTDIR to dest.
546
547     -E        Set `expert' mode.  This overrides various sanity checks, and
548               allows: DESTDIR does not have to be set to a non-root path for
549               builds, and MKUNPRIVED=yes does not have to be set when build-
550               ing as a non-root user.
551
552               Note: It is highly recommended that you know what you are doing
553               when you use this option.
554
555     -j njob   Passed through to make(1).  Makefiles should use .WAIT or have
556               explicit dependancies as necessary to enforce build ordering.
557               If you see build failures with -j, please save complete build
558               logs so the failures can be analyzed.
559
560     -M obj    Set MAKEOBJDIRPREFIX to obj.  Unsets MAKEOBJDIR.
561
562     -m mach   Set the value of MACHINE to mach.  This will also override any
563               value of MACHINE_ARCH in the process environment with a value
564               deduced from mach, unless -a is specified, or mach is a special
565               case listed below.  All cross builds require -m, but if unset
566               on a NetBSD host, the host's value of MACHINE will be detected
567               and used automatically.
568
569               Some machines support multiple values for MACHINE_ARCH.  For a
570               given value of mach, the following MACHINE and MACHINE_ARCH
571               values will result:
572
573                     mach          MACHINE    MACHINE_ARCH
574                     evbmips       evbmips    (not set)
575                     evbmips-eb    evbmips    mipseb
576                     evbmips-el    evbmips    mipsel
577                     evbsh3        evbsh3     (not set)
578                     evbsh3-eb     evbsh3     sh3eb
579                     evbsh3-el     evbsh3     sh3el
580                     sbmips        sbmips     (not set)
581                     sbmips-eb     sbmips     mipseb
582                     sbmips-el     sbmips     mipsel
583
584     -N noiselevel
585               Set the ``noisyness'' level of the build, by setting
586               MAKEVERBOSE to noiselevel.
587
588     -n        Show the commands that would be executed by build.sh, but do
589               not make any changes.  This is similar in concept to ``make
590               -n''.
591
592     -O obj    Create an appropriate transform macro for MAKEOBJDIR that will
593               place the built object files under obj.  For instance, a set-
594               ting of /usr/obj will place build-time files under
595               /usr/obj/bin, /usr/obj/lib, /usr/obj/usr.bin, and so forth.
596               Unsets MAKEOBJDIRPREFIX.
597
598     -o        Set the value of MKOBJDIRS to ``no''.  Otherwise, it will be
599               automatically set to ``yes'' (which is opposite to the default
600               behaviour).
601
602     -R rel    Set the value of RELEASEDIR to rel.
603
604     -r        Remove the contents of DESTDIR and TOOLDIR before building
605               (provides a clean starting point).  This will skip deleting
606               DESTDIR if building on a native system to the root directory.
607
608     -T tools  Set the value of TOOLDIR to tools.  If set, the bootstrap
609               ``make'' will only be rebuilt as needed (when the source files
610               for make(1) change).
611
612     -U        Set MKUNPRIVED=yes.
613
614     -u        Set MKUPDATE=yes.
615
616     -V var=[value]
617               Set the environment variable var to an optional value.  This is
618               propagated to the nbmake wrapper.
619
620     -w wrapper
621               Create the nbmake wrapper script (see below) in a custom loca-
622               tion, specified by wrapper.  This allows, for instance, to
623               place the wrapper in PATH automatically.  Note that wrapper is
624               the full name of the file, not just a directory name.
625
626     -Z var    Unset ("zap") the environment variable var.  This is propagated
627               to the nbmake wrapper.
628
629   The "nbmake-MACHINE" wrapper script
630     If using the build.sh script to build NetBSD, a nbmake-MACHINE script
631     will be created in TOOLDIR/bin upon the first build to assist in building
632     subtrees on a cross-compile host.
633
634     nbmake-MACHINE can be invoked in lieu of make(1), and will instead call
635     the up-to-date version of ``nbmake'' installed into TOOLDIR/bin with sev-
636     eral key variables pre-set, including MACHINE, MACHINE_ARCH, and TOOLDIR.
637     build.sh will also set variables specified with -V, and unset variables
638     specified with -Z.
639
640     This script can be symlinked into a directory listed in PATH, or called
641     with an absolute path.
642
643EXAMPLES
644     1.   % ./build.sh tools kernel=GENERIC
645
646          Build a new toolchain, and use the new toolchain to configure and
647          build a new GENERIC kernel.
648
649     2.   % ./build.sh -U distribution
650
651          Using unprivileged mode, build a complete distribution to a DESTDIR
652          directory that build.sh selects (and will display).
653
654     3.   # ./build.sh -U install=/
655
656          As root, install to / the distribution that was built by example 2.
657          Even though this is run as root, -U is required so that the permis-
658          sions stored in DESTDIR/METALOG are correctly applied to the files
659          as they're copied to /.
660
661     4.   % ./build.sh -U -u release
662
663          Using unprivileged mode, build a complete release to DESTDIR and
664          RELEASEDIR directories that build.sh selects (and will display).
665          MKUPDATE=yes (-u) is set to prevent the ``make cleandir'', so that
666          if this is run after example 2, it doesn't need to redo that portion
667          of the release build.
668
669OBSOLETE VARIABLES
670     NBUILDJOBS  Use the make(1) option -j, instead.
671
672     USE_NEW_TOOLCHAIN
673                 The new toolchain is now the default.  To disable, use
674                 TOOLCHAIN_MISSING=yes.
675
676SEE ALSO
677     make(1), hier(7), release(7)
678
679HISTORY
680     The build.sh based build scheme was introduced for NetBSD 1.6 as
681     USE_NEW_TOOLCHAIN, and re-worked to TOOLCHAIN_MISSING after that.
682
683BUGS
684     A few platforms are not yet using this build system.
685
686NetBSD                         December 19, 2003                        NetBSD
687