BUILDING revision 1.59.2.2
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.  (See the environment variables section below
32     if you need to override or manually select your compilers.)
33
34FILES
35   Source tree layout
36     doc/BUILDING.mdoc
37                    This document (in -mdoc troff format; the original copy).
38
39     BUILDING       This document (in plaintext).
40
41     tools/compat/README
42                    Special notes for cross-hosting a NetBSD build on non-
43                    NetBSD platforms.
44
45     Makefile       The main Makefile for NetBSD; should only be run for
46                    native builds with an appropriately up-to-date version of
47                    NetBSD make(1).  (For building from out-of-date systems or
48                    on a non-native host, see the build.sh shell script.)
49
50     UPDATING       Special notes for updating from an earlier revision of
51                    NetBSD.  It is important to read this file before every
52                    build of an updated source tree.
53
54     build.sh       Bourne-compatible shell script used for building the host
55                    build tools and the NetBSD system from scratch.  Can be
56                    used for both native and cross builds, and should be used
57                    instead of make(1) for any source tree that is updated and
58                    recompiled regularly.
59
60     crypto/dist/, dist/, gnu/dist/
61                    Sources imported verbatim from third parties, without man-
62                    gling the existing build structure.  Other source trees in
63                    bin through usr.sbin use the NetBSD make(1) ``reachover''
64                    Makefile semantics when building these programs for a
65                    native host.
66
67     distrib/, etc/
68                    Sources for items used when making a full release snap-
69                    shot, such as files installed in DESTDIR/etc on the desti-
70                    nation system, boot media, and release notes.
71
72     regress/       Regression test harness.  Can be cross-compiled, but only
73                    run natively.
74
75     sys/           NetBSD kernel sources.
76
77     tools/         ``Reachover'' build structure for the host build tools.
78                    This has a special method of determining out-of-date sta-
79                    tus.
80
81     bin/ ... usr.sbin/
82                    Sources to the NetBSD userland (non-kernel) programs.  If
83                    any of these directories are missing, they will be skipped
84                    during the build.
85
86     x11/           ``Reachover'' build structure for X11R6; the source is in
87                    X11SRCDIR.
88
89   Build tree layout
90     The NetBSD build tree is described in hier(7), and the release layout is
91     described in release(7).
92
93CONFIGURATION
94   Environment variables
95     Several environment variables control the behaviour of NetBSD builds.
96
97     HOST_SH           Path name to a POSIX-compliant shell.  If this is not
98                       set explicitly, then the default is set using heuris-
99                       tics dependent on the host platform, or from the shell
100                       under which build.sh is executed (if that can be deter-
101                       mined), or using the first copy of sh found in PATH.
102                       If the host system's /bin/sh is not POSIX-compliant, we
103                       suggest that you build using commands like
104
105                             HOST_SH=/path/to/working/shell
106                             export HOST_SH
107                             ${HOST_SH} build.sh [options]
108
109     HOST_CC           Path name to C compiler used to create the toolchain.
110
111     HOST_CXX          Path name to C++ compiler used to create the toolchain.
112
113     MACHINE           Machine type.
114
115     MACHINE_ARCH      Machine architecture.
116
117     MAKE              Path name to invoke make(1) as.
118
119     MAKEFLAGS         Flags to invoke make(1) with.
120
121     MAKEOBJDIR        Directory to use as the .OBJDIR for the current direc-
122                       tory.  The value is subjected to variable expansion by
123                       make(1).  Used only if MAKEOBJDIRPREFIX is not defined.
124                       MAKEOBJDIR can only be provided in the environment or
125                       via the -O flag of build.sh.
126
127     MAKEOBJDIRPREFIX  Top level directory of the object directory tree.  If
128                       specified, must be an absolute path.  If this is
129                       defined, ${MAKEOBJDIRPREFIX}/${.CURDIR} is used as the
130                       .OBJDIR for the current directory.  The current direc-
131                       tory may be read only.  MAKEOBJDIRPREFIX can only be
132                       provided in the environment or via the -M flag of
133                       build.sh.
134
135   "make" variables
136     Several variables control the behavior of NetBSD builds.  Unless other-
137     wise specified, these variables may be set in either the process environ-
138     ment or the make(1) configuration file specified by MAKECONF.
139
140     BUILDID     Identifier for the build.  The identifier will be appended to
141                 object directory names, and can be consulted in the make(1)
142                 configuration file in order to set additional build parame-
143                 ters, such as compiler flags.
144
145     DESTDIR     Directory to contain the built NetBSD system.  If set, spe-
146                 cial options are passed to the compilation tools to prevent
147                 their default use of the host system's /usr/include,
148                 /usr/lib, and so forth.  This pathname must be an absolute
149                 path, and should not end with a slash (/) character.  (For
150                 installation into the system's root directory, set DESTDIR to
151                 an empty string, not to ``/'').  The directory must reside on
152                 a file system which supports long file names and hard links.
153
154                 Default: Empty string if USETOOLS is ``yes''; unset other-
155                 wise.
156
157                 Note: build.sh will provide a default of destdir.MACHINE (in
158                 the top-level .OBJDIR) unless run in `expert' mode
159
160     MAKECONF    The name of the make(1) configuration file.  Only settable in
161                 the process environment.
162
163                 Default: ``/etc/mk.conf''
164
165     MAKEVERBOSE
166                 Level of verbosity of status messages.  Supported values:
167
168                 0    No descriptive messages are shown.
169
170                 1    Descriptive messages are shown.
171
172                 2    Descriptive messages (prefixed with a `#') and command
173                      output is not suppressed.
174
175                 Default: 2
176
177     MKCATPAGES  Can be set to ``yes'' or ``no''.  Indicates whether prefor-
178                 matted plaintext manual pages will be created during a build.
179
180                 Default: ``yes''
181
182     MKCRYPTO    Can be set to ``yes'' or ``no''.  Indicates whether crypto-
183                 graphic code will be included in a build; provided for the
184                 benefit of countries that do not allow strong cryptography.
185                 Will not affect use of the standard low-security password
186                 encryption system, crypt(3).
187
188                 Default: ``yes''
189
190     MKDOC       Can be set to ``yes'' or ``no''.  Indicates whether system
191                 documentation destined for DESTDIR/usr/share/doc will be
192                 installed during a build.
193
194                 Default: ``yes''
195
196     MKHOSTOBJ   Can be set to ``yes'' or ``no''.  If set to ``yes'', then for
197                 programs intended to be run on the compile host, the name,
198                 release, and architecture of the host operating system will
199                 be suffixed to the name of the object directory created by
200                 ``make obj''.  (This allows multiple host systems to compile
201                 NetBSD for a single target.)  If set to ``no'', then programs
202                 built to be run on the compile host will use the same object
203                 directory names as programs built to be run on the target.
204
205                 Default: ``no''
206
207     MKINFO      Can be set to ``yes'' or ``no''.  Indicates whether GNU Info
208                 files, used for the documentation for most of the compilation
209                 tools, will be created and installed during a build.
210
211                 Default: ``yes''
212
213     MKLINT      Can be set to ``yes'' or ``no''.  Indicates whether lint(1)
214                 will be run against portions of the NetBSD source code during
215                 the build, and whether lint libraries will be installed into
216                 DESTDIR/usr/libdata/lint.
217
218                 Default: ``yes''
219
220     MKMAN       Can be set to ``yes'' or ``no''.  Indicates whether manual
221                 pages will be installed during a build.
222
223                 Default: ``yes''
224
225     MKNLS       Can be set to ``yes'' or ``no''.  Indicates whether Native
226                 Language System locale zone files will be compiled and
227                 installed during a build.
228
229                 Default: ``yes''
230
231     MKOBJ       Can be set to ``yes'' or ``no''.  Indicates whether object
232                 directories will be created when running ``make obj''.  If
233                 set to ``no'', then all built files will be located inside
234                 the regular source tree.
235
236                 Default: ``yes''
237
238     MKPIC       Can be set to ``yes'' or ``no''.  Indicates whether shared
239                 objects and libraries will be created and installed during a
240                 build.  If set to ``no'', the entire built system will be
241                 statically linked.
242
243                 Default: Platform dependent.  As of this writing, all plat-
244                 forms except sh3 default to ``yes''.
245
246     MKPICINSTALL
247                 Can be set to ``yes'' or ``no''.  Indicates whether the ar(1)
248                 format libraries (lib*_pic.a), used to generate shared
249                 libraries, are installed during a build.
250
251                 Default: ``yes''
252
253     MKPROFILE   Can be set to ``yes'' or ``no''.  Indicates whether profiled
254                 libraries (lib*_p.a) will be built and installed during a
255                 build.
256
257                 Default: ``yes''; however, some platforms turn off MKPROFILE
258                 by default at times due to toolchain problems with profiled
259                 code.
260
261     MKSHARE     Can be set to ``yes'' or ``no''.  Indicates whether files
262                 destined to reside in DESTDIR/usr/share will be built and
263                 installed during a build.  If set to ``no'', then all of
264                 MKCATPAGES, MKDOC, MKINFO, MKMAN, and MKNLS will be set to
265                 ``no'' unconditionally.
266
267                 Default: ``yes''
268
269     MKTTINTERP  Can be set to ``yes'' or ``no''.  For X builds, decides if
270                 the TrueType bytecode interpreter is turned on.  See
271                 http://www.freetype.org/patents.html for details.
272
273                 Default: ``no''
274
275     MKUNPRIVED  Can be set to ``yes'' or ``no''.  Indicates whether an
276                 unprivileged install will occur.  The user, group, permis-
277                 sions, and file flags, will not be set on the installed
278                 items; instead the information will be appended to a file
279                 called METALOG in DESTDIR.  The contents of METALOG are used
280                 during the generation of the distribution tar files to ensure
281                 that the appropriate file ownership is stored.
282
283                 Default: ``no''
284
285     MKUPDATE    Can be set to ``yes'' or ``no''.  Indicates whether all
286                 install operations intended to write to DESTDIR will compare
287                 file timestamps before installing, and skip the install phase
288                 if the destination files are up-to-date.  This also has
289                 implications on full builds (see next subsection).
290
291                 Default: ``no''
292
293     MKX11       Can be set to ``yes'' or ``no''.  Indicates whether X11R6 is
294                 built from X11SRCDIR.
295
296                 Default: ``no''
297
298     TOOLDIR     Directory to hold the host tools, once built.  If specified,
299                 must be an absolute path.  This directory should be unique to
300                 a given host system and NetBSD source tree.  (However, multi-
301                 ple targets may share the same TOOLDIR; the target-dependent
302                 files have unique names.)  If unset, a default based on the
303                 uname(1) information of the host platform will be created in
304                 the .OBJDIR of src.
305
306                 Default: Unset.
307
308     USETOOLS    Indicates whether the tools specified by TOOLDIR should be
309                 used as part of a build in progress.  Must be set to ``yes''
310                 if cross-compiling.
311
312                 yes    Use the tools from TOOLDIR.
313
314                 no     Do not use the tools from TOOLDIR, but refuse to build
315                        native compilation tool components that are version-
316                        specific for that tool.
317
318                 never  Do not use the tools from TOOLDIR, even when building
319                        native tool components.  This is similar to the tradi-
320                        tional NetBSD build method, but does not verify that
321                        the compilation tools in use are up-to-date enough in
322                        order to build the tree successfully.  This may cause
323                        build or runtime problems when building the whole
324                        NetBSD source tree.
325
326                 Default: ``yes'' if building all or part of a whole NetBSD
327                 source tree (detected automatically); ``no'' otherwise (to
328                 preserve traditional semantics of the <bsd.*.mk> make(1)
329                 include files).
330
331     X11SRCDIR   Directory containing the X11R6 source.  If specified, must be
332                 an absolute path.  The main X11R6 source is found in
333                 X11SRCDIR/xfree/xc.
334
335                 Default: ``/usr/xsrc''
336
337   "make" variables for full builds
338     These variables only affect the top level ``Makefile'' and do not affect
339     manually building subtrees of the NetBSD source code.
340
341     INSTALLWORLDDIR  Location for the ``make installworld'' target to install
342                      to.  If specified, must be an absolute path.
343
344                      Default: ``/''
345
346     MKOBJDIRS        Can be set to ``yes'' or ``no''.  Indicates whether
347                      object directories will be created automatically (via a
348                      ``make obj'' pass) at the start of a build.
349
350                      Default: ``no''
351
352     MKUPDATE         Can be set to ``yes'' or ``no''.  If set, then in addi-
353                      tion to the effects described for MKUPDATE=yes above,
354                      this implies the effects of NOCLEANDIR (i.e., ``make
355                      cleandir'' is avoided).
356
357                      Default: ``no''
358
359     NBUILDJOBS       Now obsolete.  Use the make(1) option -j, instead (see
360                      below)
361
362                      Default: Unset.
363
364     NOCLEANDIR       If set, avoids the ``make cleandir'' phase of a full
365                      build.  This has the effect of allowing only changed
366                      files in a source tree to be recompiled.  This can speed
367                      up builds when updating only a few files in the tree.
368
369                      Default: Unset.
370
371     NODISTRIBDIRS    If set, avoids the ``make distrib-dirs'' phase of a full
372                      build.  This skips running mtree(8) on DESTDIR, useful
373                      on systems where building as an unprivileged user, or
374                      where it is known that the system-wide mtree files have
375                      not changed.
376
377                      Default: Unset.
378
379     NOINCLUDES       If set, avoids the ``make includes'' phase of a full
380                      build.  This has the effect of preventing make(1) from
381                      thinking that some programs are out-of-date simply
382                      because the system include files have changed.  However,
383                      this option should not be used when updating the entire
384                      NetBSD source tree arbitrarily; it is suggested to use
385                      MKUPDATE=yes in that case.
386
387                      Default: Unset.
388
389     RELEASEDIR       If set, specifies the directory to which a release(7)
390                      layout will be written at the end of a ``make release''.
391                      If specified, must be an absolute path.
392
393                      Default: Unset.
394
395                      Note: build.sh will provide a default of releasedir (in
396                      the top-level .OBJDIR) unless run in `expert' mode
397
398BUILDING
399   "make" command line options
400     This is not a summary of all the options available to make(1); only the
401     options used most frequently with NetBSD builds are listed here.
402
403     -j njob    Run up to njob make(1) subjobs in parallel.  Makefiles should
404                use .WAIT or have explicit dependencies as necessary to
405                enforce build ordering.  If you see build failures with -j,
406                please save complete build logs so the failures can be ana-
407                lyzed.
408
409     -m dir     Specify the default directory for searching for system Make-
410                file segments, mainly the <bsd.*.mk> files.  When building any
411                full NetBSD source tree, this should be set to the
412                ``share/mk'' directory in the source tree.  (This is set auto-
413                matically when building from the top level.)
414
415     -n         Display the commands that would have been executed, but do not
416                actually execute them.  This will still cause recursion to
417                take place.
418
419     -V var     Print make(1)'s idea of the value of var.  Does not build any
420                targets.
421
422     var=value  Set the variable var to value, overriding any setting speci-
423                fied by the process environment, the MAKECONF configuration
424                file, or the system Makefile segments.
425
426   "make" targets
427     These default targets may be built by running make(1) in any subtree of
428     the NetBSD source code.  It is recommended that none of these be used
429     from the top level Makefile; as a specific exception, ``make obj'' and
430     ``make cleandir'' are useful in that context.
431
432     all        Build programs, libraries, and preformatted documentation.
433
434     clean      Remove program and library object code files.
435
436     cleandir   Same as clean, but also remove preformatted documentation,
437                dependency files generated by ``make depend'', and any other
438                files known to be created at build time.
439
440     depend     Create dependency files (.depend) containing more detailed
441                information about the dependencies of source code on header
442                files.  Allows programs to be recompiled automatically when a
443                dependency changes.
444
445     dependall  Does a ``make depend'' immediately followed by a ``make all''.
446                This improves cache locality of the build since both passes
447                read the source files in their entirety.
448
449     distclean  Synonym for cleandir.
450
451     includes   Build and install system header files.  Typically needed
452                before any system libraries or programs can be built.
453
454     install    Install programs, libraries, and documentation into DESTDIR.
455                Few files will be installed to DESTDIR/dev, DESTDIR/etc,
456                DESTDIR/root or DESTDIR/var in order to prevent user supplied
457                configuration data from being overwritten.
458
459     lint       Run lint(1) against the C source code, where appropriate, and
460                generate system-installed lint libraries.
461
462     obj        Create object directories to be used for built files, instead
463                of building directly in the source tree.
464
465     tags       Create ctags(1) searchable function lists usable by the ex(1)
466                and vi(1) text editors.
467
468   "make" targets for the top level
469     Additional make(1) targets are usable specifically from the top source
470     level to facilitate building the entire NetBSD source tree.
471
472     build         Build the entire NetBSD system.  This orders portions of
473                   the source tree such that prerequisites will be built in
474                   the proper order.
475
476     distribution  Do a ``make build'', and then install a full distribution
477                   into DESTDIR, including files in DESTDIR/dev, DESTDIR/etc,
478                   DESTDIR/root and DESTDIR/var.
479
480     buildworld    As per ``make distribution'', except that it ensures that
481                   DESTDIR is not the root directory.
482
483     installworld  Install the distribution from DESTDIR to INSTALLWORLDDIR
484                   (which defaults to the root directory).  Ensures that
485                   INSTALLWORLDDIR is not the root directory if cross compil-
486                   ing.
487
488                   The INSTALLSETS environment variable may be set to a list
489                   of distribution sets to be installed.  By default, all sets
490                   except ``etc'' and ``xetc'' are installed (so most files in
491                   INSTALLWORLDDIR/etc will not be installed or modified).
492
493                   Note: Before performing this operation with
494                   INSTALLWORLDDIR=/, it is highly recommended that you
495                   upgrade your kernel and reboot.  After performing this
496                   operation, it is recommended that you use etcupdate(8) to
497                   update files in INSTALLWORLDDIR/etc and that you use
498                   postinstall(8) to check for inconsistencies (and possibly
499                   to fix them).
500
501     sets          Create distribution sets from DESTDIR into
502                   RELEASEDIR/MACHINE/binary/sets.  Should be run after ``make
503                   distribution'' (as ``make build'' does not install all of
504                   the required files).
505
506     sourcesets    Create source sets of the source tree into
507                   RELEASEDIR/source/sets.
508
509     syspkgs       Create syspkgs from DESTDIR into
510                   RELEASEDIR/MACHINE/binary/syspkgs.  Should be run after
511                   ``make distribution'' (as ``make build'' does not install
512                   all of the required files).
513
514     release       Do a ``make distribution'', build kernels, distribution
515                   media, and install sets (this as per ``make sets''), and
516                   then package the system into a standard release layout as
517                   described by release(7).  This requires that RELEASEDIR be
518                   set (see above).
519
520     iso-image     Create a NetBSD installation CD-ROM image in the
521                   RELEASEDIR/iso directory.  The CD-ROM file system will have
522                   a layout as described in release(7).
523
524                   For most machine types, the CD-ROM will be bootable, and
525                   will automatically run the sysinst(8) menu-based installa-
526                   tion program, which can be used to install or upgrade a
527                   NetBSD system.  Bootable CD-ROMs also contain tools that
528                   may be useful in repairing a damaged NetBSD installation.
529
530                   Before ``make iso-image'' is attempted, RELEASEDIR must be
531                   populated by ``make release'' or equivalent.
532
533                   Note that other, smaller, CD-ROM images may be created in
534                   the RELEASEDIR/MACHINE/installation/cdrom directory by
535                   ``make release''.  These smaller images usually contain the
536                   same tools as the larger images in RELEASEDIR/iso, but do
537                   not contain additional content such as the distribution
538                   sets.
539
540                   Note that the mac68k port still uses an older method of
541                   creating CD-ROM images.  This requires the mkisofs(1) util-
542                   ity, which is not part of NetBSD, but which can be
543                   installed from pkgsrc/sysutils/cdrtools.
544
545     regression-tests
546                   Can only be run after building the regression tests in the
547                   directory ``regress''.  Runs the compiled regression tests
548                   on the local host.
549
550   The "build.sh" script
551     This script file is a Bourne shell script designed to build the entire
552     NetBSD system on any host with a Bourne shell in /bin/sh, including many
553     that are not POSIX compliant.  Note that if a host system's /bin/sh is
554     unusually old and broken, the Korn Shell (/bin/ksh), if available, may be
555     a usable alternative.
556
557     All cross-compile builds, and most native builds, of the entire system
558     should make use of build.sh rather than just running ``make''.  This way,
559     the make(1) program will be bootstrapped properly, in case the host sys-
560     tem has an older or incompatible ``make'' program.
561
562     When compiling the entire system via build.sh, many make(1) variables are
563     set for you in order to help encapsulate the build process.  In the list
564     of options below, variables that are automatically set by build.sh are
565     noted where applicable.
566
567     The following operations are supported by build.sh:
568
569     build         Build the system as per ``make build''.  This option
570                   implies the obj and tools operations.
571
572     distribution  Build a full distribution as per ``make distribution''.
573                   This option implies the build operation.
574
575     release       Build a full release as per ``make release''.  This option
576                   implies the distribution operation.
577
578     makewrapper   Create the nbmake-MACHINE wrapper.  This operation is auto-
579                   matically performed for any of the other operations.
580
581     obj           Perform ``make obj''.
582
583     tools         Build and install the host tools from src/tools.
584
585     install=idir  Install the contents of DESTDIR to idir, using ``make
586                   installworld''.  Note that files that are part of the
587                   ``etc'' or ``xetc'' sets will not be installed.
588
589     kernel=kconf  Build a new kernel.  The kconf argument is the name of a
590                   configuration file suitable for use by config(1).  If kconf
591                   does not contain any `/' characters, the configuration file
592                   is expected to be found in the KERNCONFDIR directory, which
593                   is typically sys/arch/MACHINE/conf.  The new kernel will be
594                   built in a subdirectory of KERNOBJDIR, which is typically
595                   sys/arch/MACHINE/compile or an associated object directory.
596                   In order to ensure that the kernel is built using up-to-
597                   date tools, it is strongly recommended that the tools be
598                   rebuilt (using the tools operation).
599
600     releasekernel=kconf
601                   Install a gzip(1)ed copy of the kernel built by
602                   kernel=kconf into RELEASEDIR/MACHINE/binary/kernel, usually
603                   as netbsd-kconf.gz, although the ``netbsd'' prefix is
604                   determined from the ``config'' directives in kconf.
605
606     sets          Perform ``make sets''.
607
608     sourcesets    Perform ``make sourcesets''.
609
610     syspkgs       Perform ``make syspkgs''.
611
612     iso-image     Perform ``make iso-image''.
613
614     The following command line options alter the behaviour of the build.sh
615     operations described above:
616
617     -a arch   Set the value of MACHINE_ARCH to arch.
618
619     -B buildid
620               Set the value of BUILDID to buildid.  This will also append the
621               build idenfitier to the name of the ``make'' wrapper script so
622               that the resulting name is of the form
623               ``nbmake-MACHINE-BUILDID''.
624
625     -D dest   Set the value of DESTDIR to dest.  If a relative path is speci-
626               fied, it will be converted to an absolute path before being
627               used.
628
629     -E        Set `expert' mode.  This overrides various sanity checks, and
630               allows: DESTDIR does not have to be set to a non-root path for
631               builds, and MKUNPRIVED=yes does not have to be set when build-
632               ing as a non-root user.
633
634               Note: It is highly recommended that you know what you are doing
635               when you use this option.
636
637     -h        Print a help message.
638
639     -j njob   Passed through to make(1).  Makefiles should use .WAIT or have
640               explicit dependancies as necessary to enforce build ordering.
641               If you see build failures with -j, please save complete build
642               logs so the failures can be analyzed.
643
644     -M obj    Set MAKEOBJDIRPREFIX to obj.  If a relative path is specified,
645               it will be converted to an absolute path before being used.
646               Unsets MAKEOBJDIR.
647
648     -m mach   Set the value of MACHINE to mach.  This will also override any
649               value of MACHINE_ARCH in the process environment with a value
650               deduced from mach, unless -a is specified, or mach is a special
651               case listed below.  All cross builds require -m, but if unset
652               on a NetBSD host, the host's value of MACHINE will be detected
653               and used automatically.
654
655               Some machines support multiple values for MACHINE_ARCH.  For a
656               given value of mach, the following MACHINE and MACHINE_ARCH
657               values will result:
658
659                     mach          MACHINE    MACHINE_ARCH
660                     evbmips       evbmips    (not set)
661                     evbmips-eb    evbmips    mipseb
662                     evbmips-el    evbmips    mipsel
663                     evbsh3        evbsh3     (not set)
664                     evbsh3-eb     evbsh3     sh3eb
665                     evbsh3-el     evbsh3     sh3el
666                     sbmips        sbmips     (not set)
667                     sbmips-eb     sbmips     mipseb
668                     sbmips-el     sbmips     mipsel
669
670     -N noiselevel
671               Set the ``noisyness'' level of the build, by setting
672               MAKEVERBOSE to noiselevel.
673
674     -n        Show the commands that would be executed by build.sh, but do
675               not make any changes.  This is similar in concept to ``make
676               -n''.
677
678     -O obj    Create an appropriate transform macro for MAKEOBJDIR that will
679               place the built object files under obj.  If a relative path is
680               specified, it will be converted to an absolute path before
681               being used.  For instance, a setting of /usr/obj will place
682               build-time files under /usr/obj/bin, /usr/obj/lib,
683               /usr/obj/usr.bin, and so forth.  Unsets MAKEOBJDIRPREFIX.
684
685     -o        Set the value of MKOBJDIRS to ``no''.  Otherwise, it will be
686               automatically set to ``yes'' (which is opposite to the default
687               behaviour).
688
689     -R rel    Set the value of RELEASEDIR to rel.  If a relative path is
690               specified, it will be converted to an absolute path before
691               being used.
692
693     -r        Remove the contents of DESTDIR and TOOLDIR before building
694               (provides a clean starting point).  This will skip deleting
695               DESTDIR if building on a native system to the root directory.
696
697     -T tools  Set the value of TOOLDIR to tools.  If a relative path is spec-
698               ified, it will be converted to an absolute path before being
699               used.  If set, the bootstrap ``make'' will only be rebuilt as
700               needed (when the source files for make(1) change).
701
702     -U        Set MKUNPRIVED=yes.
703
704     -u        Set MKUPDATE=yes.
705
706     -V var=[value]
707               Set the environment variable var to an optional value.  This is
708               propagated to the nbmake wrapper.
709
710     -w wrapper
711               Create the nbmake wrapper script (see below) in a custom loca-
712               tion, specified by wrapper.  This allows, for instance, to
713               place the wrapper in PATH automatically.  Note that wrapper is
714               the full name of the file, not just a directory name.  If a
715               relative path is specified, it will be converted to an absolute
716               path before being used.
717
718     -X x11src
719               Set the value of X11SRCDIR to x11src.  If a relative path is
720               specified, it will be converted to an absolute path before
721               being used.
722
723     -x        Set MKX11=yes.
724
725     -Z var    Unset ("zap") the environment variable var.  This is propagated
726               to the nbmake wrapper.
727
728   The "nbmake-MACHINE" wrapper script
729     If using the build.sh script to build NetBSD, a nbmake-MACHINE script
730     will be created in TOOLDIR/bin upon the first build to assist in building
731     subtrees on a cross-compile host.
732
733     nbmake-MACHINE can be invoked in lieu of make(1), and will instead call
734     the up-to-date version of ``nbmake'' installed into TOOLDIR/bin with sev-
735     eral key variables pre-set, including MACHINE, MACHINE_ARCH, and TOOLDIR.
736     build.sh will also set variables specified with -V, and unset variables
737     specified with -Z.
738
739     This script can be symlinked into a directory listed in PATH, or called
740     with an absolute path.
741
742EXAMPLES
743     1.   % ./build.sh tools kernel=GENERIC
744
745          Build a new toolchain, and use the new toolchain to configure and
746          build a new GENERIC kernel.
747
748     2.   % ./build.sh -U distribution
749
750          Using unprivileged mode, build a complete distribution to a DESTDIR
751          directory that build.sh selects (and will display).
752
753     3.   # ./build.sh -U install=/
754
755          As root, install to / the distribution that was built by example 2.
756          Even though this is run as root, -U is required so that the permis-
757          sions stored in DESTDIR/METALOG are correctly applied to the files
758          as they're copied to /.
759
760     4.   % ./build.sh -U -u release
761
762          Using unprivileged mode, build a complete release to DESTDIR and
763          RELEASEDIR directories that build.sh selects (and will display).
764          MKUPDATE=yes (-u) is set to prevent the ``make cleandir'', so that
765          if this is run after example 2, it doesn't need to redo that portion
766          of the release build.
767
768OBSOLETE VARIABLES
769     NBUILDJOBS  Use the make(1) option -j, instead.
770
771     USE_NEW_TOOLCHAIN
772                 The new toolchain is now the default.  To disable, use
773                 TOOLCHAIN_MISSING=yes.
774
775SEE ALSO
776     make(1), hier(7), release(7), etcupdate(8), postinstall(8), sysinst(8),
777     pkgsrc/sysutils/cdrtools
778
779HISTORY
780     The build.sh based build scheme was introduced for NetBSD 1.6 as
781     USE_NEW_TOOLCHAIN, and re-worked to TOOLCHAIN_MISSING after that.
782
783BUGS
784     A few platforms are not yet using this build system.
785
786NetBSD                          April 13, 2007                          NetBSD
787