BUILDING revision 1.53
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  (For building from out-of-date systems or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_CC           Path name to C compiler used to create the toolchain.
98
99     HOST_CXX          Path name to C++ compiler used to create the toolchain.
100
101     MACHINE           Machine type.
102
103     MACHINE_ARCH      Machine architecture.
104
105     MAKE              Path name to invoke make(1) as.
106
107     MAKEFLAGS         Flags to invoke make(1) with.
108
109     MAKEOBJDIR        Directory to use as the .OBJDIR for the current direc-
110                       tory.  Used only if MAKEOBJDIRPREFIX is not defined.
111                       MAKEOBJDIR can only be provided in the environment or
112                       via the -O flag of build.sh.
113
114     MAKEOBJDIRPREFIX  Top level directory of the object directory tree.  If
115                       this is defined, ${MAKEOBJDIRPREFIX}/${.CURDIR} is used
116                       as the .OBJDIR for the current directory.  The current
117                       directory may be read only.  MAKEOBJDIRPREFIX can only
118                       be provided in the environment or via the -M flag of
119                       build.sh.
120
121   "make" variables
122     Several variables control the behavior of NetBSD builds.  Unless other-
123     wise specified, these variables may be set in either the process environ-
124     ment or the make(1) configuration file specified by MAKECONF.
125
126     BUILDID     Identifier for the build.  The identifier will be appended to
127                 object directory names, and can be consulted in the make(1)
128                 configuration file in order to set additional build parame-
129                 ters, such as compiler flags.
130
131     DESTDIR     Directory to contain the built NetBSD system.  If set, spe-
132                 cial options are passed to the compilation tools to prevent
133                 their default use of the host system's /usr/include,
134                 /usr/lib, and so forth.  This pathname should not end with a
135                 slash (/) character (for installation into the system's root
136                 directory, set DESTDIR to an empty string).  The directory
137                 must reside on a file system which supports long file names
138                 and hard links.
139
140                 Default: Empty string if USETOOLS is ``yes''; unset other-
141                 wise.
142
143                 Note: build.sh will provide a default of destdir.MACHINE (in
144                 the top-level .OBJDIR) unless run in `expert' mode
145
146     MAKECONF    The name of the make(1) configuration file.  Only settable in
147                 the process environment.
148
149                 Default: ``/etc/mk.conf''
150
151     MAKEVERBOSE
152                 Level of verbosity of status messages.  Supported values:
153
154                 0    No descriptive messages are shown.
155
156                 1    Descriptive messages are shown.
157
158                 2    Descriptive messages (prefixed with a `#') and command
159                      output is not suppressed.
160
161                 Default: 2
162
163     MKCATPAGES  Can be set to ``yes'' or ``no''.  Indicates whether prefor-
164                 matted plaintext manual pages will be created during a build.
165
166                 Default: ``yes''
167
168     MKCRYPTO    Can be set to ``yes'' or ``no''.  Indicates whether crypto-
169                 graphic code will be included in a build; provided for the
170                 benefit of countries that do not allow strong cryptography.
171                 Will not affect use of the standard low-security password
172                 encryption system, crypt(3).
173
174                 Default: ``yes''
175
176     MKDOC       Can be set to ``yes'' or ``no''.  Indicates whether system
177                 documentation destined for DESTDIR/usr/share/doc will be
178                 installed during a build.
179
180                 Default: ``yes''
181
182     MKHOSTOBJ   Can be set to ``yes'' or ``no''.  If set to ``yes'', then for
183                 programs intended to be run on the compile host, the name,
184                 release, and architecture of the host operating system will
185                 be suffixed to the name of the object directory created by
186                 ``make obj''.  (This allows multiple host systems to compile
187                 NetBSD for a single target.)  If set to ``no'', then programs
188                 built to be run on the compile host will use the same object
189                 directory names as programs built to be run on the target.
190
191                 Default: ``no''
192
193     MKINFO      Can be set to ``yes'' or ``no''.  Indicates whether GNU Info
194                 files, used for the documentation for most of the compilation
195                 tools, will be created and installed during a build.
196
197                 Default: ``yes''
198
199     MKLINT      Can be set to ``yes'' or ``no''.  Indicates whether lint(1)
200                 will be run against portions of the NetBSD source code during
201                 the build, and whether lint libraries will be installed into
202                 DESTDIR/usr/libdata/lint.
203
204                 Default: ``yes''
205
206     MKMAN       Can be set to ``yes'' or ``no''.  Indicates whether manual
207                 pages will be installed during a build.
208
209                 Default: ``yes''
210
211     MKNLS       Can be set to ``yes'' or ``no''.  Indicates whether Native
212                 Language System locale zone files will be compiled and
213                 installed during a build.
214
215                 Default: ``yes''
216
217     MKOBJ       Can be set to ``yes'' or ``no''.  Indicates whether object
218                 directories will be created when running ``make obj''.  If
219                 set to ``no'', then all built files will be located inside
220                 the regular source tree.
221
222                 Default: ``yes''
223
224     MKPIC       Can be set to ``yes'' or ``no''.  Indicates whether shared
225                 objects and libraries will be created and installed during a
226                 build.  If set to ``no'', the entire built system will be
227                 statically linked.
228
229                 Default: Platform dependent.  As of this writing, all plat-
230                 forms except sh3 default to ``yes''.
231
232     MKPICINSTALL
233                 Can be set to ``yes'' or ``no''.  Indicates whether the ar(1)
234                 format libraries (lib*_pic.a), used to generate shared
235                 libraries, are installed during a build.
236
237                 Default: ``yes''
238
239     MKPROFILE   Can be set to ``yes'' or ``no''.  Indicates whether profiled
240                 libraries (lib*_p.a) will be built and installed during a
241                 build.
242
243                 Default: ``yes''; however, some platforms turn off MKPROFILE
244                 by default at times due to toolchain problems with profiled
245                 code.
246
247     MKSHARE     Can be set to ``yes'' or ``no''.  Indicates whether files
248                 destined to reside in DESTDIR/usr/share will be built and
249                 installed during a build.  If set to ``no'', then all of
250                 MKCATPAGES, MKDOC, MKINFO, MKMAN, and MKNLS will be set to
251                 ``no'' unconditionally.
252
253                 Default: ``yes''
254
255     MKTTINTERP  Can be set to ``yes'' or ``no''.  For X builds, decides if
256                 the TrueType bytecode interpreter is turned on.  See
257                 http://www.freetype.org/patents.html for details.
258
259                 Default: ``no''
260
261     MKUNPRIVED  Can be set to ``yes'' or ``no''.  Indicates whether an
262                 unprivileged install will occur.  The user, group, permis-
263                 sions, and file flags, will not be set on the installed
264                 items; instead the information will be appended to a file
265                 called METALOG in DESTDIR.  The contents of METALOG are used
266                 during the generation of the distribution tar files to ensure
267                 that the appropriate file ownership is stored.
268
269                 Default: ``no''
270
271     MKUPDATE    Can be set to ``yes'' or ``no''.  Indicates whether all
272                 install operations intended to write to DESTDIR will compare
273                 file timestamps before installing, and skip the install phase
274                 if the destination files are up-to-date.  This also has
275                 implications on full builds (see next subsection).
276
277                 Default: ``no''
278
279     MKX11       Can be set to ``yes'' or ``no''.  Indicates whether X11R6 is
280                 built from X11SRCDIR.
281
282                 Default: ``no''
283
284     TOOLDIR     Directory to hold the host tools, once built.  This directory
285                 should be unique to a given host system and NetBSD source
286                 tree.  (However, multiple targets may share the same TOOLDIR;
287                 the target-dependent files have unique names.)  If unset, a
288                 default based on the uname(1) information of the host plat-
289                 form will be created in the .OBJDIR of src.
290
291                 Default: Unset.
292
293     USETOOLS    Indicates whether the tools specified by TOOLDIR should be
294                 used as part of a build in progress.  Must be set to ``yes''
295                 if cross-compiling.
296
297                 yes    Use the tools from TOOLDIR.
298
299                 no     Do not use the tools from TOOLDIR, but refuse to build
300                        native compilation tool components that are version-
301                        specific for that tool.
302
303                 never  Do not use the tools from TOOLDIR, even when building
304                        native tool components.  This is similar to the tradi-
305                        tional NetBSD build method, but does not verify that
306                        the compilation tools in use are up-to-date enough in
307                        order to build the tree successfully.  This may cause
308                        build or runtime problems when building the whole
309                        NetBSD source tree.
310
311                 Default: ``yes'' if building all or part of a whole NetBSD
312                 source tree (detected automatically); ``no'' otherwise (to
313                 preserve traditional semantics of the <bsd.*.mk> make(1)
314                 include files).
315
316     X11SRCDIR   Directory containing the X11R6 source.  The main X11R6 source
317                 is found in X11SRCDIR/xfree/xc.
318
319                 Default: ``/usr/xsrc''
320
321   "make" variables for full builds
322     These variables only affect the top level ``Makefile'' and do not affect
323     manually building subtrees of the NetBSD source code.
324
325     INSTALLWORLDDIR  Location for the ``make installworld'' target to install
326                      to.
327
328                      Default: ``/''
329
330     MKOBJDIRS        Can be set to ``yes'' or ``no''.  Indicates whether
331                      object directories will be created automatically (via a
332                      ``make obj'' pass) at the start of a build.
333
334                      Default: ``no''
335
336     MKUPDATE         Can be set to ``yes'' or ``no''.  If set, then in addi-
337                      tion to the effects described for MKUPDATE=yes above,
338                      this implies the effects of NOCLEANDIR (i.e., ``make
339                      cleandir'' is avoided).
340
341                      Default: ``no''
342
343     NBUILDJOBS       Now obsolete.  Use the make(1) option -j, instead (see
344                      below)
345
346                      Default: Unset.
347
348     NOCLEANDIR       If set, avoids the ``make cleandir'' phase of a full
349                      build.  This has the effect of allowing only changed
350                      files in a source tree to be recompiled.  This can speed
351                      up builds when updating only a few files in the tree.
352
353                      Default: Unset.
354
355     NODISTRIBDIRS    If set, avoids the ``make distrib-dirs'' phase of a full
356                      build.  This skips running mtree(8) on DESTDIR, useful
357                      on systems where building as an unprivileged user, or
358                      where it is known that the system-wide mtree files have
359                      not changed.
360
361                      Default: Unset.
362
363     NOINCLUDES       If set, avoids the ``make includes'' phase of a full
364                      build.  This has the effect of preventing make(1) from
365                      thinking that some programs are out-of-date simply
366                      because the system include files have changed.  However,
367                      this option should not be used when updating the entire
368                      NetBSD source tree arbitrarily; it is suggested to use
369                      MKUPDATE=yes in that case.
370
371                      Default: Unset.
372
373     RELEASEDIR       If set, specifies the directory to which a release(7)
374                      layout will be written at the end of a ``make release''.
375
376                      Default: Unset.
377
378                      Note: build.sh will provide a default of releasedir (in
379                      the top-level .OBJDIR) unless run in `expert' mode
380
381BUILDING
382   "make" command line options
383     This is not a summary of all the options available to make(1); only the
384     options used most frequently with NetBSD builds are listed here.
385
386     -j njob    Run up to njob make(1) subjobs in parallel.  Makefiles should
387                use .WAIT or have explicit dependencies as necessary to
388                enforce build ordering.  If you see build failures with -j,
389                please save complete build logs so the failures can be ana-
390                lyzed.
391
392     -m dir     Specify the default directory for searching for system Make-
393                file segments, mainly the <bsd.*.mk> files.  When building any
394                full NetBSD source tree, this should be set to the
395                ``share/mk'' directory in the source tree.  (This is set auto-
396                matically when building from the top level.)
397
398     -n         Display the commands that would have been executed, but do not
399                actually execute them.  This will still cause recursion to
400                take place.
401
402     -V var     Print make(1)'s idea of the value of var.  Does not build any
403                targets.
404
405     var=value  Set the variable var to value, overriding any setting speci-
406                fied by the process environment, the MAKECONF configuration
407                file, or the system Makefile segments.
408
409   "make" targets
410     These default targets may be built by running make(1) in any subtree of
411     the NetBSD source code.  It is recommended that none of these be used
412     from the top level Makefile; as a specific exception, ``make obj'' and
413     ``make cleandir'' are useful in that context.
414
415     all        Build programs, libraries, and preformatted documentation.
416
417     clean      Remove program and library object code files.
418
419     cleandir   Same as clean, but also remove preformatted documentation,
420                dependency files generated by ``make depend'', and any other
421                files known to be created at build time.
422
423     depend     Create dependency files (.depend) containing more detailed
424                information about the dependencies of source code on header
425                files.  Allows programs to be recompiled automatically when a
426                dependency changes.
427
428     dependall  Does a ``make depend'' immediately followed by a ``make all''.
429                This improves cache locality of the build since both passes
430                read the source files in their entirety.
431
432     distclean  Synonym for cleandir.
433
434     includes   Build and install system header files.  Typically needed
435                before any system libraries or programs can be built.
436
437     install    Install programs, libraries, and documentation into DESTDIR.
438                Few files will be installed to DESTDIR/dev, DESTDIR/etc,
439                DESTDIR/root or DESTDIR/var in order to prevent user supplied
440                configuration data from being overwritten.
441
442     lint       Run lint(1) against the C source code, where appropriate, and
443                generate system-installed lint libraries.
444
445     obj        Create object directories to be used for built files, instead
446                of building directly in the source tree.
447
448     tags       Create ctags(1) searchable function lists usable by the ex(1)
449                and vi(1) text editors.
450
451   "make" targets for the top level
452     Additional make(1) targets are usable specifically from the top source
453     level to facilitate building the entire NetBSD source tree.
454
455     build         Build the entire NetBSD system.  This orders portions of
456                   the source tree such that prerequisites will be built in
457                   the proper order.
458
459     distribution  Do a ``make build'', and then install a full distribution
460                   into DESTDIR, including files in DESTDIR/dev, DESTDIR/etc,
461                   DESTDIR/root and DESTDIR/var.
462
463     buildworld    As per ``make distribution'', except that it ensures that
464                   DESTDIR is not the root directory.
465
466     installworld  Install the distribution from DESTDIR to INSTALLWORLDDIR
467                   (which defaults to the root directory).  Ensures that
468                   INSTALLWORLDDIR is not the root directory if cross compil-
469                   ing.
470
471                   Note: It is highly recommended that you upgrade your kernel
472                   and reboot before performing this operation.
473
474     sets          Create distribution sets from DESTDIR into
475                   RELEASEDIR/MACHINE/binary/sets.  Should be run after ``make
476                   distribution'' (as ``make build'' does not install all of
477                   the required files).
478
479     sourcesets    Create source sets of the source tree into
480                   RELEASEDIR/source/sets.
481
482     release       Do a ``make distribution'', build kernels, distribution
483                   media, and install sets (this as per ``make sets''), and
484                   then package the system into a standard release layout as
485                   described by release(7).  This requires that RELEASEDIR be
486                   set (see above).
487
488     regression-tests
489                   Can only be run after building the regression tests in the
490                   directory ``regress''.  Runs the compiled regression tests
491                   on the local host.
492
493   The "build.sh" script
494     This script file is a Bourne shell script designed to build the entire
495     NetBSD system on any host with a Bourne shell in /bin/sh, including many
496     that are not POSIX compliant.  Note that if a host system's /bin/sh is
497     unusually old and broken, the Korn Shell (/bin/ksh), if available, may be
498     a usable alternative.
499
500     All cross-compile builds, and most native builds, of the entire system
501     should make use of build.sh rather than just running ``make''.  This way,
502     the make(1) program will be bootstrapped properly, in case the host sys-
503     tem has an older or incompatible ``make'' program.
504
505     When compiling the entire system via build.sh, many make(1) variables are
506     set for you in order to help encapsulate the build process.  In the list
507     of options below, variables that are automatically set by build.sh are
508     noted where applicable.
509
510     The following operations are supported by build.sh:
511
512     build         Build the system as per ``make build''.  This option
513                   implies the obj and tools operations.
514
515     distribution  Build a full distribution as per ``make distribution''.
516                   This option implies the build operation.
517
518     release       Build a full release as per ``make release''.  This option
519                   implies the distribution operation.
520
521     makewrapper   Create the nbmake-MACHINE wrapper.  This operation is auto-
522                   matically performed for any of the other operations.
523
524     obj           Perform ``make obj''.
525
526     tools         Build and install the host tools from src/tools.
527
528     install=idir  Install the contents of DESTDIR to idir, using ``make
529                   installworld''.
530
531     kernel=kconf  Build a new kernel.  The kconf argument is the name of a
532                   configuration file suitable for use by config(8).  If kconf
533                   does not contain any `/' characters, the configuration file
534                   is expected to be found in the KERNCONFDIR directory, which
535                   is typically sys/arch/MACHINE/conf.  The new kernel will be
536                   built in a subdirectory of KERNOBJDIR, which is typically
537                   sys/arch/MACHINE/compile or an associated object directory.
538                   In order to ensure that the kernel is built using up-to-
539                   date tools, it is strongly recommended that the tools be
540                   rebuilt (using the tools operation).
541
542     releasekernel=kconf
543                   Install a gzip(1)ed copy of the kernel built by
544                   kernel=kconf into RELEASEDIR/MACHINE/binary/kernel, usually
545                   as netbsd-kconf.gz, although the ``netbsd'' prefix is
546                   determined from the ``config'' directives in kconf.
547
548     sets          Perform ``make sets''.
549
550     sourcesets    Perform ``make sourcesets''.
551
552     The following command line options alter the behaviour of the build.sh
553     operations described above:
554
555     -a arch   Set the value of MACHINE_ARCH to arch.
556
557     -B buildid
558               Set the value of BUILDID to buildid.  This will also append the
559               build idenfitier to the name of the ``make'' wrapper script so
560               that the resulting name is of the form
561               ``nbmake-MACHINE-BUILDID''.
562
563     -D dest   Set the value of DESTDIR to dest.
564
565     -E        Set `expert' mode.  This overrides various sanity checks, and
566               allows: DESTDIR does not have to be set to a non-root path for
567               builds, and MKUNPRIVED=yes does not have to be set when build-
568               ing as a non-root user.
569
570               Note: It is highly recommended that you know what you are doing
571               when you use this option.
572
573     -h        Print a help message.
574
575     -j njob   Passed through to make(1).  Makefiles should use .WAIT or have
576               explicit dependancies as necessary to enforce build ordering.
577               If you see build failures with -j, please save complete build
578               logs so the failures can be analyzed.
579
580     -M obj    Set MAKEOBJDIRPREFIX to obj.  Unsets MAKEOBJDIR.
581
582     -m mach   Set the value of MACHINE to mach.  This will also override any
583               value of MACHINE_ARCH in the process environment with a value
584               deduced from mach, unless -a is specified, or mach is a special
585               case listed below.  All cross builds require -m, but if unset
586               on a NetBSD host, the host's value of MACHINE will be detected
587               and used automatically.
588
589               Some machines support multiple values for MACHINE_ARCH.  For a
590               given value of mach, the following MACHINE and MACHINE_ARCH
591               values will result:
592
593                     mach          MACHINE    MACHINE_ARCH
594                     evbmips       evbmips    (not set)
595                     evbmips-eb    evbmips    mipseb
596                     evbmips-el    evbmips    mipsel
597                     evbsh3        evbsh3     (not set)
598                     evbsh3-eb     evbsh3     sh3eb
599                     evbsh3-el     evbsh3     sh3el
600                     sbmips        sbmips     (not set)
601                     sbmips-eb     sbmips     mipseb
602                     sbmips-el     sbmips     mipsel
603
604     -N noiselevel
605               Set the ``noisyness'' level of the build, by setting
606               MAKEVERBOSE to noiselevel.
607
608     -n        Show the commands that would be executed by build.sh, but do
609               not make any changes.  This is similar in concept to ``make
610               -n''.
611
612     -O obj    Create an appropriate transform macro for MAKEOBJDIR that will
613               place the built object files under obj.  For instance, a set-
614               ting of /usr/obj will place build-time files under
615               /usr/obj/bin, /usr/obj/lib, /usr/obj/usr.bin, and so forth.
616               Unsets MAKEOBJDIRPREFIX.
617
618     -o        Set the value of MKOBJDIRS to ``no''.  Otherwise, it will be
619               automatically set to ``yes'' (which is opposite to the default
620               behaviour).
621
622     -R rel    Set the value of RELEASEDIR to rel.
623
624     -r        Remove the contents of DESTDIR and TOOLDIR before building
625               (provides a clean starting point).  This will skip deleting
626               DESTDIR if building on a native system to the root directory.
627
628     -T tools  Set the value of TOOLDIR to tools.  If set, the bootstrap
629               ``make'' will only be rebuilt as needed (when the source files
630               for make(1) change).
631
632     -U        Set MKUNPRIVED=yes.
633
634     -u        Set MKUPDATE=yes.
635
636     -V var=[value]
637               Set the environment variable var to an optional value.  This is
638               propagated to the nbmake wrapper.
639
640     -w wrapper
641               Create the nbmake wrapper script (see below) in a custom loca-
642               tion, specified by wrapper.  This allows, for instance, to
643               place the wrapper in PATH automatically.  Note that wrapper is
644               the full name of the file, not just a directory name.
645
646     -X x11src
647               Set the value of X11SRCDIR to x11src.
648
649     -x        Set MKX11=yes.
650
651     -Z var    Unset ("zap") the environment variable var.  This is propagated
652               to the nbmake wrapper.
653
654   The "nbmake-MACHINE" wrapper script
655     If using the build.sh script to build NetBSD, a nbmake-MACHINE script
656     will be created in TOOLDIR/bin upon the first build to assist in building
657     subtrees on a cross-compile host.
658
659     nbmake-MACHINE can be invoked in lieu of make(1), and will instead call
660     the up-to-date version of ``nbmake'' installed into TOOLDIR/bin with sev-
661     eral key variables pre-set, including MACHINE, MACHINE_ARCH, and TOOLDIR.
662     build.sh will also set variables specified with -V, and unset variables
663     specified with -Z.
664
665     This script can be symlinked into a directory listed in PATH, or called
666     with an absolute path.
667
668EXAMPLES
669     1.   % ./build.sh tools kernel=GENERIC
670
671          Build a new toolchain, and use the new toolchain to configure and
672          build a new GENERIC kernel.
673
674     2.   % ./build.sh -U distribution
675
676          Using unprivileged mode, build a complete distribution to a DESTDIR
677          directory that build.sh selects (and will display).
678
679     3.   # ./build.sh -U install=/
680
681          As root, install to / the distribution that was built by example 2.
682          Even though this is run as root, -U is required so that the permis-
683          sions stored in DESTDIR/METALOG are correctly applied to the files
684          as they're copied to /.
685
686     4.   % ./build.sh -U -u release
687
688          Using unprivileged mode, build a complete release to DESTDIR and
689          RELEASEDIR directories that build.sh selects (and will display).
690          MKUPDATE=yes (-u) is set to prevent the ``make cleandir'', so that
691          if this is run after example 2, it doesn't need to redo that portion
692          of the release build.
693
694OBSOLETE VARIABLES
695     NBUILDJOBS  Use the make(1) option -j, instead.
696
697     USE_NEW_TOOLCHAIN
698                 The new toolchain is now the default.  To disable, use
699                 TOOLCHAIN_MISSING=yes.
700
701SEE ALSO
702     make(1), hier(7), release(7)
703
704HISTORY
705     The build.sh based build scheme was introduced for NetBSD 1.6 as
706     USE_NEW_TOOLCHAIN, and re-worked to TOOLCHAIN_MISSING after that.
707
708BUGS
709     A few platforms are not yet using this build system.
710
711NetBSD                         February 6, 2003                         NetBSD
712