BUILDING revision 1.3
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 im-
13     plementation 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 setting of USE_NEW_TOOLCHAIN in /etc/mk.conf or
17     <bsd.own.mk>.  Platforms which have not yet been switched to the new
18     toolchain should continue building traditionally, using the notes speci-
19     fied in the file 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 host toolchain components are not yet available in
34           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
41     BUILDING.mdoc  This document (in -mdoc troff format; the original copy).
42
43     BUILDING       This document (in plaintext).
44
45     Makefile       The main Makefile for NetBSD; should only be run for na-
46                    tive 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  (For building from out-of-date systems or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 na-
65                    tive host.
66
67     distrib/, etc/
68                    Sources for items used when making a full release snap-
69                    shot, such as files installed in /etc on the destination
70                    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   Build tree layout
87     The NetBSD build tree is described in hier(7), and the release layout is
88     described in release(7).
89
90CONFIGURATION
91   "make" variables
92     Several variables control the behavior of NetBSD builds.  Unless other-
93     wise specified, these variables may be set in either the process environ-
94     ment or the make(1) configuration file specified by MAKECONF.
95
96     DESTDIR     Directory to contain the built NetBSD system.  If set, spe-
97                 cial options are passed to the compilation tools to prevent
98                 their default use of the host system's /usr/include,
99                 /usr/lib, and so forth.  This pathname should not end with a
100                 slash (/) character (for installation into the system's root
101                 directory, set DESTDIR to an empty string).
102
103                 Default: Empty string if USETOOLS is ``yes''; unset other-
104                 wise.
105
106     MAKECONF    The name of the make(1) configuration file.  Only settable in
107                 the process environment.
108
109                 Default: ``/etc/mk.conf''
110
111     MKCATPAGES  Can be set to ``yes'' or ``no''.  Indicates whether prefor-
112                 matted plaintext manual pages will be created during a build.
113
114                 Default: ``yes''
115
116     MKCRYPTO    Can be set to ``yes'' or ``no''.  Indicates whether crypto-
117                 graphic code will be included in a build; provided for the
118                 benefit of countries that do not allow strong cryptography.
119                 Will not affect use of the standard low-security password en-
120                 cryption system, crypt(3).
121
122                 Default: ``yes''
123
124     MKDOC       Can be set to ``yes'' or ``no''.  Indicates whether system
125                 documentation destined for /usr/share/doc will be installed
126                 during a build.
127
128                 Default: ``yes''
129
130     MKINFO      Can be set to ``yes'' or ``no''.  Indicates whether GNU Info
131                 files, used for the documentation for most of the compilation
132                 tools, will be created and installed during a build.
133
134                 Default: ``yes''
135
136     MKLINT      Can be set to ``yes'' or ``no''.  Indicates whether lint(1)
137                 will be run against portions of the NetBSD source code during
138                 the build, and whether lint libraries will be installed into
139                 /usr/libdata/lint.
140
141                 Default: ``yes''
142
143     MKMAN       Can be set to ``yes'' or ``no''.  Indicates whether manual
144                 pages will be installed during a build.
145
146                 Default: ``yes''
147
148     MKNLS       Can be set to ``yes'' or ``no''.  Indicates whether Native
149                 Language System locale zone files will be compiled and in-
150                 stalled during a build.
151
152                 Default: ``yes''
153
154     MKOBJ       Can be set to ``yes'' or ``no''.  Indicates whether object
155                 directories will be created when running ``make obj''.  If
156                 set to ``no'', then all built files will be located inside
157                 the regular source tree.
158
159                 Default: ``yes''
160
161     MKPIC       Can be set to ``yes'' or ``no''.  Indicates whether shared
162                 objects and libraries will be created and installed during a
163                 build.  If set to ``no'', the entire built system will be
164                 statically linked.
165
166                 Default: Platform dependent.  As of this writing, all plat-
167                 forms except sh3 default to ``yes''.
168
169     MKPICINSTALL
170                 Can be set to ``yes'' or ``no''.  Indicates whether the ar(1)
171                 format libraries (lib*_pic.a), used to generate shared li-
172                 braries, are installed during a build.
173
174                 Default: ``yes''
175
176     MKPROFILE   Can be set to ``yes'' or ``no''.  Indicates whether profiled
177                 libraries (lib*_p.a) will be built and installed during a
178                 build.
179
180                 Default: ``yes''; however, some platforms turn off MKPROFILE
181                 by default at times due to toolchain problems with profiled
182                 code.
183
184     MKSHARE     Can be set to ``yes'' or ``no''.  Indicates whether files
185                 destined to reside in /usr/share will be built and installed
186                 during a build.  If set to ``no'', then all of MKCATPAGES,
187                 MKDOC, MKINFO, MKMAN, and MKNLS will be set to ``no'' uncon-
188                 ditionally.
189
190                 Default: ``yes''
191
192     TOOLDIR     Directory to hold the host tools, once built.  This directory
193                 should be unique to a given host system and NetBSD source
194                 tree.  (However, multiple targets may share the same TOOLDIR;
195                 the target-dependent files have unique names.)  If unset, a
196                 default based on the uname(1) information of the host plat-
197                 form will be created in the .OBJDIR of src/tools.
198
199                 Default: Unset.
200
201     UPDATE      If set, then all install operations intended to write to
202                 DESTDIR will compare file timestamps before installing, and
203                 skip the install phase if the destination files are up-to-
204                 date.  This also has implications on full builds (see next
205                 subsection).
206
207                 Default: Unset.
208
209     USETOOLS    Indicates whether the tools specified by TOOLDIR should be
210                 used as part of a build in progress.  Must be set to ``yes''
211                 if cross-compiling.
212
213                 yes    Use the tools from TOOLDIR.
214
215                 no     Do not use the tools from TOOLDIR, but refuse to build
216                        native compilation tool components that are version-
217                        specific for that tool.
218
219                 never  Do not use the tools from TOOLDIR, even when building
220                        native tool components.  This is similar to the tradi-
221                        tional NetBSD build method, but does not verify that
222                        the compilation tools in use are up-to-date enough in
223                        order to build the tree successfully.  This may cause
224                        build or runtime problems when building the whole
225                        NetBSD source tree.
226
227                 Default: ``yes'' if building all or part of a whole NetBSD
228                 source tree (detected automatically); ``no'' otherwise (to
229                 preserve traditional semantics of the <bsd.*.mk> make(1) in-
230                 clude files).
231
232   "make" variables for full builds
233     These variables only affect the top level ``Makefile'' and do not manual-
234     ly building subtrees of the NetBSD source code.
235
236     MKOBJDIRS      Can be set to ``yes'' or ``no''.  Indicates whether object
237                    directories will be created automatically (via a ``make
238                    obj'' pass) at the start of a build.
239
240                    Default: ``yes''
241
242     NBUILDJOBS     If set, specifies the number of parallel make(1) processes
243                    that should be run simultaneously.  This can speed up
244                    builds on SMP machines, or machines with much more CPU
245                    power than I/O availability.  This should be used instead
246                    of the make(1) option -j, in order to ensure proper order-
247                    ing of build components.
248
249                    Default: Unset.
250
251     NOCLEANDIR     If set, avoids the ``make cleandir'' phase of a full
252                    build.  This has the effect of allowing only changed files
253                    in a source tree to be recompiled.  This can speed up
254                    builds when updating only a few files in the tree.
255
256                    Default: Unset.
257
258     NODISTRIBDIRS  If set, avoids the ``make distrib-dirs'' phase of a full
259                    build.  This skips running mtree(8) on DESTDIR, useful on
260                    systems where building as an unprivileged user, or where
261                    it is known that the system-wide mtree files have not
262                    changed.
263
264                    Default: Unset.
265
266     NOINCLUDES     If set, avoids the ``make includes'' phase of a full
267                    build.  This has the effect of preventing make(1) from
268                    thinking that some programs are out-of-date simply because
269                    the system include files have changed.  However, this op-
270                    tion should not be used when updating the entire NetBSD
271                    source tree arbitrarily; it is suggested to use UPDATE in
272                    that case.
273
274                    Default: Unset.
275
276     RELEASEDIR     If set, specifies the directory to which a release(7) lay-
277                    out will be written at the end of a ``make release''.
278
279                    Default: Unset.
280
281     UPDATE         If set, then in addition to the effects described for UP-
282                    DATE above, this implies the effects of NOCLEANDIR.
283
284BUILDING
285   "make" command line options
286     This is only a summary of options available to make(1); only the options
287     used most frequently with NetBSD builds are listed here.
288
289     -m dir     Specify the default directory for searching for system Make-
290                file segments, mainly the <bsd.*.mk> files.  When building any
291                full NetBSD source tree, this should be set to the
292                ``share/mk'' directory in the source tree.  (This is set auto-
293                matically when building from the top level.)
294
295     -n         Display the commands that would have been executed, but do not
296                actually execute them.  This will still cause recursion to
297                take place.
298
299     -v var     Print make(1)'s idea of the value of var.  Does not build any
300                targets.
301
302     var=value  Set the variable var to value, overriding any setting speci-
303                fied by the process environment, the MAKECONF configuration
304                file, or the system Makefile segments.
305
306   "make" targets
307     These default targets may be built by running make(1) in any subtree of
308     the NetBSD source code.  It is recommended that none of these be used
309     from the top level Makefile; as a specific exception, ``make obj'' and
310     ``make cleandir'' are useful in that context.
311
312     all        Build programs, libraries, and preformatted documentation.
313
314     clean      Remove program and library object code files.
315
316     cleandir   Same as clean, but also remove preformatted documentation, de-
317                pendency files generated by ``make depend'', and any other
318                files known to be created at build time.  ``make distclean''
319                may be used as a synonym, for familiarity with a similar well-
320                known convention.
321
322     depend     Create dependency files (.depend) containing more detailed in-
323                formation about the dependencies of source code on header
324                files.  Allows programs to be recompiled automatically when a
325                dependency changes.
326
327     dependall  Does a ``make depend'' immediately followed by a ``make all''.
328                This combined target recurses as an atomic unit, so that the
329                ``make depend'' phase can participate in make -j parallelism.
330
331     includes   Build and install system header files.  Typically needed be-
332                fore any system libraries or programs can be built.
333
334     install    Install programs, libraries, and documentation into DESTDIR.
335
336     lint       Run lint(1) against the C source code, where appropriate, and
337                generate system-installed lint libraries.
338
339     obj        Create object directories to be used for built files, instead
340                of building directly in the source tree.
341
342     tags       Create ctags(1) searchable function lists usable by the ex(1)
343                and vi(1) text editors.
344
345   "make" targets for the top level
346     Additional make(1) targets are usable specifically from the top source
347     level to facilitate building the entire NetBSD source tree.
348
349     build      Build the entire NetBSD system.  This orders portions of the
350                source tree such that prerequisites will be built in the prop-
351                er order.
352
353     release    Do a ``make build'', then package the system into a standard
354                release layout as described by release(7).  This requires that
355                RELEASEDIR be set (see above).
356
357     regression-tests
358                Can only be run after building the regression tests in the di-
359                rectory ``regress''.  Runs the compiled regression tests on
360                the local host.
361
362   The "build.sh" script
363     This script file is a Bourne shell script designed to build the entire
364     NetBSD system on any host with a Bourne shell in /bin/sh, including many
365     that are not POSIX compliant.  Note that if a host system's /bin/sh is
366     unusually old and broken, the Korn Shell (/bin/ksh), if available, may be
367     a usable alternative.
368
369     All cross-compile builds, and most native builds, of the entire system
370     should make use of build.sh rather than just running ``make''.  This way,
371     the make(1) program will be bootstrapped properly, in case the host sys-
372     tem has an older or incompatible ``make'' program.
373
374     When compiling the entire system via build.sh, many make(1) variables are
375     set for you in order to help encapsulate the build process.  In the list
376     of options below, variables that are automatically set by build.sh are
377     noted where applicable.
378
379     The following are available command line options that may be supplied to
380     build.sh:
381
382     -a arch   Set the value of MACHINE_ARCH to arch.
383
384     -b        Bootstrap ``make'' and create a nbmake-MACHINE script (see be-
385               low).
386
387     -j njob   Set the value of NBUILDJOBS to njob.  This provides similar
388               functionality to the familiar ``make -j'', but preserves the
389               ordering of the top level ``make build''.
390
391     -m mach   Set the value of MACHINE to mach.  This will also override any
392               value of MACHINE_ARCH in the process environment with a value
393               deduced from mach, unless -a is specified.  All cross builds
394               require -m, but if unset on a NetBSD host, the host's value of
395               MACHINE will be detected and used automatically.
396
397     -n        Show the commands that would be executed by build.sh, but do
398               not make any changes.  This is similar in concept to ``make
399               -n''.
400
401     -o        Set the value of MKOBJDIRS to ``no''.
402
403     -r        Remove the contents of DESTDIR and TOOLDIR before building
404               (provides a clean starting point).  This will skip deleting
405               DESTDIR if building on a native system to the root directory.
406
407     -t        Build and install the host tools from src/tools only.  This op-
408               tion implies -b.
409
410     -u        Set the UPDATE variable.
411
412     -w wrapper
413               Create the nbmake wrapper script (see below) in a custom loca-
414               tion, specified by wrapper.  This allows, for instance, to
415               place the wrapper in PATH automatically.  Note that wrapper is
416               the full name of the file, not just a directory name.
417
418     -D dest   Set the value of DESTDIR to dest.
419
420     -O obj    Create an appropriate transform macro for MAKEOBJDIR that will
421               place the built object files under obj.  For instance, a set-
422               ting of /usr/obj will place build-time files files under
423               /usr/obj/bin, /usr/obj/lib, and so forth.
424
425     -R rel    Set the value of RELEASEDIR to rel.  Setting this option will
426               cause build.sh to run ``make release'' instead of ``make
427               build''.
428
429     -T tools  Set the value of TOOLDIR to tools.  If set, the bootstrap
430               ``make'' will only be rebuilt as needed (when the source files
431               for make(1) change).
432
433   The "nbmake-MACHINE" wrapper script
434     If using the build.sh script to build NetBSD, a nbmake-MACHINE script
435     will be created in TOOLDIR/bin upon the first build to assist in building
436     subtrees on a cross-compile host.
437
438     nbmake-MACHINE can be invoked in lieu of make(1), and will instead call
439     the up-to-date version of ``nbmake'' installed into TOOLDIR/bin with sev-
440     eral key variables pre-set, including MACHINE, MACHINE_ARCH, and TOOLDIR.
441     This script can be symlinked into a directory listed in PATH, or called
442     with an absolute path.
443
444SEE ALSO
445     make(1), hier(7), release(7)
446
447HISTORY
448     The USE_NEW_TOOLCHAIN based build scheme was introduced in the ``NetBSD-
449     current'' development sources between NetBSD 1.5 and NetBSD 1.6.
450
451BUGS
452     Many platforms are not yet using the USE_NEW_TOOLCHAIN system.
453
454NetBSD                         November 12, 2001                             7
455