BUILDING revision 1.15
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 default setting of TOOLCHAIN_MISSING in <bsd.own.mk>.
17     Platforms which have not yet been switched to the new toolchain should
18     continue building traditionally, using the notes specified in the file
19     UPDATING.
20
21REQUIREMENTS
22     NetBSD is designed to be buildable on most POSIX-compliant host systems.
23     The basic build procedure is the same whether compiling natively (on the
24     same NetBSD architecture) or cross compiling (on another architecture or
25     OS).
26
27     This source tree contains a special subtree, ``tools'', which uses the
28     host system to create a build toolchain for the target architecture.  The
29     host system must have at least C and C++ compilers in order to create the
30     toolchain (make is not required); all other tools are created as part of
31     the NetBSD build process.
32
33           Note: A couple 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  (For building from out-of-date systems or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   Environment variables
92     Several environment variables control the behaviour of NetBSD builds.
93
94     MACHINE           Machine type.
95
96     MACHINE_ARCH      Machine architecture.
97
98     MAKE              Path name to invoke make(1) as.
99
100     MAKEFLAGS         Flags to invoke make(1) with.
101
102     MAKEOBJDIR        Directory to use as the .OBJDIR for the current direc-
103                       tory.  Used only if MAKEOBJDIRPREFIX is not defined.
104                       MAKEOBJDIR can only be provided in the environment.
105
106     MAKEOBJDIRPREFIX  Top level directory of the object directory tree.  If
107                       this is defined, ${MAKEOBJDIRPREFIX}/${.CURDIR} is used
108                       as the .OBJDIR for the current directory.  The current
109                       directory may be read only.  MAKEOBJDIRPREFIX can only
110                       be provided in the environment.
111
112   "make" variables
113     Several variables control the behavior of NetBSD builds.  Unless other-
114     wise specified, these variables may be set in either the process environ-
115     ment or the make(1) configuration file specified by MAKECONF.
116
117     BUILDID     Identifier for the build.  The identifier will be appended to
118                 object directory names, and can be consulted in the make(1)
119                 configuration file in order to set additional build parame-
120                 ters, such as compiler flags.
121
122     DESTDIR     Directory to contain the built NetBSD system.  If set, spe-
123                 cial options are passed to the compilation tools to prevent
124                 their default use of the host system's /usr/include,
125                 /usr/lib, and so forth.  This pathname should not end with a
126                 slash (/) character (for installation into the system's root
127                 directory, set DESTDIR to an empty string).  The directory
128                 must reside on a file system which supports long file names
129                 and hard links.
130
131                 Default: Empty string if USETOOLS is ``yes''; unset other-
132                 wise.
133
134     MAKECONF    The name of the make(1) configuration file.  Only settable in
135                 the process environment.
136
137                 Default: ``/etc/mk.conf''
138
139     MKCATPAGES  Can be set to ``yes'' or ``no''.  Indicates whether prefor-
140                 matted plaintext manual pages will be created during a build.
141
142                 Default: ``yes''
143
144     MKCRYPTO    Can be set to ``yes'' or ``no''.  Indicates whether crypto-
145                 graphic code will be included in a build; provided for the
146                 benefit of countries that do not allow strong cryptography.
147                 Will not affect use of the standard low-security password en-
148                 cryption system, crypt(3).
149
150                 Default: ``yes''
151
152     MKDOC       Can be set to ``yes'' or ``no''.  Indicates whether system
153                 documentation destined for /usr/share/doc will be installed
154                 during a build.
155
156                 Default: ``yes''
157
158     MKHOSTOBJ   Can be set to ``yes'' or ``no''.  If set to ``yes'', then for
159                 programs intended to be run on the compile host, the name,
160                 release, and architecture of the host operating system will
161                 be suffixed to the name of the object directory created by
162                 ``make obj''.  (This allows multiple host systems to compile
163                 NetBSD for a single target.)  If set to ``no'', then programs
164                 built to be run on the compile host will use the same object
165                 directory names as programs built to be run on the target.
166
167                 Default: ``no''
168
169     MKINFO      Can be set to ``yes'' or ``no''.  Indicates whether GNU Info
170                 files, used for the documentation for most of the compilation
171                 tools, will be created and installed during a build.
172
173                 Default: ``yes''
174
175     MKLINT      Can be set to ``yes'' or ``no''.  Indicates whether lint(1)
176                 will be run against portions of the NetBSD source code during
177                 the build, and whether lint libraries will be installed into
178                 /usr/libdata/lint.
179
180                 Default: ``yes''
181
182     MKMAN       Can be set to ``yes'' or ``no''.  Indicates whether manual
183                 pages will be installed during a build.
184
185                 Default: ``yes''
186
187     MKNLS       Can be set to ``yes'' or ``no''.  Indicates whether Native
188                 Language System locale zone files will be compiled and in-
189                 stalled during a build.
190
191                 Default: ``yes''
192
193     MKOBJ       Can be set to ``yes'' or ``no''.  Indicates whether object
194                 directories will be created when running ``make obj''.  If
195                 set to ``no'', then all built files will be located inside
196                 the regular source tree.
197
198                 Default: ``yes''
199
200     MKPIC       Can be set to ``yes'' or ``no''.  Indicates whether shared
201                 objects and libraries will be created and installed during a
202                 build.  If set to ``no'', the entire built system will be
203                 statically linked.
204
205                 Default: Platform dependent.  As of this writing, all plat-
206                 forms except sh3 default to ``yes''.
207
208     MKPICINSTALL
209                 Can be set to ``yes'' or ``no''.  Indicates whether the ar(1)
210                 format libraries (lib*_pic.a), used to generate shared li-
211                 braries, are installed during a build.
212
213                 Default: ``yes''
214
215     MKPROFILE   Can be set to ``yes'' or ``no''.  Indicates whether profiled
216                 libraries (lib*_p.a) will be built and installed during a
217                 build.
218
219                 Default: ``yes''; however, some platforms turn off MKPROFILE
220                 by default at times due to toolchain problems with profiled
221                 code.
222
223     MKSHARE     Can be set to ``yes'' or ``no''.  Indicates whether files
224                 destined to reside in /usr/share will be built and installed
225                 during a build.  If set to ``no'', then all of MKCATPAGES,
226                 MKDOC, MKINFO, MKMAN, and MKNLS will be set to ``no'' uncon-
227                 ditionally.
228
229                 Default: ``yes''
230
231     TOOLDIR     Directory to hold the host tools, once built.  This directory
232                 should be unique to a given host system and NetBSD source
233                 tree.  (However, multiple targets may share the same TOOLDIR;
234                 the target-dependent files have unique names.)  If unset, a
235                 default based on the uname(1) information of the host plat-
236                 form will be created in the .OBJDIR of src/tools.
237
238                 Default: Unset.
239
240     UNPRIVED    If set, then an unprivileged install will occur.  The user,
241                 group, permissions, and file flags, will not be set on the
242                 installed item; instead the information will be appended to a
243                 file called METALOG in DESTDIR.  The contents of METALOG is
244                 used during the generation of the distribution tar files to
245                 ensure that the appropriate file ownership is stored.
246
247                 Default: Unset.
248
249     UPDATE      If set, then all install operations intended to write to
250                 DESTDIR will compare file timestamps before installing, and
251                 skip the install phase if the destination files are up-to-
252                 date.  This also has implications on full builds (see next
253                 subsection).
254
255                 Default: Unset.
256
257     USETOOLS    Indicates whether the tools specified by TOOLDIR should be
258                 used as part of a build in progress.  Must be set to ``yes''
259                 if cross-compiling.
260
261                 yes    Use the tools from TOOLDIR.
262
263                 no     Do not use the tools from TOOLDIR, but refuse to build
264                        native compilation tool components that are version-
265                        specific for that tool.
266
267                 never  Do not use the tools from TOOLDIR, even when building
268                        native tool components.  This is similar to the tradi-
269                        tional NetBSD build method, but does not verify that
270                        the compilation tools in use are up-to-date enough in
271                        order to build the tree successfully.  This may cause
272                        build or runtime problems when building the whole
273                        NetBSD source tree.
274
275                 Default: ``yes'' if building all or part of a whole NetBSD
276                 source tree (detected automatically); ``no'' otherwise (to
277                 preserve traditional semantics of the <bsd.*.mk> make(1) in-
278                 clude files).
279
280   "make" variables for full builds
281     These variables only affect the top level ``Makefile'' and do not affect
282     manually building subtrees of the NetBSD source code.
283
284     MKOBJDIRS      Can be set to ``yes'' or ``no''.  Indicates whether object
285                    directories will be created automatically (via a ``make
286                    obj'' pass) at the start of a build.
287
288                    Default: ``yes''
289
290     NBUILDJOBS     Now obsolete.  Use the make(1) option -j, instead (see be-
291                    low)
292
293                    Default: Unset.
294
295     NOCLEANDIR     If set, avoids the ``make cleandir'' phase of a full
296                    build.  This has the effect of allowing only changed files
297                    in a source tree to be recompiled.  This can speed up
298                    builds when updating only a few files in the tree.
299
300                    Default: Unset.
301
302     NODISTRIBDIRS  If set, avoids the ``make distrib-dirs'' phase of a full
303                    build.  This skips running mtree(8) on DESTDIR, useful on
304                    systems where building as an unprivileged user, or where
305                    it is known that the system-wide mtree files have not
306                    changed.
307
308                    Default: Unset.
309
310     NOINCLUDES     If set, avoids the ``make includes'' phase of a full
311                    build.  This has the effect of preventing make(1) from
312                    thinking that some programs are out-of-date simply because
313                    the system include files have changed.  However, this op-
314                    tion should not be used when updating the entire NetBSD
315                    source tree arbitrarily; it is suggested to use UPDATE in
316                    that case.
317
318                    Default: Unset.
319
320     RELEASEDIR     If set, specifies the directory to which a release(7) lay-
321                    out will be written at the end of a ``make release''.
322
323                    Default: Unset.
324
325     UPDATE         If set, then in addition to the effects described for UP-
326                    DATE above, this implies the effects of NOCLEANDIR.
327
328BUILDING
329   "make" command line options
330     This is only a summary of options available to make(1); only the options
331     used most frequently with NetBSD builds are listed here.
332
333     -j njob    Run up to njob make(1) subjobs in parallel.  Makefiles should
334                use .WAIT or have explicit dependancies as necessary to en-
335                force build ordering.  If you see build failures with -j,
336                please save complete build logs so the failures can be ana-
337                lyzed.
338
339     -m dir     Specify the default directory for searching for system Make-
340                file segments, mainly the <bsd.*.mk> files.  When building any
341                full NetBSD source tree, this should be set to the
342                ``share/mk'' directory in the source tree.  (This is set auto-
343                matically when building from the top level.)
344
345     -n         Display the commands that would have been executed, but do not
346                actually execute them.  This will still cause recursion to
347                take place.
348
349     -v var     Print make(1)'s idea of the value of var.  Does not build any
350                targets.
351
352     var=value  Set the variable var to value, overriding any setting speci-
353                fied by the process environment, the MAKECONF configuration
354                file, or the system Makefile segments.
355
356   "make" targets
357     These default targets may be built by running make(1) in any subtree of
358     the NetBSD source code.  It is recommended that none of these be used
359     from the top level Makefile; as a specific exception, ``make obj'' and
360     ``make cleandir'' are useful in that context.
361
362     all        Build programs, libraries, and preformatted documentation.
363
364     clean      Remove program and library object code files.
365
366     cleandir   Same as clean, but also remove preformatted documentation, de-
367                pendency files generated by ``make depend'', and any other
368                files known to be created at build time.  ``make distclean''
369                may be used as a synonym, for familiarity with a similar well-
370                known convention.
371
372     depend     Create dependency files (.depend) containing more detailed in-
373                formation about the dependencies of source code on header
374                files.  Allows programs to be recompiled automatically when a
375                dependency changes.
376
377     dependall  Does a ``make depend'' immediately followed by a ``make all''.
378                This improves cache locality of the build since both passes
379                read the source files in their entirety.
380
381     includes   Build and install system header files.  Typically needed be-
382                fore any system libraries or programs can be built.
383
384     install    Install programs, libraries, and documentation into DESTDIR.
385                Few files will be installed to /dev, /etc, /root or /var in
386                order to prevent user supplied configuration data from being
387                overwritten.
388
389     lint       Run lint(1) against the C source code, where appropriate, and
390                generate system-installed lint libraries.
391
392     obj        Create object directories to be used for built files, instead
393                of building directly in the source tree.
394
395     tags       Create ctags(1) searchable function lists usable by the ex(1)
396                and vi(1) text editors.
397
398   "make" targets for the top level
399     Additional make(1) targets are usable specifically from the top source
400     level to facilitate building the entire NetBSD source tree.
401
402     build      Build the entire NetBSD system.  This orders portions of the
403                source tree such that prerequisites will be built in the prop-
404                er order.
405
406     release    Do a ``make build'', then package the system into a standard
407                release layout as described by release(7).  This requires that
408                RELEASEDIR be set (see above).
409
410     regression-tests
411                Can only be run after building the regression tests in the di-
412                rectory ``regress''.  Runs the compiled regression tests on
413                the local host.
414
415   The "build.sh" script
416     This script file is a Bourne shell script designed to build the entire
417     NetBSD system on any host with a Bourne shell in /bin/sh, including many
418     that are not POSIX compliant.  Note that if a host system's /bin/sh is
419     unusually old and broken, the Korn Shell (/bin/ksh), if available, may be
420     a usable alternative.
421
422     All cross-compile builds, and most native builds, of the entire system
423     should make use of build.sh rather than just running ``make''.  This way,
424     the make(1) program will be bootstrapped properly, in case the host sys-
425     tem has an older or incompatible ``make'' program.
426
427     When compiling the entire system via build.sh, many make(1) variables are
428     set for you in order to help encapsulate the build process.  In the list
429     of options below, variables that are automatically set by build.sh are
430     noted where applicable.
431
432     The following are available command line options that may be supplied to
433     build.sh:
434
435     -a arch   Set the value of MACHINE_ARCH to arch.
436
437     -B buildid
438               Set the value of BUILDID to buildid.  This will also append the
439               build idenfitier to the name of the ``make'' wrapper script so
440               that the resulting name is of the form ``nbmake-MACHINE-
441               BUILDID''.
442
443     -b        Bootstrap ``make'' and create a nbmake-MACHINE script (see be-
444               low).
445
446     -d        Build a full distribution.  This differs from a default build
447               in that files will also be installed to /dev, /etc, /root and
448               /var.  Note this does not build a ``release''; no release sets
449               are placed in ${RELEASEDIR}.  -d is implied by -R.
450
451     -j njob   Passed through to make(1).  Makefiles should use .WAIT or have
452               explicit dependancies as necessary to enforce build ordering.
453               If you see build failures with -j, please save complete build
454               logs so the failures can be analyzed.
455
456     -m mach   Set the value of MACHINE to mach.  This will also override any
457               value of MACHINE_ARCH in the process environment with a value
458               deduced from mach, unless -a is specified.  All cross builds
459               require -m, but if unset on a NetBSD host, the host's value of
460               MACHINE will be detected and used automatically.
461
462     -n        Show the commands that would be executed by build.sh, but do
463               not make any changes.  This is similar in concept to ``make
464               -n''.
465
466     -o        Set the value of MKOBJDIRS to ``no''.
467
468     -r        Remove the contents of DESTDIR and TOOLDIR before building
469               (provides a clean starting point).  This will skip deleting
470               DESTDIR if building on a native system to the root directory.
471
472     -t        Build and install the host tools from src/tools only.  This op-
473               tion implies -b.
474
475     -u        Set the UPDATE variable.
476
477     -w wrapper
478               Create the nbmake wrapper script (see below) in a custom loca-
479               tion, specified by wrapper.  This allows, for instance, to
480               place the wrapper in PATH automatically.  Note that wrapper is
481               the full name of the file, not just a directory name.
482
483     -D dest   Set the value of DESTDIR to dest.
484
485     -M obj    Set MAKEOBJDIRPREFIX to obj.
486
487     -O obj    Create an appropriate transform macro for MAKEOBJDIR that will
488               place the built object files under obj.  For instance, a set-
489               ting of /usr/obj will place build-time files under
490               /usr/obj/bin, /usr/obj/lib, and so forth.
491
492     -R rel    Set the value of RELEASEDIR to rel.  Setting this option will
493               cause build.sh to run ``make release'' instead of ``make
494               build''.
495
496     -T tools  Set the value of TOOLDIR to tools.  If set, the bootstrap
497               ``make'' will only be rebuilt as needed (when the source files
498               for make(1) change).
499
500     -U        Set the UNPRIVED variable.
501
502   The "nbmake-MACHINE" wrapper script
503     If using the build.sh script to build NetBSD, a nbmake-MACHINE script
504     will be created in TOOLDIR/bin upon the first build to assist in building
505     subtrees on a cross-compile host.
506
507     nbmake-MACHINE can be invoked in lieu of make(1), and will instead call
508     the up-to-date version of ``nbmake'' installed into TOOLDIR/bin with sev-
509     eral key variables pre-set, including MACHINE, MACHINE_ARCH, and TOOLDIR.
510     This script can be symlinked into a directory listed in PATH, or called
511     with an absolute path.
512
513OBSOLETE VARIABLES
514     NBUILDJOBS  Use the make(1) option -j, instead.
515
516     USE_NEW_TOOLCHAIN
517                 The new toolchain is now the default.  To disable, use
518                 TOOLCHAIN_MISSING=yes.
519
520SEE ALSO
521     make(1), hier(7), release(7)
522
523HISTORY
524     The build.sh based build scheme was introduced for NetBSD 1.6 as
525     USE_NEW_TOOLCHAIN, and re-worked to TOOLCHAIN_MISSING after that.
526
527BUGS
528     A few platforms are not yet using this build system.
529
530NetBSD                        September 21, 2002                             8
531