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BUILDING revision 1.157
      1 BUILDING(8)                 System Manager's Manual                BUILDING(8)
      2 
      3 NAME
      4      BUILDING - Procedure for building NetBSD from source code
      5 
      6 REQUIREMENTS
      7      NetBSD is designed to be buildable on most POSIX-compliant host systems.
      8      The basic build procedure is the same whether compiling natively (on the
      9      same NetBSD architecture) or cross compiling (on another architecture or
     10      OS).
     11 
     12      This source tree contains the build.sh shell script which supports both
     13      native and cross builds of NetBSD.
     14 
     15      This source tree contains a special subtree, "tools", which uses the host
     16      system to create a build toolchain for the target architecture.  The host
     17      system must have at least C and C++ compilers in order to create the
     18      toolchain (make(1) is not required); all other tools (including make(1)
     19      as nbmake) are created as part of the NetBSD build process.  (See the
     20      Environment variables section below if you need to override or manually
     21      select your compilers.)
     22 
     23      Note: Within this document, cross-references to manual pages are to the
     24      NetBSD manual pages, not the host system manual pages.  The mdoc(7)
     25      source to the NetBSD manual pages can be found within the source tree,
     26      and these and can be formatted with mandoc(1) or nroff(1) if those are
     27      available on the host system.  The NetBSD manual pages are also available
     28      at https://man.netbsd.org
     29 
     30 FILES
     31    Source tree layout
     32      BUILDING       This document (in plaintext).  Generated from
     33                     doc/BUILDING.mdoc.
     34 
     35      Makefile       The main Makefile for NetBSD; should only be run for
     36                     native builds with an appropriately up-to-date version of
     37                     NetBSD make(1).  Intended for expert use with knowledge of
     38                     its shortcomings, it has been superseded by the build.sh
     39                     shell script as the recommended means for building NetBSD.
     40 
     41      UPDATING       Special notes for updating from an earlier revision of
     42                     NetBSD.  It is important to read this file before every
     43                     build of an updated source tree.
     44 
     45      build.sh       Bourne-compatible shell script used for building the host
     46                     build tools and the NetBSD system from scratch.  Can be
     47                     used for both native and cross builds, and should be used
     48                     instead of make(1) as it performs additional checks to
     49                     prevent common issues going undetected, such as building
     50                     with an outdated version of make(1).
     51 
     52      crypto/dist/, dist/, gnu/dist/
     53                     Sources imported verbatim from third parties, without
     54                     mangling the existing build structure.  Other source trees
     55                     in bin through usr.sbin use the NetBSD make(1) "reachover"
     56                     Makefile semantics when building these programs for a
     57                     native host.
     58 
     59      distrib/, etc/
     60                     Sources for items used when making a full release
     61                     snapshot, such as files installed in DESTDIR/etc on the
     62                     destination system, boot media, and release notes.
     63 
     64      doc/BUILDING.mdoc
     65                     The source to this document, in mdoc(7) format.  Used to
     66                     generate BUILDING.
     67 
     68      external, sys/external
     69                     Sources and build infrastructure for components imported
     70                     (mostly) unchanged from upstream maintainers, sorted by
     71                     applicable license.  This is (slowly) replacing the
     72                     crypto/dist, dist, and gnu/dist directories.
     73 
     74      external/mit/xorg/
     75                     "Reachover" build structure for modular Xorg; the source
     76                     is in X11SRCDIR.
     77 
     78      mk.conf        Optional source tree specific mk.conf(5), used (if
     79                     present) instead of /etc/mk.conf unless MAKECONF is
     80                     defined.
     81 
     82                     Note: Not part of the NetBSD source repository.
     83 
     84      regress/, tests/
     85                     Regression test harness.  Can be cross-compiled, but only
     86                     run natively.  tests/ uses the atf(7) test framework;
     87                     regress/ contains older tests that have not yet been
     88                     migrated to atf(7).
     89 
     90      sys/           NetBSD kernel sources.
     91 
     92      tools/         "Reachover" build structure for the host build tools.
     93                     This has a special method of determining out-of-date
     94                     status.
     95 
     96      tools/compat/README
     97                     Special notes for cross-hosting a NetBSD build on non-
     98                     NetBSD platforms.
     99 
    100      Other directories including bin/ ... usr.sbin/
    101                     Sources to the NetBSD userland (non-kernel) programs.  If
    102                     any of these directories are missing, they will be skipped
    103                     during the build.
    104 
    105    Build tree layout
    106      The NetBSD build tree is described in hier(7) (whose mdoc(7) source is in
    107      share/man/man7/hier.7), and the release layout is described in release(7)
    108      (whose mdoc(7) source is in share/man/man7/release.7).
    109 
    110 CONFIGURATION
    111    Environment variables
    112      Several environment variables control the behaviour of NetBSD builds.
    113 
    114      HOST_CC         Path name to C compiler used to create the toolchain.
    115 
    116                      Default: "cc".
    117 
    118      HOST_CFLAGS     Flags passed to the host C compiler.
    119 
    120                      Default: "-O".
    121 
    122      HOST_CPPFLAGS   Flags passed to the host C/C++ pre-processor.
    123 
    124                      Default: Unset.
    125 
    126      HOST_CXX        Path name to C++ compiler used to create the toolchain.
    127 
    128                      Default: Unset, but defaults to "c++" where required.
    129 
    130      HOST_CXXFLAGS   Flags passed to the host C++ compiler.
    131 
    132                      Default: Unset.
    133 
    134      HOST_SH         Path name to a shell available on the host system and
    135                      suitable for use during the build.  The NetBSD build
    136                      system requires a modern Bourne-like shell with POSIX-
    137                      compliant features, and also requires support for the
    138                      "local" keyword to declare local variables in shell
    139                      functions (which is a widely-implemented but non-
    140                      standardised feature).
    141 
    142                      Depending on the host system, a suitable shell may be
    143                      /bin/sh, /usr/xpg4/bin/sh, /bin/ksh (provided it is a
    144                      variant of ksh that supports the "local" keyword, such as
    145                      ksh88, but not ksh93), or /usr/local/bin/bash.
    146 
    147                      Most parts of the build require HOST_SH to be an absolute
    148                      path; however, build.sh allows it to be a simple command
    149                      name, which will be converted to an absolute path by
    150                      searching the PATH.
    151 
    152                      Default: "sh".
    153 
    154      INSTALLBOOT_UBOOT_PATHS
    155                      A colon-separated list of search paths used by
    156                      installboot(8) to find U-Boot packages.
    157 
    158                      Default: Unset.
    159 
    160      MACHINE         Machine type, e.g., "macppc".
    161 
    162                      Default: Unset.
    163 
    164      MACHINE_ARCH    Machine architecture, e.g., "powerpc".
    165 
    166                      Default: Unset.
    167 
    168      MAKE            Path name to invoke make(1) as.
    169 
    170                      Default: "make".
    171 
    172      MAKECONF        The name of the make(1) configuration file.  See "make"
    173                      variables and mk.conf(5).
    174 
    175                      Note: Only settable in the process environment.
    176 
    177                      Default: "/etc/mk.conf", although build.sh will set the
    178                      default to the full path to mk.conf if the latter is
    179                      present in the same directory as build.sh.
    180 
    181      MAKEFLAGS       Flags to invoke make(1) with.
    182 
    183                      Note: build.sh ignores the value of MAKEFLAGS passed in
    184                      the environment, but allows MAKEFLAGS to be set via the
    185                      -V option.
    186 
    187                      Default: "-X" on systems with a small ARG_MAX (Cygwin,
    188                      Darwin, FreeBSD); otherwise unset.
    189 
    190      MAKEOBJDIR      Directory to use as the .OBJDIR for the current
    191                      directory.  The value is subjected to variable expansion
    192                      by make(1).  Typical usage is to set this variable to a
    193                      value involving the use of `${.CURDIR:S...}' or
    194                      `${.CURDIR:C...}', to derive the value of .OBJDIR from
    195                      the value of .CURDIR.  Used only if MAKEOBJDIRPREFIX is
    196                      not defined.
    197 
    198                      Note: MAKEOBJDIR can be provided only in the environment
    199                      or via the -O flag of build.sh; it cannot usefully be set
    200                      inside a Makefile, including in mk.conf(5) or MAKECONF.
    201 
    202                      Default: Unset.
    203 
    204      MAKEOBJDIRPREFIX
    205                      Top level directory of the object directory tree.  The
    206                      value is subjected to variable expansion by make(1).
    207                      build.sh will create the ${MAKEOBJDIRPREFIX} directory if
    208                      necessary, but if make(1) is used without build.sh, then
    209                      rules in <bsd.obj.mk> will abort the build if the
    210                      ${MAKEOBJDIRPREFIX} directory does not exist.  If the
    211                      value is defined and valid, then
    212                      ${MAKEOBJDIRPREFIX}/${.CURDIR} is used as the .OBJDIR for
    213                      the current directory.  The current directory may be read
    214                      only.
    215 
    216                      Note: MAKEOBJDIRPREFIX can be provided only in the
    217                      environment or via the -M flag of build.sh; it cannot
    218                      usefully be set inside a Makefile, including in
    219                      mk.conf(5) or MAKECONF.
    220 
    221                      Default: Unset.
    222 
    223      TMPDIR          Top-level directory to store temporary directories used
    224                      by build.sh before paths to other directories such as
    225                      .OBJDIR can be determined.
    226 
    227                      Note: Must support execution of binaries.  I.e., without
    228                      mount(8)'s -o noexec option.
    229 
    230                      Default: "/tmp".
    231 
    232    "make" variables
    233      Variables that control the behavior of NetBSD builds are documented in
    234      mk.conf(5) (whose mdoc(7) source is in share/man/man5/mk.conf.5).
    235 
    236      Unless otherwise specified, these variables may be set in either the
    237      process environment or the make(1) configuration file mk.conf(5)
    238      specified by MAKECONF.
    239 
    240 BUILDING
    241    "make" command line options
    242      This is not a summary of all the options available to make(1); only the
    243      options used most frequently with NetBSD builds are listed here.
    244 
    245      -j njob    Run up to njob make(1) subjobs in parallel.  Makefiles should
    246                 use .WAIT or have explicit dependencies as necessary to
    247                 enforce build ordering.
    248 
    249      -m dir     Specify the default directory for searching for system
    250                 Makefile segments, mainly the <bsd.*.mk> files.  When building
    251                 any full NetBSD source tree, this should be set to the
    252                 "share/mk" directory in the source tree.  This is set
    253                 automatically when building from the top level, or when using
    254                 build.sh.
    255 
    256      -n         Show the commands that would have been executed, but do not
    257                 actually execute them.  This will still cause recursion to
    258                 take place.
    259 
    260      -V var     Show make(1)'s idea of the value of var.  Does not build any
    261                 targets.
    262 
    263      var=value  Set the variable var to value, overriding any setting
    264                 specified by the process environment, the MAKECONF
    265                 configuration file, or the system Makefile segments.
    266 
    267    "make" targets
    268      These default targets may be built by running make(1) in any subtree of
    269      the NetBSD source code.  It is recommended that none of these be used
    270      from the top level Makefile; as a specific exception, "make obj" and
    271      "make cleandir" are useful in that context.
    272 
    273      all        Build programs, libraries, and preformatted documentation.
    274 
    275      clean      Remove program and library object code files.
    276 
    277      cleandir   Same as clean, but also remove preformatted documentation,
    278                 dependency files generated by "make depend", and any other
    279                 files known to be created at build time.
    280 
    281      depend     Create dependency files (.depend) containing more detailed
    282                 information about the dependencies of source code on header
    283                 files.  Allows programs to be recompiled automatically when a
    284                 dependency changes.
    285 
    286      dependall  Does a "make depend" immediately followed by a "make all".
    287                 This improves cache locality of the build since both passes
    288                 read the source files in their entirety.
    289 
    290      distclean  Synonym for cleandir.
    291 
    292      includes   Build and install system header files.  Typically needed
    293                 before any system libraries or programs can be built.
    294 
    295      install    Install programs, libraries, and documentation into DESTDIR.
    296                 Few files will be installed to DESTDIR/dev, DESTDIR/etc,
    297                 DESTDIR/root or DESTDIR/var in order to prevent user supplied
    298                 configuration data from being overwritten.
    299 
    300      lint       Run lint(1) against the C source code, where appropriate, and
    301                 generate system-installed lint libraries.
    302 
    303      obj        Create object directories to be used for built files, instead
    304                 of building directly in the source tree.
    305 
    306      tags       Create ctags(1) searchable function lists usable by the ex(1)
    307                 and vi(1) text editors.
    308 
    309    "make" targets for the top level
    310      Additional make(1) targets are usable specifically from the top source
    311      level to facilitate building the entire NetBSD source tree.
    312 
    313      build         Build the entire NetBSD system (except the kernel).  This
    314                    orders portions of the source tree such that prerequisites
    315                    will be built in the proper order.
    316 
    317      distribution  Do a "make build", and then install a full distribution
    318                    (which does not include a kernel) into DESTDIR, including
    319                    files in DESTDIR/dev, DESTDIR/etc, DESTDIR/root and
    320                    DESTDIR/var.
    321 
    322      buildworld    As per "make distribution", except that it ensures that
    323                    DESTDIR is not the root directory.
    324 
    325      installworld  Install the distribution from DESTDIR to INSTALLWORLDDIR,
    326                    which defaults to the root directory.  Ensures that
    327                    INSTALLWORLDDIR is not the root directory if cross
    328                    compiling.
    329 
    330                    The INSTALLSETS environment variable may be set to a space-
    331                    separated list of distribution sets to be installed.  By
    332                    default, all sets except "etc" and "xetc" are installed, so
    333                    most files in INSTALLWORLDDIR/etc will not be installed or
    334                    modified.
    335 
    336                    Note: Before performing this operation with
    337                    INSTALLWORLDDIR=/, it is highly recommended that you
    338                    upgrade your kernel and reboot.  After performing this
    339                    operation, it is recommended that you use etcupdate(8) to
    340                    update files in INSTALLWORLDDIR/etc, and postinstall(8) to
    341                    check for or fix inconsistencies.
    342 
    343      sets          Create distribution sets from DESTDIR into
    344                    RELEASEDIR/RELEASEMACHINEDIR/binary/sets.  Should be run
    345                    after "make distribution", as "make build" alone does not
    346                    install all of the required files.
    347 
    348      sourcesets    Create source sets of the source tree into
    349                    RELEASEDIR/source/sets.
    350 
    351      syspkgs       Create syspkgs from DESTDIR into
    352                    RELEASEDIR/RELEASEMACHINEDIR/binary/syspkgs.  Should be run
    353                    after "make distribution", as "make build" alone does not
    354                    install all of the required files.
    355 
    356      release       Do a "make distribution", build kernels, distribution
    357                    media, and install sets (this as per "make sets"), and then
    358                    package the system into a standard release layout as
    359                    described by release(7).  This requires that RELEASEDIR be
    360                    set (see above).
    361 
    362      iso-image     Create a NetBSD installation CD-ROM image in the
    363                    RELEASEDIR/images directory.  The CD-ROM file system will
    364                    have a layout as described in release(7).
    365 
    366                    For most machine types, the CD-ROM will be bootable, and
    367                    will automatically run the sysinst(8) menu-based
    368                    installation program, which can be used to install or
    369                    upgrade a NetBSD system.  Bootable CD-ROMs also contain
    370                    tools that may be useful in repairing a damaged NetBSD
    371                    installation.
    372 
    373                    Before "make iso-image" is attempted, RELEASEDIR must be
    374                    populated by "make release" or equivalent.
    375 
    376                    Note: Other, smaller, CD-ROM images may be created in the
    377                    RELEASEDIR/RELEASEMACHINEDIR/installation/cdrom directory
    378                    by "make release".  These smaller images usually contain
    379                    the same tools as the larger images in RELEASEDIR/images,
    380                    but do not contain additional content such as the
    381                    distribution sets.
    382 
    383                    Note: The mac68k port still uses an older method of
    384                    creating CD-ROM images.  This requires the mkisofs(1)
    385                    utility, which is not part of NetBSD, but which can be
    386                    installed from pkgsrc/sysutils/cdrtools.
    387 
    388      iso-image-source
    389                    Create a NetBSD installation CD-ROM image in the
    390                    RELEASEDIR/images directory.  The CD-ROM file system will
    391                    have a layout as described in release(7).  It will have top
    392                    level directories for the machine type and source.
    393 
    394                    For most machine types, the CD-ROM will be bootable, and
    395                    will automatically run the sysinst(8) menu-based
    396                    installation program, which can be used to install or
    397                    upgrade a NetBSD system.  Bootable CD-ROMs also contain
    398                    tools that may be useful in repairing a damaged NetBSD
    399                    installation.
    400 
    401                    Before "make iso-image-source" is attempted, RELEASEDIR
    402                    must be populated by "make sourcesets release" or
    403                    equivalent.
    404 
    405                    Note: Other, smaller, CD-ROM images may be created in the
    406                    RELEASEDIR/RELEASEMACHINEDIR/installation/cdrom directory
    407                    by "make release".  These smaller images usually contain
    408                    the same tools as the larger images in RELEASEDIR/images,
    409                    but do not contain additional content such as the
    410                    distribution sets.
    411 
    412                    Note: The mac68k port still uses an older method of
    413                    creating CD-ROM images.  This requires the mkisofs(1)
    414                    utility, which is not part of NetBSD, but which can be
    415                    installed from pkgsrc/sysutils/cdrtools.
    416 
    417      install-image
    418                    Create a bootable NetBSD installation disk image in the
    419                    RELEASEDIR/images directory.  The installation disk image
    420                    is suitable for copying to bootable USB flash memory
    421                    sticks, etc., for machines which are able to boot from such
    422                    devices.  The file system in the bootable disk image will
    423                    have a layout as described in release(7).
    424 
    425                    The installation image is bootable, and will automatically
    426                    run the sysinst(8) menu-based installation program, which
    427                    can be used to install or upgrade a NetBSD system.  The
    428                    image also contains tools that may be useful in repairing a
    429                    damaged NetBSD installation.
    430 
    431                    Before "make install-image" is attempted, RELEASEDIR must
    432                    be populated by "make release" or equivalent.  The build
    433                    must have been performed with MKUNPRIVED=yes because "make
    434                    install-image" relies on information in DESTDIR/METALOG.
    435 
    436      live-image    Create NetBSD live images in the RELEASEDIR/images
    437                    directory.  The live image contains all necessary files to
    438                    boot NetBSD up to multi-user mode, including all files
    439                    which should be extracted during installation, NetBSD
    440                    disklabel, bootloaders, etc.
    441 
    442                    The live image is suitable for use as a disk image in
    443                    virtual machine environments such as QEMU, and also useful
    444                    to boot NetBSD from a USB flash memory stick on a real
    445                    machine, without the need for installation.
    446 
    447                    Before "make live-image" is attempted, RELEASEDIR must be
    448                    populated by "make release" or equivalent.  The build must
    449                    have been performed with MKUNPRIVED=yes because "make
    450                    install-image" relies on information in DESTDIR/METALOG.
    451 
    452      regression-tests
    453                    Can only be run after building the regression tests in the
    454                    directory "regress".  Runs those compiled regression tests
    455                    on the local host.
    456 
    457                    Note: Most tests are now managed instead using atf(7); this
    458                    target should probably run those as well but currently does
    459                    not.
    460 
    461    The "build.sh" script
    462      This script file is a shell script designed to build the entire NetBSD
    463      system on any host with a suitable modern shell and some common
    464      utilities.  The required shell features are described under the HOST_SH
    465      variable.
    466 
    467      If a host system's default shell does support the required features, then
    468      we suggest that you explicitly specify a suitable shell using a command
    469      like
    470 
    471            /path/to/suitable/shell build.sh [options]
    472 
    473      The above command will usually enable build.sh to automatically set
    474      HOST_SH=/path/to/suitable/shell, but if that fails, then the following
    475      set of commands may be used instead:
    476 
    477            HOST_SH=/path/to/suitable/shell
    478            export HOST_SH
    479            ${HOST_SH} build.sh [options]
    480 
    481      If build.sh detects that it is being executed under an unsuitable shell,
    482      it attempts to exec a suitable shell instead, or shows an error message.
    483      If HOST_SH is not set explicitly, then build.sh sets a default using
    484      heuristics dependent on the host platform, or from the shell under which
    485      build.sh is executed (if that can be determined), or using the first copy
    486      of sh found in PATH.
    487 
    488      All cross-compile builds, and most native builds, of the entire system
    489      should make use of build.sh rather than just running "make".  This way,
    490      the make(1) program will be bootstrapped properly, in case the host
    491      system has an older or incompatible "make" program.
    492 
    493      When compiling the entire system via build.sh, many make(1) variables are
    494      set for you in order to help encapsulate the build process.  In the list
    495      of options below, variables that are automatically set by build.sh are
    496      noted where applicable.
    497 
    498      The following operations are supported by build.sh:
    499 
    500      build         Build the system as per "make build".  Before the main part
    501                    of the build commences, this command runs the obj operation
    502                    (unless the -o option is given), "make cleandir" (unless
    503                    the -u option is given), and the tools operation.
    504 
    505      distribution  Build a full distribution as per "make distribution".  This
    506                    command first runs the build operation.
    507 
    508      release       Build a full release as per "make release".  This command
    509                    first runs the distribution operation.
    510 
    511      help          Show a help message, and exit.
    512 
    513      makewrapper   Create the nbmake-MACHINE wrapper.  This operation is
    514                    automatically performed for any of the other operations.
    515 
    516      cleandir      Perform "make cleandir".
    517 
    518      obj           Perform "make obj".
    519 
    520      tools         Build and install the host tools from src/tools.  This
    521                    command will first run "make obj" and "make cleandir" in
    522                    the tools subdirectory unless the -o or -u options
    523                    (respectively) are given.
    524 
    525      install=idir  Install the contents of DESTDIR to idir, using "make
    526                    installworld".
    527 
    528                    Note: Files that are part of the "etc" or "xetc" sets will
    529                    not be installed, unless overridden by the INSTALLSETS
    530                    environment variable.
    531 
    532      kernel=kconf  Build a new kernel.  The kconf argument is the name of a
    533                    configuration file suitable for use by config(1).  If kconf
    534                    does not contain any `/' characters, the configuration file
    535                    is expected to be found in the KERNCONFDIR directory, which
    536                    is typically sys/arch/MACHINE/conf.  The new kernel will be
    537                    built in a subdirectory of KERNOBJDIR, which is typically
    538                    sys/arch/MACHINE/compile or an associated object directory.
    539 
    540                    This command does not imply the tools command; run the
    541                    tools command first unless it is certain that the tools
    542                    already exist and are up to date.
    543 
    544                    This command will run "make cleandir" on the kernel in
    545                    question first unless the -u option is given.
    546 
    547      kernel.gdb=kconf
    548                    Build a new kernel with debug information.  Similar to the
    549                    above kernel=kconf operation, but creates a netbsd.gdb file
    550                    alongside of the kernel netbsd, which contains a full
    551                    symbol table and can be used for debugging (for example
    552                    with a cross-gdb built by MKCROSSGDB).
    553 
    554      kernels       This command will build all kernels defined in port
    555                    specific release build procedure.
    556 
    557                    This command internally calls the kernel=kconf operation
    558                    for each found kernel configuration file.
    559 
    560      modules       This command will build kernel modules and install them
    561                    into DESTDIR.
    562 
    563      releasekernel=kconf
    564                    Install a gzip(1)ed copy of the kernel previously built by
    565                    kernel=kconf into
    566                    RELEASEDIR/RELEASEMACHINEDIR/binary/kernel, usually as
    567                    netbsd-kconf.gz, although the "netbsd" prefix is determined
    568                    from the "config" directives in kconf.
    569 
    570      sets          Perform "make sets".
    571 
    572      sourcesets    Perform "make sourcesets".
    573 
    574      syspkgs       Perform "make syspkgs".
    575 
    576      iso-image     Perform "make iso-image".
    577 
    578      iso-image-source
    579                    Perform "make iso-image-source".
    580 
    581      install-image
    582                    Perform "make install-image".
    583 
    584      live-image    Perform "make live-image".
    585 
    586      list-arch     Show a list of valid MACHINE and MACHINE_ARCH settings, the
    587                    default MACHINE_ARCH for each MACHINE, and aliases for
    588                    MACHINE/MACHINE_ARCH pairs, and then exits.  The -m or -a
    589                    options (or both) may be used to specify glob patterns that
    590                    will be used to narrow the list of results; for example,
    591                    "build.sh -m 'evb*' -a '*arm*' list-arch" will list all
    592                    known MACHINE/MACHINE_ARCH values in which either MACHINE
    593                    or ALIAS matches the pattern `evb*', and MACHINE_ARCH
    594                    matches the pattern `*arm*'.
    595 
    596      The following command line options alter the behaviour of the build.sh
    597      operations described above:
    598 
    599      -a arch   Set the value of MACHINE_ARCH to arch.  See the -m option for
    600                more information.
    601 
    602      -B buildid
    603                Set the value of BUILDID to buildid.  This will also append the
    604                build identifier to the name of the "make" wrapper script so
    605                that the resulting name is of the form
    606                "nbmake-MACHINE-BUILDID".
    607 
    608      -C cdextras
    609                Append cdextras to the CDEXTRA variable, which is a space-
    610                separated list of files or directories that will be added to
    611                the CD-ROM image that may be create by the "iso-image" or
    612                "iso-image-source" operations.  Files will be added to the root
    613                of the CD-ROM image, whereas directories will be copied
    614                recursively.  If relative paths are specified, they will be
    615                converted to absolute paths before being used.  Multiple paths
    616                may be specified via multiple -C options, or via a single
    617                option whose argument contains multiple space-separated paths.
    618 
    619      -c compiler
    620                Select the compiler for the toolchain to build NetBSD and for
    621                inclusion in the NetBSD distribution.  Supported choices:
    622 
    623                      clang
    624 
    625                      gcc [default]
    626 
    627                The compiler used to build the toolchain can be different; see
    628                HOST_CC and HOST_CXX.
    629 
    630      -D dest   Set the value of DESTDIR to dest.  If a relative path is
    631                specified, it will be converted to an absolute path before
    632                being used.
    633 
    634      -E        Set `expert' mode.  This overrides various sanity checks, and
    635                allows: DESTDIR does not have to be set to a non-root path for
    636                builds, and MKUNPRIVED=yes does not have to be set when
    637                building as a non-root user.
    638 
    639                Note: It is highly recommended that you know what you are doing
    640                when you use this option.
    641 
    642      -h        Show a help message, and exit.
    643 
    644      -j njob   Run up to njob make(1) subjobs in parallel; passed through to
    645                make(1).  If you see failures for reasons other than running
    646                out of memory while using build.sh with -j, please save
    647                complete build logs so the failures can be analyzed.
    648 
    649                To achieve the fastest builds, -j values between (1 + the
    650                number of CPUs) and (2 * the number of CPUs) are recommended.
    651                Use lower values on machines with limited memory or I/O
    652                bandwidth.
    653 
    654      -M obj    Set MAKEOBJDIRPREFIX to obj.  Unsets MAKEOBJDIR.  See "-O obj"
    655                for more information.
    656 
    657                For instance, if the source directory is /usr/src, a setting of
    658                "-M /usr/obj" will place build-time files under
    659                /usr/obj/usr/src/bin, /usr/obj/usr/src/lib,
    660                /usr/obj/usr/src/usr.bin, and so forth.
    661 
    662                If a relative path is specified, it will be converted to an
    663                absolute path before being used.  build.sh imposes the
    664                restriction that the argument to the -M option must not begin
    665                with a "$" (dollar sign) character; otherwise it would be too
    666                difficult to determine whether the value is an absolute or a
    667                relative path.  If the directory does not already exist,
    668                build.sh will create it.
    669 
    670      -m mach   Set the value of MACHINE to mach, unless the mach argument is
    671                an alias that refers to a MACHINE/MACHINE_ARCH pair, in which
    672                case both MACHINE and MACHINE_ARCH are set from the alias.
    673                Such aliases are interpreted entirely by build.sh; they are not
    674                used by any other part of the build system.  The MACHINE_ARCH
    675                setting implied by mach will override any value of MACHINE_ARCH
    676                in the process environment, but will not override a value set
    677                by the -a option.  All cross builds require -m, but if unset on
    678                a NetBSD host, the host's value of MACHINE will be detected and
    679                used automatically.
    680 
    681                See the list-arch operation for a way to get a list of valid
    682                MACHINE and MACHINE_ARCH settings.
    683 
    684      -N noiselevel
    685                Set the "noisyness" level of the build, by setting MAKEVERBOSE
    686                to noiselevel.
    687 
    688      -n        Show the commands that would be executed by build.sh, but do
    689                not make any changes.  This is similar in concept to "make -n".
    690 
    691      -O obj    Create an appropriate transform macro for MAKEOBJDIR that will
    692                place the built object files under obj.  Unsets
    693                MAKEOBJDIRPREFIX.
    694 
    695                For instance, a setting of "-O /usr/obj" will place build-time
    696                files under /usr/obj/bin, /usr/obj/lib, /usr/obj/usr.bin, and
    697                so forth.
    698 
    699                If a relative path is specified, it will be converted to an
    700                absolute path before being used.  build.sh imposes the
    701                restriction that the argument to the -O option must not contain
    702                a "$" (dollar sign) character.  If the directory does not
    703                already exist, build.sh will create it.
    704 
    705                In normal use, exactly one of the -M or -O options should be
    706                specified.  If neither -M nor -O is specified, then a default
    707                object directory will be chosen according to rules in
    708                <bsd.obj.mk>.  Relying on this default is not recommended
    709                because it is determined by complex rules that are influenced
    710                by the values of several variables and by the location of the
    711                source directory.
    712 
    713                Note: Placing the obj directory location outside of the default
    714                source tree hierarchy makes it easier to manually clear out old
    715                files in the event the "make cleandir" operation is unable to
    716                do so.  (See CAVEATS below.)
    717 
    718                Note: The use of one of -M or -O is the only means of building
    719                multiple machine architecture userlands from the same source
    720                tree without cleaning between builds (in which case, one would
    721                specify distinct obj locations for each).
    722 
    723      -o        Set the value of MKOBJDIRS to "no".  Otherwise, it will be
    724                automatically set to "yes".  This default is opposite to the
    725                behaviour when not using build.sh.
    726 
    727      -P        Set the value of MKREPRO and MKREPRO_TIMESTAMP to the latest
    728                source CVS timestamp for reproducible builds.
    729 
    730      -R rel    Set the value of RELEASEDIR to rel.  If a relative path is
    731                specified, it will be converted to an absolute path before
    732                being used.
    733 
    734      -r        Remove the contents of DESTDIR and TOOLDIR before building
    735                (provides a clean starting point).  This will skip deleting
    736                DESTDIR if building on a native system to the root directory.
    737 
    738      -S seed   Change the value of BUILDSEED to seed.  This should rarely be
    739                necessary.
    740 
    741      -T tools  Set the value of TOOLDIR to tools.  If a relative path is
    742                specified, it will be converted to an absolute path before
    743                being used.  If set, the bootstrap "make" will only be rebuilt
    744                if the source files for make(1) have changed.
    745 
    746      -U        Set MKUNPRIVED=yes.
    747 
    748      -u        Set MKUPDATE=yes.
    749 
    750      -V var=[value]
    751                Set the environment variable var to an optional value.  This is
    752                propagated to the nbmake wrapper.
    753 
    754      -w wrapper
    755                Create the nbmake wrapper script (see below) in a custom
    756                location, specified by wrapper.  This allows, for instance, to
    757                place the wrapper in PATH automatically.
    758 
    759                Note: wrapper is the full name of the file, not just a
    760                directory name.  If a relative path is specified, it will be
    761                converted to an absolute path before being used.
    762 
    763      -X x11src
    764                Set the value of X11SRCDIR to x11src.  If a relative path is
    765                specified, it will be converted to an absolute path before
    766                being used.
    767 
    768      -x        Set MKX11=yes.
    769 
    770      -Z var    Unset ("zap") the environment variable var.  This is propagated
    771                to the nbmake wrapper.
    772 
    773      -?        Show a help message, and exit.
    774 
    775    The "nbmake-MACHINE" wrapper script
    776      If using the build.sh script to build NetBSD, a nbmake-MACHINE script
    777      will be created in TOOLDIR/bin upon the first build to assist in building
    778      subtrees on a cross-compile host.
    779 
    780      nbmake-MACHINE can be invoked in lieu of make(1), and will instead call
    781      the up-to-date version of "nbmake" installed into TOOLDIR/bin with
    782      several key variables pre-set, including MACHINE, MACHINE_ARCH, and
    783      TOOLDIR.  nbmake-MACHINE will also set variables specified with -V, and
    784      unset variables specified with -Z.
    785 
    786      This script can be symlinked into a directory listed in PATH, or called
    787      with an absolute path.
    788 
    789 EXAMPLES
    790      1.   % ./build.sh [OPTIONS] tools kernel=GENERIC
    791 
    792           Build a new toolchain, and use the new toolchain to configure and
    793           build a new GENERIC kernel.
    794 
    795      2.   % ./build.sh [OPTIONS] -U distribution
    796 
    797           Using unprivileged mode, build a complete distribution to a DESTDIR
    798           directory that build.sh selects (and will show).
    799 
    800      3.   # ./build.sh [OPTIONS] -U install=/
    801 
    802           As root, install to / the distribution that was built by example 2.
    803           Even though this is run as root, -U is required so that the
    804           permissions stored in DESTDIR/METALOG are correctly applied to the
    805           files as they're copied to /.
    806 
    807      4.   % ./build.sh [OPTIONS] -U -u release
    808 
    809           Using unprivileged mode, build a complete release to DESTDIR and
    810           RELEASEDIR directories that build.sh selects (and will show).
    811           MKUPDATE=yes (-u) is set to prevent the "make cleandir", so that if
    812           this is run after example 2, it doesn't need to redo that portion of
    813           the release build.
    814 
    815 SEE ALSO
    816      config(1), ctags(1), ex(1), gzip(1), lint(1), make(1), mandoc(1),
    817      mkisofs(1), nroff(1), vi(1), mk.conf(5), atf(7), hier(7), mdoc(7),
    818      release(7), etcupdate(8), installboot(8), mount(8), postinstall(8),
    819      sysinst(8), pkgsrc/sysutils/cdrtools
    820 
    821      Note: The NetBSD manual pages are also available at
    822      https://man.netbsd.org
    823 
    824 HISTORY
    825      The build.sh based build scheme was introduced for NetBSD 1.6 as
    826      USE_NEW_TOOLCHAIN, and re-worked to TOOLCHAIN_MISSING after that.
    827 
    828 CAVEATS
    829      After significant updates to third-party components in the source tree,
    830      the "make cleandir" operation may be insufficient to clean out old files
    831      in object directories.  Instead, one may have to manually remove the
    832      files.  Consult the UPDATING file for notices concerning this.
    833 
    834 NetBSD                           July 18, 2023                          NetBSD
    835