BUILDING(8) System Manager's Manual BUILDING(8)

BUILDING(8) System Manager's Manual BUILDING(8)

NAME
BUILDING - Procedure for building NetBSD from source code

REQUIREMENTS
NetBSD is designed to be buildable on most POSIX-compliant host systems.
The basic build procedure is the same whether compiling natively (on the
same NetBSD architecture) or cross compiling (on another architecture or
OS).

This source tree contains the build.sh shell script which supports both
native and cross builds of NetBSD.

This source tree contains a special subtree, "tools", which uses the host
system to create a build toolchain for the target architecture. The host
system must have at least C and C++ compilers in order to create the
toolchain (make(1) is not required); all other tools (including make(1)
as nbmake) are created as part of the NetBSD build process. (See the
Environment variables section below if you need to override or manually
select your compilers.)

Note: Within this document, cross-references to manual pages are to the
NetBSD manual pages, not the host system manual pages. The mdoc(7)
source to the NetBSD manual pages can be found within the source tree,
and these and can be formatted with mandoc(1) or nroff(1) if those are
available on the host system. The NetBSD manual pages are also available
at https://man.netbsd.org

FILES
Source tree layout
BUILDING This document (in plaintext). Generated from
doc/BUILDING.mdoc.

Makefile The main Makefile for NetBSD; should only be run for
native builds with an appropriately up-to-date version of
NetBSD make(1). Intended for expert use with knowledge of
its shortcomings, it has been superseded by the build.sh
shell script as the recommended means for building NetBSD.

UPDATING Special notes for updating from an earlier revision of
NetBSD. It is important to read this file before every
build of an updated source tree.

build.sh Bourne-compatible shell script used for building the host
build tools and the NetBSD system from scratch. Can be
used for both native and cross builds, and should be used
instead of make(1) as it performs additional checks to
prevent common issues going undetected, such as building
with an outdated version of make(1).

crypto/dist/, dist/, gnu/dist/
Sources imported verbatim from third parties, without
mangling the existing build structure. Other source trees
in bin through usr.sbin use the NetBSD make(1) "reachover"
Makefile semantics when building these programs for a
native host.

distrib/, etc/
Sources for items used when making a full release
snapshot, such as files installed in DESTDIR/etc on the
destination system, boot media, and release notes.

doc/BUILDING.mdoc
The source to this document, in mdoc(7) format. Used to
generate BUILDING.

external/, sys/external/
Sources and build infrastructure for components imported
(mostly) unchanged from upstream maintainers, sorted by
applicable license. This is (slowly) replacing the
crypto/dist, dist, and gnu/dist directories.

external/mit/xorg/
"Reachover" build structure for modular Xorg; the source
is in X11SRCDIR.

mk.conf Optional source tree specific mk.conf(5), used (if
present) instead of /etc/mk.conf unless MAKECONF is
defined.

Note: Not part of the NetBSD source repository.

regress/, tests/
Regression test harness. Can be cross-compiled, but only
run natively. tests/ uses the atf(7) test framework;
regress/ contains older tests that have not yet been
migrated to atf(7).

sys/ NetBSD kernel sources.

tools/ "Reachover" build structure for the host build tools.
This has a special method of determining out-of-date
status.

tools/compat/README
Special notes for cross-hosting a NetBSD build on non-
NetBSD platforms.

Other directories including bin/ ... usr.sbin/
Sources to the NetBSD userland (non-kernel) programs. If
any of these directories are missing, they will be skipped
during the build.

Build tree layout
The NetBSD build tree is described in hier(7) (whose mdoc(7) source is in
share/man/man7/hier.7), and the release layout is described in release(7)
(whose mdoc(7) source is in share/man/man7/release.7).

CONFIGURATION
Environment variables
Several environment variables control the behaviour of NetBSD builds.

HOST_CC Path name to C compiler used to create the toolchain.

Default: "cc".

HOST_CFLAGS Flags passed to the host C compiler.

Default: "-O".

HOST_CPPFLAGS Flags passed to the host C/C++ pre-processor.

Default: Unset.

HOST_CXX Path name to C++ compiler used to create the toolchain.

Default: Unset, but defaults to "c++" where required.

HOST_CXXFLAGS Flags passed to the host C++ compiler.

Default: Unset.

HOST_SH Path name to a shell available on the host system and
suitable for use during the build. The NetBSD build
system requires a modern Bourne-like shell with POSIX-
compliant features, and also requires support for the
"local" keyword to declare local variables in shell
functions (which is a widely-implemented but non-
standardised feature).

Depending on the host system, a suitable shell may be
/bin/sh, /usr/xpg4/bin/sh, /bin/ksh (provided it is a
variant of ksh that supports the "local" keyword, such as
ksh88, but not ksh93), or /usr/local/bin/bash.

Most parts of the build require HOST_SH to be an absolute
path; however, build.sh allows it to be a simple command
name, which will be converted to an absolute path by
searching the PATH.

Default: "sh".

INSTALLBOOT_UBOOT_PATHS
A colon-separated list of search paths used by
installboot(8) to find U-Boot packages.

Default: Unset.

MACHINE Machine type, e.g., "macppc".

Default: Unset.

MACHINE_ARCH Machine architecture, e.g., "powerpc".

Default: Unset.

MAKE Path name to invoke make(1) as.

Default: "make".

MAKECONF The name of the make(1) configuration file. See make
variables and mk.conf(5).

Note: Only settable in the process environment.

Default: "/etc/mk.conf", although build.sh will set the
default to the full path to mk.conf if the latter is
present in the same directory as build.sh.

MAKEFLAGS Flags to invoke make(1) with.

Note: build.sh ignores the value of MAKEFLAGS passed in
the environment, but allows MAKEFLAGS to be set via the
-V option.

Default: "-X" on systems with a small ARG_MAX (Cygwin,
Darwin, FreeBSD); otherwise unset.

MAKEOBJDIR Directory to use as the .OBJDIR for the current
directory. The value is subjected to variable expansion
by make(1). Typical usage is to set this variable to a
value involving the use of `${.CURDIR:S...}' or
`${.CURDIR:C...}', to derive the value of .OBJDIR from
the value of .CURDIR. Used only if MAKEOBJDIRPREFIX is
not defined.

Note: MAKEOBJDIR can be provided only in the environment
or via the -O flag of build.sh; it cannot usefully be set
inside a Makefile, including in mk.conf(5) or MAKECONF.

Default: Unset.

MAKEOBJDIRPREFIX
Top level directory of the object directory tree. The
value is subjected to variable expansion by make(1).
build.sh will create the ${MAKEOBJDIRPREFIX} directory if
necessary, but if make(1) is used without build.sh, then
rules in <bsd.obj.mk> will abort the build if the
${MAKEOBJDIRPREFIX} directory does not exist. If the
value is defined and valid, then
${MAKEOBJDIRPREFIX}/${.CURDIR} is used as the .OBJDIR for
the current directory. The current directory may be read
only.

Note: MAKEOBJDIRPREFIX can be provided only in the
environment or via the -M flag of build.sh; it cannot
usefully be set inside a Makefile, including in
mk.conf(5) or MAKECONF.

Default: Unset.

TMPDIR Top-level directory to store temporary directories used
by build.sh before paths to other directories such as
.OBJDIR can be determined.

Note: Must support execution of binaries. I.e., without
mount(8)'s -o noexec option.

Default: "/tmp".

make variables
Variables that control the behavior of NetBSD builds are documented in
mk.conf(5) (whose mdoc(7) source is in share/man/man5/mk.conf.5).

Unless otherwise specified, these variables may be set in either the
process environment or the make(1) configuration file mk.conf(5)
specified by MAKECONF.

Note: Variables set in the environment, either directly or via build.sh
options to set specific values in the nbmake-MACHINE wrapper script do
not override variables set in the mk.conf(5) file. To allow variables in
mk.conf(5) to be overridden by the environment or build.sh options,
define the variables using the "?=" make(1) variable assignment operator.
For example,

MAKEVERBOSE?=1

The supported mk.conf(5) make variables are:

BSDOBJDIR, BSDSRCDIR, BUILD, BUILDID, BUILDINFO, BUILDSEED,
CDEXTRA, CONFIGOPTS, COPTS, CPUFLAGS, DESTDIR, EXTERNAL_TOOLCHAIN,
INSTALLBOOT_BOARDS, INSTALLWORLDDIR, KERNARCHDIR, KERNCONFDIR,
KERNEL_DIR, KERNOBJDIR, KERNSRCDIR, LOCALTIME, MAKEVERBOSE,
MKAMDGPUFIRMWARE, MKARGON2, MKARZERO, MKATF, MKBINUTILS, MKBSDGREP,
MKBSDTAR, MKCATPAGES, MKCLEANSRC, MKCLEANVERIFY, MKCOMPAT,
MKCOMPATMODULES, MKCOMPATTESTS, MKCOMPATX11, MKCOMPLEX, MKCROSSGDB,
MKCTF, MKCVS, MKCXX, MKDEBUG, MKDEBUGKERNEL, MKDEBUGLIB,
MKDEBUGTOOLS, MKDEPINCLUDES, MKDOC, MKDTB, MKDTC, MKDTRACE,
MKDYNAMICROOT, MKFIRMWARE, MKGCC, MKGCCCMDS, MKGDB, MKGROFF,
MKGROFFHTMLDOC, MKHESIOD, MKHOSTOBJ, MKHTML, MKIEEEFP, MKINET6,
MKINFO, MKIPFILTER, MKISCSI, MKKERBEROS, MKKMOD, MKKYUA, MKLDAP,
MKLIBCSANITIZER, MKLIBCXX, MKLIBSTDCXX, MKLINKLIB, MKLINT, MKLLVM,
MKLLVMRT, MKLVM, MKMAKEMANDB, MKMAN, MKMANDOC, MKMANZ, MKMDNS,
MKNLS, MKNOUVEAUFIRMWARE, MKNPF, MKNSD, MKOBJ, MKOBJDIRS, MKPAM,
MKPCC, MKPF, MKPIC, MKPICINSTALL, MKPICLIB, MKPIE, MKPIGZGZIP,
MKPOSTFIX, MKPROFILE, MKRADEONFIRMWARE, MKRELRO, MKREPRO,
MKREPRO_TIMESTAMP, MKRUMP, MKSANITIZER, MKSHARE, MKSKEY, MKSLJIT,
MKSOFTFLOAT, MKSTATICLIB, MKSTATICPIE, MKSTRIPIDENT, MKSTRIPSYM,
MKTEGRAFIRMWARE, MKTPM, MKUNBOUND, MKUNPRIVED, MKUPDATE, MKX11,
MKX11FONTS, MKX11MOTIF, MKXORG_SERVER, MKYP, MKZFS, NETBSDSRCDIR,
NETBSD_OFFICIAL_RELEASE, NOCLEANDIR, NODISTRIBDIRS, NOINCLUDES,
OBJMACHINE, RELEASEDIR, RUMPUSER_THREADS, RUMP_CURLWP, RUMP_DEBUG,
RUMP_DIAGNOSTIC, RUMP_KTRACE, RUMP_LOCKDEBUG, RUMP_LOCKS_UP,
RUMP_NBCOMPAT, RUMP_VIRTIF, RUMP_VNODE_LOCKDEBUG,
TOOLCHAIN_MISSING, TOOLDIR, USETOOLS, USE_FORT, USE_HESIOD,
USE_INET6, USE_JEMALLOC, USE_KERBEROS, USE_LDAP, USE_LIBCSANITIZER,
USE_PAM, USE_PIGZGZIP, USE_SANITIZER, USE_SKEY, USE_SSP,
USE_XZ_SETS, USE_YP, X11MOTIFPATH, X11SRCDIR.

The obsolete mk.conf(5) make variables are:

EXTSRCSRCDIR, MKBFD, MKCRYPTO, MKEXTSRC, MKKDEBUG, MKKERBEROS4,
MKLLD, MKLLDB, MKMCLINKER, MKPERFUSE, MKTOOLSDEBUG, NBUILDJOBS,
SHAREDSTRINGS, USE_COMBINE, USE_NEW_TOOLCHAIN.

BUILDING
make command line options
This is not a summary of all the options available to make(1); only the
options used most frequently with NetBSD builds are listed here.

-j njob Run up to njob make(1) subjobs in parallel. Makefiles should
use .WAIT or have explicit dependencies as necessary to
enforce build ordering.

-m dir Specify the default directory for searching for system
Makefile segments, mainly the <bsd.*.mk> files. When building
any full NetBSD source tree, this should be set to the
"share/mk" directory in the source tree. This is set
automatically when building from the top level, or when using
build.sh.

-n Show the commands that would have been executed, but do not
actually execute them. This will still cause recursion to
take place.

-V var Show make(1)'s idea of the value of var. Does not build any
targets.

var=value Set the variable var to value, overriding any setting
specified by the process environment, the MAKECONF
configuration file, or the system Makefile segments.

make targets
These default targets may be built by running make(1) in any subtree of
the NetBSD source code. It is recommended that none of these be used
from the top level Makefile; as a specific exception, "make obj" and
"make cleandir" are useful in that context.

all Build programs, libraries, and preformatted documentation.

clean Remove program and library object code files.

cleandir Same as clean, but also remove preformatted documentation,
dependency files generated by "make depend", and any other
files known to be created at build time.

depend Create dependency files (.depend) containing more detailed
information about the dependencies of source code on header
files. Allows programs to be recompiled automatically when a
dependency changes.

dependall Does a "make depend" immediately followed by a "make all".
This improves cache locality of the build since both passes
read the source files in their entirety.

distclean Synonym for cleandir.

includes Build and install system header files. Typically needed
before any system libraries or programs can be built.

install Install programs, libraries, and documentation into DESTDIR.
Few files will be installed to DESTDIR/dev, DESTDIR/etc,
DESTDIR/root or DESTDIR/var in order to prevent user supplied
configuration data from being overwritten.

lint Run lint(1) against the C source code, where appropriate, and
generate system-installed lint libraries.

obj Create object directories to be used for built files, instead
of building directly in the source tree.

tags Create ctags(1) searchable function lists usable by the ex(1)
and vi(1) text editors.

make targets for the top level
Additional make(1) targets are usable specifically from the top source
level to facilitate building the entire NetBSD source tree.

build Build the entire NetBSD system (except the kernel). This
orders portions of the source tree such that prerequisites
will be built in the proper order.

distribution Do a "make build", and then install a full distribution
(which does not include a kernel) into DESTDIR, including
files in DESTDIR/dev, DESTDIR/etc, DESTDIR/root and
DESTDIR/var.

buildworld As per "make distribution", except that it ensures that
DESTDIR is not the root directory.

installworld Install the distribution from DESTDIR to INSTALLWORLDDIR,
which defaults to the root directory. Ensures that
INSTALLWORLDDIR is not the root directory if cross
compiling.

The INSTALLSETS environment variable may be set to a space-
separated list of distribution sets to be installed. By
default, all sets except "etc" and "xetc" are installed, so
most files in INSTALLWORLDDIR/etc will not be installed or
modified.

Note: Before performing this operation with
INSTALLWORLDDIR=/, it is highly recommended that you
upgrade your kernel and reboot. After performing this
operation, it is recommended that you use etcupdate(8) to
update files in INSTALLWORLDDIR/etc, and postinstall(8) to
check for or fix inconsistencies.

sets Create distribution sets from DESTDIR into
RELEASEDIR/RELEASEMACHINEDIR/binary/sets. Should be run
after "make distribution", as "make build" alone does not
install all of the required files.

sourcesets Create source sets of the source tree into
RELEASEDIR/source/sets.

syspkgs Create syspkgs from DESTDIR into
RELEASEDIR/RELEASEMACHINEDIR/binary/syspkgs. Should be run
after "make distribution", as "make build" alone does not
install all of the required files.

release Do a "make distribution", build kernels, distribution
media, and install sets (this as per "make sets"), and then
package the system into a standard release layout as
described by release(7). This requires that RELEASEDIR be
set (see above).

iso-image Create a NetBSD installation CD-ROM image in the
RELEASEDIR/images directory. The CD-ROM file system will
have a layout as described in release(7).

For most machine types, the CD-ROM will be bootable, and
will automatically run the sysinst(8) menu-based
installation program, which can be used to install or
upgrade a NetBSD system. Bootable CD-ROMs also contain
tools that may be useful in repairing a damaged NetBSD
installation.

Before "make iso-image" is attempted, RELEASEDIR must be
populated by "make release" or equivalent.

Note: Other, smaller, CD-ROM images may be created in the
RELEASEDIR/RELEASEMACHINEDIR/installation/cdrom directory
by "make release". These smaller images usually contain
the same tools as the larger images in RELEASEDIR/images,
but do not contain additional content such as the
distribution sets.

Note: The mac68k port still uses an older method of
creating CD-ROM images. This requires the mkisofs(1)
utility, which is not part of NetBSD, but which can be
installed from pkgsrc/sysutils/cdrtools.

iso-image-source
Create a NetBSD installation CD-ROM image in the
RELEASEDIR/images directory. The CD-ROM file system will
have a layout as described in release(7). It will have top
level directories for the machine type and source.

For most machine types, the CD-ROM will be bootable, and
will automatically run the sysinst(8) menu-based
installation program, which can be used to install or
upgrade a NetBSD system. Bootable CD-ROMs also contain
tools that may be useful in repairing a damaged NetBSD
installation.

Before "make iso-image-source" is attempted, RELEASEDIR
must be populated by "make sourcesets release" or
equivalent.

Note: Other, smaller, CD-ROM images may be created in the
RELEASEDIR/RELEASEMACHINEDIR/installation/cdrom directory
by "make release". These smaller images usually contain
the same tools as the larger images in RELEASEDIR/images,
but do not contain additional content such as the
distribution sets.

Note: The mac68k port still uses an older method of
creating CD-ROM images. This requires the mkisofs(1)
utility, which is not part of NetBSD, but which can be
installed from pkgsrc/sysutils/cdrtools.

install-image
Create a bootable NetBSD installation disk image in the
RELEASEDIR/images directory. The installation disk image
is suitable for copying to bootable USB flash memory
sticks, etc., for machines which are able to boot from such
devices. The file system in the bootable disk image will
have a layout as described in release(7).

The installation image is bootable, and will automatically
run the sysinst(8) menu-based installation program, which
can be used to install or upgrade a NetBSD system. The
image also contains tools that may be useful in repairing a
damaged NetBSD installation.

Before "make install-image" is attempted, RELEASEDIR must
be populated by "make release" or equivalent. The build
must have been performed with MKUNPRIVED=yes because "make
install-image" relies on information in DESTDIR/METALOG.

live-image Create NetBSD live images in the RELEASEDIR/images
directory. The live image contains all necessary files to
boot NetBSD up to multi-user mode, including all files
which should be extracted during installation, NetBSD
disklabel, bootloaders, etc.

The live image is suitable for use as a disk image in
virtual machine environments such as QEMU, and also useful
to boot NetBSD from a USB flash memory stick on a real
machine, without the need for installation.

Before "make live-image" is attempted, RELEASEDIR must be
populated by "make release" or equivalent. The build must
have been performed with MKUNPRIVED=yes because "make
install-image" relies on information in DESTDIR/METALOG.

regression-tests
Can only be run after building the regression tests in the
directory "regress". Runs those compiled regression tests
on the local host.

Note: Most tests are now managed instead using atf(7); this
target should probably run those as well but currently does
not.

The build.sh script
This script file is a shell script designed to build the entire NetBSD
system on any host with a suitable modern shell and some common
utilities. The required shell features are described under the HOST_SH
variable.

If a host system's default shell does support the required features, then
we suggest that you explicitly specify a suitable shell using a command
like

/path/to/suitable/shell build.sh [options]

The above command will usually enable build.sh to automatically set
HOST_SH=/path/to/suitable/shell, but if that fails, then the following
set of commands may be used instead:

HOST_SH=/path/to/suitable/shell
export HOST_SH
${HOST_SH} build.sh [options]

If build.sh detects that it is being executed under an unsuitable shell,
it attempts to exec a suitable shell instead, or shows an error message.
If HOST_SH is not set explicitly, then build.sh sets a default using
heuristics dependent on the host platform, or from the shell under which
build.sh is executed (if that can be determined), or using the first copy
of sh found in PATH.

All cross-compile builds, and most native builds, of the entire system
should make use of build.sh rather than just running "make". This way,
the make(1) program will be bootstrapped properly, in case the host
system has an older or incompatible "make" program.

When compiling the entire system via build.sh, many make(1) variables are
set for you in order to help encapsulate the build process. In the list
of options below, variables that are automatically set by build.sh are
noted where applicable.

The following operations are supported by build.sh:

build Build the system as per "make build". Before the main part
of the build commences, this command runs the obj operation
(unless the -o option is given), "make cleandir" (unless
the -u option is given), and the tools operation.

distribution Build a full distribution as per "make distribution". This
command first runs the build operation.

release Build a full release as per "make release". This command
first runs the distribution operation.

help Show a help message, and exit.

makewrapper Create the nbmake-MACHINE wrapper script. This operation
is automatically performed for any of the other operations.

cleandir Perform "make cleandir".

obj Perform "make obj".

tools Build and install the host tools from src/tools. This
command will first run "make obj" and "make cleandir" in
the tools subdirectory unless the -o or -u options
(respectively) are given.

install=idir Install the contents of DESTDIR to idir, using "make
installworld".

Note: Files that are part of the "etc" or "xetc" sets will
not be installed, unless overridden by the INSTALLSETS
environment variable.

kernel=kconf Build a new kernel. The kconf argument is the name of a
configuration file suitable for use by config(1). If kconf
does not contain any `/' characters, the configuration file
is expected to be found in the KERNCONFDIR directory, which
is typically sys/arch/MACHINE/conf. The new kernel will be
built in a subdirectory of KERNOBJDIR, which is typically
sys/arch/MACHINE/compile or an associated object directory.

This command does not imply the tools command; run the
tools command first unless it is certain that the tools
already exist and are up to date.

This command will run "make cleandir" on the kernel in
question first unless the -u option is given.

kernel.gdb=kconf
Build a new kernel with debug information. Similar to the
above kernel=kconf operation, but creates a netbsd.gdb file
alongside of the kernel netbsd, which contains a full
symbol table and can be used for debugging (for example
with a cross-gdb built by MKCROSSGDB).

kernels This command will build all kernels defined in port
specific release build procedure.

This command internally calls the kernel=kconf operation
for each found kernel configuration file.

modules This command will build kernel modules and install them
into DESTDIR.

releasekernel=kconf
Install a gzip(1)ed copy of the kernel previously built by
kernel=kconf into
RELEASEDIR/RELEASEMACHINEDIR/binary/kernel, usually as
netbsd-kconf.gz, although the "netbsd" prefix is determined
from the "config" directives in kconf.

sets Perform "make sets".

sourcesets Perform "make sourcesets".

syspkgs Perform "make syspkgs".

iso-image Perform "make iso-image".

iso-image-source
Perform "make iso-image-source".

install-image
Perform "make install-image".

live-image Perform "make live-image".

list-arch Show a list of valid MACHINE and MACHINE_ARCH settings, the
default MACHINE_ARCH for each MACHINE, and aliases for
MACHINE/MACHINE_ARCH pairs, and then exits. The -m or -a
options (or both) may be used to specify glob patterns that
will be used to narrow the list of results; for example,
"build.sh -m 'evb*' -a '*arm*' list-arch" will list all
known MACHINE/MACHINE_ARCH values in which either MACHINE
or ALIAS matches the pattern `evb*', and MACHINE_ARCH
matches the pattern `*arm*'.

The following command line options alter the behaviour of the build.sh
operations described above:

-a arch Set the value of MACHINE_ARCH to arch. See the -m option for
more information.

-B buildid
Set the value of BUILDID to buildid. This will also append the
build identifier to the name of the nbmake-MACHINE wrapper
script so that the resulting name is of the form
"nbmake-MACHINE-BUILDID".

-C cdextras
Append cdextras to the CDEXTRA variable, which is a space-
separated list of files or directories that will be added to
the CD-ROM image that may be create by the "iso-image" or
"iso-image-source" operations. Files will be added to the root
of the CD-ROM image, whereas directories will be copied
recursively. If relative paths are specified, they will be
converted to absolute paths before being used. Multiple paths
may be specified via multiple -C options, or via a single
option whose argument contains multiple space-separated paths.

-c compiler
Select the compiler for the toolchain to build NetBSD and for
inclusion in the NetBSD distribution. Supported choices:

clang

gcc [default]

The compiler used to build the toolchain can be different; see
HOST_CC and HOST_CXX.

-D dest Set the value of DESTDIR to dest. If a relative path is
specified, it will be converted to an absolute path before
being used.

-E Set `expert' mode. This overrides various sanity checks, and
allows: DESTDIR does not have to be set to a non-root path for
builds, and MKUNPRIVED=yes does not have to be set when
building as a non-root user.

Note: It is highly recommended that you know what you are doing
when you use this option.

-h Show a help message, and exit.

-j njob Run up to njob make(1) subjobs in parallel; passed through to
make(1). If you see failures for reasons other than running
out of memory while using build.sh with -j, please save
complete build logs so the failures can be analyzed.

To achieve the fastest builds, -j values between (1 + the
number of CPUs) and (2 * the number of CPUs) are recommended.
Use lower values on machines with limited memory or I/O
bandwidth.

-M obj Set MAKEOBJDIRPREFIX to obj. Unsets MAKEOBJDIR. See "-O obj"
for more information.

For instance, if the source directory is /usr/src, a setting of
"-M /usr/obj" will place build-time files under
/usr/obj/usr/src/bin, /usr/obj/usr/src/lib,
/usr/obj/usr/src/usr.bin, and so forth.

If a relative path is specified, it will be converted to an
absolute path before being used. build.sh imposes the
restriction that the argument to the -M option must not begin
with a "$" (dollar sign) character; otherwise it would be too
difficult to determine whether the value is an absolute or a
relative path. If the directory does not already exist,
build.sh will create it.

-m mach Set the value of MACHINE to mach, unless the mach argument is
an alias that refers to a MACHINE/MACHINE_ARCH pair, in which
case both MACHINE and MACHINE_ARCH are set from the alias.
Such aliases are interpreted entirely by build.sh; they are not
used by any other part of the build system. The MACHINE_ARCH
setting implied by mach will override any value of MACHINE_ARCH
in the process environment, but will not override a value set
by the -a option. All cross builds require -m, but if unset on
a NetBSD host, the host's value of MACHINE will be detected and
used automatically.

See the list-arch operation for a way to get a list of valid
MACHINE and MACHINE_ARCH settings.

-N noiselevel
Set the "noisiness" level of the build, by setting MAKEVERBOSE
to noiselevel.

-n Show the commands that would be executed by build.sh, but do
not make any changes. This is similar in concept to "make -n".

-O obj Create an appropriate transform macro for MAKEOBJDIR that will
place the built object files under obj. Unsets
MAKEOBJDIRPREFIX.

For instance, a setting of "-O /usr/obj" will place build-time
files under /usr/obj/bin, /usr/obj/lib, /usr/obj/usr.bin, and
so forth.

If a relative path is specified, it will be converted to an
absolute path before being used. build.sh imposes the
restriction that the argument to the -O option must not contain
a "$" (dollar sign) character. If the directory does not
already exist, build.sh will create it.

In normal use, exactly one of the -M or -O options should be
specified. If neither -M nor -O is specified, then a default
object directory will be chosen according to rules in
<bsd.obj.mk>. Relying on this default is not recommended
because it is determined by complex rules that are influenced
by the values of several variables and by the location of the
source directory.

Note: Placing the obj directory location outside of the default
source tree hierarchy makes it easier to manually clear out old
files in the event the "make cleandir" operation is unable to
do so. (See CAVEATS below.)

Note: The use of one of -M or -O is the only means of building
multiple machine architecture userlands from the same source
tree without cleaning between builds (in which case, one would
specify distinct obj locations for each).

-o Set the value of MKOBJDIRS to "no". Otherwise, it will be
automatically set to "yes". This default is opposite to the
behaviour when not using build.sh.

-P Set the value of MKREPRO and MKREPRO_TIMESTAMP to the latest
source CVS timestamp for reproducible builds.

-R rel Set the value of RELEASEDIR to rel. If a relative path is
specified, it will be converted to an absolute path before
being used.

-r Remove the contents of DESTDIR and TOOLDIR before building
(provides a clean starting point). This will skip deleting
DESTDIR if building on a native system to the root directory.

-S seed Change the value of BUILDSEED to seed. This should rarely be
necessary.

-T tools Set the value of TOOLDIR to tools. If a relative path is
specified, it will be converted to an absolute path before
being used. If set, the bootstrap "make" will only be rebuilt
if the source files for make(1) have changed.

-U Set MKUNPRIVED=yes.

-u Set MKUPDATE=yes.

-V var=[value]
Set the environment variable var to an optional value. This is
propagated to the nbmake-MACHINE wrapper script.

-w wrapper
Create the nbmake-MACHINE wrapper script (see below) in a
custom location, specified by wrapper. This allows, for
instance, to place the wrapper script in PATH automatically.

Note: wrapper is the full name of the file, not just a
directory name. If a relative path is specified, it will be
converted to an absolute path before being used.

-X x11src
Set the value of X11SRCDIR to x11src. If a relative path is
specified, it will be converted to an absolute path before
being used.

-x Set MKX11=yes.

-Z var Unset ("zap") the environment variable var. This is propagated
to the nbmake-MACHINE wrapper script.

-? Show a help message, and exit.

The nbmake-MACHINE wrapper script
If using the build.sh script to build NetBSD, a nbmake-MACHINE wrapper
script will be created in TOOLDIR/bin upon the first build to assist in
building subtrees on a cross-compile host.

The nbmake-MACHINE wrapper script can be invoked in lieu of make(1), and
will instead call the up-to-date version of "nbmake" installed into
TOOLDIR/bin with several key variables pre-set, including MACHINE,
MACHINE_ARCH, and TOOLDIR. nbmake-MACHINE will also set variables
specified with -V, and unset variables specified with -Z. Note that by
default these variables will not override mk.conf(5); see make variables
for more details.

This wrapper script can be symlinked into a directory listed in PATH, or
called with an absolute path.

EXAMPLES
1. % ./build.sh [OPTIONS] tools kernel=GENERIC

Build a new toolchain, and use the new toolchain to configure and
build a new GENERIC kernel.

2. % ./build.sh [OPTIONS] -U distribution

Using unprivileged mode, build a complete distribution to a DESTDIR
directory that build.sh selects (and will show).

3. # ./build.sh [OPTIONS] -U install=/

As root, install to / the distribution that was built by example 2.
Even though this is run as root, -U is required so that the
permissions stored in DESTDIR/METALOG are correctly applied to the
files as they're copied to /.

4. % ./build.sh [OPTIONS] -U -u release

Using unprivileged mode, build a complete release to DESTDIR and
RELEASEDIR directories that build.sh selects (and will show).
MKUPDATE=yes (-u) is set to prevent the "make cleandir", so that if
this is run after example 2, it doesn't need to redo that portion of
the release build.

SEE ALSO
config(1), ctags(1), ex(1), gzip(1), lint(1), make(1), mandoc(1),
mkisofs(1), nroff(1), vi(1), mk.conf(5), atf(7), hier(7), mdoc(7),
release(7), etcupdate(8), installboot(8), mount(8), postinstall(8),
sysinst(8), pkgsrc/sysutils/cdrtools

Note: The NetBSD manual pages are also available at
https://man.netbsd.org

HISTORY
The build.sh based build scheme was introduced for NetBSD 1.6 as
USE_NEW_TOOLCHAIN, and re-worked to TOOLCHAIN_MISSING after that.

CAVEATS
After significant updates to third-party components in the source tree,
the "make cleandir" operation may be insufficient to clean out old files
in object directories. Instead, one may have to manually remove the
files. Consult the UPDATING file for notices concerning this.

NetBSD July 21, 2023 NetBSD