RELEASE(7) FreeBSD Miscellaneous Information Manual RELEASE(7)
NAME
release - release building infrastructure
DESCRIPTION
FreeBSD provides a complete build environment suitable for users to make
full releases of the FreeBSD operating system. All of the tools
necessary to build a release are available from the FreeBSD source code
repository in src/release. A complete release can be built with only a
single command, including the creation of ISO images suitable for burning
to CD-ROM, memory stick images, and a network install directory. This
command is aptly named "make release".
For some users, it may be desirable to provide an absolutely clean build
environment, with no local modifications to the source tree or to
make.conf(5), and with clean checkouts of specific versions of the doc,
src, and ports trees. For this purpose, a script
(src/release/release.sh) is provided to automate these checkouts and then
execute "make release" in a clean chroot(8).
Before attempting to build a release, the user is expected to be familiar
with the contents of build(7), and should have experience upgrading
systems from source.
The release build process requires that /usr/obj be populated with the
output of "make buildworld" and "make buildkernel". This is necessary to
provide the object files for the release or, when using release.sh, so
that the object files for a complete system can be installed into a clean
chroot(8) environment.
If the target release build is for a different architecture or machine
type, the TARGET and TARGET_ARCH variables must be used. See the
supported release.conf variables for more information.
The release procedure on some architectures may also require that the
md(4) (memory disk) device driver be present in the kernel (either by
being compiled in or available as a module).
This document does not cover source code management, quality assurance,
or other aspects of the release engineering process.
CLEAN RELEASE GENERATION
Official releases of FreeBSD are produced in a clean environment to
ensure consistency between the versions of the src, ports, and doc trees
and to avoid contamination from the host system (such as local patches,
changes to make.conf(5), etc.). This is accomplished using the wrapper
script src/release/release.sh.
release.sh [-c release.conf]
release.sh checks out the src/, ports/, and doc/ trees to CHROOTDIR, then
calls "make buildworld" and "make installworld" to generate a chroot(8)
environment. Next, "make release" is run within the chroot(8)
environment and places the result in $CHROOTDIR/R.
The optional release.conf configuration file supports the following
variables:
CHROOTDIR The directory within which the release will be built.
Defaults to /scratch.
CHROOT_MAKEENV Additional make(1) arguments to pass through, which
directly affect the tuning of the build chroot.
NOGIT Do not explicitly require the git(1) port to be
installed.
GITROOT The git(1) host used to check out the various trees.
Defaults to https://git.FreeBSD.org.
SRCBRANCH The src/ branch to use. Defaults to -b main.
PORTBRANCH The ports/ branch to use. Defaults to head/@rHEAD.
TARGET The target machine type for cross-building a release.
TARGET_ARCH The target machine architecture for cross-building a
release.
For the supported list of TARGET and TARGET_ARCH
combinations, consult the output of "make targets" as
documented in build(7).
KERNEL The target kernel configuration to use. Defaults to
GENERIC. Multiple KERNEL entries may be specified.
MAKE_CONF The make.conf(5) to use for the release build. Defaults
to /dev/null to prevent polluting the release with local
system changes.
SRC_CONF The src.conf(5) to use for the release build. Defaults
to /dev/null to prevent polluting the release with local
system changes.
MAKE_FLAGS Additional flags to pass to make(1).
WORLD_FLAGS Additional flags to pass to make(1) during the
"buildworld" phase. Defaults to setting the number of
make(1) jobs (-j) to the number of CPUs available on a
SMP-capable system.
KERNEL_FLAGS Additional flags to pass to make(1) during the
"buildkernel" phase. Defaults to setting the number of
make(1) jobs (-j) to half the number of CPUs available
on a SMP-capable system.
NOPORTS Set to a non-empty value to skip the ports/ tree
checkout. When set, NOPORTS will prevent the ports.txz
distribution package from being created.
WITH_DVD Set to a non-empty value to include the dvdrom target.
WITH_COMPRESSED_IMAGES
Set to a non-empty value to compress the release images
with xz(1). The original (uncompressed) images are not
removed.
XZ_THREADS (int)
Set to the number of threads xz(1) should use when
compressing images. By default, XZ_THREADS is set to 0,
which uses all available cores on the system.
VCSCMD The command run to obtain the source trees. Defaults to
"git clone -q".
CHROOTBUILD_SKIP
If defined, the buildworld, installworld, and
distribution stages of the chroot(8) build environment
setup are skipped. This is intended solely for cases
where the chroot(8) userland are provided by alternate
means.
SRC_UPDATE_SKIP Set to a non-empty value to prevent checkout or update
of /usr/src within the chroot(8). This is intended for
use only when /usr/src is expected to exist by
alternative means.
PORTS_UPDATE_SKIP
Set to a non-empty value to prevent checkout or update
of /usr/ports within the chroot(8). This is intended
for use only when /usr/ports is expected to exist by
alternative means.
PKGBASE Include base system packages for use with pkg(8) on the
install media, instead of legacy tarball distribution
sets.
PKG_CMD A path to the pkg(8) executable to use when installing
packages in release images as a non-root user.
PKG_REPOS_DIR An optional path to a directory containing pkg(8)
repository configuration files. These configuration
files will be used when installing packages in release
images as a non-root user.
PKG_REPO_NAME The name of the repository configuration to use when
installing packages in release images as a non-root
user.
EMBEDDED BUILDS
The following release.conf variables are relevant only to release builds
for embedded systems:
EMBEDDEDBUILD Set to a non-null value to enable functionality for
embedded device release builds.
When set, WITH_DVD is unset. Additionally,
EMBEDDED_TARGET and EMBEDDED_TARGET_ARCH must also be
defined. When the build environment is created,
release.sh runs a separate build script located in an
architecture-specific directory in
src/release/${EMBEDDED_TARGET}/.
EMBEDDEDPORTS Set to the list of any ports that are required for the
target device in the format of category/port.
EMBEDDED_TARGET When set, its value is passed to make(1) to set the
TARGET (value of uname -m) to cross build the target
userland.
EMBEDDED_TARGET_ARCH
When set, its value is passed to make(1) to set the
TARGET_ARCH (value of uname -p) to cross build the
target userland.
VIRTUAL MACHINE DISK IMAGES
The following release.conf variables are relevant only to virtual machine
disk image builds:
WITH_VMIMAGES Set to a non-null value to build virtual machine disk
images as part of the release build. WITH_VMIMAGES may
also be specified as an environment variable passed to
make(1).
WITH_COMPRESSED_VMIMAGES
Set to a non-null value to compress the virtual machine
disk images with xz(1) as part of the install make(1)
target. Note that compressing virtual machine disk
images may take a very long time on some systems.
VMBASE Set to change the name of the resulting virtual machine
disk image file. The default value is vm.
VMSIZE Set to change the size of the virtual machine disk
capacity. The default value is 20g. See makefs(8) for
valid values.
Virtual machine disk images are, by default, created as
sparse images. When WITH_COMPRESSED_VMIMAGES is used,
the resulting files compressed with xz(1) compress to
roughly the same size, regardless of the specified disk
image size.
VMFS (Deprecated.) Set to specify which of the filesystem(s)
listed in VMFSLIST is linked to the historical non-
filesystem-labelled file name. Valid values are ufs and
zfs. The default value is ufs.
VMFSLIST Set to specify the list of file system types to build
images for. Valid values are one or both of ufs and
zfs. The default value is ufs zfs.
VMFORMATS Set to the target virtual disk image format(s) to
create. By default, the vhdf, vmdk, qcow2, and raw
formats are created. See mkimg(1) for valid format
values.
For a list of supported VMFORMATS values (including cloud hosting
provider formats) along with a brief description, run:
cd /usr/src
make -C release list-vmtargets
CLOUD HOSTING MACHINE IMAGES
The FreeBSD release build tools support building virtual machine images
for various cloud hosting providers, each with their own specific
configuration to include support for each hosting provider by default.
The following make(1) environment variables are supported:
CLOUDWARE Set to a list of one or more cloud hosting providers,
enclosed in quotes. Requires WITH_CLOUDWARE to also be
set.
WITH_CLOUDWARE Set to a non-empty value to enable building virtual
machine images for various cloud hosting providers.
Requires CLOUDWARE to also be set.
Additionally, the CLOUDWARE and WITH_CLOUDWARE variables can be added to
release.conf, and used in conjunction with release.sh.
For a list of supported CLOUDWARE values, run:
cd /usr/src
make -C release list-cloudware
OCI IMAGES
The FreeBSD release build tools have experimental support for building
Open Container Initiative (OCI) format container base images. This is
enabled using a release.conf variable:
WITH_OCIIMAGES Set to a non-null value to build OCI base images.
MAKEFILE TARGETS
The release makefile (src/release/Makefile) is fairly abstruse. Most
developers will only be concerned with the release and install targets.
release Meta-target to build all release media and distributions
applicable to this platform.
install Copy all produced release media to ${DESTDIR}.
cdrom Builds installation CD-ROM images. This may require the
md(4) (memory disk) device driver be present in the kernel
(either by being compiled in or available as a module).
This target produces files called disc1.iso and
bootonly.iso as its output.
dvdrom Builds installation DVD-ROM images. This may require the
md(4) (memory disk) device driver be present in the kernel
(either by being compiled in or available as a module).
This target produces the dvd1.iso file as its output.
memstick Builds an installation memory stick image named
memstick.img. Not applicable on all platforms. Requires
that the md(4) (memory disk) device driver be present in
the kernel (either by being compiled in or available as a
module).
mini-memstick Similar to memstick, with the exception that the
installation distribution sets are not included.
ftp Creates a directory named ftp containing the distribution
files used in network installations and suitable for
upload to an FTP mirror.
vm-image Creates virtual machine disk images in various formats.
The vm-image target requires the WITH_VMIMAGES make(1)
environment variable to be set to a non-null value.
vm-cloudware Builds FreeBSD virtual machine images for various cloud
hosting providers. See "CLOUD HOSTING MACHINE IMAGES" for
implementation details.
list-cloudware
Displays the list of valid CLOUDWARE values.
list-vmtargets
Displays the list of valid VMFORMATS and CLOUDWARE values.
Major subtargets called by targets above:
packagesystem Generates all the distribution archives (base, kernel,
ports, doc) applicable on this platform.
disc1 Builds a bootable installation system containing all the
distribution files packaged by the packagesystem target,
and suitable for imaging by the cdrom, dvdrom and memstick
targets.
reldoc Builds the release documentation. This includes the
release notes, hardware guide, and installation
instructions. Other documentation, such as the Handbook,
is built during the base.txz target invoked by
packagesystem.
ENVIRONMENT
Optional variables:
OSRELEASE Optional base name for generated media images when invoking
the install target (e.g., FreeBSD-12.1-RELEASE-amd64).
Defaults to the output of `uname -s`-`uname -r`-`uname -p`
within the chroot.
WORLDDIR Location of a directory containing the src tree. By
default, the directory above the one containing the makefile
(src).
PORTSDIR Location of a directory containing the ports tree. By
default, /usr/ports. If it is unset or cannot be found,
ports will not be included in the release.
NOPORTS If defined, the Ports Collection will be omitted from the
release.
NOSRC If set, do not include system source code in the release.
TARGET The target hardware platform. This is analogous to the
"uname -m" output. This is necessary to cross-build some
target architectures. For example, cross-building for ARM64
machines requires TARGET_ARCH=aarch64 and TARGET=arm64. If
not set, TARGET defaults to the current hardware platform.
TARGET_ARCH The target machine processor architecture. This is
analogous to the "uname -p" output. Set this to cross-build
for a different architecture. If not set, TARGET_ARCH
defaults to the current machine architecture, unless TARGET
is also set, in which case it defaults to the appropriate
value for that platform. Typically, one only needs to set
TARGET.
FILES
/scratch
/usr/doc/Makefile
/usr/doc/share/mk/doc.project.mk
/usr/ports/Mk/bsd.port.mk
/usr/ports/Mk/bsd.sites.mk
/usr/share/examples/etc/make.conf
/usr/src/Makefile
/usr/src/Makefile.inc1
/usr/src/release/Makefile
/usr/src/release/Makefile.vm
/usr/src/release/release.sh
/usr/src/release/release.conf.sample
/usr/src/release/tools/*.conf
/usr/src/release/tools/vmimage.subr
EXAMPLES
The following sequence of commands can be used to build a "-CURRENT
snapshot":
cd /usr
git clone -b main https://git.freebsd.org/src.git src
cd src
make buildworld buildkernel
cd release
make obj
make release
make install DESTDIR=/var/freebsd-snapshot
After running these commands, all produced distribution files (tarballs
for FTP, CD-ROM images, etc.) are available in the /var/freebsd-snapshot
directory.
The following sequence of commands can be used to build a "-CURRENT
snapshot" in a clean environment, including ports and documentation:
cd /usr/src/release
sh release.sh
Optionally, a configuration file can be used to customize the release
build:
cd /usr/src/release
sh release.sh -c $HOME/release.conf
Configuration files specific to various supported embedded systems, such
as the Raspberry Pi, exist in the directory corresponding to the TARGET
make(1) variable. For example, to build an image for 64-bit Raspberry
Pis:
cd /usr/src/release
sh release.sh -c arm64/RPI.conf
After running these commands, all prepared release files are available in
the /scratch directory. The target directory can be changed by
specifying the CHROOTDIR variable in release.conf.
COMPATIBILITY
The reldoc target was removed in commit f61e92ca5a23, and DOCDIR,
DOCBRANCH, DOC_UPDATE_SKIP, and NODOC are therefore no longer supported.
SEE ALSO
cc(1), git(1) (ports/devel/git), install(1), make(1), mkimg(1), uname(1),
md(4), make.conf(5), build(7), ports(7), chroot(8), mtree(8), sysctl(8)
FreeBSD Release Engineering,
https://docs.freebsd.org/en/articles/freebsd-releng/.
FreeBSD Developers' Handbook,
https://docs.freebsd.org/en/books/developers-handbook/.
HISTORY
FreeBSD 1.x used a manual checklist, compiled by Rod Grimes, to produce a
release. Apart from being incomplete, the list put a lot of specific
demands on available file systems and was quite torturous to execute.
As part of the FreeBSD 2.0 release engineering effort, significant effort
was spent getting src/release/Makefile into a shape where it could at
least automate most of the tediousness of building a release in a sterile
environment.
For the FreeBSD 9.0 release, src/release/Makefile was overhauled and the
wrapper script src/release/generate-release.sh introduced to support the
introduction of a new installer.
For the FreeBSD 9.2 release, src/release/release.sh was introduced to
support per-build configuration files. src/release/release.sh is heavily
based on the src/release/generate-release.sh script.
At near 1000 revisions spread over multiple branches, the git(1) log of
src/release/Makefile contains a vivid historical record of some of the
hardships release engineers go through.
AUTHORS
src/release/Makefile was originally written by Rod Grimes, Jordan
Hubbard, and Poul-Henning Kamp.
This manual page was originally written by Murray Stokely
<murray@FreeBSD.org>.
It was updated by Nathan Whitehorn <nwhitehorn@FreeBSD.org> to include
the generate-release.sh script used for the FreeBSD 9.0 release cycle.
It was later updated by Glen Barber <gjb@FreeBSD.org> to include the
release.sh script used for the FreeBSD 9.2 release cycle.
FreeBSD 15.1-STABLE-HBSD October 13, 2025 RELEASE(7)