FreeBSD “releases” can be built by anyone with a fast machine and access to a source repository. (That should be everyone, since we offer anonymous CVS! See The Handbook for details.) The only special requirement is that the md(4) device must be available. If the device is not loaded into your kernel, then the kernel module should be automatically loaded when mdconfig(8) is executed during the boot media creation phase. All of the tools necessary to build a release are available from the CVS repository in src/release. These tools aim to provide a consistent way to build FreeBSD releases. A complete release can actually be built with only a single command, including the creation of ISO images suitable for burning to CDROM, installation floppies, and an FTP install directory. This command is aptly named make release.
To successfully build a release, you must first populate /usr/obj by running make world or simply make buildworld. The release target requires several variables be set properly to build a release:
CHROOTDIR - The directory to be used as the chroot environment for the entire release build.
BUILDNAME - The name of the release to be built.
CVSROOT - The location of a CVS Repository.
RELEASETAG - The CVS tag corresponding to the release you would like to build.
If you do not already have access to a local CVS repository, then you may mirror one with CVSup. The supplied supfile, /usr/share/examples/cvsup/cvs-supfile, is a useful starting point for mirroring the CVS repository.
If RELEASETAG is omitted, then the release will be built from the HEAD (aka -CURRENT) branch. Releases built from this branch are normally referred to as “-CURRENT snapshots”.
There are many other variables available to customize the release build. Most of these variables are documented at the top of src/release/Makefile. The exact command used to build the official FreeBSD 4.7 (x86) release was:
make release CHROOTDIR=/local3/release \
BUILDNAME=4.7-RELEASE \
CVSROOT=/host/cvs/usr/home/ncvs \
RELEASETAG=RELENG_4_7_0_RELEASE
The release Makefile can be broken down into several distinct steps.
Creation of a sanitized system environment in a separate directory hierarchy with “make installworld”.
Checkout from CVS of a clean version of the system source, documentation, and ports into the release build hierarchy.
Population of /etc and /dev in the chrooted environment.
chroot into the release build hierarchy, to make it harder for the outside environment to taint this build.
make world in the chrooted environment.
Build of Kerberos-related binaries.
Build GENERIC kernel.
Creation of a staging directory tree where the binary distributions will be built and packaged.
Build and installation of the documentation toolchain needed to convert the documentation source (SGML) into HTML and text documents that will accompany the release.
Build and installation of the actual documentation (user manuals, tutorials, release notes, hardware compatibility lists, and so on.)
Build of the “crunched” binaries used for installation floppies.
Package up distribution tarballs of the binaries and sources.
Create the boot media and a “fixit” floppy.
Create FTP installation hierarchy.
(optionally) Create ISO images for CDROM/DVD media.
For more information about the release build infrastructure, please see release(7).
Note: It is important to remove any site-specific settings from /etc/make.conf. For example, it would be unwise to distribute binaries that were built on a system with
CPUTYPEset to a specific processor.
The FreeBSD Ports collection
is a collection of over 24,000 third-party software packages available for FreeBSD. The
Ports Management Team <portmgr@FreeBSD.org> is responsible for
maintaining a consistent ports tree that can be used to create the binary packages that
accompany official FreeBSD releases.
The release engineering activities for our collection of third-party packages is beyond the scope of this document. A separate article, The Release Engineering of Third Party Packages, covers this topic in depth.
Starting with FreeBSD 4.4, the FreeBSD Project decided to release all four ISO images that were previously sold on the BSDi/Wind River Systems/FreeBSD Mall “official” CDROM distributions. Each of the four discs must contain a README.TXT file that explains the contents of the disc, a CDROM.INF file that provides meta-data for the disc so that sysinstall(8) can validate and use the contents, and a filename.txt file that provides a manifest for the disc. This manifest can be created with a simple command:
/stage/cdrom# find . -type f | sed -e 's/^\.\///' | sort > filename.txt
The specific requirements of each CD are outlined below.
The first disc is almost completely created by make release. The only changes that should be made to the disc1 directory are the addition of a tools directory, and as many popular third party software packages as will fit on the disc. The tools directory contains software that allow users to create installation floppies from other operating systems. This disc should be made bootable so that users of modern PCs do not need to create installation floppy disks.
If a custom kernel of FreeBSD is to be included, then sysinstall(8) and release(7) must be updated to include installation instructions. The relevant code is contained in src/release and src/usr.sbin/sysinstall. Specifically, the file src/release/Makefile, and dist.c, dist.h, menus.c, install.c, and Makefile will need to be updated under src/usr.sbin/sysinstall. Optionally, you may choose to update sysinstall.8.
The second disc is also largely created by make release. This disc contains a “live filesystem” that can be used from sysinstall(8) to troubleshoot a FreeBSD installation. This disc should be bootable and should also contain a compressed copy of the CVS repository in the CVSROOT directory and commercial software demos in the commerce directory.
The remaining two discs contain additional software packages for FreeBSD. The packages should be clustered so that a package and all of its dependencies are included on the same disc. More information about the creation of these discs is provided in the The Release Engineering of Third Party Packages article.
Sysinstall supports multiple volume package installations. This requires that each disc have an INDEX file containing all of the packages on all volumes of a set, along with an extra field that indicates which volume that particular package is on. Each volume in the set must also have the CD_VOLUME variable set in the cdrom.inf file so that sysinstall can tell which volume is which. When a user attempts to install a package that is not on the current disc, sysinstall will prompt the user to insert the appropriate one.