.\" Copyright (c) 2000
.\"	Mike W. Meyer
.\"
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.\" modification, are permitted provided that the following conditions
.\" are met:
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.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" $FreeBSD: src/share/man/man7/build.7,v 1.19.2.1 2002/03/18 08:33:02 murray Exp $
.\"
.Dd November 23, 2018
.Dt BUILD 7
.Os
.Sh NAME
.Nm build
.Nd information on how to build the system
.Sh DESCRIPTION
The source for the
.Dx
system and applications is located in
.Pa /usr/src .
This directory contains the
.Dq "base system"
sources, which is loosely defined as the things required to rebuild
the system to a useful state.
It also contains the source for the system documentation, including
manual pages.
Refer to
.Xr development 7
for more information on how to obtain the
.Dx
sources.
.Pp
Third party applications have to be built using the
.Xr dports 7
system.
The file
.Pa /usr/Makefile
has targets for obtaining the dports tree.
Typing
.Li make
in
.Pa /usr
gives specifics on how to obtain the tree for building packages.
.Pp
The
.Xr make 1
command is used in
.Pa /usr/src
to build and install the things in that directory.
Issuing the
.Xr make 1
command in any directory or
subdirectory of those directories has the same effect as issuing the
same command in all subdirectories of that directory.
With no target specified, the things in that directory are just built.
The following list provides the names and actions for other targets:
.Bl -tag -width ".Cm install"
.It Cm clean
Removes any files created during the build process.
.It Cm install
Installs the results of the build for this directory.
.El
.Pp
The other
.Pa /usr/src
make targets are:
.Bl -tag -width ".Cm installworld-force"
.It Cm buildworld
Rebuild everything but the kernel.
.It Cm quickworld
Same as
.Cm buildworld ,
but skip bootstrap, build and cross-build tool steps.
This target can be used for incremental upgrades once a full build of the
world has been done with
.Cm buildworld .
.It Cm realquickworld
Same as
.Cm quickworld ,
but also skip the depend step.
.It Cm crossworld
Just do the bootstrap, build and cross-build steps.
.It Cm installworld
Install everything built by
.Cm buildworld ,
as well as the rescue tools and the initial ramdisk if they do not exist
yet.
.It Cm installworld-force
Force an
.Cm installworld .
This will install to a temporary directory, then copy the main binaries
and libraries with a static
.Xr cpdup 1
to
.Ev DESTDIR
and finally will issue a normal
.Cm installworld
and
.Cm upgrade .
It is a special case to be used on older systems as a last resort when
the normal
.Cm installworld
doesn't work.
.It Cm world
.Cm buildworld +
.Cm installworld .
.It Cm buildkernel
Rebuild the kernel and the kernel-modules.
.It Cm nativekernel
Rebuild the kernel and the kernel-modules using native tools.
.It Cm quickkernel
Same as
.Cm buildkernel ,
but do not clean out the obj modules.
This target can be used for incremental upgrades once a full
build of the kernel has been done with
.Cm buildkernel .
.It Cm realquickkernel
Same as
.Cm quickkernel ,
but also skip the depend step.
.It Cm installkernel
Install the kernel and the kernel-modules.
.It Cm reinstallkernel
Reinstall the kernel and the kernel-modules.
.It Cm kernel
.Cm buildkernel +
.Cm installkernel .
.It Cm preupgrade
Perform certain upgrades that have to be done before
.Cm installworld ,
such as adding new users and groups.
.Cm installworld
will complain if they have not been done.
.It Cm upgrade
Upgrade the files in /etc and also setup the rest of the system for
the version of
.Dx
just installed.
.It Cm initrd
Install the statically linked rescue tools and the initial ramdisk built by
.Cm buildworld .
.It Cm backupworld
Manually archive binaries from installed world to location specified by
.Ev WORLD_BACKUP .
.It Cm backup-clean
Delete archive created by
.Cm backupworld .
.It Cm backup-auto-clean
Delete archive created automatically during
.Cm installworld .
.It Cm restoreworld
Restore binaries from archive created by
.Cm backupworld .
.It Cm restoreworld-auto
Restore binaries from archive created automatically during
.Cm installworld .
The archive location is specified by
.Ev AUTO_BACKUP .
.El
.Sh ENVIRONMENT
.Bl -tag -width ".Ev MAKEOBJDIRPREFIX"
.It Ev TARGET_ARCH , TARGET_PLATFORM
The target machine processor architecture and hardware platform.
These have to be set for cross-building.
.Ev TARGET_ARCH
is analogous to the
.Dq Nm uname Fl p
output.
For the 64 bit
.Tn AMD
architecture known as AMD64, x86-64 or Intel 64, use:
.Bd -literal -offset indent
TARGET_ARCH=x86_64
TARGET_PLATFORM=pc64
.Ed
.It Ev DESTDIR
An existing directory to be the root of
the hierarchy where the resulting binaries will be
installed (the default is
.Pa / ) .
.It Ev MAKEOBJDIRPREFIX
The directory hierarchy where the object files will be built (the default is
.Pa /usr/obj ) .
.It Ev __MAKE_CONF
Used to override the path of
.Xr make.conf 5
(the default is
.Pa /etc/make.conf ) .
.It Ev KERNCONF
The name of one or more kernel configurations from which kernels should
be built (the default is
.Li X86_64_GENERIC ) .
.It Ev KERNCONFDIR
The directory where the kernel configuration files are kept (the default is
.Pa /usr/src/sys/config ) .
.It Ev DESTLABEL
Common suffix added to kernel and modules directory names, prefixed by
a single dot.  For example,
.Bd -literal -offset indent
make DESTLABEL=test installkernel
.Ed
.Pp
installs them as
.Pa /boot/kernel.test/kernel
and
.Pa /boot/kernel.test ,
respectively.
.It Ev DESTKERNDIR
Where to install the kernel and the modules (the default is
.Pa /boot ) ,
in the directory hierarchy specified by the environment variable
.Ev DESTDIR .
.It Ev DESTKERNNAME
The name of the installed kernel file (the default is
.Pa kernel ) ,
under the directory specified by
.Ev DESTKERNDIR .
This overrides the effect of
.Ev DESTLABEL .
.It Ev DESTMODULESNAME
The name of the directory to install the kernel modules (the default is
.Pa modules ) ,
under the directory specified by
.Ev DESTKERNDIR .
This overrides the effect of
.Ev DESTLABEL .
.It Ev WORLD_BACKUP
Directory for manual backup of binaries of installed world (default:
.Pa /var/backups/world_backup ) .
.It Ev AUTO_BACKUP
Directory for automatic backup of binaries of installed world (default:
.Ev MAKEOBJDIRPREFIX Ns /world_binaries/ Ns Ev DESTDIR ) .
.It Ev NO_BACKUP
When defined, the automatic backup feature of
.Cm installworld
is inhibited.
.It Ev COPTFLAGS
Overrides the default optimization flags for kernel and module compiles.
.It Ev KCFLAGS
Allows you to add additional compiler flags for kernel and module compiles.
But use
.Ev COPTFLAGS
to specify any optimization overrides, as some modules may have to override
it to enforce a lower optimization level.
.El
.Sh OTHER
There are two other mechanisms that users should be aware of.  First,
when you issue a
.Cm installkernel
.Dx
will make a backup of the current kernel in
.Pa /boot/kernel.old .
Because people often do multiple installkernel operations, this backup
kernel can also get lost in the noise.
It is usually prudent to make a backup of the old kernel manually
every once in a while when you know that it is a good kernel.  you can
do this after issuing the
.Cm installkernel
by running the command:
.Bd -literal -offset indent
cpdup /boot/kernel.old /boot/kernel.bak
.Ed
.Pp
The advantage of this is that no installation mechanism will overwrite
your
.Pa /boot/kernel.bak ,
and in addition to that the loader's boot menu will check for its
existence and present a menu option 'b' to allow you to boot from it.
.Pp
The second mechanism is related to the two-stage root mount.
When using an encrypted root, the system will actually boot from a
small initial ramdisk (a.k.a. initrd) image stored as
.Pa /boot/kernel/initrd.img.gz .
This image will handle the encrypted configuration, mount, and chroot
to the real root.
This image is also used as the rescue ramdisk boot menu option.
This image is NOT updated automatically by
.Cm installworld
or
.Cm installkernel .
Instead, updating this image has to be done by running the manual command:
.Bd -literal -offset indent
make initrd
.Ed
.Pp
It is usually a good idea to run this command after rebooting into the new
world that you installed (so you know the world you installed is good).
This command will update the initrd image in
.Pa /boot/kernel
and the rescue tools in
.Pa /rescue .
.Sh FILES
.Bl -tag -width ".Pa /usr/src/Makefile_upgrade.inc" -compact
.It Pa /etc/make.conf
.It Pa /etc/defaults/make.conf
.It Pa /usr/src/share/doc/Makefile
.It Pa /usr/src/Makefile
.It Pa /usr/src/Makefile.inc1
.It Pa /usr/src/Makefile_upgrade.inc
.El
.Sh EXAMPLES
The
.Dq approved
method of updating your system from the latest sources is:
.Bd -literal -offset indent
make buildworld
make buildkernel KERNCONF=FOO
make installkernel KERNCONF=FOO
make installworld
make upgrade
reboot
make initrd
.Ed
.Pp
The above mentioned build and install order enforces that the new kernel
is installed before the new world.
Sometimes it might be necessary to reboot the system between those two
steps.
In this case
.Dq Nm make Cm installworld
will tell you to do so.
.Sh SEE ALSO
.Xr cc 1 ,
.Xr install 1 ,
.Xr make 1 ,
.Xr wmake 1 ,
.Xr make.conf 5 ,
.Xr development 7 ,
.Xr dports 7 ,
.Xr release 7 ,
.Xr config 8 ,
.Xr reboot 8 ,
.Xr shutdown 8
.Sh AUTHORS
.An -nosplit
.An Mike W. Meyer Aq Mt mwm@mired.org
and
.An Sascha Wildner Aq Mt swildner@gmail.com .