// -*- mode:doc; -*-
// vim: set syntax=asciidoc:
=== Infrastructure for packages with specific build systems
By 'packages with specific build systems' we mean all the packages
whose build system is not one of the standard ones, such as
'autotools' or 'CMake'. This typically includes packages whose build
system is based on hand-written Makefiles or shell scripts.
==== +generic-package+ tutorial
03: # libfoo
07: LIBFOO_VERSION = 1.0
08: LIBFOO_SOURCE = libfoo-$(LIBFOO_VERSION).tar.gz
09: LIBFOO_SITE = http://www.foosoftware.org/download
10: LIBFOO_LICENSE = GPL-3.0+
11: LIBFOO_LICENSE_FILES = COPYING
12: LIBFOO_INSTALL_STAGING = YES
13: LIBFOO_CONFIG_SCRIPTS = libfoo-config
14: LIBFOO_DEPENDENCIES = host-libaaa libbbb
16: define LIBFOO_BUILD_CMDS
17: $(MAKE) $(TARGET_CONFIGURE_OPTS) -C $(@D) all
20: define LIBFOO_INSTALL_STAGING_CMDS
21: $(INSTALL) -D -m 0755 $(@D)/libfoo.a $(STAGING_DIR)/usr/lib/libfoo.a
22: $(INSTALL) -D -m 0644 $(@D)/foo.h $(STAGING_DIR)/usr/include/foo.h
23: $(INSTALL) -D -m 0755 $(@D)/libfoo.so* $(STAGING_DIR)/usr/lib
26: define LIBFOO_INSTALL_TARGET_CMDS
27: $(INSTALL) -D -m 0755 $(@D)/libfoo.so* $(TARGET_DIR)/usr/lib
28: $(INSTALL) -d -m 0755 $(TARGET_DIR)/etc/foo.d
31: define LIBFOO_USERS
32: foo -1 libfoo -1 * - - - LibFoo daemon
35: define LIBFOO_DEVICES
36: /dev/foo c 666 0 0 42 0 - - -
39: define LIBFOO_PERMISSIONS
40: /bin/foo f 4755 foo libfoo - - - - -
43: $(eval $(generic-package))
The Makefile begins on line 7 to 11 with metadata information: the
version of the package (+LIBFOO_VERSION+), the name of the
tarball containing the package (+LIBFOO_SOURCE+) (xz-ed tarball recommended)
the Internet location at which the tarball can be downloaded from
(+LIBFOO_SITE+), the license (+LIBFOO_LICENSE+) and file with the
license text (+LIBFOO_LICENSE_FILES+). All variables must start with
the same prefix, +LIBFOO_+ in this case. This prefix is always the
uppercased version of the package name (see below to understand where
the package name is defined).
On line 12, we specify that this package wants to install something to
the staging space. This is often needed for libraries, since they must
install header files and other development files in the staging space.
This will ensure that the commands listed in the
+LIBFOO_INSTALL_STAGING_CMDS+ variable will be executed.
On line 13, we specify that there is some fixing to be done to some
of the 'libfoo-config' files that were installed during
These *-config files are executable shell script files that are
located in '$(STAGING_DIR)/usr/bin' directory and are executed
by other 3rd party packages to find out the location and the linking
flags of this particular package.
The problem is that all these *-config files by default give wrong,
host system linking flags that are unsuitable for cross-compiling.
For example: '-I/usr/include' instead of '-I$(STAGING_DIR)/usr/include'
or: '-L/usr/lib' instead of '-L$(STAGING_DIR)/usr/lib'
So some sed magic is done to these scripts to make them give correct
The argument to be given to +LIBFOO_CONFIG_SCRIPTS+ is the file name(s)
of the shell script(s) needing fixing. All these names are relative to
'$(STAGING_DIR)/usr/bin' and if needed multiple names can be given.
In addition, the scripts listed in +LIBFOO_CONFIG_SCRIPTS+ are removed
from +$(TARGET_DIR)/usr/bin+, since they are not needed on the target.
.Config script: 'divine' package
Package divine installs shell script '$(STAGING_DIR)/usr/bin/divine-config'.
So its fixup would be:
DIVINE_CONFIG_SCRIPTS = divine-config
.Config script: 'imagemagick' package:
Package imagemagick installs the following scripts:
So it's fixup would be:
IMAGEMAGICK_CONFIG_SCRIPTS = \
Magick-config Magick++-config \
MagickCore-config MagickWand-config Wand-config
On line 14, we specify the list of dependencies this package relies
on. These dependencies are listed in terms of lower-case package names,
which can be packages for the target (without the +host-+
prefix) or packages for the host (with the +host-+) prefix).
Buildroot will ensure that all these packages are built and installed
'before' the current package starts its configuration.
The rest of the Makefile, lines 16..29, defines what should be done
at the different steps of the package configuration, compilation and
+LIBFOO_BUILD_CMDS+ tells what steps should be performed to
build the package. +LIBFOO_INSTALL_STAGING_CMDS+ tells what
steps should be performed to install the package in the staging space.
+LIBFOO_INSTALL_TARGET_CMDS+ tells what steps should be
performed to install the package in the target space.
All these steps rely on the +$(@D)+ variable, which
contains the directory where the source code of the package has been
On lines 31..43, we define a user that is used by this package (e.g.
to run a daemon as non-root) (+LIBFOO_USERS+).
On line 35..37, we define a device-node file used by this package
On line 39..41, we define the permissions to set to specific files
installed by this package (+LIBFOO_PERMISSIONS+).
Finally, on line 43, we call the +generic-package+ function, which
generates, according to the variables defined previously, all the
Makefile code necessary to make your package working.
==== +generic-package+ reference
There are two variants of the generic target. The +generic-package+ macro is
used for packages to be cross-compiled for the target. The
+host-generic-package+ macro is used for host packages, natively compiled
for the host. It is possible to call both of them in a single +.mk+
file: once to create the rules to generate a target
package and once to create the rules to generate a host package:
This might be useful if the compilation of the target package requires
some tools to be installed on the host. If the package name is
+libfoo+, then the name of the package for the target is also
+libfoo+, while the name of the package for the host is
+host-libfoo+. These names should be used in the DEPENDENCIES
variables of other packages, if they depend on +libfoo+ or
The call to the +generic-package+ and/or +host-generic-package+ macro
*must* be at the end of the +.mk+ file, after all variable definitions.
The call to +host-generic-package+ *must* be after the call to
+generic-package+, if any.
For the target package, the +generic-package+ uses the variables defined by
the .mk file and prefixed by the uppercased package name:
+LIBFOO_*+. +host-generic-package+ uses the +HOST_LIBFOO_*+ variables. For
'some' variables, if the +HOST_LIBFOO_+ prefixed variable doesn't
exist, the package infrastructure uses the corresponding variable
prefixed by +LIBFOO_+. This is done for variables that are likely to
have the same value for both the target and host packages. See below
The list of variables that can be set in a +.mk+ file to give metadata
information is (assuming the package name is +libfoo+) :
* +LIBFOO_VERSION+, mandatory, must contain the version of the
package. Note that if +HOST_LIBFOO_VERSION+ doesn't exist, it is
assumed to be the same as +LIBFOO_VERSION+. It can also be a
revision number or a tag for packages that are fetched directly
from their version control system. Do not use a branch name as
version; it does not work. Examples:
** a version for a release tarball: +LIBFOO_VERSION = 0.1.2+
** a sha1 for a git tree: +LIBFOO_VERSION = cb9d6aa9429e838f0e54faa3d455bcbab5eef057+
** a tag for a git tree +LIBFOO_VERSION = v0.1.2+
* +LIBFOO_SOURCE+ may contain the name of the tarball of the package,
which Buildroot will use to download the tarball from
+LIBFOO_SITE+. If +HOST_LIBFOO_SOURCE+ is not specified, it defaults
to +LIBFOO_SOURCE+. If none are specified, then the value is assumed
to be +libfoo-$(LIBFOO_VERSION).tar.gz+. +
Example: +LIBFOO_SOURCE = foobar-$(LIBFOO_VERSION).tar.bz2+
* +LIBFOO_PATCH+ may contain a space-separated list of patch file
names, that Buildroot will download and apply to the package source
code. If an entry contains +://+, then Buildroot will assume it is a
full URL and download the patch from this location. Otherwise,
Buildroot will assume that the patch should be downloaded from
+LIBFOO_SITE+. If +HOST_LIBFOO_PATCH+ is not specified, it defaults
to +LIBFOO_PATCH+. Note that patches that are included in Buildroot
itself use a different mechanism: all files of the form
+*.patch+ present in the package directory inside
Buildroot will be applied to the package after extraction (see
xref:patch-policy[patching a package]). Finally, patches listed in
the +LIBFOO_PATCH+ variable are applied _before_ the patches stored
in the Buildroot package directory.
* +LIBFOO_SITE+ provides the location of the package, which can be a
URL or a local filesystem path. HTTP, FTP and SCP are supported URL
types for retrieving package tarballs. In these cases don't include a
trailing slash: it will be added by Buildroot between the directory
and the filename as appropriate. Git, Subversion, Mercurial,
and Bazaar are supported URL types for retrieving packages directly
from source code management systems. There is a helper function to make
it easier to download source tarballs from GitHub (refer to
xref:github-download-url for details). A filesystem path may be used
to specify either a tarball or a directory containing the package
source code. See +LIBFOO_SITE_METHOD+ below for more details on how
retrieval works. +
Note that SCP URLs should be of the form
+scp://[user@]host:filepath+, and that filepath is relative to the
user's home directory, so you may want to prepend the path with a
slash for absolute paths:
If +HOST_LIBFOO_SITE+ is not specified, it defaults to
* +LIBFOO_DL_OPTS+ is a space-separated list of additional options to
pass to the downloader. Useful for retrieving documents with
server-side checking for user logins and passwords, or to use a proxy.
All download methods valid for +LIBFOO_SITE_METHOD+ are supported;
valid options depend on the download method (consult the man page
for the respective download utilities).
* +LIBFOO_EXTRA_DOWNLOADS+ is a space-separated list of additional
files that Buildroot should download. If an entry contains +://+
then Buildroot will assume it is a complete URL and will download
the file using this URL. Otherwise, Buildroot will assume the file
to be downloaded is located at +LIBFOO_SITE+. Buildroot will not do
anything with those additional files, except download them: it will
be up to the package recipe to use them from +$(LIBFOO_DL_DIR)+.
* +LIBFOO_SITE_METHOD+ determines the method used to fetch or copy the
package source code. In many cases, Buildroot guesses the method
from the contents of +LIBFOO_SITE+ and setting +LIBFOO_SITE_METHOD+
is unnecessary. When +HOST_LIBFOO_SITE_METHOD+ is not specified, it
defaults to the value of +LIBFOO_SITE_METHOD+. +
The possible values of +LIBFOO_SITE_METHOD+ are:
** +wget+ for normal FTP/HTTP downloads of tarballs. Used by
default when +LIBFOO_SITE+ begins with +http://+, +https://+ or
** +scp+ for downloads of tarballs over SSH with scp. Used by
default when +LIBFOO_SITE+ begins with +scp://+.
** +svn+ for retrieving source code from a Subversion repository.
Used by default when +LIBFOO_SITE+ begins with +svn://+. When a
+http://+ Subversion repository URL is specified in
+LIBFOO_SITE+, one 'must' specify +LIBFOO_SITE_METHOD=svn+.
Buildroot performs a checkout which is preserved as a tarball in
the download cache; subsequent builds use the tarball instead of
performing another checkout.
** +cvs+ for retrieving source code from a CVS repository.
Used by default when +LIBFOO_SITE+ begins with +cvs://+.
The downloaded source code is cached as with the +svn+ method.
Anonymous pserver mode is assumed otherwise explicitly defined
on +LIBFOO_SITE+. Both
are accepted, on the former anonymous pserver access mode is
+LIBFOO_SITE+ 'must' contain the source URL as well as the remote
repository directory. The module is the package name.
+LIBFOO_VERSION+ is 'mandatory' and 'must' be a tag, a branch, or
a date (e.g. "2014-10-20", "2014-10-20 13:45", "2014-10-20
13:45+01" see "man cvs" for further details).
** +git+ for retrieving source code from a Git repository. Used by
default when +LIBFOO_SITE+ begins with +git://+. The downloaded
source code is cached as with the +svn+
** +hg+ for retrieving source code from a Mercurial repository. One
'must' specify +LIBFOO_SITE_METHOD=hg+ when +LIBFOO_SITE+
contains a Mercurial repository URL. The downloaded source code
is cached as with the +svn+ method.
** +bzr+ for retrieving source code from a Bazaar repository. Used
by default when +LIBFOO_SITE+ begins with +bzr://+. The
downloaded source code is cached as with the +svn+ method.
** +file+ for a local tarball. One should use this when
+LIBFOO_SITE+ specifies a package tarball as a local filename.
Useful for software that isn't available publicly or in version
** +local+ for a local source code directory. One should use this
when +LIBFOO_SITE+ specifies a local directory path containing
the package source code. Buildroot copies the contents of the
source directory into the package's build directory. Note that
for +local+ packages, no patches are applied. If you need to
still patch the source code, use +LIBFOO_POST_RSYNC_HOOKS+, see
* +LIBFOO_GIT_SUBMODULES+ can be set to +YES+ to create an archive
with the git submodules in the repository. This is only available
for packages downloaded with git (i.e. when
+LIBFOO_SITE_METHOD=git+). Note that we try not to use such git
submodules when they contain bundled libraries, in which case we
prefer to use those libraries from their own package.
* +LIBFOO_STRIP_COMPONENTS+ is the number of leading components
(directories) that tar must strip from file names on extraction.
The tarball for most packages has one leading component named
"<pkg-name>-<pkg-version>", thus Buildroot passes
--strip-components=1 to tar to remove it.
For non-standard packages that don't have this component, or
that have more than one leading component to strip, set this
variable with the value to be passed to tar. Default: 1.
* +LIBFOO_EXCLUDES+ is a space-separated list of patterns to exclude
when extracting the archive. Each item from that list is passed as
a tar's +--exclude+ option. By default, empty.
* +LIBFOO_DEPENDENCIES+ lists the dependencies (in terms of package
name) that are required for the current target package to
compile. These dependencies are guaranteed to be compiled and
installed before the configuration of the current package starts. In
a similar way, +HOST_LIBFOO_DEPENDENCIES+ lists the dependencies for
the current host package.
* +LIBFOO_EXTRACT_DEPENDENCIES+ lists the dependencies (in terms of
package name) that are required for the current target package to be
extracted. These dependencies are guaranteed to be compiled and
installed before the extract step of the current package
starts. This is only used internally by the package infrastructure,
and should typically not be used directly by packages.
* +LIBFOO_PATCH_DEPENDENCIES+ lists the dependencies (in terms of
package name) that are required for the current package to be
patched. These dependencies are guaranteed to be extracted and
patched before the current package is patched. In a similar way,
+HOST_LIBFOO_PATCH_DEPENDENCIES+ lists the dependencies for the
current host package.
This is seldom used; usually, +LIBFOO_DEPENDENCIES+ is what you
really want to use.
* +LIBFOO_PROVIDES+ lists all the virtual packages +libfoo+ is an
implementation of. See xref:virtual-package-tutorial.
* +LIBFOO_INSTALL_STAGING+ can be set to +YES+ or +NO+ (default). If
set to +YES+, then the commands in the +LIBFOO_INSTALL_STAGING_CMDS+
variables are executed to install the package into the staging
* +LIBFOO_INSTALL_TARGET+ can be set to +YES+ (default) or +NO+. If
set to +YES+, then the commands in the +LIBFOO_INSTALL_TARGET_CMDS+
variables are executed to install the package into the target
* +LIBFOO_INSTALL_IMAGES+ can be set to +YES+ or +NO+ (default). If
set to +YES+, then the commands in the +LIBFOO_INSTALL_IMAGES_CMDS+
variable are executed to install the package into the images
* +LIBFOO_CONFIG_SCRIPTS+ lists the names of the files in
'$(STAGING_DIR)/usr/bin' that need some special fixing to make them
cross-compiling friendly. Multiple file names separated by space can
be given and all are relative to '$(STAGING_DIR)/usr/bin'. The files
listed in +LIBFOO_CONFIG_SCRIPTS+ are also removed from
+$(TARGET_DIR)/usr/bin+ since they are not needed on the target.
* +LIBFOO_DEVICES+ lists the device files to be created by Buildroot
when using the static device table. The syntax to use is the
makedevs one. You can find some documentation for this syntax in the
xref:makedev-syntax. This variable is optional.
* +LIBFOO_PERMISSIONS+ lists the changes of permissions to be done at
the end of the build process. The syntax is once again the makedevs one.
You can find some documentation for this syntax in the xref:makedev-syntax.
This variable is optional.
* +LIBFOO_USERS+ lists the users to create for this package, if it installs
a program you want to run as a specific user (e.g. as a daemon, or as a
cron-job). The syntax is similar in spirit to the makedevs one, and is
described in the xref:makeuser-syntax. This variable is optional.
* +LIBFOO_LICENSE+ defines the license (or licenses) under which the package
This name will appear in the manifest file produced by +make legal-info+.
If the license appears in https://spdx.org/licenses/[the SPDX License List],
use the SPDX short identifier to make the manifest file uniform.
Otherwise, describe the license in a precise and concise way, avoiding
ambiguous names such as +BSD+ which actually name a family of licenses.
This variable is optional. If it is not defined, +unknown+ will appear in
the +license+ field of the manifest file for this package. +
The expected format for this variable must comply with the following rules:
** If different parts of the package are released under different
licenses, then +comma+ separate licenses (e.g. +`LIBFOO_LICENSE =
GPL-2.0+, LGPL-2.1+`+). If there is clear distinction between which
component is licensed under what license, then annotate the license
with that component, between parenthesis (e.g. +`LIBFOO_LICENSE =
GPL-2.0+ (programs), LGPL-2.1+ (libraries)`+).
** If the package is dual licensed, then separate licenses with the
+or+ keyword (e.g. +`LIBFOO_LICENSE = AFL-2.1 or GPL-2.0+`+).
* +LIBFOO_LICENSE_FILES+ is a space-separated list of files in the package
tarball that contain the license(s) under which the package is released.
+make legal-info+ copies all of these files in the +legal-info+ directory.
See xref:legal-info for more information.
This variable is optional. If it is not defined, a warning will be produced
to let you know, and +not saved+ will appear in the +license files+ field
of the manifest file for this package.
* +LIBFOO_ACTUAL_SOURCE_TARBALL+ only applies to packages whose
+LIBFOO_SITE+ / +LIBTOO_SOURCE+ pair points to an archive that does
not actually contain source code, but binary code. This a very
uncommon case, only known to apply to external toolchains which come
already compiled, although theoretically it might apply to other
packages. In such cases a separate tarball is usually available with
the actual source code. Set +LIBFOO_ACTUAL_SOURCE_TARBALL+ to the
name of the actual source code archive and Buildroot will download
it and use it when you run +make legal-info+ to collect
legally-relevant material. Note this file will not be downloaded
during regular builds nor by +make source+.
* +LIBFOO_ACTUAL_SOURCE_SITE+ provides the location of the actual
source tarball. The default value is +LIBFOO_SITE+, so you don't
need to set this variable if the binary and source archives are
hosted on the same directory. If +LIBFOO_ACTUAL_SOURCE_TARBALL+ is
not set, it doesn't make sense to define
* +LIBFOO_REDISTRIBUTE+ can be set to +YES+ (default) or +NO+ to indicate if
the package source code is allowed to be redistributed. Set it to +NO+ for
non-opensource packages: Buildroot will not save the source code for this
package when collecting the +legal-info+.
* +LIBFOO_FLAT_STACKSIZE+ defines the stack size of an application built into
the FLAT binary format. The application stack size on the NOMMU architecture
processors can't be enlarged at run time. The default stack size for the
FLAT binary format is only 4k bytes. If the application consumes more stack,
append the required number here.
* +LIBFOO_BIN_ARCH_EXCLUDE+ is a space-separated list of paths (relative
to the target directory) to ignore when checking that the package
installs correctly cross-compiled binaries. You seldom need to set this
variable, unless the package installs binary blobs outside the default
locations, `/lib/firmware`, `/usr/lib/firmware`, `/lib/modules`,
`/usr/lib/modules`, and `/usr/share`, which are automatically excluded.
The recommended way to define these variables is to use the following
LIBFOO_VERSION = 2.32
Now, the variables that define what should be performed at the
different steps of the build process.
* +LIBFOO_EXTRACT_CMDS+ lists the actions to be performed to extract
the package. This is generally not needed as tarballs are
automatically handled by Buildroot. However, if the package uses a
non-standard archive format, such as a ZIP or RAR file, or has a
tarball with a non-standard organization, this variable allows to
override the package infrastructure default behavior.
* +LIBFOO_CONFIGURE_CMDS+ lists the actions to be performed to
configure the package before its compilation.
* +LIBFOO_BUILD_CMDS+ lists the actions to be performed to
compile the package.
* +HOST_LIBFOO_INSTALL_CMDS+ lists the actions to be performed
to install the package, when the package is a host package. The
package must install its files to the directory given by
+$(HOST_DIR)+. All files, including development files such as
headers should be installed, since other packages might be compiled
on top of this package.
* +LIBFOO_INSTALL_TARGET_CMDS+ lists the actions to be
performed to install the package to the target directory, when the
package is a target package. The package must install its files to
the directory given by +$(TARGET_DIR)+. Only the files required for
'execution' of the package have to be
installed. Header files, static libraries and documentation will be
removed again when the target filesystem is finalized.
* +LIBFOO_INSTALL_STAGING_CMDS+ lists the actions to be
performed to install the package to the staging directory, when the
package is a target package. The package must install its files to
the directory given by +$(STAGING_DIR)+. All development files
should be installed, since they might be needed to compile other
* +LIBFOO_INSTALL_IMAGES_CMDS+ lists the actions to be performed to
install the package to the images directory, when the package is a
target package. The package must install its files to the directory
given by +$(BINARIES_DIR)+. Only files that are binary images (aka
images) that do not belong in the +TARGET_DIR+ but are necessary
for booting the board should be placed here. For example, a package
should utilize this step if it has binaries which would be similar
to the kernel image, bootloader or root filesystem images.
* +LIBFOO_INSTALL_INIT_SYSV+ and +LIBFOO_INSTALL_INIT_SYSTEMD+ list the
actions to install init scripts either for the systemV-like init systems
(busybox, sysvinit, etc.) or for the systemd units. These commands
will be run only when the relevant init system is installed (i.e. if
systemd is selected as the init system in the configuration, only
+LIBFOO_INSTALL_INIT_SYSTEMD+ will be run).
* +LIBFOO_HELP_CMDS+ lists the actions to print the package help, which
is included to the main +make help+ output. These commands can print
anything in any format.
This is seldom used, as packages rarely have custom rules. *Do not use
this variable*, unless you really know that you need to print help.
The preferred way to define these variables is:
In the action definitions, you can use the following variables:
* +$(LIBFOO_PKGDIR)+ contains the path to the directory containing the
+libfoo.mk+ and +Config.in+ files. This variable is useful when it is
necessary to install a file bundled in Buildroot, like a runtime
configuration file, a splashscreen image...
* +$(@D)+, which contains the directory in which the package source
code has been uncompressed.
* +$(LIBFOO_DL_DIR)+ contains the path to the directory where all the downloads
made by Buildroot for +libfoo+ are stored in.
* +$(TARGET_CC)+, +$(TARGET_LD)+, etc. to get the target
* +$(TARGET_CROSS)+ to get the cross-compilation toolchain prefix
* Of course the +$(HOST_DIR)+, +$(STAGING_DIR)+ and +$(TARGET_DIR)+
variables to install the packages properly.
Finally, you can also use hooks. See xref:hooks for more information.