From 019952d4bc6df642cb4aa26ac0bed026da3f3aa6 Mon Sep 17 00:00:00 2001
From: Peter Korsgaard Buildroot usage and documentation
- by Thomas Petazzoni. Contributions from Karsten Kruse, Ned Ludd, Martin
+ Buildroot usage and documentation
+ by Thomas Petazzoni. Contributions from Karsten Kruse, Ned Ludd, Martin
Herren and others.Buildroot
-
@@ -53,39 +53,39 @@
binutils
) and a C standard library (for example
GNU Libc,
uClibc or
- dietlibc). The system installed
- on your development station certainly already has a compilation
- toolchain that you can use to compile an application that runs on your
- system. If you're using a PC, your compilation toolchain runs on an x86
- processor and generates code for an x86 processor. Under most Linux
- systems, the compilation toolchain uses the GNU libc (glibc) as the C
- standard library. This compilation toolchain is called the "host
- compilation toolchain". The machine on which it is running, and on
- which you're working, is called the "host system". The
- compilation toolchain is provided by your distribution, and Buildroot
- has nothing to do with it (other than using it to build a
- cross-compilation toolchain and other tools that are run on the
+ dietlibc). The system installed
+ on your development station certainly already has a compilation
+ toolchain that you can use to compile an application that runs on your
+ system. If you're using a PC, your compilation toolchain runs on an x86
+ processor and generates code for an x86 processor. Under most Linux
+ systems, the compilation toolchain uses the GNU libc (glibc) as the C
+ standard library. This compilation toolchain is called the "host
+ compilation toolchain". The machine on which it is running, and on
+ which you're working, is called the "host system". The
+ compilation toolchain is provided by your distribution, and Buildroot
+ has nothing to do with it (other than using it to build a
+ cross-compilation toolchain and other tools that are run on the
development host).
As said above, the compilation toolchain that comes with your system - runs on and generates code for the processor in your host system. As - your embedded system has a different processor, you need a - cross-compilation toolchain — a compilation toolchain that runs on - your host system but generates code for your target system (and target - processor). For example, if your host system uses x86 and your target - system uses ARM, the regular compilation toolchain on your host runs on - x86 and generates code for x86, while the cross-compilation toolchain +
As said above, the compilation toolchain that comes with your system + runs on and generates code for the processor in your host system. As + your embedded system has a different processor, you need a + cross-compilation toolchain — a compilation toolchain that runs on + your host system but generates code for your target system (and target + processor). For example, if your host system uses x86 and your target + system uses ARM, the regular compilation toolchain on your host runs on + x86 and generates code for x86, while the cross-compilation toolchain runs on x86 and generates code for ARM.
-Even if your embedded system uses an x86 processor, you might be +
Even if your embedded system uses an x86 processor, you might be interested in Buildroot for two reasons:
You might wonder why such a tool is needed when you can compile
gcc
, binutils
, uClibc
and all
- the other tools by hand. Of course doing so is possible but, dealing with
- all of the configure options and problems of every gcc
or
- binutils
version is very time-consuming and uninteresting.
- Buildroot automates this process through the use of Makefiles and has a
- collection of patches for each gcc
and binutils
+ the other tools by hand. Of course doing so is possible but, dealing with
+ all of the configure options and problems of every gcc
or
+ binutils
version is very time-consuming and uninteresting.
+ Buildroot automates this process through the use of Makefiles and has a
+ collection of patches for each gcc
and binutils
version to make them work on most architectures.
Moreover, Buildroot provides an infrastructure for reproducing - the build process of your kernel, cross-toolchain, and embedded root - filesystem. Being able to reproduce the build process will be useful when a - component needs to be patched or updated or when another person is supposed + the build process of your kernel, cross-toolchain, and embedded root + filesystem. Being able to reproduce the build process will be useful when a + component needs to be patched or updated or when another person is supposed to take over the project.
Releases are available at +
Releases are available at http://buildroot.net/downloads/.
-The latest snapshot is always available at +
The latest snapshot is always available at http://buildroot.net/downloads/snapshots/buildroot-snapshot.tar.bz2, - and previous snapshots are also available at + and previous snapshots are also available at http://buildroot.net/downloads/snapshots/.
To download Buildroot using Git, you can simply follow - the rules described on the "Accessing Git" page + the rules described on the "Accessing Git" page (http://buildroot.net/git.html) - of the Buildroot website + of the Buildroot website (http://buildroot.net). For the impatient, here's a quick recipe:
@@ -135,11 +135,11 @@Buildroot has a nice configuration tool similar to the one you can find - in the Linux kernel + in the Linux kernel (http://www.kernel.org/) or in Busybox (http://www.busybox.org/). Note that - you can (and should) build everything as a normal user. There is no need to - be root to configure and use Buildroot. The first step is to run the + you can (and should) build everything as a normal user. There is no need to + be root to configure and use Buildroot. The first step is to run the configuration assistant:
@@ -160,15 +160,15 @@to run the Qt3 or GTK-based configurators.
-All of these "make" commands will need to build a configuration - utility, so you may need to install "development" packages for relevant - libraries used by the configuration utilities. On Debian-like systems, +
All of these "make" commands will need to build a configuration + utility, so you may need to install "development" packages for relevant + libraries used by the configuration utilities. On Debian-like systems, the
-libncurses5-dev
package is required to use the - menuconfig interface,libqt3-mt-dev
is required to use - the xconfig interface, andlibglib2.0-dev, libgtk2.0-dev + menuconfig interface,
libqt3-mt-dev
is required to use + the xconfig interface, andlibglib2.0-dev, libgtk2.0-dev and libglade2-dev
are needed to use the gconfig interface.For each menu entry in the configuration tool, you can find associated +
For each menu entry in the configuration tool, you can find associated help that describes the purpose of the entry.
Once everything is configured, the configuration tool generates a @@ -195,50 +195,50 @@ selected in the Buildroot configuration.
-Buildroot output is stored in a single directory,
output/
. +Buildroot output is stored in a single directory,
output/
. This directory contains several subdirectories:
images/
where all the images (kernel image,
+ images/
where all the images (kernel image,
bootloader and root filesystem images) are stored.build/
where all the components except for the
- cross-compilation toolchain are built (this includes tools needed to
- run Buildroot on the host and packages compiled for the target). The
- build/
directory contains one subdirectory for each of
+ build/
where all the components except for the
+ cross-compilation toolchain are built (this includes tools needed to
+ run Buildroot on the host and packages compiled for the target). The
+ build/
directory contains one subdirectory for each of
these components.staging/
which contains a hierarchy similar to a root
- filesystem hierarchy. This directory contains the installation of the
- cross-compilation toolchain and all the userspace packages selected
- for the target. However, this directory is not intended to be
- the root filesystem for the target: it contains a lot of development
- files, unstripped binaries and libraries that make it far too big for
- an embedded system. These development files are used to compile
- libraries and applications for the target that depend on other
+ staging/
which contains a hierarchy similar to a root
+ filesystem hierarchy. This directory contains the installation of the
+ cross-compilation toolchain and all the userspace packages selected
+ for the target. However, this directory is not intended to be
+ the root filesystem for the target: it contains a lot of development
+ files, unstripped binaries and libraries that make it far too big for
+ an embedded system. These development files are used to compile
+ libraries and applications for the target that depend on other
libraries.target/
which contains almost the complete
- root filesystem for the target: everything needed is present except
- the device files in /dev/
(Buildroot can't create them
- because Buildroot doesn't run as root and doesn't want to run as
+ target/
which contains almost the complete
+ root filesystem for the target: everything needed is present except
+ the device files in /dev/
(Buildroot can't create them
+ because Buildroot doesn't run as root and doesn't want to run as
root). Therefore, this directory should not be used on your target.
- Instead, you should use one of the images built in the
- images/
directory. If you need an extracted image of the
- root filesystem for booting over NFS, then use the tarball image
- generated in images/
and extract it as root.staging/
, target/
contains only the
- files and libraries needed to run the selected target applications:
+ Instead, you should use one of the images built in the
+ images/
directory. If you need an extracted image of the
+ root filesystem for booting over NFS, then use the tarball image
+ generated in images/
and extract it as root.staging/
, target/
contains only the
+ files and libraries needed to run the selected target applications:
the development files (headers, etc.) are not present, unless the
development files in target filesystem
option is selected.
host/
contains the installation of tools compiled for
- the host that are needed for the proper execution of Buildroot, except
- for the cross-compilation toolchain which is installed under
+ host/
contains the installation of tools compiled for
+ the host that are needed for the proper execution of Buildroot, except
+ for the cross-compilation toolchain which is installed under
staging/
.toolchain/
contains the build directories for the
+ toolchain/
contains the build directories for the
various components of the cross-compilation toolchain.Buildroot supports building out of tree with a syntax similar to the - Linux kernel. To use it, add O=<directory> to the make command +
Buildroot supports building out of tree with a syntax similar to the + Linux kernel. To use it, add O=<directory> to the make command line:
@@ -273,14 +273,14 @@All the output files will be located under
-/tmp/build
.When using out-of-tree builds, the Buildroot
.config
and - temporary files are also stored in the output directory. This means that - you can safely run multiple builds in parallel using the same source +When using out-of-tree builds, the Buildroot
-.config
and + temporary files are also stored in the output directory. This means that + you can safely run multiple builds in parallel using the same source tree as long as they use unique output directories.For ease of use, Buildroot generates a Makefile wrapper in the output - directory - So after the first run, you no longer need to pass -
O=..
and-C ..
, simply run (in the output +For ease of use, Buildroot generates a Makefile wrapper in the output + directory - So after the first run, you no longer need to pass +
O=..
and-C ..
, simply run (in the output directory):@@ -294,12 +294,12 @@
HOSTCXX
, the host C++ compiler to useHOSTCC
, the host C compiler to useUCLIBC_CONFIG_FILE=<path/to/.config>
, path to
- the uClibc configuration file, used to compile uClibc, if an
+ UCLIBC_CONFIG_FILE=<path/to/.config>
, path to
+ the uClibc configuration file, used to compile uClibc, if an
internal toolchain is being builtBUSYBOX_CONFIG_FILE=<path/to/.config>
, path to
+ BUSYBOX_CONFIG_FILE=<path/to/.config>
, path to
the Busybox configuration fileBUILDROOT_DL_DIR
to override the directory in which
+ BUILDROOT_DL_DIR
to override the directory in which
Buildroot stores/retrieves downloaded filesThere are a few ways to customize the resulting target filesystem:
output/target/
.
- You can simply make your changes here and run make afterwards —
- this will rebuild the target filesystem image. This method allows you
- to do anything to the target filesystem, but if you decide to
- completely rebuild your toolchain and tools, these changes will be
+ output/target/
.
+ You can simply make your changes here and run make afterwards —
+ this will rebuild the target filesystem image. This method allows you
+ to do anything to the target filesystem, but if you decide to
+ completely rebuild your toolchain and tools, these changes will be
lost.
- fs/skeleton/
. You can customize configuration files or other
- stuff here. However, the full file hierarchy is not yet present
- because it's created during the compilation process. Therefore, you
- can't do everything on this target filesystem skeleton, but changes to
- it do remain even if you completely rebuild the cross-compilation
+ fs/skeleton/. You can customize configuration files or other
+ stuff here. However, the full file hierarchy is not yet present
+ because it's created during the compilation process. Therefore, you
+ can't do everything on this target filesystem skeleton, but changes to
+ it do remain even if you completely rebuild the cross-compilation
toolchain and the tools.
- target/generic/device_table.txt
file, which is used by the
- tools that generate the target filesystem image to properly set
- permissions and create device nodes.output/target/
just before the actual image
- is made. Simply rebuilding the image by running make should propagate
+ target/generic/device_table.txt file, which is used by the
+ tools that generate the target filesystem image to properly set
+ permissions and create device nodes.output/target/
just before the actual image
+ is made. Simply rebuilding the image by running make should propagate
any new changes to the image.Busybox is very configurable, - and you may want to customize it. You can follow these simple steps to +
Busybox is very configurable, + and you may want to customize it. You can follow these simple steps to do so. This method isn't optimal, but it's simple, and it works:
make busybox-menuconfig
.
@@ -387,13 +387,13 @@
package/busybox/busybox-<version>.config
file, if you
know the options you want to change, without using the configuration tool.
-
+
If you want to use an existing config file for busybox, then see section environment variables.
Just like BusyBox, +
Just like BusyBox, uClibc offers a lot of configuration options. They allow you to select various functionalities depending on your needs and limitations.
@@ -430,11 +430,11 @@The Linux kernel configuration can be customized just like - BusyBox and +
The Linux kernel configuration can be customized just like
+ BusyBox and
uClibc using make linux26-menuconfig
-
. Make sure you have enabled the kernel build in make
- menuconfig
first. Once done, run make
to (re)build
+ . Make sure you have enabled the kernel build in make
+ menuconfig
first. Once done, run make
to (re)build
everything.
If you want to use an existing config file for Linux, then see
@@ -482,8 +482,8 @@
from the compilation step (execution of make
).
For other packages, an analysis of the specific package.mk - file is needed. For example, the zlib Makefile used to look like this +
For other packages, an analysis of the specific package.mk + file is needed. For example, the zlib Makefile used to look like this (before it was converted to the generic package infrastructure):
@@ -509,14 +509,14 @@ $(ZLIB_DIR)/libz.a: $(ZLIB_DIR)/.configuredHow Buildroot works
-As mentioned above, Buildroot is basically a set of Makefiles that - download, configure, and compile software with the correct options. It - also includes patches for various software packages — mainly the - ones involved in the cross-compilation tool chain (
gcc
, +As mentioned above, Buildroot is basically a set of Makefiles that + download, configure, and compile software with the correct options. It + also includes patches for various software packages — mainly the + ones involved in the cross-compilation tool chain (
-gcc
,binutils
anduClibc
).There is basically one Makefile per software package, and they are - named with the
.mk
extension. Makefiles are split into +There is basically one Makefile per software package, and they are + named with the
.mk
extension. Makefiles are split into three main sections:
something
.Config.in
is a part of the configuration tool
- description file. It describes the options related to the
+ description file. It describes the options related to the
package.You may want to compile, for your target, your own programs or other - software that are not packaged in Buildroot. In order to do this you can +
You may want to compile, for your target, your own programs or other + software that are not packaged in Buildroot. In order to do this you can use the toolchain that was generated by Buildroot.
-The toolchain generated by Buildroot is located by default in
- output/staging/
. The simplest way to use it is to add
- output/staging/usr/bin/
to your PATH environment variable and
- then to use ARCH-linux-gcc
, ARCH-linux-objdump
,
+
The toolchain generated by Buildroot is located by default in
+ output/staging/
. The simplest way to use it is to add
+ output/staging/usr/bin/
to your PATH environment variable and
+ then to use ARCH-linux-gcc
, ARCH-linux-objdump
,
ARCH-linux-ld
, etc.
Important: do not try to move a gcc-3.x toolchain to another
- directory — it won't work because there are some hardcoded paths
- in the gcc-3.x configuration. If you are using a current gcc-4.x, it is
- possible to relocate the toolchain — but then --sysroot
- must be passed every time the compiler is called to tell where the
+
Important: do not try to move a gcc-3.x toolchain to another
+ directory — it won't work because there are some hardcoded paths
+ in the gcc-3.x configuration. If you are using a current gcc-4.x, it is
+ possible to relocate the toolchain — but then --sysroot
+ must be passed every time the compiler is called to tell where the
libraries and header files are.
It is also possible to generate the Buildroot toolchain in a +
It is also possible to generate the Buildroot toolchain in a
directory other than output/staging
by using the
- Build options -> Toolchain and header file location
options.
+ Build options -> Toolchain and header file location options.
This could be useful if the toolchain must be shared with other users.
It might be useful to know that the various tarballs that are
- downloaded by the Makefiles are all stored in the DL_DIR
- which by default is the dl
directory. It's useful, for
- example, if you want to keep a complete version of Buildroot which is
- known to be working with the associated tarballs. This will allow you to
- regenerate the toolchain and the target filesystem with exactly the same
+ downloaded by the Makefiles are all stored in the DL_DIR
+ which by default is the dl
directory. It's useful, for
+ example, if you want to keep a complete version of Buildroot which is
+ known to be working with the associated tarballs. This will allow you to
+ regenerate the toolchain and the target filesystem with exactly the same
versions.
If you maintain several Buildroot trees, it might be better to have a - shared download location. This can be accessed by creating a symbolic +
If you maintain several Buildroot trees, it might be better to have a
+ shared download location. This can be accessed by creating a symbolic
link from the dl
directory to the shared download location:
@@ -742,7 +742,7 @@ endif toolchain is based on glibc, you'll have to change these values according to your cross-compiling toolchain. -To generate external toolchains, we recommend using +
To generate external toolchains, we recommend using Crosstool-NG. It allows generating toolchains based on uClibc, glibc and eglibc for a wide range of architectures and has good @@ -751,8 +751,8 @@ endif
Adding new packages to Buildroot
This section covers how new packages (userspace libraries or - applications) can be integrated into Buildroot. It also shows how existing - packages are integrated, which is needed for fixing issues or tuning their + applications) can be integrated into Buildroot. It also shows how existing + packages are integrated, which is needed for fixing issues or tuning their configuration.
The Makefile begins on line 6 to 8 with metadata information: the
- version of the package (LIBFOO_VERSION
), the name of the
- tarball containing the package (LIBFOO_SOURCE
) and the
- Internet location at which the tarball can be downloaded
- (LIBFOO_SITE
). 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
+
The Makefile begins on line 6 to 8 with metadata information: the
+ version of the package (LIBFOO_VERSION
), the name of the
+ tarball containing the package (LIBFOO_SOURCE
) and the
+ Internet location at which the tarball can be downloaded
+ (LIBFOO_SITE
). 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 9, 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 +
On line 9, 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 10, 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
+
On line 10, 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 defines what should be done at the different
- steps of the package configuration, compilation and installation.
- 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
+
The rest of the Makefile defines what should be done at the different
+ steps of the package configuration, compilation and installation.
+ 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
+
All these steps rely on the $(@D)
variable, which
+ contains the directory where the source code of the package has been
extracted.
Finally, on line 27, we call the GENTARGETS
which
- generates, according to the variables defined previously, all the
+
Finally, on line 27, we call the GENTARGETS
which
+ generates, according to the variables defined previously, all the
Makefile code necessary to make your package working.
The GENTARGETS
macro takes three arguments:
package/libfoo
, then the directory prefix
- is package
. If your package is in
- package/editors/foo
, then the directory prefix must be
+ package/libfoo
, then the directory prefix
+ is package
. If your package is in
+ package/editors/foo
, then the directory prefix must be
package/editors
..mk
file and must
- match the configuration option name in the Config.in
- file. For example, if the package name is libfoo
, then the
- variables in the .mk
file must start with
- LIBFOO_
and the configuration option in the
+ .mk
file and must
+ match the configuration option name in the Config.in
+ file. For example, if the package name is libfoo
, then the
+ variables in the .mk
file must start with
+ LIBFOO_
and the configuration option in the
Config.in
file must be BR2_PACKAGE_LIBFOO
.For a given package, in a single .mk
file, it is
- possible to call GENTARGETS twice, once to create the rules to generate
+
For a given package, in a single .mk
file, it is
+ possible to call GENTARGETS twice, 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
+
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
host-libfoo
.
The call to the GENTARGETS
macro must be at the
+
The call to the GENTARGETS
macro must be at the
end of the .mk
file, after all variable definitions.
For the target package, the GENTARGETS
uses the
- variables defined by the .mk file and prefixed by the uppercased package
- name: LIBFOO_*
. For the host package, it uses the
- HOST_LIBFOO_*
. 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 for
+
For the target package, the GENTARGETS
uses the
+ variables defined by the .mk file and prefixed by the uppercased package
+ name: LIBFOO_*
. For the host package, it uses the
+ HOST_LIBFOO_*
. 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 for
details.
The list of variables that can be set in a .mk
file to
- give metadata information is (assuming the package name is
+
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
+ 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
.LIBFOO_VERSION = 0.1.2
LIBFOO_SOURCE
may contain the name of the tarball of
- the package. If HOST_LIBFOO_SOURCE
is not specified, it
- defaults to LIBFOO_VERSION
. If none are specified, then
- the value is assumed to be
- packagename-$(LIBFOO_VERSION).tar.gz
.LIBFOO_SOURCE
may contain the name of the tarball of
+ the package. If HOST_LIBFOO_SOURCE
is not specified, it
+ defaults to LIBFOO_VERSION
. If none are specified, then
+ the value is assumed to be
+ packagename-$(LIBFOO_VERSION).tar.gz
.LIBFOO_SOURCE = foobar-$(LIBFOO_VERSION).tar.bz2
LIBFOO_PATCH
may contain the name of a patch, that
- will be downloaded from the same location as the tarball indicated in
- LIBFOO_SOURCE
. If HOST_LIBFOO_PATCH
is not
- specified, it defaults to LIBFOO_PATCH
. Also note that
- another mechanism is available to patch a package: all files of the
- form packagename-packageversion-description.patch
present
- in the package directory inside Buildroot will be applied to the
+ LIBFOO_PATCH
may contain the name of a patch, that
+ will be downloaded from the same location as the tarball indicated in
+ LIBFOO_SOURCE
. If HOST_LIBFOO_PATCH
is not
+ specified, it defaults to LIBFOO_PATCH
. Also note that
+ another mechanism is available to patch a package: all files of the
+ form packagename-packageversion-description.patch
present
+ in the package directory inside Buildroot will be applied to the
package after extraction.LIBFOO_SITE
may contain the Internet location of the
- tarball of the package. If HOST_LIBFOO_SITE
is not
- specified, it defaults to LIBFOO_SITE
. If none are
- specified, then the location is assumed to be
+ LIBFOO_SITE
may contain the Internet location of the
+ tarball of the package. If HOST_LIBFOO_SITE
is not
+ specified, it defaults to LIBFOO_SITE
. If none are
+ specified, then the location is assumed to be
http://$$(BR2_SOURCEFORGE_MIRROR).dl.sourceforge.net/sourceforge/packagename
.
- LIBFOO_SITE=http://www.libfoosoftware.org/libfoo
.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
+ 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
dependency for the current host package.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
+ 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 directory.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
+ 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 directory.The recommended way to define these variables is to use the following +
The recommended way to define these variables is to use the following syntax:
LIBFOO_VERSION = 2.32-
Now, the variables that define what should be performed at the +
Now, the variables that define what should be performed at the different steps of the build process.
LIBFOO_CONFIGURE_CMDS
, used to list the actions to be
+ LIBFOO_CONFIGURE_CMDS
, used to list the actions to be
performed to configure the package before its compilationLIBFOO_BUILD_CMDS
, used to list the actions to be
+ LIBFOO_BUILD_CMDS
, used to list the actions to be
performed to compile the packageHOST_LIBFOO_INSTALL_CMDS
, used to list 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
+ HOST_LIBFOO_INSTALL_CMDS
, used to list 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
, used to list 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 documentation and execution of the package
- should be installed. Header files should not be installed, they will
- be copied to the target, if the
+ LIBFOO_INSTALL_TARGET_CMDS
, used to list 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 documentation and execution of the package
+ should be installed. Header files should not be installed, they will
+ be copied to the target, if the
development files in target filesystem
option is selected.
LIBFOO_INSTALL_STAGING_CMDS
, used to list 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_STAGING_CMDS
, used to list 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
packages.LIBFOO_CLEAN_CMDS
, used to list the actions to
+ LIBFOO_CLEAN_CMDS
, used to list the actions to
perform to clean up the build directory of the package.LIBFOO_UNINSTALL_TARGET_CMDS
, used to list the actions
+ LIBFOO_UNINSTALL_TARGET_CMDS
, used to list the actions
to uninstall the package from the target directory
$(TARGET_DIR)
LIBFOO_UNINSTALL_STAGING_CMDS
, used to list the
- actions to uninstall the package from the staging directory
+ LIBFOO_UNINSTALL_STAGING_CMDS
, used to list the
+ actions to uninstall the package from the staging directory
$(STAGING_DIR)
.In the action definitions, you can use the following variables:
$(@D)
, which contains the directory in which the
+ $(@D)
, which contains the directory in which the
package source code has been uncompressed.$(TARGET_CC)
, $(TARGET_LD)
, etc. to get
+ $(TARGET_CC)
, $(TARGET_LD)
, etc. to get
the target cross-compilation utilities$(TARGET_CROSS)
to get the cross-compilation
+ $(TARGET_CROSS)
to get the cross-compilation
toolchain prefix$(HOST_DIR)
, $(STAGING_DIR)
- and $(TARGET_DIR)
variables to install the packages
+ and $(TARGET_DIR)
variables to install the packages
properly.The last feature of the generic infrastructure is the ability to add
- hooks. These define further actions to perform after existing steps.
- Most hooks aren't really useful for generic packages, since the
- .mk
file already has full control over the actions
- performed in each step of the package construction. The hooks are more
- useful for packages using the autotools infrastructure described below.
- However, since they are provided by the generic infrastructure, they are
- documented here. The exception is LIBFOO_POST_PATCH_HOOKS
.
- Patching the package is not user definable, so
+
The last feature of the generic infrastructure is the ability to add
+ hooks. These define further actions to perform after existing steps.
+ Most hooks aren't really useful for generic packages, since the
+ .mk
file already has full control over the actions
+ performed in each step of the package construction. The hooks are more
+ useful for packages using the autotools infrastructure described below.
+ However, since they are provided by the generic infrastructure, they are
+ documented here. The exception is LIBFOO_POST_PATCH_HOOKS
.
+ Patching the package is not user definable, so
LIBFOO_POST_PATCH_HOOKS
will be userful for generic packages.
LIBFOO_POST_INSTALL_TARGET_HOOKS
(for target packages only)These variables are lists of variable names containing actions - to be performed at this hook point. This allows several hooks to be +
These variables are lists of variable names containing actions + to be performed at this hook point. This allows several hooks to be registered at a given hook point. Here is an example:
@@ -1145,7 +1145,7 @@ LIBFOO_POST_PATCH_HOOKS += LIBFOO_POST_PATCH_FIXUPMakefile for autotools-based packages : tutorial
-First, let's see how to write a
.mk
file for an +First, let's see how to write a
.mk
file for an autotools-based package, with an example :@@ -1166,163 +1166,163 @@ LIBFOO_POST_PATCH_HOOKS += LIBFOO_POST_PATCH_FIXUPOn line 6, we declare the version of the package.
- -On line 7 and 8, we declare the name of the tarball and the location - of the tarball on the Web. Buildroot will automatically download the + +
On line 7 and 8, we declare the name of the tarball and the location + of the tarball on the Web. Buildroot will automatically download the tarball from this location.
-On line 9, we tell Buildroot to install the package to the staging +
On line 9, we tell Buildroot to install the package to the staging directory. The staging directory, located in
-output/staging/
- is the directory where all the packages are installed, including their - development files, etc. By default, packages are not installed to the - staging directory, since usually, only libraries need to be installed in - the staging directory: their development files are needed to compile - other libraries or applications depending on them. Also by default, when - staging installation is enabled, packages are installed in this location + is the directory where all the packages are installed, including their + development files, etc. By default, packages are not installed to the + staging directory, since usually, only libraries need to be installed in + the staging directory: their development files are needed to compile + other libraries or applications depending on them. Also by default, when + staging installation is enabled, packages are installed in this location using themake install
command.On line 10, we tell Buildroot to also install the package to the - target directory. This directory contains what will become the root - filesystem running on the target. Usually, we try not to install header - files and to install stripped versions of the binary. By default, target - installation is enabled, so in fact, this line is not strictly - necessary. Also by default, packages are installed in this location +
On line 10, we tell Buildroot to also install the package to the + target directory. This directory contains what will become the root + filesystem running on the target. Usually, we try not to install header + files and to install stripped versions of the binary. By default, target + installation is enabled, so in fact, this line is not strictly + necessary. Also by default, packages are installed in this location using the
-make install
command.On line 11, we tell Buildroot to pass a custom configure option, that - will be passed to the
./configure
script before configuring +On line 11, we tell Buildroot to pass a custom configure option, that + will be passed to the
-./configure
script before configuring and building the package.On line 12, we declare our dependencies, so that they are built +
On line 12, we declare our dependencies, so that they are built before the build process of our package starts.
-Finally, on line line 14, we invoke the
AUTOTARGETS
- macro that generates all the Makefile rules that actually allows the +Finally, on line line 14, we invoke the
AUTOTARGETS
+ macro that generates all the Makefile rules that actually allows the package to be built.Makefile for autotools packages : reference
-The main macro of the autotools package infrastructure is -
AUTOTARGETS
. It has the same number of arguments and the - same semantic as theGENTARGETS
macro, which is the main - macro of the generic package infrastructure. For autotools packages, the - ability to have target and host packages is also available (and is +The main macro of the autotools package infrastructure is +
-AUTOTARGETS
. It has the same number of arguments and the + same semantic as theGENTARGETS
macro, which is the main + macro of the generic package infrastructure. For autotools packages, the + ability to have target and host packages is also available (and is actually widely used).Just like the generic infrastructure, the autotools infrastructure - works by defining a number of variables before calling the +
Just like the generic infrastructure, the autotools infrastructure + works by defining a number of variables before calling the
-AUTOTARGETS
macro.First, all the package metadata information variables that exist in the - generic infrastructure also exist in the autotools infrastructure: -
LIBFOO_VERSION
,LIBFOO_SOURCE
, -LIBFOO_PATCH
,LIBFOO_SITE
, -LIBFOO_SUBDIR
,LIBFOO_DEPENDENCIES
, +First, all the package metadata information variables that exist in the + generic infrastructure also exist in the autotools infrastructure: +
-LIBFOO_VERSION
,LIBFOO_SOURCE
, +LIBFOO_PATCH
,LIBFOO_SITE
, +LIBFOO_SUBDIR
,LIBFOO_DEPENDENCIES
,LIBFOO_INSTALL_STAGING
,LIBFOO_INSTALL_TARGET
.A few additional variables, specific to the autotools infrastructure, - can also be defined. Many of them are only useful in very specific +
A few additional variables, specific to the autotools infrastructure, + can also be defined. Many of them are only useful in very specific cases, typical packages will therefore only use a few of them.
LIBFOO_SUBDIR
may contain the name of a subdirectory
- inside the package that contains the configure script. This is useful,
- if for example, the main configure script is not at the root of the
- tree extracted by the tarball. If HOST_LIBFOO_SUBDIR
is
+ LIBFOO_SUBDIR
may contain the name of a subdirectory
+ inside the package that contains the configure script. This is useful,
+ if for example, the main configure script is not at the root of the
+ tree extracted by the tarball. If HOST_LIBFOO_SUBDIR
is
not specified, it defaults to LIBFOO_SUBDIR
.LIBFOO_CONF_ENV
, to specify additional environment
+ LIBFOO_CONF_ENV
, to specify additional environment
variables to pass to the configure script. By default, empty.LIBFOO_CONF_OPT
, to specify additional configure
+ LIBFOO_CONF_OPT
, to specify additional configure
options to pass to the configure script. By default, empty.LIBFOO_MAKE
, to specify an alternate make
- command. This is typically useful when parallel make is enabled in
- the configuration (using BR2_JLEVEL
) but that this
- feature should be disabled for the given package, for one reason or
- another. By default, set to $(MAKE)
. If parallel building
- is not supported by the package, then it should be set to
+ command. This is typically useful when parallel make is enabled in
+ the configuration (using BR2_JLEVEL
) but that this
+ feature should be disabled for the given package, for one reason or
+ another. By default, set to $(MAKE)
. If parallel building
+ is not supported by the package, then it should be set to
LIBFOO_MAKE=$(MAKE1)
.LIBFOO_MAKE_ENV
, to specify additional environment
- variables to pass to make in the build step. These are passed before
+ LIBFOO_MAKE_ENV
, to specify additional environment
+ variables to pass to make in the build step. These are passed before
the make
command. By default, empty.LIBFOO_MAKE_OPT
, to specify additional variables to
- pass to make in the build step. These are passed after the
+ LIBFOO_MAKE_OPT
, to specify additional variables to
+ pass to make in the build step. These are passed after the
make
command. By default, empty.LIBFOO_AUTORECONF
, tells whether the package should
- be autoreconfigured or not (i.e, if the configure script and
- Makefile.in files should be re-generated by re-running autoconf,
- automake, libtool, etc.). Valid values are YES
and
+ LIBFOO_AUTORECONF
, tells whether the package should
+ be autoreconfigured or not (i.e, if the configure script and
+ Makefile.in files should be re-generated by re-running autoconf,
+ automake, libtool, etc.). Valid values are YES
and
NO
. By default, the value is NO
LIBFOO_AUTORECONF_OPT
to specify additional options
- passed to the autoreconf program if
+ LIBFOO_AUTORECONF_OPT
to specify additional options
+ passed to the autoreconf program if
LIBFOO_AUTORECONF=YES
. By default, empty.LIBFOO_LIBTOOL_PATCH
tells whether the Buildroot
- patch to fix libtool cross-compilation issues should be applied or
- not. Valid values are YES
and NO
. By
+ LIBFOO_LIBTOOL_PATCH
tells whether the Buildroot
+ patch to fix libtool cross-compilation issues should be applied or
+ not. Valid values are YES
and NO
. By
default, the value is YES
LIBFOO_USE_CONFIG_CACHE
tells whether the configure
- script should use the central configure cache, which caches test
- results from previous configure scripts. Usually, this variable should
- be left to its default value. Only packages having issues with the
- configure cache, can set this variable to the NO
value
+ LIBFOO_USE_CONFIG_CACHE
tells whether the configure
+ script should use the central configure cache, which caches test
+ results from previous configure scripts. Usually, this variable should
+ be left to its default value. Only packages having issues with the
+ configure cache, can set this variable to the NO
value
(but this is more of a work-around than a fix)LIBFOO_INSTALL_STAGING_OPT
contains the make options
- used to install the package to the staging directory. By default, the
- value is DESTDIR=$$(STAGING_DIR) install
, which is
- correct for most autotools packages. It is still possible to override
+ LIBFOO_INSTALL_STAGING_OPT
contains the make options
+ used to install the package to the staging directory. By default, the
+ value is DESTDIR=$$(STAGING_DIR) install
, which is
+ correct for most autotools packages. It is still possible to override
it.LIBFOO_INSTALL_TARGET_OPT
contains the make options
- used to install the package to the target directory. By default, the
- value is DESTDIR=$$(TARGET_DIR) install
. The default
- value is correct for most autotools packages, but it is still possible
+ LIBFOO_INSTALL_TARGET_OPT
contains the make options
+ used to install the package to the target directory. By default, the
+ value is DESTDIR=$$(TARGET_DIR) install
. The default
+ value is correct for most autotools packages, but it is still possible
to override it if needed.LIBFOO_CLEAN_OPT
contains the make options used to
+ LIBFOO_CLEAN_OPT
contains the make options used to
clean the package. By default, the value is clean
.LIBFOO_UNINSTALL_STAGING_OPT
, contains the make
- options used to uninstall the package from the staging directory. By
+ LIBFOO_UNINSTALL_STAGING_OPT
, contains the make
+ options used to uninstall the package from the staging directory. By
default, the value is DESTDIR=$$(STAGING_DIR) uninstall
.LIBFOO_UNINSTALL_TARGET_OPT
, contains the make
- options used to uninstall the package from the target directory. By
+ LIBFOO_UNINSTALL_TARGET_OPT
, contains the make
+ options used to uninstall the package from the target directory. By
default, the value is DESTDIR=$$(TARGET_DIR) uninstall
.With the autotools infrastructure, all the steps required to build - and install the packages are already defined, and they generally work - well for most autotools-based packages. However, when required, it is +
With the autotools infrastructure, all the steps required to build + and install the packages are already defined, and they generally work + well for most autotools-based packages. However, when required, it is still possible to customize what is done in any particular step:
.mk
file defines its
- own LIBFOO_CONFIGURE_CMDS
variable, it will be used
- instead of the default autotools one. However, using this method
- should be restricted to very specific cases. Do not use it in the
+ .mk
file defines its
+ own LIBFOO_CONFIGURE_CMDS
variable, it will be used
+ instead of the default autotools one. However, using this method
+ should be restricted to very specific cases. Do not use it in the
general case.NOTE: new manual makefiles should not be created, and existing - manual makefiles should be converted either to the generic - infrastructure or the autotools infrastructure. This section is only - kept to document the existing manual makefiles and to help understand +
NOTE: new manual makefiles should not be created, and existing + manual makefiles should be converted either to the generic + infrastructure or the autotools infrastructure. This section is only + kept to document the existing manual makefiles and to help understand how they work.
@@ -1386,134 +1386,134 @@ LIBFOO_POST_PATCH_HOOKS += LIBFOO_POST_PATCH_FIXUP 58: endif-
First of all, this Makefile example works for a package which
- comprises a single binary executable. For other software, such as
- libraries or more complex stuff with multiple binaries, it must be
- adapted. For examples look at the other *.mk
files in the
+
First of all, this Makefile example works for a package which
+ comprises a single binary executable. For other software, such as
+ libraries or more complex stuff with multiple binaries, it must be
+ adapted. For examples look at the other *.mk
files in the
package
directory.
At lines 6-11, a couple of useful variables are defined:
LIBFOO_VERSION
: The version of libfoo that
+ LIBFOO_VERSION
: The version of libfoo that
should be downloaded.LIBFOO_SOURCE
: The name of the tarball of libfoo
- on the download website or FTP site. As you can see
+ LIBFOO_SOURCE
: The name of the tarball of libfoo
+ on the download website or FTP site. As you can see
LIBFOO_VERSION
is used.LIBFOO_SITE
: The HTTP or FTP site from which
- libfoo archive is downloaded. It must include the complete path to
+ LIBFOO_SITE
: The HTTP or FTP site from which
+ libfoo archive is downloaded. It must include the complete path to
the directory where LIBFOO_SOURCE
can be found.LIBFOO_DIR
: The directory into which the software will
- be configured and compiled. Basically, it's a subdirectory of
+ LIBFOO_DIR
: The directory into which the software will
+ be configured and compiled. Basically, it's a subdirectory of
BUILD_DIR
which is created upon decompression of the tarball.
LIBFOO_BINARY
: Software binary name. As said previously,
+ LIBFOO_BINARY
: Software binary name. As said previously,
this is an example for a package with a single binary.LIBFOO_TARGET_BINARY
: The full path of the binary inside
+ LIBFOO_TARGET_BINARY
: The full path of the binary inside
the target filesystem.Lines 13-14 define a target that downloads - the tarball from the remote site to the download directory +
Lines 13-14 define a target that downloads
+ the tarball from the remote site to the download directory
(DL_DIR
).
Lines 16-18 define a target and associated - rules that uncompress the downloaded tarball. As you can see, this - target depends on the tarball file so that the previous target (lines - 13-14) is called before executing the rules of - the current target. Uncompressing is followed by touching a - hidden file to mark the software as having been uncompressed. This trick - is used everywhere in a Buildroot Makefile to split steps (download, - uncompress, configure, compile, install) while still having correct +
Lines 16-18 define a target and associated + rules that uncompress the downloaded tarball. As you can see, this + target depends on the tarball file so that the previous target (lines + 13-14) is called before executing the rules of + the current target. Uncompressing is followed by touching a + hidden file to mark the software as having been uncompressed. This trick + is used everywhere in a Buildroot Makefile to split steps (download, + uncompress, configure, compile, install) while still having correct dependencies.
-Lines 20-31 define a target and associated
- rules that configure the software. It depends on the previous target
- (the hidden .source
file) so that we are sure the software
- has been uncompressed. In order to configure the package, it basically
- runs the well-known ./configure
script. As we may be doing
- cross-compilation, target
, host
and
- build
arguments are given. The prefix is also set to
- /usr
, not because the software will be installed in
- /usr
on your host system, but because the software will be
- installed in /usr
on the target filesystem. Finally it
- creates a .configured
file to mark the software as
+
Lines 20-31 define a target and associated
+ rules that configure the software. It depends on the previous target
+ (the hidden .source
file) so that we are sure the software
+ has been uncompressed. In order to configure the package, it basically
+ runs the well-known ./configure
script. As we may be doing
+ cross-compilation, target
, host
and
+ build
arguments are given. The prefix is also set to
+ /usr
, not because the software will be installed in
+ /usr
on your host system, but because the software will be
+ installed in /usr
on the target filesystem. Finally it
+ creates a .configured
file to mark the software as
configured.
Lines 33-34 define a target and a rule that
- compile the software. This target will create the binary file in the
- compilation directory and depends on the software being already
- configured (hence the reference to the .configured
file).
+
Lines 33-34 define a target and a rule that
+ compile the software. This target will create the binary file in the
+ compilation directory and depends on the software being already
+ configured (hence the reference to the .configured
file).
It basically runs make
inside the source directory.
Lines 36-38 define a target and associated
- rules that install the software inside the target filesystem. They
- depend on the binary file in the source directory to make sure the
- software has been compiled. They use the install-strip
- target of the software Makefile
by passing a
- DESTDIR
argument so that the Makefile
doesn't
- try to install the software in the host /usr
but rather in
- the target /usr
. After the installation, the
- /usr/man
directory inside the target filesystem is removed
+
Lines 36-38 define a target and associated
+ rules that install the software inside the target filesystem. They
+ depend on the binary file in the source directory to make sure the
+ software has been compiled. They use the install-strip
+ target of the software Makefile
by passing a
+ DESTDIR
argument so that the Makefile
doesn't
+ try to install the software in the host /usr
but rather in
+ the target /usr
. After the installation, the
+ /usr/man
directory inside the target filesystem is removed
to save space.
Line 40 defines the main target of the
- software — the one that will eventually be used by the top level
- Makefile
to download, compile, and then install this
- package. This target should first of all depend on all needed
- dependencies of the software (in our example, uclibc and
- ncurses) and also depend on the final binary. This last dependency
+
Line 40 defines the main target of the
+ software — the one that will eventually be used by the top level
+ Makefile
to download, compile, and then install this
+ package. This target should first of all depend on all needed
+ dependencies of the software (in our example, uclibc and
+ ncurses) and also depend on the final binary. This last dependency
will call all previous dependencies in the correct order.
Line 42 defines a simple target that only
- downloads the code source. This is not used during normal operation of
- Buildroot, but is needed if you intend to download all required sources
- at once for later offline build. Note that if you add a new package,
- providing a libfoo-source
target is mandatory to
- support users that wish to do offline-builds. Furthermore, it eases
+
Line 42 defines a simple target that only
+ downloads the code source. This is not used during normal operation of
+ Buildroot, but is needed if you intend to download all required sources
+ at once for later offline build. Note that if you add a new package,
+ providing a libfoo-source
target is mandatory to
+ support users that wish to do offline-builds. Furthermore, it eases
checking if all package-sources are downloadable.
Lines 44-46 define a simple target to clean
- the software build by calling the Makefile with the appropriate options.
- The -clean
target should run make clean
on
- $(BUILD_DIR)/package-version and MUST uninstall all files of the package
+
Lines 44-46 define a simple target to clean
+ the software build by calling the Makefile with the appropriate options.
+ The -clean
target should run make clean
on
+ $(BUILD_DIR)/package-version and MUST uninstall all files of the package
from $(STAGING_DIR) and from $(TARGET_DIR).
Lines 48-49 define a simple target to
- completely remove the directory in which the software was uncompressed,
- configured and compiled. The -dirclean
target MUST
+
Lines 48-49 define a simple target to
+ completely remove the directory in which the software was uncompressed,
+ configured and compiled. The -dirclean
target MUST
completely rm $(BUILD_DIR)/ package-version.
Lines 51-58 add the target libfoo
- to the list of targets to be compiled by Buildroot, by first checking if
- the configuration option for this package has been enabled using the
- configuration tool. If so, it then "subscribes" this package
- to be compiled by adding the package to the TARGETS global variable.
- The name added to the TARGETS global variable is the name of this
- package's target, as defined on line 40, which
+
Lines 51-58 add the target libfoo
+ to the list of targets to be compiled by Buildroot, by first checking if
+ the configuration option for this package has been enabled using the
+ configuration tool. If so, it then "subscribes" this package
+ to be compiled by adding the package to the TARGETS global variable.
+ The name added to the TARGETS global variable is the name of this
+ package's target, as defined on line 40, which
is used by Buildroot to download, compile, and then install this package.
Many packages that support internationalization use the gettext - library. Dependencies for this library are fairly complicated and therefore, +
Many packages that support internationalization use the gettext + library. Dependencies for this library are fairly complicated and therefore, deserves some explanation.
-The uClibc C library doesn't implement gettext functionality, - therefore with this C library, a separate gettext must be compiled. On - the other hand, the glibc C library does integrate its own - gettext, and in this case, the separate gettext library should not be +
The uClibc C library doesn't implement gettext functionality, + therefore with this C library, a separate gettext must be compiled. On + the other hand, the glibc C library does integrate its own + gettext, and in this case, the separate gettext library should not be compiled, because it creates various kinds of build failures.
-Additionally, some packages (such as libglib2) do require gettext
- unconditionally, while other packages (those who support
- --disable-nls
in general) only require gettext when locale
+
Additionally, some packages (such as libglib2) do require gettext
+ unconditionally, while other packages (those who support
+ --disable-nls
in general) only require gettext when locale
support is enabled.
Therefore, Buildroot defines two configuration options:
@@ -1522,18 +1522,18 @@ LIBFOO_POST_PATCH_HOOKS += LIBFOO_POST_PATCH_FIXUPBR2_NEEDS_GETTEXT
, which is true as soon as the
toolchain doesn't provide its own gettext implementationBR2_NEEDS_GETTEXT_IF_LOCALE
, which is true if the
- toolchain doesn't provide its own gettext implementation and if locale
+ BR2_NEEDS_GETTEXT_IF_LOCALE
, which is true if the
+ toolchain doesn't provide its own gettext implementation and if locale
support is enabledTherefore, packages that unconditionally need gettext should:
select BR2_PACKAGE_GETTEXT if BR2_NEEDS_GETTEXT
- and possibly select BR2_PACKAGE_LIBINTL if BR2_NEEDS_GETTEXT
,
+ select BR2_PACKAGE_GETTEXT if BR2_NEEDS_GETTEXT
+ and possibly select BR2_PACKAGE_LIBINTL if BR2_NEEDS_GETTEXT
,
if libintl is also needed$(if $(BR2_NEEDS_GETTEXT),gettext)
in the package
+ $(if $(BR2_NEEDS_GETTEXT),gettext)
in the package
DEPENDENCIES
variableselect BR2_PACKAGE_GETTEXT if BR2_NEEDS_GETTEXT_IF_LOCALE
- and possibly
- select BR2_PACKAGE_LIBINTL if BR2_NEEDS_GETTEXT_IF_LOCALE
,
+ select BR2_PACKAGE_GETTEXT if BR2_NEEDS_GETTEXT_IF_LOCALE
+ and possibly
+ select BR2_PACKAGE_LIBINTL if BR2_NEEDS_GETTEXT_IF_LOCALE
,
if libintl is also needed$(if $(BR2_NEEDS_GETTEXT_IF_LOCALE),gettext)
in
+ $(if $(BR2_NEEDS_GETTEXT_IF_LOCALE),gettext)
in
the package DEPENDENCIES
variableAs you can see, adding a software package to Buildroot is simply a - matter of writing a Makefile using an existing example and modifying it +
As you can see, adding a software package to Buildroot is simply a + matter of writing a Makefile using an existing example and modifying it according to the compilation process required by the package.
-If you package software that might be useful for other people, don't +
If you package software that might be useful for other people, don't forget to send a patch to Buildroot developers!