Table of Contents
Config.in: depends on vs selectConfig.in file.mk fileBuildroot usage and documentation by Thomas Petazzoni. Contributions from Karsten Kruse, Ned Ludd, Martin Herren and others.

Buildroot provides a full-featured environment for cross-development. Buildroot is able to generate a cross-compilation toolchain, a root filesystem, a Linux kernel image and a bootloader for your target. Buildroot can be used for any combination of these options, independently.
Buildroot is useful mainly for people working with embedded systems. Embedded systems often use processors that are not the regular x86 processors everyone is used to having in his PC. They can be PowerPC processors, MIPS processors, ARM processors, etc.
Buildroot supports numerous processors and their variants; it also comes with default configurations for several boards available off-the-shelf. Besides this, a number of third-party projects are based on, or develop their BSP [1] or SDK [2] on top of Buildroot.
Buildroot is designed to run on Linux systems.
Buildroot needs some software to be already installed on the host system; here are the lists of the mandatory and optional packages (package names may vary between distributions).
Take care to install both runtime and development data, especially for the libraries that may be packaged in 2 distinct packages.
Build tools:
which
sed
make (version 3.81 or any later)
binutils
build-essential (only for Debian based systems)
gcc (version 2.95 or any later)
g++ (version 2.95 or any later)
bash
gawk
bison
flex
gettext
patch
gzip
bzip2
perl
tar
cpio
python (version 2.6 or 2.7)
unzip
rsync
texinfo (required for internal Buildroot toolchain backend)
Source fetching tools:
wget
Source fetching tools:
In the official tree, most of the package sources are retrieved
using wget; a few are only available through their git, mercurial,
or svn repository.
All other source fetching methods are implemented and may be used in a development context (further details: refer to Section 6.4, “Download infrastructure”).
bazaar
cvs
git
mercurial
rsync
scp
subversion
Configuration interface dependencies (requires development libraries):
ncurses5 to use the menuconfig interface
qt4 to use the xconfig interface
glib2, gtk2 and glade2 to use the gconfig interface
Development libraries:
zlib1
netpbm10 (for fbtest)
python-xcbgen (for Matchbox on Debian based system)
Documentation generation tools:
asciidoc
Buildroot releases are made approximately every 3 months. Direct Git access and daily snapshots are also available, if you want more bleeding edge.
Releases are available at http://buildroot.net/downloads/.
The latest snapshot is always available at http://buildroot.net/downloads/snapshots/buildroot-snapshot.tar.bz2, 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 (http://buildroot.net/git.html) of the Buildroot website (http://buildroot.net). For the impatient, here’s a quick recipe:
$ git clone git://git.buildroot.net/buildroot
Buildroot has a nice configuration tool similar to the one you can find in the Linux kernel or in Busybox. 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 configuration assistant:
$ make menuconfig
to run the curses-based configurator, or
$ make xconfig
or
$ make gconfig
to run the Qt or GTK-based configurators.
All of these "make" commands will need to build a configuration utility (including the interface), so you may need to install "development" packages for relevant libraries used by the configuration utilities. Check Section 2.1, “System requirements” to know what Buildroot needs, and specifically the optional requirements Section 2.1.2, “Optional packages” to get the dependencies of your favorite interface.
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
.config file that contains the description of your
configuration. It will be used by the Makefiles to do what’s needed.
Let’s go:
$ make
You should never use make -jN with Buildroot: it does not support
top-level parallel make. Instead, use the BR2_JLEVEL option to
tell Buildroot to run each package compilation with make -jN.
The make command will generally perform the following steps:
Buildroot output is stored in a single directory, output/.
This directory contains several subdirectories:
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 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
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 root). Also, it doesn’t have the correct
permissions (e.g. setuid for the busybox binary). 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. Compared to staging/, target/ contains only the files and
libraries needed to run the selected target applications: the
development files (headers, etc.) are not present, the binaries are
stripped.
host/ contains the installation of tools compiled for the host
that are needed for the proper execution of Buildroot, including the
cross-compilation toolchain.
toolchain/ contains the build directories for the various
components of the cross-compilation toolchain.
These commands, make menuconfig|gconfig|xconfig and make, are the
basic ones that allow to easily and quickly generate images fitting
your needs, with all the supports and applications you enabled.
More details about the "make" command usage are given in Section 3.1, “make tips”.
This section explains how you can customize Buildroot to fit your needs.
This is a collection of tips that help you make the most of Buildroot.
Configuration searches: The make *config commands offer a search tool. Read the help message in
the different frontend menus to know how to use it:
/;
Ctrl + f.
The result of the search shows the help message of the matching items.
Display all commands executed by make:
$ make V=1 <target>
Display all available targets:
$ make help
Not all targets are always available,. some settings in the .config file may hide some targets:
linux-menuconfig and linux-savedefconfig only work when
linux is enabled;
uclibc-menuconfig is only available when the
Buildroot internal toolchain backend is used;
ctng-menuconfig is only available when the
crosstool-NG backend is used;
barebox-menuconfig and barebox-savedefconfig only work when the
barebox bootloader is enabled.
Cleaning: Explicit cleaning is required when any of the architecture or toolchain configuration options are changed.
To delete all build products (including build directories, host, staging and target trees, the images and the toolchain):
$ make clean
To delete all build products as well as the configuration:
$ make distclean
Note that if ccache is enabled, running make clean or distclean does
not empty the compiler cache used by Buildroot. To delete it, refer
to Section 5.3.3, “Using ccache in Buildroot”.
Besides changing one or another configuration through make *config,
there 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 lost.
Changes do not survive the make clean command.
system/skeleton and then customize it to
suit your needs. The BR2_ROOTFS_SKELETON_CUSTOM and
BR2_ROOTFS_SKELETON_CUSTOM_PATH will allow you to specify the
location of your custom skeleton. These options can be found in the
System configuration menu. At build time, the contents of the
skeleton are copied to output/target before any package
installation.
BR2_ROOTFS_POST_BUILD_SCRIPT will allow you to
specify the location of your post-build script. This option can be
found in the System configuration menu. The destination root
filesystem folder is given as the first argument to this script,
and this script can then be used to copy programs, static data or
any other needed file to your target filesystem. You should,
however, use this feature with care. Whenever you find that a
certain package generates wrong or unneeded files, you should fix
that package rather than work around it with a post-build cleanup
script. Among these first 3 methods, this one should be preferred.
package/customize can be
used. You can put all the files that you want to see in the final
target root filesystem in package/customize/source, and then
enable this special package in the configuration system. This
method is marked as deprecated.
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.
The nice configuration tool appears, and you can
customize everything.
Otherwise, you can simply change the
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 3.3.5, “Environment variables”.
Just like BusyBox Section 3.2.2, “Customizing the Busybox configuration”, uClibc offers a lot of configuration options. They allow you to select various functionalities depending on your needs and limitations.
The easiest way to modify the configuration of uClibc is to follow these steps:
make uclibc-menuconfig. The nice configuration assistant,
similar to the one used in the Linux kernel or Buildroot,
appears. Make your configuration changes as appropriate.
$(O)/toolchain/uClibc-VERSION/.config file to a different
place (e.g. board/MANUFACTURER/BOARDNAME/uClibc.config) and adjust
the uClibc configuration file option BR2_UCLIBC_CONFIG to refer to this
configuration instead of the default one.
Otherwise, you can simply change toolchain/uClibc/uClibc-VERSION.config,
without running the configuration assistant.
If you want to use an existing config file for uClibc, then see Section 3.3.5, “Environment variables”.
The Linux kernel configuration can be customized just like
BusyBox
Section 3.2.2, “Customizing the Busybox configuration” and uClibc
Section 3.2.3, “Customizing the uClibc configuration” using
make linux-menuconfig. 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 Section 3.3.5, “Environment variables”.
There are three distinct types of toolchain backend supported in Buildroot,
available under the menu Toolchain, invoking make menuconfig.
There is no way of tuning an external toolchain since Buildroot does not generate it.
It also requires to set the Buildroot settings according to the toolchain ones (see Section 5.3.2, “Using an external toolchain”).
The internal Buildroot toolchain backend only allows to generate uClibc-based toolchains.
However, it allows to tune major settings, such as:
These settings are available after selecting the Buildroot toolchain type in
the menu Toolchain.
The crosstool-NG toolchain backend enables a rather
limited set of settings under the Buildroot Toolchain menu:
Then, the toolchain can be fine-tuned by invoking make ctng-menuconfig.
A full rebuild is achieved by running:
$ make clean all
In some cases, a full rebuild is mandatory:
each time the toolchain properties are changed, this includes:
make ctng-menuconfig (if the crosstool-NG backend
is used);
make uclibc-menuconfig.
In some cases, a full rebuild is recommended:
In other cases, it is up to you to decide if you should run a full rebuild, but you should know what is impacted and understand what you are doing anyway.
One of the most common questions asked by Buildroot users is how to rebuild a given package or how to remove a package without rebuilding everything from scratch.
Removing a package is unsupported by Buildroot without
rebuilding from scratch. This is because Buildroot doesn’t keep track
of which package installs what files in the output/staging and
output/target directories, or which package would be compiled differently
depending on the availability of another package.
The easiest way to rebuild a single package from scratch is to remove
its build directory in output/build. Buildroot will then re-extract,
re-configure, re-compile and re-install this package from scratch. You
can ask buildroot to do this with the make <package>-dirclean command.
For convenience, the special make targets <package>-reconfigure and <package>-rebuild repeat the configure resp. build steps.
However, if you don’t want to rebuild the package completely from scratch, a better understanding of the Buildroot internals is needed. Internally, to keep track of which steps have been done and which steps remain to be done, Buildroot maintains stamp files (empty files that just tell whether this or that action has been done):
output/build/<package>-<version>/.stamp_configured. If removed,
Buildroot will trigger the recompilation of the package from the
configuration step (execution of ./configure).
output/build/<package>-<version>/.stamp_built. If removed,
Buildroot will trigger the recompilation of the package from the
compilation step (execution of make).
Note: toolchain packages use custom makefiles. Their stamp files are named differently.
Further details about package special make targets are explained in Section 5.3.5, “Package-specific make targets”.
If you intend to do an offline build and just want to download all sources that you previously selected in the configurator (menuconfig, xconfig or gconfig), then issue:
$ make source
You can now disconnect or copy the content of your dl
directory to the build-host.
As default, everything built by Buildroot is stored in the directory
output in the Buildroot tree.
Buildroot also supports building out of tree with a syntax similar to
the Linux kernel. To use it, add O=<directory> to the make command
line:
$ make O=/tmp/build
Or:
$ cd /tmp/build; make O=$PWD -C path/to/buildroot
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 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 directory):
$ make <target>
Buildroot also honors some environment variables, when they are passed
to make or set in the environment:
HOSTCXX, the host C++ compiler to use
HOSTCC, the host C compiler to use
UCLIBC_CONFIG_FILE=<path/to/.config>, path to
the uClibc configuration file, used to compile uClibc, if an
internal toolchain is being built.
Note that the uClibc configuration file can also be set from the
configuration interface, so through the Buildroot .config file; this
is the recommended way of setting it.
BUSYBOX_CONFIG_FILE=<path/to/.config>, path to
the Busybox configuration file.
Note that the Busybox configuration file can also be set from the
configuration interface, so through the Buildroot .config file; this
is the recommended way of setting it.
BUILDROOT_DL_DIR to override the directory in which
Buildroot stores/retrieves downloaded files
Note that the Buildroot download directory can also be set from the
configuration interface, so through the Buildroot .config file; this
is the recommended way of setting it.
An example that uses config files located in the toplevel directory and in your $HOME:
$ make UCLIBC_CONFIG_FILE=uClibc.config BUSYBOX_CONFIG_FILE=$HOME/bb.config
If you want to use a compiler other than the default gcc
or g++ for building helper-binaries on your host, then do
$ make HOSTCXX=g++-4.3-HEAD HOSTCC=gcc-4.3-HEAD
If Buildroot does not yet fit all your requirements, you may be interested in hacking it to add:
If the boot process seems to hang after the following messages (messages not necessarily exactly similar, depending on the list of packages selected):
Freeing init memory: 3972K Initializing random number generator... done. Starting network... Starting dropbear sshd: generating rsa key... generating dsa key... OK
then it means that your system is running, but didn’t start a shell on
the serial console. In order to have the system start a shell on your
serial console, you have to go into the Buildroot configuration, System
configuration, and modify Port to run a getty (login prompt) on and
Baudrate to use as appropriate. This will automatically tune the
/etc/inittab file of the generated system so that a shell starts on
the correct serial port.
If the build of module-init-tools for the host fails with:
/usr/bin/ld: cannot find -lc
then probably you are running a Fedora (or similar) distribution, and
you should install the glibc-static package. This is because the
module-init-tools build process wants to link statically against the
C library.
It has been decided that support for the native compiler on the target would be stopped from the Buildroot-2012.11 release because:
If you need a compiler on your target anyway, then Buildroot is not suitable for your purpose. In such case, you need a real distribution and you should opt for something like:
Since there is no compiler available on the target (see Section 4.3, “Why is there no compiler on the target?”), it does not make sense to waste space with headers or static libraries.
Therefore, those files are always removed from the target since the Buildroot-2012.11 release.
Because Buildroot mostly targets small or very small target hardware with limited resource onboard (CPU, ram, mass-storage), it does not make sense to waste space with the documentation data.
If you need documentation data on your target anyway, then Buildroot is not suitable for your purpose, and you should look for a real distribution (see: Section 4.3, “Why is there no compiler on the target?”).
When adding a new package to Buildroot, you will most likely have to deal with expressing the dependencies of this package.
In the Config.in file, dependencies may be expressed following two
semantics.
See choosing between depends and select
the section called “Choosing depends on or select”.
If a package exists in the Buildroot tree and does not appear in the config menu, this most likely means that some of the package’s dependencies are not met.
To know more about the dependencies of a package, search for the package symbol in the config menu (see Section 3.1, “make tips”).
Then, you may have to recursively enable several options (which correspond to the unmet dependencies) to finally be able to select the package.
If the package is not visible due to some unmet toolchain options, then you should certainly run a full rebuild (see Section 3.1, “make tips” for more explanations).
There are plenty of reasons to not use the target directory a chroot one, among these:
For these reasons, commands run through chroot, using the target directory as the new root, will most likely fail.
If you want to run the target filesystem inside a chroot, or as an NFS
root, then use the tarball image generated in images/ and extract it
as root.
When developing an embedded system, there are a number of choices to address:
Some of these may be influenced by the target hardware.
Some of the choices may also add some constraints when you develop the final application for which your target is designed (e.g. some functions may be provided by some C libraries and missing in some others, …). So, these choices should be carefully made.
Buildroot allows you to set most of these options to fit your needs.
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 to take over the project.
A compilation toolchain is the set of tools that allows you to compile
code for your system. It consists of a compiler (in our case, gcc),
binary utils like assembler and linker (in our case, 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" [3].
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 runs on x86 and generates code for ARM.
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 version to make them work on most architectures.
Buildroot offers a number of options and settings that can be tuned when defining the cross-toolchain (refer to Section 3.2.5, “Customizing the toolchain”).
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 toolchain (gcc, binutils and
uClibc).
There is basically one Makefile per software package, and they are
named with the .mk extension. Makefiles are split into many different
parts.
toolchain/ directory contains the Makefiles
and associated files for all software related to the
cross-compilation toolchain: binutils, gcc, gdb,
kernel-headers and uClibc.
arch/ directory contains the definitions for all the processor
architectures that are supported by Buildroot.
package/ directory contains the Makefiles and
associated files for all user-space tools and libraries that Buildroot
can compile and add to the target root filesystem. There is one
sub-directory per package.
linux/ directory contains the Makefiles and associated files for
the Linux kernel.
boot/ directory contains the Makefiles and associated files for
the bootloaders supported by Buildroot.
system/ directory contains support for system integration, e.g.
the target filesystem skeleton and the selection of an init system.
fs/ directory contains the Makefiles and
associated files for software related to the generation of the
target root filesystem image.
Each directory contains at least 2 files:
something.mk is the Makefile that downloads, configures,
compiles and installs the package something.
Config.in is a part of the configuration tool
description file. It describes the options related to the
package.
The main Makefile performs the following steps (once the configuration is done):
staging, target, build,
stamps, etc. in the output directory (output/ by default,
another value can be specified using O=)
BASE_TARGETS variable. When
an internal toolchain is used, this means generating the
cross-compilation toolchain. When an external toolchain is used,
this means checking the features of the external toolchain and
importing it into the Buildroot environment.
TARGETS variable. This
variable is filled by all the individual components'
Makefiles. Generating these targets will trigger the compilation of
the userspace packages (libraries, programs), the kernel, the
bootloader and the generation of the root filesystem images,
depending on the configuration.
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/host/. The simplest way to use it is to add
output/host/usr/bin/ to your PATH environment variable and then to
use ARCH-linux-gcc, ARCH-linux-objdump, ARCH-linux-ld, etc.
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 directory
other than output/host by using the Build options → Host dir
option. This could be useful if the toolchain must be shared with
other users.
Using an already existing toolchain is useful for different reasons:
Buildroot supports using existing toolchains through a mechanism
called external toolchain. The external toolchain mechanism is
enabled in the Toolchain menu, by selecting External toolchain in
Toolchain type.
Then, you have three solutions to use an external toolchain:
Toolchain from the
available ones. This is definitely the easiest solution.
Toolchain through the available
ones, unselect Download toolchain automatically, and fill the
Toolchain path text entry with the path to your cross-compiling
toolchain.
Custom toolchain solution in the Toolchain list. You
need to fill the Toolchain path, Toolchain prefix and External
toolchain C library options. Then, you have to tell Buildroot what
your external toolchain supports. If your external toolchain uses
the glibc library, you only have to tell whether your toolchain
supports C+\+ or not and whether it has built-in RPC support. If
your external toolchain uses the uClibc
library, then you have to tell Buildroot if it supports largefile,
IPv6, RPC, wide-char, locale, program invocation, threads and
C++. At the beginning of the execution, Buildroot will tell you if
the selected options do not match the toolchain configuration.
Our external toolchain support has been tested with toolchains from CodeSourcery and Linaro, toolchains generated by crosstool-NG, and toolchains generated by Buildroot itself. In general, all toolchains that support the sysroot feature should work. If not, do not hesitate to contact the developers.
We do not support toolchains from the ELDK of Denx, for two reasons:
CROSS_COMPILE environment variable. This non-standard behaviour
makes it difficult to support ELDK in Buildroot.
We also do not support using the distribution toolchain (i.e the gcc/binutils/C library installed by your distribution) as the toolchain to build software for the target. This is because your distribution toolchain is not a "pure" toolchain (i.e only with the C/C++ library), so we cannot import it properly into the Buildroot build environment. So even if you are building a system for a x86 or x86_64 target, you have to generate a cross-compilation toolchain with Buildroot or crosstool-NG.
ccache is a compiler cache. It stores the object files resulting from each compilation process, and is able to skip future compilation of the same source file (with same compiler and same arguments) by using the pre-existing object files. When doing almost identical builds from scratch a number of times, it can nicely speed up the build process.
ccache support is integrated in Buildroot. You just have to enable
Enable compiler cache in Build options. This will automatically
build ccache and use it for every host and target compilation.
The cache is located in $HOME/.buildroot-ccache. It is stored
outside of Buildroot output directory so that it can be shared by
separate Buildroot builds. If you want to get rid of the cache, simply
remove this directory.
You can get statistics on the cache (its size, number of hits,
misses, etc.) by running make ccache-stats.
The various tarballs that are downloaded by Buildroot are all stored in
DL_DIR, which by default is the dl directory. If you want
to keep a complete version of Buildroot which is known to be working
with the associated tarballs, you can make a copy of this directory.
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
link from the dl directory to the shared download location:
$ ln -s <shared download location> dl
Another way of accessing a shared download location is to create the
BUILDROOT_DL_DIR environment variable. If this is set, then the
value of DL_DIR in the project is overridden. The following line
should be added to <~/.bashrc>.
$ export BUILDROOT_DL_DIR <shared download location>
The download location can also be set in the .config file, with the
BR2_DL_DIR option. This value is overridden by the BUILDROOT_DL_DIR
environment variable.
Running make <package> builds and installs that particular package
and its dependencies.
For packages relying on the Buildroot infrastructure, there are numerous special make targets that can be called independently like this:
make <package>-<target>
The package build targets are (in the order they are executed):
| command/target | Description |
|---|---|
| Fetch the source (download the tarball, clone the source repository, etc) |
| Build and install all dependencies required to build the package |
| Put the source in the package build directory (extract the tarball, copy the source, etc) |
| Apply the patches, if any |
| Run the configure commands, if any |
| Run the compilation commands |
| target package: Run the installation of the package in the staging directory, if necessary |
| target package: Run the installation of the package in the target directory, if necessary |
| target package: Run the 2 previous installation commands host package: Run the installation of the package in the host directory |
Additionally, there are some other useful make targets:
| command/target | Description |
|---|---|
| Displays the dependencies required to build the package |
| Run the clean command of the package, also uninstall the package from both the target and the staging directory; note that this is not implemented for all packages |
| Remove the whole package build directory |
| Re-run the compilation commands - this only makes
sense when using the |
| Re-run the configure commands, then rebuild - this only
makes sense when using the |
[3] This terminology differs from what is used by GNU configure, where the host is the machine on which the application will run (which is usually the same as target)
Overall, these coding style rules are here to help you to add new files in Buildroot or refactor existing ones.
If you slightly modify some existing file, the important thing is to keep the consistency of the whole file, so you can:
Config.in files contain entries for almost anything configurable in
Buildroot.
An entry has the following pattern:
config BR2_PACKAGE_LIBFOO
bool "libfoo"
depends on BR2_PACKAGE_LIBBAZ
select BR2_PACKAGE_LIBBAR
help
This is a comment that explains what libfoo is.
http://foosoftware.org/libfoo/bool, depends on, select and help lines are indented
with one tab.
The Config.in files are the input for the configuration tool
used in Buildroot, which is the regular Kconfig. For further
details about the Kconfig language, refer to
http://kernel.org/doc/Documentation/kbuild/kconfig-language.txt.
Assignment: use = preceded and followed by one space:
LIBFOO_VERSION = 1.0 LIBFOO_CONF_OPT += --without-python-support
It is also possible to align the = signs:
LIBFOO_VERSION = 1.0 LIBFOO_SOURCE = foo-$(LIBFOO_VERSION).tar.gz LIBFOO_CONF_OPT += --without-python-support
Indentation: use tab only:
define LIBFOO_REMOVE_DOC
$(RM) -fr $(TARGET_DIR)/usr/share/libfoo/doc \
$(TARGET_DIR)/usr/share/man/man3/libfoo*
endefNote that commands inside a define block should always start with a tab,
so make recognizes them as commands.
Optional dependency:
Prefer multi-line syntax.
YES:
ifeq ($(BR2_PACKAGE_PYTHON),y) LIBFOO_CONF_OPT += --with-python-support LIBFOO_DEPENDENCIES += python else LIBFOO_CONF_OPT += --without-python-support endif
NO:
LIBFOO_CONF_OPT += --with$(if $(BR2_PACKAGE_PYTHON),,out)-python-support LIBFOO_DEPENDENCIES += $(if $(BR2_PACKAGE_PYTHON),python,)
Optional hooks: keep hook definition and assignment together in one if block.
YES:
ifneq ($(BR2_LIBFOO_INSTALL_DATA),y)
define LIBFOO_REMOVE_DATA
$(RM) -fr $(TARGET_DIR)/usr/share/libfoo/data
endef
LIBFOO_POST_INSTALL_TARGET_HOOKS += LIBFOO_REMOVE_DATA
endifNO:
define LIBFOO_REMOVE_DATA
$(RM) -fr $(TARGET_DIR)/usr/share/libfoo/data
endef
ifneq ($(BR2_LIBFOO_INSTALL_DATA),y)
LIBFOO_POST_INSTALL_TARGET_HOOKS += LIBFOO_REMOVE_DATA
endifThe documentation uses the asciidoc format.
For further details about the asciidoc syntax, refer to http://www.methods.co.nz/asciidoc/userguide.html.
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 configuration.
First of all, create a directory under the package directory for
your software, for example libfoo.
Some packages have been grouped by topic in a sub-directory:
multimedia, x11r7, efl and matchbox. If your package fits in
one of these categories, then create your package directory in these.
New subdirectories are discouraged, however.
Then, create a file named Config.in. This file will contain the
option descriptions related to our libfoo software that will be used
and displayed in the configuration tool. It should basically contain:
config BR2_PACKAGE_LIBFOO
bool "libfoo"
help
This is a comment that explains what libfoo is.
http://foosoftware.org/libfoo/The bool line, help line and other meta-informations about the
configuration option must be indented with one tab. The help text
itself should be indented with one tab and two spaces, and it must
mention the upstream URL of the project.
You can add other sub-options into a if
BR2_PACKAGE_LIBFOO…endif statement to configure particular things
in your software. You can look at examples in other packages. The
syntax of the Config.in file is the same as the one for the kernel
Kconfig file. The documentation for this syntax is available at
http://kernel.org/doc/Documentation/kbuild/kconfig-language.txt
Finally you have to add your new libfoo/Config.in to
package/Config.in (or in a category subdirectory if you decided to
put your package in one of the existing categories). The files
included there are sorted alphabetically per category and are NOT
supposed to contain anything but the bare name of the package.
source "package/libfoo/Config.in"
The Config.in file of your package must also ensure that
dependencies are enabled. Typically, Buildroot uses the following
rules:
select type of dependency for dependencies on
libraries. These dependencies are generally not obvious and it
therefore make sense to have the kconfig system ensure that the
dependencies are selected. For example, the libgtk2 package uses
select BR2_PACKAGE_LIBGLIB2 to make sure this library is also
enabled.
The select keyword express the dependency with a backward
semantic.
depends on type of dependency when the user really needs to
be aware of the dependency. Typically, Buildroot uses this type of
dependency for dependencies on toolchain options (target
architecture, MMU support, C library, C++ support, large file
support, thread support, RPC support, IPV6 support, WCHAR support),
or for dependencies on "big" things, such as the X.org system. For
dependencies on toolchain options, there should be a comment that
is displayed when the option is not
enabled, so that the user knows why the package is not available.
The depends on keyword express the dependency with a forward
semantic.
Note. The current problem with the kconfig language is that these two dependency semantics are not internally linked. Therefore, it may be possible to select a package, whom one of its dependencies/requirement is not met.
An example illustrates both the usage of select and depends on.
config BR2_PACKAGE_ACL
bool "acl"
select BR2_PACKAGE_ATTR
depends on BR2_LARGEFILE
help
POSIX Access Control Lists, which are used to define more
fine-grained discretionary access rights for files and
directories.
This package also provides libacl.
http://savannah.nongnu.org/projects/acl
comment "acl requires a toolchain with LARGEFILE support"
depends on !BR2_LARGEFILENote that these two dependency types are only transitive with the dependencies of the same kind.
This means, in the following example:
config BR2_PACKAGE_A
bool "Package A"
config BR2_PACKAGE_B
bool "Package B"
depends on BR2_PACKAGE_A
config BR2_PACKAGE_C
bool "Package C"
depends on BR2_PACKAGE_B
config BR2_PACKAGE_D
bool "Package D"
select BR2_PACKAGE_B
config BR2_PACKAGE_E
bool "Package E"
select BR2_PACKAGE_DPackage C will be visible if Package B has been
selected, which in turn is only visible if Package A has been
selected.
Package E will select Package D, which will select
Package B, it will not check for the dependencies of Package B,
so it will not select Package A.
Package B is selected but Package A is not, this violates
the dependency of Package B on Package A. Therefore, in such a
situation, the transitive dependency has to be added explicitly:
config BR2_PACKAGE_D
bool "Package D"
select BR2_PACKAGE_B
depends on BR2_PACKAGE_A
config BR2_PACKAGE_E
bool "Package E"
select BR2_PACKAGE_D
depends on BR2_PACKAGE_AOverall, for package library dependencies, select should be
preferred.
Note that such dependencies will ensure that the dependency option
is also enabled, but not necessarily built before your package. To do
so, the dependency also needs to be expressed in the .mk file of the
package.
Further formatting details: see the
coding style
Section 6.1.1, “Config.in file”.
Finally, here’s the hardest part. Create a file named libfoo.mk. It
describes how the package should be downloaded, configured, built,
installed, etc.
Depending on the package type, the .mk file must be written in a
different way, using different infrastructures:
generic-package Tutorial” and a
reference
the section called “generic-package Reference”.
autotools-package tutorial”
and reference
the section called “autotools-package reference”.
cmake-package tutorial”
and reference
the section called “cmake-package reference”.
Further formating details: see the writing
rules
Section 6.1.2, “The .mk file”.
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.
01: ############################################################# 02: # 03: # libfoo 04: # 05: ############################################################# 06: LIBFOO_VERSION = 1.0 07: LIBFOO_SOURCE = libfoo-$(LIBFOO_VERSION).tar.gz 08: LIBFOO_SITE = http://www.foosoftware.org/download 09: LIBFOO_LICENSE = GPLv3+ 10: LIBFOO_LICENSE_FILES = COPYING 11: LIBFOO_INSTALL_STAGING = YES 12: LIBFOO_DEPENDENCIES = host-libaaa libbbb 13: 14: define LIBFOO_BUILD_CMDS 15: $(MAKE) CC="$(TARGET_CC)" LD="$(TARGET_LD)" -C $(@D) all 16: endef 17: 18: define LIBFOO_INSTALL_STAGING_CMDS 19: $(INSTALL) -D -m 0755 $(@D)/libfoo.a $(STAGING_DIR)/usr/lib/libfoo.a 20: $(INSTALL) -D -m 0644 $(@D)/foo.h $(STAGING_DIR)/usr/include/foo.h 21: $(INSTALL) -D -m 0755 $(@D)/libfoo.so* $(STAGING_DIR)/usr/lib 22: endef 23: 24: define LIBFOO_INSTALL_TARGET_CMDS 25: $(INSTALL) -D -m 0755 $(@D)/libfoo.so* $(TARGET_DIR)/usr/lib 26: $(INSTALL) -d -m 0755 $(TARGET_DIR)/etc/foo.d 27: endef 28: 29: define LIBFOO_DEVICES 30: /dev/foo c 666 0 0 42 0 - - - 31: endef 32: 33: define LIBFOO_PERMISSIONS 34: /bin/foo f 4755 0 0 - - - - - 35: endef 36: 37: $(eval $(generic-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
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
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
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
extracted.
Finally, on line 35, we call the generic-package which
generates, according to the variables defined previously, all the
Makefile code necessary to make your package working.
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:
$(eval $(generic-package)) $(eval $(host-generic-package))
This might be useful if the compilation of the target package requires
some tools to be installed on the host. If the package name is
libfoo, then the name of the package for the target is also
libfoo, while the name of the package for the host is
host-libfoo. These names should be used in the DEPENDENCIES
variables of other packages, if they depend on libfoo or
host-libfoo.
The call to the generic-package and/or host-generic-package macro must be
at the end of the .mk file, after all variable definitions.
For the target package, the generic-package uses the variables defined by
the .mk file and prefixed by the uppercased package name:
LIBFOO_*. host-generic-package uses the HOST_LIBFOO_* variables. For
some variables, if the HOST_LIBFOO_ prefixed variable doesn’t
exist, the package infrastructure uses the corresponding variable
prefixed by LIBFOO_. This is done for variables that are likely to
have the same value for both the target and host packages. See below
for details.
The list of variables that can be set in a .mk file to give metadata
information is (assuming the package name is libfoo) :
LIBFOO_VERSION, mandatory, must contain the version of the
package. Note that if HOST_LIBFOO_VERSION doesn’t exist, it is
assumed to be the same as LIBFOO_VERSION. It can also be a
revision number, branch or tag for packages that are fetched
directly from their revision control system.
Examples:
LIBFOO_VERSION = 0.1.2
LIBFOO_VERSION = cb9d6aa9429e838f0e54faa3d455bcbab5eef057
LIBFOO_VERSION = stable
LIBFOO_SOURCE may contain the name of the tarball of
the package. If HOST_LIBFOO_SOURCE is not specified, it
defaults to LIBFOO_SOURCE. If none are specified, then
the value is assumed to be
packagename-$(LIBFOO_VERSION).tar.gz.
Example: LIBFOO_SOURCE = foobar-$(LIBFOO_VERSION).tar.bz2
LIBFOO_PATCH may contain the name of a patch, that will be
downloaded from the same location as the tarball indicated in
LIBFOO_SOURCE. If HOST_LIBFOO_PATCH is not specified, it
defaults to LIBFOO_PATCH. Note that patches that are included
in Buildroot itself use a different mechanism: all files of the
form <packagename>-*.patch present in the package directory inside
Buildroot will be applied to the package after extraction (see
patching a package
Section 6.3, “Patching a package”).
LIBFOO_SITE provides the location of the package, which can be a
URL or a local filesystem path. HTTP, FTP and SCP are supported URL
types for retrieving package tarballs. Git, Subversion, Mercurial,
and Bazaar are supported URL types for retrieving packages directly
from source code management systems. A filesystem path may be used
to specify either a tarball or a directory containing the package
source code. See LIBFOO_SITE_METHOD below for more details on how
retrieval works.
Note that SCP URLs should be of the form
scp://[user@]host:filepath, and that filepath is relative to the
user’s home directory, so you may want to prepend the path with a
slash for absolute paths:
scp://[user@]host:/absolutepath.
If HOST_LIBFOO_SITE is not specified, it defaults to
LIBFOO_SITE.
Examples:
LIBFOO_SITE=http://www.libfoosoftware.org/libfoo
LIBFOO_SITE=http://svn.xiph.org/trunk/Tremor/
LIBFOO_SITE=git://github.com/kergoth/tslib.git
LIBFOO_SITE=/opt/software/libfoo.tar.gz
LIBFOO_SITE=$(TOPDIR)/../src/libfoo/
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
ftp://.
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.
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
method.
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
control.
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.
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_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 executed to install the package into the target
directory.
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
Section 11.1, “Makedev syntax documentation”. 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 Section 11.1, “Makedev syntax documentation”.
This variable is optional.
LIBFOO_LICENSE defines the license (or licenses) under which the package
is released.
This name will appear in the manifest file produced by make legal-info.
If the license appears in the following list
Section 7.2, “License abbreviations”,
use the same string 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.
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 Chapter 7, Legal notice and licensing 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_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.
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 different steps of the build process.
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
packages.
LIBFOO_CLEAN_CMDS, lists the actions to perform to clean up
the build directory of the package.
LIBFOO_UNINSTALL_TARGET_CMDS lists the actions to
uninstall the package from the target directory $(TARGET_DIR)
LIBFOO_UNINSTALL_STAGING_CMDS lists the actions to
uninstall the package from the staging directory $(STAGING_DIR).
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).
The preferred way to define these variables is:
define LIBFOO_CONFIGURE_CMDS
action 1
action 2
action 3
endefIn the action definitions, you can use the following variables:
$(@D), which contains the directory in which the package source
code has been uncompressed.
$(TARGET_CC), $(TARGET_LD), etc. to get the target
cross-compilation utilities
$(TARGET_CROSS) to get the cross-compilation toolchain prefix
$(HOST_DIR), $(STAGING_DIR) and $(TARGET_DIR)
variables to install the packages properly.
The last feature of the generic infrastructure is the ability to add
hooks. These define further actions to perform after existing steps.
Most hooks aren’t really useful for generic packages, since the .mk
file already has full control over the actions performed in each step
of the package construction. The hooks are more useful for packages
using the autotools infrastructure described below. However, since
they are provided by the generic infrastructure, they are documented
here. The exception is LIBFOO_POST_PATCH_HOOKS. Patching the
package and producing legal info are not user definable, so
LIBFOO_POST_PATCH_HOOKS and LIBFOO_POST_LEGAL_INFO_HOOKS are
useful for generic packages.
The following hook points are available:
LIBFOO_POST_DOWNLOAD_HOOKS
LIBFOO_POST_EXTRACT_HOOKS
LIBFOO_PRE_PATCH_HOOKS
LIBFOO_POST_PATCH_HOOKS
LIBFOO_PRE_CONFIGURE_HOOKS
LIBFOO_POST_CONFIGURE_HOOKS
LIBFOO_POST_BUILD_HOOKS
LIBFOO_POST_INSTALL_HOOKS (for host packages only)
LIBFOO_POST_INSTALL_STAGING_HOOKS (for target packages only)
LIBFOO_POST_INSTALL_TARGET_HOOKS (for target packages only)
LIBFOO_POST_LEGAL_INFO_HOOKS
These variables are lists of variable names containing actions to be performed at this hook point. This allows several hooks to be registered at a given hook point. Here is an example:
define LIBFOO_POST_PATCH_FIXUP
action1
action2
endef
LIBFOO_POST_PATCH_HOOKS += LIBFOO_POST_PATCH_FIXUPFirst, let’s see how to write a .mk file for an autotools-based
package, with an example :
01: ############################################################# 02: # 03: # libfoo 04: # 05: ############################################################# 06: LIBFOO_VERSION = 1.0 07: LIBFOO_SOURCE = libfoo-$(LIBFOO_VERSION).tar.gz 08: LIBFOO_SITE = http://www.foosoftware.org/download 09: LIBFOO_INSTALL_STAGING = YES 10: LIBFOO_INSTALL_TARGET = NO 11: LIBFOO_CONF_OPT = --disable-shared 12: LIBFOO_DEPENDENCIES = libglib2 host-pkgconf 13: 14: $(eval $(autotools-package))
On 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 tarball from this location.
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
using the make install command.
On line 10, we tell Buildroot to not install the package to the
target directory. This directory contains what will become the root
filesystem running on the target. For purely static libraries, it is
not necessary to install them in the target directory because they will
not be used at runtime. By default, target installation is enabled; setting
this variable to NO is almost never needed. 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
and building the package.
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 autotools-package
macro that generates all the Makefile rules that actually allows the
package to be built.
The main macro of the autotools package infrastructure is
autotools-package. It is similar to the generic-package macro. The ability to
have target and host packages is also available, with the
host-autotools-package macro.
Just like the generic infrastructure, the autotools infrastructure
works by defining a number of variables before calling the
autotools-package 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,
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 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
not specified, it defaults to LIBFOO_SUBDIR.
LIBFOO_CONF_ENV, to specify additional environment
variables to pass to the configure script. By default, empty.
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 $(MAKE). If parallel building
is not supported by the package, then it should be set to
LIBFOO_MAKE=$(MAKE1).
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
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
NO. By default, the value is NO
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
default, the value is YES
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
to override it if needed.
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
default, the value is DESTDIR=$$(STAGING_DIR) uninstall.
LIBFOO_UNINSTALL_TARGET_OPT, contains the make
options used to uninstall the package from the target directory. By
default, the value is DESTDIR=$$(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 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
general case.
First, let’s see how to write a .mk file for a CMake-based package,
with an example :
01: ############################################################# 02: # 03: # libfoo 04: # 05: ############################################################# 06: LIBFOO_VERSION = 1.0 07: LIBFOO_SOURCE = libfoo-$(LIBFOO_VERSION).tar.gz 08: LIBFOO_SITE = http://www.foosoftware.org/download 09: LIBFOO_INSTALL_STAGING = YES 10: LIBFOO_INSTALL_TARGET = NO 11: LIBFOO_CONF_OPT = -DBUILD_DEMOS=ON 12: LIBFOO_DEPENDENCIES = libglib2 host-pkgconf 13: 14: $(eval $(cmake-package))
On 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 tarball from this location.
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
using the make install command.
On line 10, we tell Buildroot to not install the package to the
target directory. This directory contains what will become the root
filesystem running on the target. For purely static libraries, it is
not necessary to install them in the target directory because they will
not be used at runtime. By default, target installation is enabled; setting
this variable to NO is almost never needed. Also by default, packages are
installed in this location using the make install command.
On line 11, we tell Buildroot to pass custom options to CMake when it is configuring the package.
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 cmake-package
macro that generates all the Makefile rules that actually allows the
package to be built.
The main macro of the CMake package infrastructure is
cmake-package. It is similar to the generic-package macro. The ability to
have target and host packages is also available, with the
host-cmake-package macro.
Just like the generic infrastructure, the CMake infrastructure works
by defining a number of variables before calling the cmake-package
macro.
First, all the package metadata information variables that exist in
the generic infrastructure also exist in the CMake 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 CMake 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 main CMakeLists.txt file. This is useful,
if for example, the main CMakeLists.txt file 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 variables to
pass to CMake. By default, empty.
LIBFOO_CONF_OPT, to specify additional configure options to pass
to CMake. 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
$(MAKE). If parallel building is not supported by the package,
then it should be set to LIBFOO_MAKE=$(MAKE1).
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 make command. By
default, empty.
LIBFOO_INSTALL_STAGING_OPT contains the make options used to
install the package to the staging directory. By default, the value
is DESTDIR=$(STAGING_DIR) install, which is correct for most
CMake packages. It is still possible to override it.
LIBFOO_INSTALL_TARGET_OPT contains the make options used to
install the package to the target directory. By default, the value
is DESTDIR=$(TARGET_DIR) install. The default value is correct
for most CMake packages, but it is still possible to override it if
needed.
LIBFOO_CLEAN_OPT contains the make options used to clean the
package. By default, the value is clean.
With the CMake infrastructure, all the steps required to build and install the packages are already defined, and they generally work well for most CMake-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 CMake one. However, using this method should be restricted
to very specific cases. Do not use it in the general case.
Many packages that support internationalization use the gettext library. Dependencies for this library are fairly complicated and therefore, deserve 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 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 support
is enabled.
Therefore, Buildroot defines two configuration options:
BR2_NEEDS_GETTEXT, which is true as soon as the toolchain doesn’t
provide its own gettext implementation
BR2_NEEDS_GETTEXT_IF_LOCALE, which is true if the toolchain
doesn’t provide its own gettext implementation and if locale support
is enabled
Packages that need gettext only when locale support is enabled should:
select BR2_PACKAGE_GETTEXT if BR2_NEEDS_GETTEXT_IF_LOCALE in the
Config.in file;
$(if $(BR2_NEEDS_GETTEXT_IF_LOCALE),gettext) in the package
DEPENDENCIES variable in the .mk file.
Packages that unconditionally need gettext (which should be very rare) should:
select BR2_PACKAGE_GETTEXT if BR2_NEEDS_GETTEXT in the Config.in
file;
$(if $(BR2_NEEDS_GETTEXT),gettext) in the package
DEPENDENCIES variable in the .mk file.
In Buildroot, there is some relationship between:
*.mk file);
Config.in file;
It is mandatory to maintain consistency between these elements, using the following rules:
*.mk name are the package name
itself (e.g.: package/foo-bar_boo/foo-bar_boo.mk);
foo-bar_boo);
. and -
characters substituted with _, prefixed with BR2_PACKAGE_ (e.g.:
BR2_PACKAGE_FOO_BAR_BOO);
*.mk file variable prefix is the upper case package name
. and - characters substituted with _ (e.g.:
FOO_BAR_BOO_VERSION).
Packages on github often don’t have a download area with release tarballs. However, it is possible to download tarballs directly from the repository on github.
If the package version matches a tag, then this tag should be used to identify the version:
FOO_VERSION = v1.0 FOO_SITE = http://github.com/<user>/<package>/tarball/$(FOO_VERSION)
If the package has no release version, or its version cannot be identified using tag, then the SHA1 of the particular commit should be used to identify the version (the first 7 characters of the SHA1 are enough):
FOO_VERSION = 1234567 FOO_SITE = http://github.com/<user>/<package>/tarball/<branch>
Note that the name of the tarball is the default foo-1234567.tar.gz
so it is not necessary to specify it in the .mk file.
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 forget to send a patch to the Buildroot mailing list (see Section 10.1, “Submitting patches”)!
While integrating a new package or updating an existing one, it may be necessary to patch the source of the software to get it cross-built within Buildroot.
Buildroot offers an infrastructure to automatically handle this during the builds. It supports two ways of applying patch sets: downloaded patches and patches supplied within buildroot.
If it is necessary to apply a patch that is available for download, then it
to the <packagename>_PATCH variable. It is downloaded from the same site
as the package itself. It can be a single patch, or a tarball containing a
patch series.
This method is typically used for packages from Debian.
Most patches are provided within Buildroot, in the package directory; these typically aim to fix cross-compilation, libc support, or other such issues.
These patch files should be named <packagename>-*.patch.
A series file, as used by quilt, may also be added in the
package directory. In that case, the series file defines the patch
application order.
<packagename>_PRE_PATCH_HOOKS commands if defined;
*.rej files;
<packagename>_PATCH is defined, then patches from these
tarballs are applied;
If there are some *.patch files in the package directory or in the
a package subdirectory named <packagename>-<packageversion>, then:
series file exists in the package directory, then patches are
applied according to the series file;
<packagename>-*.patch or
<packagename>-*.patch.<arch> (where <arch> is the architecture
name) are applied following the ls command order.
<packagename>_POST_PATCH_HOOKS commands if defined.
If something goes wrong in the steps 3 or 4, then the build fails.
Patches are released under the same license as the software that is modified.
A message explaining what the patch does, and why it is needed, should be added in the header commentary of the patch.
You should add a Signed-off-by statement in the header of the each
patch to help with keeping track of the changes and to certify that the
patch is released under the same license as the software that is modified.
If the software is under version control, it is recommended to use the upstream SCM software to generate the patch set.
Otherwise, concatenate the header with the output of the
diff -purN package-version.orig/ package-version/ command.
At the end, the patch should look like:
configure.ac: add C++ support test signed-off-by John Doe <john.doe@noname.org> --- configure.ac.orig +++ configure.ac @@ -40,2 +40,12 @@ AC_PROG_MAKE_SET + +AC_CACHE_CHECK([whether the C++ compiler works], + [rw_cv_prog_cxx_works], + [AC_LANG_PUSH([C++]) + AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])], + [rw_cv_prog_cxx_works=yes], + [rw_cv_prog_cxx_works=no]) + AC_LANG_POP([C++])]) + +AM_CONDITIONAL([CXX_WORKS], [test "x$rw_cv_prog_cxx_works" = "xyes"])
When integrating a patch of which you are not the author, you have to add a few things in the header of the patch itself.
Depending on whether the patch has been obtained from the project repository itself, or from somewhere on the web, add one of the following tags:
Backported from: <some commit id>
or
Fetch from: <some url>
It is also sensible to add a few words about any changes to the patch that may have been necessary.
Creating your own board support in Buildroot allows users of a particular hardware platform to easily build a system that is known to work.
To do so, you need to create a normal Buildroot configuration that builds a basic system for the hardware: toolchain, kernel, bootloader, filesystem and a simple Busybox-only userspace. No specific package should be selected: the configuration should be as minimal as possible, and should only build a working basic Busybox system for the target platform. You can of course use more complicated configurations for your internal projects, but the Buildroot project will only integrate basic board configurations. This is because package selections are highly application-specific.
Once you have a known working configuration, run make
savedefconfig. This will generate a minimal defconfig file at the
root of the Buildroot source tree. Move this file into the configs/
directory, and rename it BOARDNAME_defconfig.
It is recommended to use upstream versions of the Linux kernel and bootloaders where possible, and also to use default kernel and bootloader configurations if possible. If the defaults are incorrect for your board, or no default exists, we encourage you to send fixes to the corresponding upstream projects.
However, in the mean time, you may want to store kernel or bootloader
configuration or patches specific to your target platform. To do so,
create a directory board/MANUFACTURER and a subdirectory
board/MANUFACTURER/BOARDNAME (after replacing, of course,
MANUFACTURER and BOARDNAME with the appropriate values, in lower case
letters). You can then store your patches and configurations in these
directories, and reference them from the main Buildroot configuration.
All of the end products of Buildroot (toolchain, root filesystem, kernel, bootloaders) contain open source software, released under various licenses.
Using open source software gives you the freedom to build rich embedded systems, choosing from a wide range of packages, but also imposes some obligations that you must know and honour. Some licenses require you to publish the license text in the documentation of your product. Others require you to redistribute the source code of the software to those that receive your product.
The exact requirements of each license are documented in each package, and
it is your responsibility (or that of your legal office) to comply with those
requirements.
To make this easier for you, Buildroot can collect for you some material you
will probably need. To produce this material, after you have configured
Buildroot with make menuconfig, make xconfig or make gconfig, run:
make legal-info
Buildroot will collect legally-relevant material in your output directory,
under the legal-info/ subdirectory.
There you will find:
README file, that summarizes the produced material and contains warnings
about material that Buildroot could not produce.
buildroot.config: this is the Buildroot configuration file that is usually
produced with make menuconfig, and which is necessary to reproduce the
build.
sources/
subdirectory (except for proprietary packages, whose source code is not
saved);
patches applied to some packages by Buildroot are distributed with the
Buildroot sources and are not duplicated in the sources/ subdirectory.
licenses/ subdirectory, which contains the license text of packages.
If the license file(s) are not defined in Buildroot, the file is not produced
and a warning in the README indicates this.
Please note that the aim of the legal-info feature of Buildroot is to
produce all the material that is somehow relevant for legal compliance with the
package licenses. Buildroot does not try to produce the exact material that
you must somehow make public. Certainly, more material is produced than is
needed for a strict legal compliance. For example, it produces the source code
for packages released under BSD-like licenses, that you are not required to
redistribute in source form.
Moreover, due to technical limitations, Buildroot does not produce some
material that you will or may need, such as the toolchain source code and the
Buildroot source code itself (including patches to packages for which source
distribution is required).
When you run make legal-info, Buildroot produces warnings in the README
file to inform you of relevant material that could not be saved.
Here is a list of the licenses that are most widely used by packages in Buildroot, with the name used in the manifest file:
GPLv2:
GNU General Public License, version 2;
GPLv2+:
GNU General Public License, version 2
or (at your option) any later version;
GPLv3:
GNU General Public License, version 3;
GPLv3+:
GNU General Public License, version 3
or (at your option) any later version;
GPL:
GNU General Public License (any version);
LGPLv2:
GNU Library General Public License, version 2;
LGPLv2+:
GNU Library General Public License, version 2.1
or (at your option) any later version;
LGPLv2.1:
GNU Lesser General Public License, version 2.1;
LGPLv2.1+:
GNU Lesser General Public License, version 2.1
or (at your option) any later version;
LGPLv3:
GNU Lesser General Public License, version 3;
LGPLv3+:
GNU Lesser General Public License, version 3
or (at your option) any later version;
LGPL:
GNU Lesser General Public License (any version);
BSD-4c: Original BSD 4-clause license;
BSD-3c: BSD 3-clause license;
BSD-2c: BSD 2-clause license;
MIT: MIT-style license.
Buildroot itself is an open source software, released under the GNU General Public License, version 2 or (at your option) any later version. However, being a build system, it is not normally part of the end product: if you develop the root filesystem, kernel, bootloader or toolchain for a device, the code of Buildroot is only present on the development machine, not in the device storage.
Nevertheless, the general view of the Buildroot developers is that you should release the Buildroot source code along with the source code of other packages when releasing a product that contains GPL-licensed software. This is because the GNU GPL defines the "complete source code" for an executable work as "all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable". Buildroot is part of the scripts used to control compilation and installation of the executable, and as such it is considered part of the material that must be redistributed.
Keep in mind that this is only the Buildroot developers' opinion, and you should consult your legal department or lawyer in case of any doubt.
To achieve NFS-boot, enable tar root filesystem in the Filesystem images menu.
After a complete build, just run the following commands to setup the NFS-root directory:
sudo tar -xavf /path/to/output_dir/rootfs.tar -C /path/to/nfs_root_dir
Remember to add this path to /etc/exports.
Then, you can execute a NFS-boot from your target.
If you want to chroot in a generated image, then there are few thing you should be aware of:
qemu-* binary and correctly set it
within the binfmt properties to be able to run the binaries built
for the target on your host machine;
host-qemu and binfmt
correctly built and set for that kind of use.
Like any open source project, Buildroot has different ways to share information in its community and outside.
One piece of it is the document you are currently reading ;-).
Each of those ways may interest you if you are looking for some help, want to understand Buildroot or contribute to the project.
Buildroot has a mailing list http://lists.busybox.net/pipermail/buildroot for discussion and development.
You can subscribe by visiting http://lists.busybox.net/mailman/listinfo/buildroot. Only subscribers to the Buildroot mailing list are allowed to post to this list.
The list is also available through Gmane http://gmane.org, at
gmane.comp.lib.uclibc.buildroot
http://dir.gmane.org/gmane.comp.lib.uclibc.buildroot.
Please search the mailing list archives before asking questions on the mailing list, since there is a good chance someone else has asked the same question before. Checking the archives is a great way to avoid annoying everyone on the list with frequently asked questions…
The Buildroot IRC is irc://freenode.net/#buildroot.
The channel #buildroot is hosted on Freenode
http://webchat.freenode.net.
When asking for help on IRC, share relevant logs or pieces of code using a code sharing website.
The Buildroot patch management interface is at http://patchwork.buildroot.org.
All patches and comments sent through the mailing list are automatically indexed in patchwork.
The Buildroot bugtracker is at https://bugs.busybox.net.
To open a bug, see Section 10.4, “Reporting issues/bugs, get help”.
After the Buildroot developer day on February 3, 2012, a page dedicated to Buildroot has been created on elinux.org.
This page is reachable at http://elinux.org/Buildroot.
Currently, this page is mainly used as a todo-list.
If you want to contribute to Buildroot, you will need a git view of the project. Refer to Section 2.2, “Getting Buildroot” to get it.
Currently, the mailing list is the central place for contribution. If you have not already subscribed to it, then refer to Section 9.1.1, “Subscribing to the mailing list”.
Recently, a web interface is also used to manage patches sent to the mailing list, see Section 9.3, “Patchwork”.
Please, do not attach patches to bugs, send them to the mailing list instead (see Section 10.1, “Submitting patches”).
When your changes are done, and committed in your local git view, rebase your development branch on top of the upstream tree before generating the patch set. To do so, run:
$ git fetch --all --tags $ git rebase origin/master
Here, you are ready to generate then submit your patch set.
To generate it, run:
$ git format-patch -M -n -s -o outgoing origin/master
This will generate patch files in the outgoing subdirectory,
automatically adding the signed-off-by line.
If you want to present the whole patch set in a separate mail, add
--cover-letter to the previous command line (man git-format-patch
for further information).
Once patch files are generated, you can review/edit the commit message before submitting them using your favorite text editor.
Lastly, send/submit your patch set to the Buildroot mailing list:
$ git send-email --to buildroot@busybox.net outgoing/*
Note that git should be configured to use your mail account.
To configure git, see man git-send-email or google it.
Make sure posted patches are not line-wrapped, otherwise they cannot
easily be applied. In such a case, fix your e-mail client, or better,
use git send-email to send your patches.
In the review process, do not hesitate to respond to patch submissions for remarks, suggestions or anything that will help everyone to understand the patches and make them better.
Some tags are used to help following the state of any patch posted on the mailing-list:
The Buildroot community is currently setting up automatic builds in order to test more and more configurations. All build results are available at http://autobuild.buildroot.org
A good way to contribute is by fixing broken builds.
In the commit message of a patch fixing an autobuild, add a
reference to the build result directory (the dir link in the data
column):
Fixes http://autobuild.buildroot.org/results/51000a9d4656afe9e0ea6f07b9f8ed374c2e4069
Before reporting any issue, please check the mailing list archive Section 9.1.1, “Subscribing to the mailing list” in case someone has already reported and fixed a similar problem.
However you choose to report bugs or get help, opening a bug Section 9.4, “Bugtracker” or send a mail to the mailing list Section 9.1.1, “Subscribing to the mailing list”, there are a number of details to provide in order to help people reproduce and find a solution to the issue.
Try to think as if you were trying to help someone else; in that case, what would you need?
Here is a short list of details to provide in such case:
Additionnally, your can add the .config file.
If some of these details are too large, do not hesitate to use a pastebin service (see http://www.similarsitesearch.com/alternatives-to/pastebin.com).
The makedev syntax is used in several places in Buildroot to define changes to be made for permissions, or which device files to create and how to create them, in order to avoid calls to mknod.
This syntax is derived from the makedev utility, and more complete
documentation can be found in the package/makedevs/README file.
It takes the form of a line for each file, with the following layout:
name | type | mode | uid | gid | major | minor | start | inc | count |
There are a few non-trivial blocks here:
name is the path to the file you want to create/modify
type is the type of the file, being one of:
mode, uid and gid are the usual permissions settings
major and minor are here for device files - set to - for other
files
start, inc and count are for when you want to create a batch
of files, and can be reduced to a loop, beginning at start,
incrementing its counter by inc until it reaches count
Let’s say you want to change the permissions of a given file; using this syntax, you will need to put:
/usr/bin/foobar f 644 0 0 - - - - -
On the other hand, if you want to create the device file /dev/hda
and the corresponding 15 files for the partitions, you will need for
/dev/hda:
/dev/hda b 640 0 0 3 0 0 0 -
and then for device files corresponding to the partitions of
/dev/hda, /dev/hdaX, X ranging from 1 to 15:
/dev/hda b 640 0 0 3 1 1 1 15
The following stuff are marked as deprecated in Buildroot due to their status either too old or unmaintained.
Packages:
busybox 1.18.x
customize
lzma
microperl
netkitbase
netkittelnet
pkg-config
squashfs3
ttcp
Toolchain:
gdb 6.8
gdb 7.0.1
gdb 7.1
kernel headers 2.6.37
kernel headers 2.6.38
kernel headers 2.6.39
Bootloaders:
u-boot 2011-06
u-boot 2011-09
Output images: