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- <title>Buildroot - Usage and documentation</title>
+ <title>OpenWrt Buildroot - Usage and documentation</title>
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- <h1>Buildroot</h1>
+ <h1>OpenWrt Buildroot</h1>
</div>
- <p>Usage and documentation by Thomas Petazzoni. Contributions from
- Karsten Kruse, Ned Ludd, Martin Herren.</p>
+ <p>Usage and documentation by Felix Fietkau and Waldemar Brodkorb, based on uClibc Buildroot
+ documentation by Thomas Petazzoni. Contributions from Karsten Kruse,
+ Ned Ludd, Martin Herren. OpenWrt Kernel Module Creation Howto by Markus Becker.</p>
<p><small>Last modification : $Id$</small></p>
<ul>
- <li><a href="#about">About Buildroot</a></li>
- <li><a href="#download">Obtaining Buildroot</a></li>
- <li><a href="#using">Using Buildroot</a></li>
+ <li><a href="#about">About OpenWrt Buildroot</a></li>
+ <li><a href="#download">Obtaining OpenWrt Buildroot</a></li>
+ <li><a href="#using">Using OpenWrt Buildroot</a></li>
<li><a href="#custom_targetfs">Customizing the target filesystem</a></li>
<li><a href="#custom_busybox">Customizing the Busybox
configuration</a></li>
<li><a href="#custom_uclibc">Customizing the uClibc
configuration</a></li>
- <li><a href="#buildroot_innards">How Buildroot works</a></li>
+ <li><a href="#buildroot_innards">How OpenWrt Buildroot works</a></li>
<li><a href="#using_toolchain">Using the uClibc toolchain</a></li>
<li><a href="#toolchain_standalone">Using the uClibc toolchain
outside of Buildroot</a></li>
<li><a href="#downloaded_packages">Location of downloaded packages</a></li>
- <li><a href="#add_software">Extending Buildroot with more
- Software</a></li>
+ <li><a href="#add_software">Extending OpenWrt with more Software</a></li>
<li><a href="#links">Ressources</a></li>
+<br>
+ <li><a href="#about_module">About OpenWrt Kernel Module Compilation</a></li>
+ <li><a href="#kernel">Enable the kernel options</a></li>
+ <li><a href="#buildroot_option">Create a buildroot option</a></li>
+ <li><a href="#binary">Define the binary files for the kernel module</a></li>
+ <li><a href="#control">Specify the ipkg control file</a></li>
+ <li><a href="#compile">Compile the kernel module</a></li>
+
</ul>
- <h2><a name="about" id="about"></a>About Buildroot</h2>
+ <h2><a name="about" id="about"></a>About OpenWrt Buildroot</h2>
- <p>Buildroot is a set of Makefiles and patches that allows to easily
+ <p>OpenWrt Buildroot is a set of Makefiles and patches that allows to easily
generate both a cross-compilation toolchain and a root filesystem for your
-
target. The cross-compilation toolchain uses uClibc (<a href=
+
Wireless Router. The cross-compilation toolchain uses uClibc (<a href=
"http://www.uclibc.org/">http://www.uclibc.org/</a>), a tiny C standard
library.</p>
- <p>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 have on his PC. It can be PowerPC
- processors, MIPS processors, ARM processors, etc.</p>
-
<p>A compilation toolchain is the set of tools that allows to
compile code for your system. It consists of a compiler (in our
case, <code>gcc</code>), binary utils like assembler and linker
toolchain is called the "host compilation toolchain", and more
generally, 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
+ provided by your distribution, and OpenWrt Buildroot has nothing to do
with it.</p>
<p>As said above, the compilation toolchain that comes with your system
embedded system has a different processor, you need a cross-compilation
toolchain: it's a compilation toolchain that runs on your host system but
that generates code for your target system (and target processor). For
- example, if your host system uses x86 and your target system uses ARM, the
+ example, if your host system uses x86 and your target system uses MIPS, the
regular compilation toolchain of your host runs on x86 and generates code
for x86, while the cross-compilation toolchain runs on x86 and generates
- code for ARM.</p>
-
- <p>Even if your embedded system uses a x86 processor, you might interested
- in Buildroot, for two reasons:</p>
-
- <ul>
- <li>The compilation toolchain of your host certainly uses the GNU Libc
- which is a complete but huge C standard library. Instead of using GNU
- Libc on your target system, you can use uClibc which is a tiny C standard
- library. If you want to use this C library, then you need a compilation
- toolchain to generate binaries linked with it. Buildroot can do it for
- you.</li>
-
- <li>Buildroot automates the building of a root filesystem with all needed
- tools like busybox. It makes it much easier than doing it by hand.</li>
- </ul>
+ code for MIPS.</p>
<p>You might wonder why such a tool is needed when you can compile
<code>gcc</code>, <code>binutils</code>, uClibc and all the tools by hand.
Of course, doing so is possible. But dealing with all configure options,
with all problems of every <code>gcc</code> or <code>binutils</code>
- version it very time-consuming and uninteresting. Buildroot automates this
+ version is very time-consuming and uninteresting. OpenWrt Buildroot automates this
process through the use of Makefiles, and has a collection of patches for
each <code>gcc</code> and <code>binutils</code> version to make them work
- on most architectures.</p>
-
- <h2><a name="download" id="download"></a>Obtaining Buildroot</h2>
+ on the MIPS architecture of most Wireless Routers.</p>
- <p>Buildroot is available as daily CVS snapshots or directly using
- CVS.</p>
+ <h2><a name="download" id="download"></a>Obtaining OpenWrt Buildroot</h2>
- <p>The latest snapshot is always available at <a
- href="http://uclibc.org/downloads/snapshots/buildroot-snapshot.tar.bz2">http://uclibc.org/downloads/snapshots/buildroot-snapshot.tar.bz2</a>,
- and previous snapshots are also available at <a
- href="http://uclibc.org/downloads/snapshots/">http://uclibc.org/downloads/snapshots/</a>.</p>
-
- <p>To download Buildroot using CVS, you can simply follow
- the rules described on the "Accessing CVS"-page (<a href=
- "http://www.uclibc.org/cvs_anon.html">http://www.uclibc.org/cvs_anon.html</a>)
- of the uClibc website (<a href=
- "http://www.uclibc.org">http://www.uclibc.org</a>), and download the
- <code>buildroot</code> CVS module. For the impatient, here's a quick
- recipe:</p>
-
- <pre>
- $ cvs -d:pserver:anonymous@uclibc.org:/var/cvs login
- $ cvs -z3 -d:pserver:anonymous@uclibc.org:/var/cvs co buildroot
+ <p>OpenWrt Buildroot is available via CVS - Concurrent Version System.
+ For any kind of development you should get the latest version from cvs via:</p>
+<pre>
+ $ cvs -d:pserver:anonymous@openwrt.org:/openwrt co openwrt
</pre>
- <h2><a name="using" id="using"></a>Using Buildroot</h2>
+ <h2><a name="using" id="using"></a>Using OpenWrt Buildroot</h2>
- <p>Buildroot has a nice configuration tool similar to the one you can find
- in the Linux Kernel (<a href=
- "http://www.kernel.org/">http://www.kernel.org/</a>) or in Busybox
- (<a href="http://www.busybox.org/">http://www.busybox.org/</a>). Note that
- you can run 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
+ <p>OpenWrt Buildroot has a nice configuration tool similar to the one you can find
+ in the Linux Kernel (<a href="http://www.kernel.org/">http://www.kernel.org/</a>)
+ or in Busybox (<a href="http://www.busybox.org/">http://www.busybox.org/</a>).
+ Note that you can run everything as a normal user. There is no need to be root to
+ configure and use the Buildroot. The first step is to run the configuration
assistant:</p>
<pre>
</pre>
<p>This command will download, configure and compile all the selected
- tools, and finally generate a target filesystem. The target filesystem will
- be named <code>root_fs_ARCH.EXT</code> where <code>ARCH</code> is your
- architecture and <code>EXT</code> depends on the type of target filesystem
- selected in the <code>Target options</code> section of the configuration
- tool.</p>
-
+ tools, and finally generate target firmware images and additional packages
+ (depending on your selections in <code>make menuconfig</code>.
+ All the target files can be found in the <code>bin/</code> subdirectory.
+ You can compile firmware images containing two different filesystem types:
+ <ul>
+ <li>jffs2</li>
+ <li>squashfs</li>
+ </ul>
+ <p><code>jffs2</code> contains a writable root filesystem, which will expand to
+ the size of your flash image. Note: if you use the generic firmware image, you
+ need to pick the right image for your flash size, because of different
+ eraseblock sizes.</p>
+
+ <p><code>squashfs</code> contains a read-only root filesystem using a modified
+ <code>squashfs</code> filesystem with LZMA compression. When booting it, you can
+ create a writable second filesystem, which will contain your modifications to
+ the root filesystem, including the packages you install.
+
<h2><a name="custom_targetfs" id="custom_targetfs"></a>Customizing the
target filesystem</h2>
<ul>
<li>Customize the target filesystem directly, and rebuild the image. The
target filesystem is available under <code>build_ARCH/root/</code> where
- <code>ARCH</code> is the chosen target architecture. You can simply make
- your changes here, and run make afterwards, which will rebuild the target
- filesystem image. This method allows to do everything on the target
- filesystem, but if you decide to completely rebuild your toolchain and
- tools, these changes will be lost.</li>
+ <code>ARCH</code> is the chosen target architecture, usually mipsel.
+ You can simply make your changes here, and run make target_install afterwards,
+ which will rebuild the target filesystem image. This method allows to do
+ everything on the target filesystem, but if you decide to rebuild your toolchain,
+ tools or packages, these changes will be lost.</li>
<li>Customize the target filesystem skeleton, available under
<code>target/default/target_skeleton/</code>. 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.
So you can't do everything on this target filesystem skeleton, but
- changes to it remains even you completely rebuild the cross-compilation
+ changes to it remains even when you completely rebuild the cross-compilation
toolchain and the tools.<br />
- You can also customize the <code>target/default/device_table.txt</code>
- file which is used by the tools that generate the target filesystem image
- to properly set permissions and create device nodes. The
- <code>target/default/skel.tar.gz</code> file contains the main
- directories of a root filesystem and there is no obvious reason for which
- it should be changed. These main directories are in an tarball inside of
- inside the skeleton because it contains symlinks that would be broken
- otherwise.</li>
</ul>
<h2><a name="custom_busybox" id="custom_busybox"></a>Customizing the
Busybox configuration</h2>
- <p>Busybox is very configurable, and you may want to customize it. You can
- follow these simple steps to do it. It's not an optimal way, but it's
- simple and it works.</p>
-
- <ol>
- <li>Make a first compilation of buildroot with busybox without trying to
- customize it.</li>
-
- <li>Go into <code>build_ARCH/busybox/</code> and run <code>make
- menuconfig</code>. The nice configuration tool appears and you can
- customize everything.</li>
-
- <li>Copy the <code>.config</code> file to
- <code>package/busybox/busybox.config</code> so that your customized
- configuration will remains even if you remove the cross-compilation
- toolchain.</li>
-
- <li>Run the compilation of buildroot again.</li>
- </ol>
-
- <p>Otherwise, you can simply change the
- <code>package/busybox/busybox.config</code> file if you know the options
- you want to change without using the configuration tool.</p>
+ <p>Busybox is very configurable, and you may want to customize it.
+ Its configuration is completely integrated into the main menuconfig system.
+ You can find it under "OpenWrt Package Selection" => "Busybox Configuration"</p>
<h2><a name="custom_uclibc" id="custom_uclibc"></a>Customizing the uClibc
configuration</h2>
<li>Go into the directory
<code>toolchain_build_ARCH/uClibc/</code> and run <code>make
menuconfig</code>. The nice configuration assistant, similar to
- the one used in the Linux Kernel or in Buildroot appears. Make
+ the one used in the Linux Kernel appears. Make
your configuration as appropriate.</li>
<li>Copy the <code>.config</code> file to
<code>toolchain/uClibc/uClibc.config</code> or
<code>toolchain/uClibc/uClibc.config-locale</code>. The former
- is used if you haven't selected locale support in Buildroot
+ is used if you haven't selected locale support in the Buildroot
configuration, and the latter is used if you have selected
locale support.</li>
- <li>Run the compilation of Buildroot again</li>
+ <li>Run the compilation again.</li>
</ol>
<code>toolchain/uClibc/uClibc.config-locale</code> without running
the configuration assistant.</p>
- <h2><a name="buildroot_innards" id="buildroot_innards"></a>How Buildroot
+ <h2><a name="buildroot_innards" id="buildroot_innards"></a>How OpenWrt Buildroot
works</h2>
- <p>As said above, Buildroot is basically a set of Makefiles that download,
+ <p>As said above, OpenWrt is basically a set of Makefiles that download,
configure and compiles software with the correct options. It also includes
some patches for various software, mainly the ones involved in the
cross-compilation tool chain (<code>gcc</code>, <code>binutils</code> and
uClibc).</p>
- <p>There is basically one Makefile per software, and they are named with
- the <code>.mk</code> extension. Makefiles are split into three
- sections:</p>
+ <p>There is basically one Makefile per software, and they are named <code>Makefile</code>.
+ Makefiles are split into three sections:</p>
<ul>
<li><b>package</b> (in the <code>package/</code> directory) contains the
<li><b>target</b> (in the <code>target</code> directory) contains the
Makefiles and associated files for software related to the generation of
- the target root filesystem image. Four types of filesystems are supported
- : ext2, jffs2, cramfs and squashfs. For each of them, there's a
- sub-directory with the required files. There is also a
- <code>default/</code> directory that contains the target filesystem
- skeleton.</li>
+ the target root filesystem image and the linux kernel for the different
+ system on a chip boards, used in the Wireless Routers.
+ Two types of filesystems are supported
+ : jffs2 and squashfs.
</ul>
- <p>Each directory contains at least 3 files :</p>
+ <p>Each directory contains at least 2 files :</p>
<ul>
- <li><code>something.mk</code> is the Makefile that downloads, configures,
+ <li><code>Makefile</code> is the Makefile that downloads, configures,
compiles and installs the software <code>something</code>.</li>
<li><code>Config.in</code> is a part of the configuration tool
description file. It describes the option related to the current
software.</li>
-
- <li><code>Makefile.in</code> is a part of Makefile that sets various
- variables according to the configuration given through the configuration
- tool. For most tools it simply involves adding the name of the tool to
- the <code>TARGETS</code> variable.</li>
</ul>
<p>The main Makefile do the job through the following steps (once the
is your architecture). This is where the cross compilation toolchain will
be compiled.</li>
- <li>Setup the staging directory (<code>build_ARCH/staging_dir/</code> by
+ <li>Setup the staging directory (<code>staging_dir_ARCH/</code> by
default). This is where the cross-compilation toolchain will be
installed. If you want to use the same cross-compilation toolchain for
other purposes, such as compiling third-party applications, you can add
- <code>build_ARCH/staging_dir/bin</code> to your PATH, and then use
+ <code>staging_dir_ARCH/bin</code> to your PATH, and then use
<code>arch-linux-gcc</code> to compile your application. In order to
setup this staging directory, it first removes it, and then it creates
various subdirectories and symlinks inside it.</li>
<li>Create the target directory (<code>build_ARCH/root/</code> by
default) and the target filesystem skeleton. This directory will contain
- the final root filesystem. To setup it up, it first deletes it, then it
- uncompress the <code>target/default/skel.tar.gz</code> file to create the
- main subdirectories and symlinks, copies the skeleton available in
- <code>target/default/target_skeleton</code> and then removes useless
- <code>CVS/</code> directories.</li>
-
- <li>Make the <code>TARGETS</code> dependency. This is where all the job
- is done : all <code>Makefile.in</code> files "subscribe" targets into
- this global variable, so that the needed tools gets compiled.</li>
+ the final root filesystem. To set it up, it first deletes it, then it
+ copies the skeleton available in <code>target/default/target_skeleton</code>
+ and then removes useless <code>CVS/</code> directories.</li>
+
+ <li>Call the <code>prepare</code>, <code>compile</code> and <code>install</code>
+ targets for the subdirectories <code>toolchain</code>, <code>package</code>
+ and <code>target</code></li>
</ol>
<h2><a name="using_toolchain" id="using_toolchain"></a>Using the
uClibc toolchain</h2>
<p>You may want to compile 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.</p>
+ that are not packaged in OpenWrt. In order to do this, you can
+ use the toolchain that was generated by the Buildroot.</p>
- <p>The toolchain generated by Buildroot by default is located in
- <code>build_ARCH/staging_dir/</code>. The simplest way to use it
- is to add <code>build_ARCH/staging_dir/bin/</code> to your PATH
- environnement variable, and then to use
+ <p>The toolchain generated by the Buildroot by default is located in
+ <code>staging_dir_ARCH</code>. The simplest way to use it
+ is to add <code>staging_dir_ARCH/bin/</code> to your PATH
+ environment variable, and then to use
<code>arch-linux-gcc</code>, <code>arch-linux-objdump</code>,
<code>arch-linux-ld</code>, etc.</p>
<p>For example, you may add the following to your
<code>.bashrc</code> (considering you're building for the MIPS
architecture and that Buildroot is located in
- <code>~/buildroot/</code>) :</p>
+ <code>~/openwrt/</code>) :</p>
<pre>
-export PATH=$PATH:~/buildroot/build_mips/bin/
+export PATH=$PATH:~/openwrt/staging_dir_mipsel/bin/
</pre>
<p>Then you can simply do :</p>
<pre>
-mips-linux-gcc -o foo foo.c
+mipsel-linux-uclibc-gcc -o foo foo.c
</pre>
<p><b>Important</b> : do not try to move the toolchain to an other
uClibc toolchain outside of buildroot</h2>
<p>By default, the cross-compilation toolchain is generated inside
- <code>build_ARCH/staging_dir/</code>. But sometimes, it may be useful to
+ <code>staging_dir_ARCH/</code>. But sometimes, it may be useful to
install it somewhere else, so that it can be used to compile other programs
- or by other users. Moving the <code>build_ARCH/staging_dir/</code>
+ or by other users. Moving the <code>staging_dir_ARCH/</code>
directory elsewhere is <b>not possible</b>, because they are some hardcoded
paths in the toolchain configuration.</p>
<p>If you want to use the generated toolchain for other purposes,
you can configure Buildroot to generate it elsewhere using the
- option of the configuration tool : <code>Build options ->
+ option of the configuration tool : <code>Build options ->
Toolchain and header file location</code>, which defaults to
- <code>$(BUILD_DIR)/staging_dir/</code>.</p>
+ <code>staging_dir_ARCH/</code>.</p>
<h2><a name="downloaded_packages"
id="downloaded_packages"></a>Location of downloaded packages</h2>
downloaded by the <i>Makefiles</i> are all stored in the
<code>DL_DIR</code> which by default is the <code>dl</code>
directory. It's useful for example if you want to keep a complete
- version of Buildroot which is know to be working with the
+ 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.</p>
- <h2><a name="add_software" id="add_software"></a>Extending Buildroot with
+ <h2><a name="add_software" id="add_software"></a>Extending OpenWrt with
more software</h2>
<p>This section will only consider the case in which you want to
<pre>
config BR2_PACKAGE_FOO
- bool "foo"
- default n
+ tristate "foo - some nice tool"
+ default m if CONFIG_DEVEL
help
This is a comment that explains what foo is.
</pre>
+ <p>If you depend on other software or library inside the Buildroot, it
+ is important that you automatically select these packages in your
+ <code>Config.in</code>. Example if foo depends on bar library:
+ </p>
+<pre>
+config BR2_PACKAGE_FOO
+ tristate "foo - some nice tool"
+ default m if CONFIG_DEVEL
+ select BR2_PACKAGE_LIBBAR
+ help
+ This is a comment that explains what foo is.
+</pre>
+
<p>Of course, you can add other options to configure particular
things in your software.</p>
- <h3><code>Makefile.in</code> file</h3>
+ <h3><code>Config.in</code> in the package directory</h3>
+
+ <p>To add your package to the configuration tool, you need
+ to add the following line to <code>package/Config.in</code>,
+ please add it to a section, which fits the purpose of foo:
- <p>Then, write a <code>Makefile.in</code> file. Basically, this is
- a very short <i>Makefile</i> that adds the name of the software to
- the list of <code>TARGETS</code> that Buildroot will generate. In
- fact, the name of the software is the the identifier of the target
- inside the real <i>Makefile</i> that will do everything (download,
- compile, install), and that we study below. Back to
- <code>Makefile.in</code>, here is an example :</p>
+<pre>
+comment "Networking"
+source "package/foo/Config.in"
+</pre>
+
+ <h3><code>Makefile</code> in the package directory</h3>
+
+ <p>To add your package to the build process, you need to edit
+ the Makefile in the <code>package/</code> directory. Locate the
+ lines that look like the following:</p>
<pre>
-ifeq ($(strip $(BR2_PACKAGE_FOO)),y)
-TARGETS+=foo
-endif
+package-$(BR2_PACKAGE_FOO) += foo
</pre>
- <p>As you can see, this short <i>Makefile</i> simply adds the
- target <code>foo</code> to the list of targets handled by Buildroot
- if software <i>foo</i> was selected using the configuration tool.</p>
+ <p>As you can see, this short line simply adds the target
+ <code>foo</code> to the list of targets handled by OpenWrt Buildroot.</p>
+
+ <p>In addition to the default dependencies, you make your package
+ depend on another package (e.g. a library) by adding a line:
+
+<pre>
+foo-compile: bar-compile
+</pre>
+
+ <h3>The ipkg control file</h3>
+ <p>Additionally, you need to create a control file which contains
+ information about your package, readable by the <i>ipkg</i> package
+ utility. It should be created as file:
+ <code>package/foo/ipkg/foo.control</code></p>
+
+ <p>The file looks like this</p>
+
+<pre>
+ 1 Package: foo
+ 2 Priority: optional
+ 3 Section: net
+ 4 Maintainer: Foo Software <foo@foosoftware.com>
+ 5 Source: http://foosoftware.com
+ 6 Depends: libbar
+ 7 Description: Package Description
+</pre>
+
+ <p>You can skip the usual <code>Version:</code> and <code>Architecture</code>
+ fields, as they will be generated by the <code>make-ipkg-dir.sh</code> script
+ called from your Makefile. The Depends field is important, so that ipkg will
+ automatically fetch all dependend software on your target system.</p>
<h3>The real <i>Makefile</i></h3>
<p>Finally, here's the hardest part. Create a file named
- <code>foo.mk</code>. It will contain the <i>Makefile</i> rules that
+ <code>Makefile</code>. It will contain the <i>Makefile</i> rules that
are in charge of downloading, configuring, compiling and installing
- the software. Below is an example that we will comment
- afterwards.</p>
+ the software. Below is an example that we will comment afterwards.</p>
<pre>
- 1 #############################################################
- 2 #
- 3 # foo
- 4 #
- 5 #############################################################
- 6 FOO_VERSION:=1.0
- 7 FOO_SOURCE:=less-$(FOO_VERSION).tar.gz
- 8 FOO_SITE:=http://www.foosoftware.org/downloads
- 9 FOO_DIR:=$(BUILD_DIR)/less-$(FOO_VERSION)
- 10 FOO_BINARY:=foo
- 11 FOO_TARGET_BINARY:=usr/bin/foo
- 12
- 13 $(DL_DIR)/$(FOO_SOURCE):
- 14 $(WGET) -P $(DL_DIR) $(FOO_SITE)/$(FOO_SOURCE)
- 15
- 16 $(FOO_DIR)/.source: $(DL_DIR)/$(FOO_SOURCE)
- 17 zcat $(DL_DIR)/$(FOO_SOURCE) | tar -C $(BUILD_DIR) $(TAR_OPTIONS) -
- 18 touch $(FOO_DIR)/.source
- 19
- 20 $(FOO_DIR)/.configured: $(FOO_DIR)/.source
- 21 (cd $(FOO_DIR); \
- 22 $(TARGET_CONFIGURE_OPTS) \
- 23 CFLAGS="$(TARGET_CFLAGS)" \
- 24 ./configure \
- 25 --target=$(GNU_TARGET_NAME) \
- 26 --host=$(GNU_TARGET_NAME) \
- 27 --build=$(GNU_HOST_NAME) \
- 28 --prefix=/usr \
- 29 --sysconfdir=/etc \
- 30 );
- 31 touch $(FOO_DIR)/.configured;
- 32
- 33 $(FOO_DIR)/$(FOO_BINARY): $(FOO_DIR)/.configured
- 34 $(MAKE) CC=$(TARGET_CC) -C $(FOO_DIR)
- 35
- 36 $(TARGET_DIR)/$(FOO_TARGET_BINARY): $(FOO_DIR)/$(FOO_BINARY)
- 37 $(MAKE) prefix=$(TARGET_DIR)/usr -C $(FOO_DIR) install
- 38 rm -Rf $(TARGET_DIR)/usr/man
- 39
- 40 foo: uclibc ncurses $(TARGET_DIR)/$(FOO_TARGET_BINARY)
- 41
- 42 foo-source: $(DL_DIR)/$(FOO_SOURCE)
- 43
- 44 foo-clean:
- 45 $(MAKE) prefix=$(TARGET_DIR)/usr -C $(FOO_DIR) uninstall
- 46 -$(MAKE) -C $(FOO_DIR) clean
- 47
- 48 foo-dirclean:
- 49 rm -rf $(FOO_DIR)
- 50
+ 1 # $Id$
+ 2
+ 3 include $(TOPDIR)/rules.mk
+ 4
+ 5 PKG_NAME:=foo
+ 6 PKG_VERSION:=1.0
+ 7 PKG_RELEASE:=1
+ 8 PKG_MD5SUM:=4584f226523776a3cdd2fb6f8212ba8d
+ 9
+ 10 PKG_SOURCE_URL:=http://www.foosoftware.org/downloads
+ 11 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
+ 12 PKG_CAT:=zcat
+ 13
+ 14 PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)-$(PKG_VERSION)
+ 15 PKG_INSTALL_DIR:=$(PKG_BUILD_DIR)/ipkg-install
+ 16
+ 17 include $(TOPDIR)/package/rules.mk
+ 18
+ 19 $(eval $(call PKG_template,FOO,foo,$(PKG_VERSION)-$(PKG_RELEASE),$(ARCH)))
+ 20
+ 21 $(PKG_BUILD_DIR)/.configured: $(PKG_BUILD_DIR)/.prepared
+ 22 (cd $(PKG_BUILD_DIR); \
+ 23 $(TARGET_CONFIGURE_OPTS) \
+ 24 CFLAGS="$(TARGET_CFLAGS)" \
+ 25 ./configure \
+ 26 --target=$(GNU_TARGET_NAME) \
+ 27 --host=$(GNU_TARGET_NAME) \
+ 28 --build=$(GNU_HOST_NAME) \
+ 29 --prefix=/usr \
+ 30 --sysconfdir=/etc \
+ 31 --with-bar="$(STAGING_DIR)/usr" \
+ 32 );
+ 33 touch $@
+ 34
+ 35 $(PKG_BUILD_DIR)/.built:
+ 36 rm -rf $(PKG_INSTALL_DIR)
+ 37 mkdir -p $(PKG_INSTALL_DIR)
+ 38 $(MAKE) -C $(PKG_BUILD_DIR) \
+ 39 $(TARGET_CONFIGURE_OPTS) \
+ 40 install_prefix="$(PKG_INSTALL_DIR)" \
+ 41 all install
+ 42 touch $@
+ 43
+ 44 $(IPKG_FOO):
+ 46 install -d -m0755 $(IDIR_FOO)/usr/sbin
+ 47 cp -fpR $(PKG_INSTALL_DIR)/usr/sbin/foo $(IDIR_FOO)/usr/sbin
+ 49 $(RSTRIP) $(IDIR_FOO)
+ 50 $(IPKG_BUILD) $(IDIR_FOO) $(PACKAGE_DIR)
+ 51
+ 52 mostlyclean:
+ 53 make -C $(PKG_BUILD_DIR) clean
+ 54 rm $(PKG_BUILD_DIR)/.built
</pre>
<p>First of all, this <i>Makefile</i> example works for a single
binary software. For other software such as libraries or more
complex stuff with multiple binaries, it should be adapted. Look at
- the other <code>*.mk</code> files in the <code>package</code>
+ the other <code>Makefile</code> files in the <code>package/</code>
directory.</p>
- <p>At lines 6-11, a couple of useful variables are defined :</p>
+ <p>At lines 5-15, a couple of useful variables are defined:</p>
<ul>
-
- <li><code>FOO_VERSION</code> : The version of <i>foo</i> that
+ <li><code>PKG_NAME</code> : The package name, e.g. <i>foo</i>.</li>
+
+ <li><code>PKG_VERSION</code> : The version of the package that
should be downloaded.</li>
- <li><code>FOO_SOURCE</code> : The name of the tarball of
- <i>foo</i> on the download website of FTP site. As you can see
- <code>FOO_VERSION</code> is used.</li>
+ <li><code>PKG_RELEASE</code> : The release number that will be
+ appended to the version number of your <i>ipkg</i> package.</li>
+
+ <li><code>PKG_MD5SUM</code> : The md5sum of the software archive.</li>
- <li><code>FOO_SITE</code> : The HTTP or FTP site from which
- <i>foo</i> archive is downloaded. It must include the complete
+ <li><code>PKG_SOURCE_URL</code> : Space separated list of the HTTP
+ or FTP sites from which the archive is downloaded. It must include the complete
path to the directory where <code>FOO_SOURCE</code> can be
found.</li>
- <li><code>FOO_DIR</code> : The directory into which the software
+ <li><code>PKG_SOURCE</code> : The name of the tarball of
+ your package on the download website of FTP site. As you can see
+ <code>PKG_NAME</code> and <code>PKG_VERSION</code> are used.</li>
+
+ <li><code>PKG_CAT</code> : The tool needed for extraction of the
+ software archive.</li>
+
+ <li><code>PKG_BUILD_DIR</code> : The directory into which the software
will be configured and compiled. Basically, it's a subdirectory
- of <code>BUILD_DIR</code> which is created upon decompression of
+ of <code>BUILD_DIR</code> which is created upon extraction of
the tarball.</li>
- <li><code>FOO_BINARY</code> : Software binary name. As said
- previously, this is an example for a single binary software.</li>
-
- <li><code>FOO_TARGET_BINARY</code> : The full path of the binary
- inside the target filesystem.</li>
+ <li><code>PKG_INSTALL_DIR</code> : The directory into the software
+ will be installed. It is a subdirectory of <code>PKG_BUILD_DIR</code>.</li>
</ul>
- <p>Lines 13-14 defines a target that downloads the tarball from
- the remote site to the download directory
- (<code>DL_DIR</code>).</p>
-
- <p>Lines 16-18 defines 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 (line
- 13-14) is called before executing the rules of the current
- target. Uncompressing is followed by <i>touching</i> a hidden file
- to mark the software has having been uncompressed. This trick is
- used everywhere in Buildroot <i>Makefile</i> to split steps
- (download, uncompress, configure, compile, install) while still
- having correct dependencies.</p>
-
- <p>Lines 20-31 defines a target and associated rules that
+ <p>In Line 3 and 17 we include common variables and routines to simplify
+ the process of ipkg creation. It includes routines to download, verify
+ and extract the software package archives.</p>
+
+ <p>Line 19 contains the magic line which automatically creates the
+ ipkg for us.</p>
+
+ <p>Lines 21-33 defines a target and associated rules that
configures the software. It depends on the previous target (the
- hidden <code>.source</code> file) so that we are sure the software has
+ hidden <code>.prepared</code> file) so that we are sure the software has
been uncompressed. In order to configure it, it basically runs the
well-known <code>./configure</code>script. As we may be doing
cross-compilation, <code>target</code>, <code>host</code> and
filesystem. Finally it creates a <code>.configured</code> file to
mark the software as configured.</p>
- <p>Lines 33-34 defines a target and a rule that compiles the
+ <p>Lines 35-42 defines a target and a rule that compiles 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 <code>.configured</code>
- file). It basically runs <code>make</code> inside the source
- directory.</p>
+ file). Afterwards it installs the resulting binary into the
+ <code>PKG_INSTALL_DIR</code>. It basically runs
+ <code>make install</code> inside the source directory.</p>
- <p>Lines 36-38 defines a target and associated rules that install
- the software inside the target filesystem. It depends on the
- binary file in the source directory, to make sure the software has
- been compiled. It uses the <code>install</code> target of the
- software <code>Makefile</code> by passing a <code>prefix</code>
- argument, so that the <code>Makefile</code> doesn't try to install
- the software inside host <code>/usr</code> but inside target
- <code>/usr</code>. After the installation, the
- <code>/usr/man</code> directory inside the target filesystem is
- removed to save space.</p>
-
- <p>Line 40 defines the main target of the software, the one
- referenced in the <code>Makefile.in</code> file. This targets
- should first of all depends on the dependecies of the software (in
- our example, <i>uclibc</i> and <i>ncurses</i>), and then to the
- final binary. This last dependency will call all previous
- dependencies in the right order. </p>
-
- <p>Line 42 defines a simple target that only downloads the code
- source. This is not used during normal operation of Buildroot, but
- might be useful.</p>
-
- <p>Lignes 44-46 define a simple target to clean the software build
- by calling the <i>Makefiles</i> with the appropriate option.</p>
-
- <p>Lines 48-49 define a simple target to completely remove the
- directory in which the software was uncompressed, configured and
- compiled.</p>
+ <p>Lines 44-50 defines a target and associated rules that create
+ the <i>ipkg</i> package, which can optionally be embedded into
+ the resulting firmware image. It manually installs all files you
+ want to integrate in your resulting ipkg. <code>RSTRIP</code> will
+ recursevily strip all binaries and libraries.
+ Finally <code>IPKG_BUILD</code> is called to create the package.</p>
<h3>Conclusion</h3>
the software.</p>
<p>If you package software that might be useful for other persons,
- don't forget to send a patch to Buildroot developers !</p>
+ don't forget to send a patch to OpenWrt developers!
+ Use the mail address: patches@openwrt.org
+ </p>
- <h2><a name="links" id="links"></a>Ressources</h2>
+ <h2><a name="links" id="links"></a>Resources</h2>
- <p>To learn more about Buildroot you can visit these
- websites:</p>
+ <p>To learn more about OpenWrt you can visit this website:
+ <a href="http://openwrt.org/">http://openwrt.org/</a></p>
- <ul>
- <li><a href="http://www.uclibc.org/">http://www.uclibc.org/</a></li>
- <li><a href="http://www.busybox.net/">http://www.busybox.net/</a></li>
- </ul>
+ </div>
+
+ <div class="main">
+ <div class="titre">
+ <h1>OpenWrt Kernel Module Creation Howto</h1>
+ </div>
+
+ <h2><a name="about_module" id="about_module"></a>About OpenWrt Kernel Module Compilation</h2>
+
+ <p>You are planning to compile a kernel module? This howto will
+explain what you have to do, to have your kernel module installable as
+an ipkg.</p>
+
+ <h2><a name="kernel" id="kernel"></a>Enable the kernel options</h2>
+
+ <p>Enable the kernel options you want by modifying
+build_mipsel/linux/.config. We are assuming, that you already had your
+kernel compiled once here. You can do the modification by hand or by
+
+<pre>
+$ cd build_mipsel/linux
+$ make menuconfig
+</pre>
+
+And copy it, so your changes are not getting lost, when doing a 'make
+dirclean'. Here we assume that you are compiling for Broadcom chipset
+based devices:
+
+<pre> $ cp .config ../../../target/linux/linux-2.4/config/brcm </pre>
+
+</p>
+ <h2><a name="buildroot_option" id="buildroot_option"></a>Create a buildroot option</h2>
+
+ <p>Create a buildroot option by modifying/inserting into
+target/linux/Config.in, e.g.
+<pre>
+config BR2_PACKAGE_KMOD_USB_KEYBOARD
+ tristate "Support for USB keyboards"
+ default m
+ depends BR2_PACKAGE_KMOD_USB_CONTROLLER
+</pre>
+</p>
+
+ <h2><a name="binary" id="binary"></a>Define the binary files for the kernel module</h2>
+
+ <p>Define the binary files for the kernel module by modifying/inserting into
+target/linux/linux-2.4/Makefile, e.g.
+
+<pre>
+$(eval $(call KMOD_template,USB_KEYBOARD,usb-kbd,\
+ $(MODULES_DIR)/kernel/drivers/input/input.o \
+ $(MODULES_DIR)/kernel/drivers/input/keybdev.o \
+ $(MODULES_DIR)/kernel/drivers/usb/usbkbd.o \
+,CONFIG_USB_KEYB,kmod-usb-core,60,input keybdev usbkbd))
+</pre>
+
+Where CONFIG_USB_KEYB is the kernel option, USB_KEYBOARD is the last
+part of BR2_PACKAGE_KMOD_USB_KEYBOARD and usb-kbd is part of the
+filename of the created ipkg.</p>
+
+ <h2><a name="control" id="control"></a>Specify the ipkg control file</h2>
+
+ <p>Create e.g. target/linux/control/kmod-usb-kbd.control with content similar to this:
+
+<pre>
+Package: kmod-usb-kbd
+Priority: optional
+Section: sys
+Maintainer: Markus Becker <mab@comnets.uni-bremen.de>
+Source: buildroot internal
+Description: Kernel Support for USB Keyboards
+</pre>
+ </p>
+
+ <h2><a name="compile" id="compile"></a>Compile the kernel module</h2>
+
+ <p>Enable the kernel module with
+<pre>
+$ make menuconfig
+</pre>
+ in TOPDIR and selecting it.<br>
+
+ Compile with
+<pre>
+$ make dirclean && make
+</pre>
+ </p>
</div>
+
</body>
</html>
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