diff options
Diffstat (limited to 'docs/buildroot-documentation.html')
| -rw-r--r-- | docs/buildroot-documentation.html | 710 |
1 files changed, 0 insertions, 710 deletions
diff --git a/docs/buildroot-documentation.html b/docs/buildroot-documentation.html deleted file mode 100644 index 4d2b00b62..000000000 --- a/docs/buildroot-documentation.html +++ /dev/null @@ -1,710 +0,0 @@ -<?xml version="1.0" encoding="iso-8859-1"?> -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" - "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> - -<html xmlns="http://www.w3.org/1999/xhtml"> -<head> - <title>OpenWrt Buildroot - Usage and documentation</title> - <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> - <link rel="stylesheet" type="text/css" href="stylesheet.css?format=raw" /> -</head> - -<body> - <div class="main"> - <div class="titre"> - <h1>OpenWrt Buildroot</h1> - </div> - - <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 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 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 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 OpenWrt Buildroot</h2> - - <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 - 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>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 - (in our case, <code>binutils</code>) and a C standard library (for - example <a href="http://www.gnu.org/software/libc/libc.html">GNU - Libc</a>, <a href="http://www.uclibc.org">uClibc</a> or <a - href="http://www.fefe.de/dietlibc/">dietlibc</a>). The system - installed on your development station certainly already has a - compilation toolchain that you can use to compile application that - runs on your system. If you're using a PC, your compilation - toolchain runs on an x86 processor and generates code for a x86 - processor. Under most Linux systems, the compilation toolchain - uses the GNU libc as C standard library. This compilation - 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 OpenWrt Buildroot has nothing to do - with it.</p> - - <p>As said above, the compilation toolchain that comes with your system - runs and generates code for the processor of your host system. As your - 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 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 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 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 the MIPS architecture of most Wireless Routers.</p> - - <h2><a name="download" id="download"></a>Obtaining OpenWrt Buildroot</h2> - - <p>OpenWrt Buildroot is available via SVN aka subversion. - For any kind of OpenWrt development you should get the latest version from svn via:</p> -<pre> - $ svn co https://svn.openwrt.org/openwrt/trunk/ -</pre> - <p>If you only like to create your own custom firmware images and packages we - strongly suggest to use the SVN branch of the stable version (whiterussian): - </p> -<pre> - $ svn co https://svn.openwrt.org/openwrt/branches/whiterussian/ -</pre> - - - <h2><a name="using" id="using"></a>Using OpenWrt Buildroot</h2> - - <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> - $ make menuconfig -</pre> - - <p>For each entry of the configuration tool, you can find associated help - that describes the purpose of the entry.</p> - - <p>Once everything is configured, the configuration tool has generated a - <code>.config</code> file that contains the description of your - configuration. It will be used by the Makefiles to do what's needed.</p> - - <p>Let's go:</p> - -<pre> - $ make -</pre> - - <p>This command will download, configure and compile all the selected - 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> - - <p>There are two ways to customize the resulting target filesystem:</p> - - <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, 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>package/base-files/default/</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 when you completely rebuild the cross-compilation - toolchain and the tools.<br /> - </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. - 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> - - <p>Just like <a href="#custom_busybox">BusyBox</a>, <a - href="http://www.uclibc.org">uClibc</a> offers a lot of - configuration options. They allow to select various - functionalities, depending on your needs and limitations.</p> - - <p>The easiest way to modify the configuration of uClibc is to - follow these steps :</p> - - <ol> - - <li>Make a first compilation of buildroot without trying to - customize uClibc.</li> - - <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 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 the Buildroot - configuration, and the latter is used if you have selected - locale support.</li> - - <li>Run the compilation again.</li> - - </ol> - - <p>Otherwise, you can simply change - <code>toolchain/uClibc/uClibc.config</code> or - <code>toolchain/uClibc/uClibc.config-locale</code> without running - the configuration assistant.</p> - - <h2><a name="buildroot_innards" id="buildroot_innards"></a>How OpenWrt Buildroot - works</h2> - - <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 <code>Makefile</code>. - Makefiles are split into three sections:</p> - - <ul> - <li><b>package</b> (in the <code>package/</code> directory) contains the - Makefiles and associated files for all user-space tools that Buildroot - can compile and add to the target root filesystem. There is one - sub-directory per tool.</li> - - <li><b>toolchain</b> (in the <code>toolchain/</code> directory) contains - the Makefiles and associated files for all software related to the - cross-compilation toolchain : <code>binutils</code>, <code>ccache</code>, - <code>gcc</code>, <code>gdb</code>, <code>kernel-headers</code> and - <code>uClibc</code>.</li> - - <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 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 2 files :</p> - - <ul> - <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> - </ul> - - <p>The main Makefile do the job through the following steps (once the - configuration is done):</p> - - <ol> - <li>Create the download directory (<code>dl/</code> by default). This is - where the tarballs will be downloaded. It is interesting to know that the - tarballs are in this directory because it may be useful to save them - somewhere to avoid further downloads.</li> - - <li>Create the build directory (<code>build_ARCH/</code> by default, - where <code>ARCH</code> is your architecture). This is where all - user-space tools while be compiled.</li> - - <li>Create the toolchain build directory - (<code>toolchain_build_ARCH/</code> by default, where <code>ARCH</code> - is your architecture). This is where the cross compilation toolchain will - be compiled.</li> - - <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>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 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>SVN/</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 OpenWrt. In order to do this, you can - use the toolchain that was generated by the Buildroot.</p> - - <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>~/openwrt/</code>) :</p> - -<pre> -export PATH=$PATH:~/openwrt/staging_dir_mipsel/bin/ -</pre> - - <p>Then you can simply do :</p> - -<pre> -mipsel-linux-uclibc-gcc -o foo foo.c -</pre> - - <p><b>Important</b> : do not try to move the toolchain to an other - directory, it won't work. There are some hard-coded paths in the - <i>gcc</i> configuration. If the default toolchain directory - doesn't suit your needs, please refer to the <a - href="#toolchain_standalone">Using the uClibc toolchain outside of - buildroot</a> section.</p> - - <h2><a name="toolchain_standalone" id="toolchain_standalone"></a>Using the - uClibc toolchain outside of buildroot</h2> - - <p>By default, the cross-compilation toolchain is generated inside - <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>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 -> - Toolchain and header file location</code>, which defaults to - <code>staging_dir_ARCH/</code>.</p> - - <h2><a name="downloaded_packages" - id="downloaded_packages"></a>Location of downloaded packages</h2> - - <p>It might be useful to know that the various tarballs that are - 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 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 OpenWrt with - more software</h2> - - <p>This section will only consider the case in which you want to - add user-space software.</p> - - <h3>Package directory</h3> - - <p>First of all, create a directory under the <code>package</code> - directory for your software, for example <code>foo</code>.</p> - - <h3><code>Config.in</code> file</h3> - - <p>Then, create a file named <code>Config.in</code>. This file - will contain the portion of options description related to our - <code>foo</code> software that will be used and displayed in the - configuration tool. It should basically contain :</p> - -<pre> -config BR2_PACKAGE_FOO - 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>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: - -<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> -package-$(BR2_PACKAGE_FOO) += foo -</pre> - - <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>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> - -<pre> - 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>Makefile</code> files in the <code>package/</code> - directory.</p> - - <p>At lines 5-15, a couple of useful variables are defined:</p> - - <ul> - <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>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>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>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 extraction of - the tarball.</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>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>.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 - <code>build</code> arguments are given. The prefix is also set to - <code>/usr</code>, not because the software will be installed in - <code>/usr</code> on your host system, but in the target - filesystem. Finally it creates a <code>.configured</code> file to - mark the software as configured.</p> - - <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). 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 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> - - <p>As you can see, adding a software to buildroot is simply a - matter of writing a <i>Makefile</i> using an already existing - example and to modify it according to the compilation process of - the software.</p> - - <p>If you package software that might be useful for other persons, - don't forget to send a patch to OpenWrt developers! - Use the mail address: openwrt-devel@openwrt.org - </p> - - <h2><a name="links" id="links"></a>Resources</h2> - - <p>To learn more about OpenWrt you can visit this website: - <a href="http://openwrt.org/">http://openwrt.org/</a></p> - - </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> |