--- /dev/null
+Infrastructure for autotools-based packages
+-------------------------------------------
+
+[[autotargets-tutorial]]
+
++AUTOTARGETS+ tutorial
+~~~~~~~~~~~~~~~~~~~~~~
+
+First, 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 = YES
+11: LIBFOO_CONF_OPT = --enable-shared
+12: LIBFOO_DEPENDENCIES = libglib2 host-pkg-config
+13:
+14: $(eval $(call AUTOTARGETS,package,libfoo))
+------------------------
+
+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 also install the package to the
+target directory. This directory contains what will become the root
+filesystem running on the target. Usually, we try not to install header
+files and to install stripped versions of the binary. By default, target
+installation is enabled, so in fact, this line is not strictly
+necessary. Also by default, packages are installed in this location
+using the +make install+ command.
+
+On line 11, we tell Buildroot to pass a custom configure option, that
+will be passed to the +./configure+ script before configuring
+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 +AUTOTARGETS+
+macro that generates all the Makefile rules that actually allows the
+package to be built.
+
+[[autotargets-reference]]
+
++AUTOTARGETS+ reference
+~~~~~~~~~~~~~~~~~~~~~~~
+
+The main macro of the autotools package infrastructure is
++AUTOTARGETS+. It has the same number of arguments and the
+same semantic as the +GENTARGETS+ macro, which is the main
+macro of the generic package infrastructure. For autotools packages, the
+ability to have target and host packages is also available (and is
+actually widely used).
+
+Just like the generic infrastructure, the autotools infrastructure
+works by defining a number of variables before calling the
++AUTOTARGETS+ macro.
+
+First, all the package metadata information variables that exist in the
+generic infrastructure also exist in the autotools infrastructure:
++LIBFOO_VERSION+, +LIBFOO_SOURCE+,
++LIBFOO_PATCH+, +LIBFOO_SITE+,
++LIBFOO_SUBDIR+, +LIBFOO_DEPENDENCIES+,
++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:
+
+* By adding a post-operation hook (after extract, patch, configure,
+ build or install). See the reference documentation of the generic
+ infrastructure for details.
+
+* By overriding one of the steps. For example, even if the autotools
+ infrastructure is used, if the package +.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.
--- /dev/null
+Infrastructure for CMake-based packages
+---------------------------------------
+
+[[cmaketargets-tutorial]]
+
++CMAKETARGETS+ tutorial
+~~~~~~~~~~~~~~~~~~~~~~~
+
+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 = YES
+11: LIBFOO_CONF_OPT = -DBUILD_DEMOS=ON
+12: LIBFOO_DEPENDENCIES = libglib2 host-pkg-config
+13:
+14: $(eval $(call CMAKETARGETS,package,libfoo))
+------------------------
+
+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 also install the package to the
+target directory. This directory contains what will become the root
+filesystem running on the target. Usually, we try not to install header
+files and to install stripped versions of the binary. By default, target
+installation is enabled, so in fact, this line is not strictly
+necessary. Also by default, packages are installed in this location
+using the +make install+ command.
+
+On line 11, we tell Buildroot to pass 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 +CMAKETARGETS+
+macro that generates all the Makefile rules that actually allows the
+package to be built.
+
+[[cmaketargets-reference]]
+
++CMAKETARGETS+ reference
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+The main macro of the CMake package infrastructure is
++CMAKETARGETS+. It has the same number of arguments and the same
+semantic as the +GENTARGETS+ macro, which is the main macro of the
+generic package infrastructure. For CMake packages, the ability to
+have target and host packages is also available.
+
+Just like the generic infrastructure, the CMake infrastructure works
+by defining a number of variables before calling the +CMAKETARGETS+
+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:
+
+* By adding a post-operation hook (after extract, patch, configure,
+ build or install). See the reference documentation of the generic
+ infrastructure for details.
+
+* By overriding one of the steps. For example, even if the CMake
+ infrastructure is used, if the package +.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.
--- /dev/null
+Conclusion
+----------
+
+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 Buildroot developers!
+
--- /dev/null
+Package directory
+-----------------
+
+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+, +java+, +x11r7+, and +games+. If your package fits in
+one of these categories, then create your package directory in these.
+
++Config.in+ file
+~~~~~~~~~~~~~~~~
+
+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/
+---------------------------
+
+Of course, you can add other options 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://lxr.free-electrons.com/source/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 +.mk+ 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:
+
+* *Makefiles for generic packages* (not using autotools): These are
+ based on an infrastructure similar to the one used for
+ autotools-based packages, but requires a little more work from the
+ developer. They specify what should be done for the configuration,
+ compilation, installation and cleanup of the package. This
+ infrastructure must be used for all packages that do not use the
+ autotools as their build system. In the future, other specialized
+ infrastructures might be written for other build systems. We cover
+ them through in a xref:gentargets-tutorial[tutorial] and a
+ xref:gentargets-reference[reference].
+
+* *Makefiles for autotools-based software* (autoconf, automake, etc.):
+ We provide a dedicated infrastructure for such packages, since
+ autotools is a very common build system. This infrastructure 'must'
+ be used for new packages that rely on the autotools as their build
+ system. We cover them through a xref:autotargets-tutorial[tutorial]
+ and xref:autotargets-reference[reference].
+
+* *Hand-written Makefiles:* These are currently obsolete, and no new
+ manual Makefiles should be added. However, since there are still
+ many of them in the tree, we keep them documented in a
+ xref:handwritten-tutorial[tutorial].
+
--- /dev/null
+Infrastructure for packages with specific build systems
+-------------------------------------------------------
+
+By 'packages with specific build systems' we mean all the packages
+whose build system is not one of the standard ones, such as
+'autotools' or 'CMake'. This typically includes packages whose build
+system is based on hand-written Makefiles or shell scripts.
+
+[[gentargets-tutorial]]
+
++GENTARGETS+ Tutorial
+~~~~~~~~~~~~~~~~~~~~~
+
+------------------------------
+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_DEPENDENCIES = host-libaaa libbbb
+11:
+12: define LIBFOO_BUILD_CMDS
+13: $(MAKE) CC=$(TARGET_CC) LD=$(TARGET_LD) -C $(@D) all
+14: endef
+15:
+16: define LIBFOO_INSTALL_STAGING_CMDS
+17: $(INSTALL) -D -m 0755 $(@D)/libfoo.a $(STAGING_DIR)/usr/lib/libfoo.a
+18: $(INSTALL) -D -m 0644 $(@D)/foo.h $(STAGING_DIR)/usr/include/foo.h
+19: $(INSTALL) -D -m 0755 $(@D)/libfoo.so* $(STAGING_DIR)/usr/lib
+20: endef
+21:
+22: define LIBFOO_INSTALL_TARGET_CMDS
+23: $(INSTALL) -D -m 0755 $(@D)/libfoo.so* $(TARGET_DIR)/usr/lib
+24: $(INSTALL) -d -m 0755 $(TARGET_DIR)/etc/foo.d
+25: endef
+26:
+27: $(eval $(call GENTARGETS,package,libfoo))
+--------------------------------
+
+The Makefile begins on line 6 to 8 with metadata information: the
+version of the package (+LIBFOO_VERSION+), the name of the
+tarball containing the package (+LIBFOO_SOURCE+) and the
+Internet location at which the tarball can be downloaded
+(+LIBFOO_SITE+). All variables must start with the same prefix,
++LIBFOO_+ in this case. This prefix is always the uppercased
+version of the package name (see below to understand where the package
+name is defined).
+
+On line 9, we specify that this package wants to install something to
+the staging space. This is often needed for libraries, since they must
+install header files and other development files in the staging space.
+This will ensure that the commands listed in the
++LIBFOO_INSTALL_STAGING_CMDS+ variable will be executed.
+
+On line 10, we specify the list of dependencies this package relies
+on. These dependencies are listed in terms of lower-case package names,
+which can be packages for the target (without the +host-+
+prefix) or packages for the host (with the +host-+) prefix).
+Buildroot will ensure that all these packages are built and installed
+'before' the current package starts its configuration.
+
+The rest of the Makefile defines what should be done at the different
+steps of the package configuration, compilation and installation.
++LIBFOO_BUILD_CMDS+ tells what steps should be performed to
+build the package. +LIBFOO_INSTALL_STAGING_CMDS+ tells what
+steps should be performed to install the package in the staging space.
++LIBFOO_INSTALL_TARGET_CMDS+ tells what steps should be
+performed to install the package in the target space.
+
+All these steps rely on the +$(@D)+ variable, which
+contains the directory where the source code of the package has been
+extracted.
+
+Finally, on line 27, we call the +GENTARGETS+ which
+generates, according to the variables defined previously, all the
+Makefile code necessary to make your package working.
+
+[[gentargets-reference]]
+
++GENTARGETS+ Reference
+~~~~~~~~~~~~~~~~~~~~~~
+
+The +GENTARGETS+ macro takes three arguments:
+
+* The first argument is the package directory prefix. If your package
+ is in +package/libfoo+, then the directory prefix is +package+. If
+ your package is in +package/editors/foo+, then the directory prefix
+ must be +package/editors+.
+
+* The second argument is the lower-cased package name. It must match
+ the prefix of the variables in the +.mk+ file and must match the
+ configuration option name in the +Config.in+ file. For example, if
+ the package name is +libfoo+, then the variables in the +.mk+ file
+ must start with +LIBFOO_+ and the configuration option in the
+ +Config.in+ file must be +BR2_PACKAGE_LIBFOO+.
+
+* The third argument is optional. It can be used to tell if the
+ package is a target package (cross-compiled for the target) or a
+ host package (natively compiled for the host). If unspecified, it is
+ assumed that it is a target package. See below for details.
+
+For a given package, in a single +.mk+ file, it is possible to call
+GENTARGETS twice, once to create the rules to generate a target
+package and once to create the rules to generate a host package:
+
+----------------------
+$(eval $(call GENTARGETS,package,libfoo))
+$(eval $(call GENTARGETS,package,libfoo,host))
+----------------------
+
+This might be useful if the compilation of the target package requires
+some tools to be installed on the host. If the package name is
++libfoo+, then the name of the package for the target is also
++libfoo+, while the name of the package for the host is
++host-libfoo+. These names should be used in the DEPENDENCIES
+variables of other packages, if they depend on +libfoo+ or
++host-libfoo+.
+
+The call to the +GENTARGETS+ macro *must* be at the end of the +.mk+
+file, after all variable definitions.
+
+For the target package, the +GENTARGETS+ uses the variables defined by
+the .mk file and prefixed by the uppercased package name:
++LIBFOO_*+. For the host package, it uses the +HOST_LIBFOO_*+. For
+'some' variables, if the +HOST_LIBFOO_+ prefixed variable doesn't
+exist, the package infrastructure uses the corresponding variable
+prefixed by +LIBFOO_+. This is done for variables that are likely to
+have the same value for both the target and host packages. See below
+for details.
+
+The list of variables that can be set in a +.mk+ file to give metadata
+information is (assuming the package name is +libfoo+) :
+
+* +LIBFOO_VERSION+, mandatory, must contain the version of the
+ package. Note that if +HOST_LIBFOO_VERSION+ doesn't exist, it is
+ assumed to be the same as +LIBFOO_VERSION+. It can also be a
+ Subversion or Git branch or tag, for packages that are fetched
+ directly from their revision control system. +
+ Example: +LIBFOO_VERSION = 0.1.2+
+
+* +LIBFOO_SOURCE+ may contain the name of the tarball of
+ the package. If +HOST_LIBFOO_SOURCE+ is not specified, it
+ defaults to +LIBFOO_VERSION+. If none are specified, then
+ the value is assumed to be
+ +packagename-$(LIBFOO_VERSION).tar.gz+. +
+ 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+. Also note that another mechanism is
+ available to patch a package: all files of the form
+ +packagename-packageversion-description.patch+ present in the
+ package directory inside Buildroot will be applied to the package
+ after extraction.
+
+* +LIBFOO_SITE+ may contain the Internet location of the package. It
+ can either be the HTTP or FTP location of a tarball, or the URL of a
+ Git or Subversion repository (see +LIBFOO_SITE_METHOD+ below). If
+ +HOST_LIBFOO_SITE+ is not specified, it defaults to
+ +LIBFOO_SITE+. If none are specified, then the location is assumed
+ to be
+ +http://$$(BR2_SOURCEFORGE_MIRROR).dl.sourceforge.net/sourceforge/packagename+. +
+ Examples: +LIBFOO_SITE=http://www.libfoosoftware.org/libfoo+ +
+ +LIBFOO_SITE=http://svn.xiph.org/trunk/Tremor/+
+
+* +LIBFOO_SITE_METHOD+ may contain the method to fetch the package
+ source code. It can either be +wget+ (for normal FTP/HTTP downloads
+ of tarballs), +svn+, +git+ or +bzr+. When not specified, it is
+ guessed from the URL given in +LIBFOO_SITE+: +svn://+, +git://+ and
+ +bzr://+ URLs will use the +svn+, +git+ and +bzr+ methods
+ respectively. All other URL-types will use the +wget+ method. So for
+ example, in the case of a package whose source code is available
+ through Subversion repository on HTTP, one 'must' specifiy
+ +LIBFOO_SITE_METHOD=svn+. For +svn+ and +git+ methods, what
+ Buildroot does is a checkout/clone of the repository which is then
+ tarballed and stored into the download cache. Next builds will not
+ checkout/clone again, but will use the tarball directly. When
+ +HOST_LIBFOO_SITE_METHOD+ is not specified, it defaults to the value
+ of +LIBFOO_SITE_METHOD+. See +package/multimedia/tremor/+ for an
+ example.
+
+* +LIBFOO_DEPENDENCIES+ lists the dependencies (in terms of package
+ name) that are required for the current target package to
+ compile. These dependencies are guaranteed to be compiled and
+ installed before the configuration of the current package starts. In
+ a similar way, +HOST_LIBFOO_DEPENDENCIES+ lists the dependency for
+ the current host package.
+
+* +LIBFOO_INSTALL_STAGING+ can be set to +YES+ or +NO+ (default). If
+ set to +YES+, then the commands in the +LIBFOO_INSTALL_STAGING_CMDS+
+ variables are 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.
+
+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+, used to list the actions to be performed to
+ configure the package before its compilation
+
+* +LIBFOO_BUILD_CMDS+, used to list the actions to be performed to
+ compile the package
+
+* +HOST_LIBFOO_INSTALL_CMDS+, used to list the actions to be performed
+ to install the package, when the package is a host package. The
+ package must install its files to the directory given by
+ +$(HOST_DIR)+. All files, including development files such as
+ headers should be installed, since other packages might be compiled
+ on top of this package.
+
+* +LIBFOO_INSTALL_TARGET_CMDS+, used to list the actions to be
+ performed to install the package to the target directory, when the
+ package is a target package. The package must install its files to
+ the directory given by +$(TARGET_DIR)+. Only the files required for
+ 'documentation' and 'execution' of the package should be
+ installed. Header files should not be installed, they will be copied
+ to the target, if the +development files in target filesystem+
+ option is selected.
+
+* +LIBFOO_INSTALL_STAGING_CMDS+, used to list the actions to be
+ performed to install the package to the staging directory, when the
+ package is a target package. The package must install its files to
+ the directory given by +$(STAGING_DIR)+. All development files
+ should be installed, since they might be needed to compile other
+ packages.
+
+* +LIBFOO_CLEAN_CMDS+, used to list the actions to perform to clean up
+ the build directory of the package.
+
+* +LIBFOO_UNINSTALL_TARGET_CMDS+, used to list the actions to
+ uninstall the package from the target directory +$(TARGET_DIR)+
+
+* +LIBFOO_UNINSTALL_STAGING_CMDS+, used to list the actions to
+ uninstall the package from the staging directory +$(STAGING_DIR)+.
+
+The preferred way to define these variables is:
+
+----------------------
+define LIBFOO_CONFIGURE_CMDS
+ action 1
+ action 2
+ action 3
+endef
+----------------------
+
+In the action definitions, you can use the following variables:
+
+* +$(@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
+
+* +$(TARGET_CROSS)+ to get the cross-compilation toolchain prefix
+
+* Of course the +$(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 is not user definable, so +LIBFOO_POST_PATCH_HOOKS+ will be
+userful for generic packages.
+
+The following hook points are available:
+
+* +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)
+
+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_FIXUP
+----------------------
--- /dev/null
+Gettext integration and interaction with packages
+-------------------------------------------------
+
+Many packages that support internationalization use the gettext
+library. Dependencies for this library are fairly complicated and
+therefore, deserves some explanation.
+
+The 'uClibc' C library doesn't implement gettext functionality,
+therefore with this C library, a separate gettext must be compiled. On
+the other hand, the 'glibc' C library does integrate its own gettext,
+and in this case, the separate gettext library should not be 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
+
+Therefore, packages that unconditionally need gettext should:
+
+* Use +select BR2_PACKAGE_GETTEXT if BR2_NEEDS_GETTEXT+ and possibly
+ +select BR2_PACKAGE_LIBINTL if BR2_NEEDS_GETTEXT+, if libintl is
+ also needed
+
+* Use +$(if $(BR2_NEEDS_GETTEXT),gettext)+ in the package
+ +DEPENDENCIES+ variable
+
+Packages that need gettext only when locale support is enabled should:
+
+* Use +select BR2_PACKAGE_GETTEXT if BR2_NEEDS_GETTEXT_IF_LOCALE+ and
+ possibly +select BR2_PACKAGE_LIBINTL if
+ BR2_NEEDS_GETTEXT_IF_LOCALE+, if libintl is also needed
+
+* Use +$(if $(BR2_NEEDS_GETTEXT_IF_LOCALE),gettext)+ in the package
+ +DEPENDENCIES+ variable
--- /dev/null
+[[handwritten-tutorial]]
+
+Manual Makefile
+---------------
+
+*NOTE: new manual makefiles should not be created, and existing manual
+makefiles should be converted either to the generic, autotools or
+cmake infrastructure. This section is only kept to document the
+existing manual makefiles and to help understand how they work.*
+
+------------------------
+01: #############################################################
+02: #
+03: # libfoo
+04: #
+05: #############################################################
+06: LIBFOO_VERSION:=1.0
+07: LIBFOO_SOURCE:=libfoo-$(LIBFOO_VERSION).tar.gz
+08: LIBFOO_SITE:=http://www.foosoftware.org/downloads
+09: LIBFOO_DIR:=$(BUILD_DIR)/foo-$(FOO_VERSION)
+10: LIBFOO_BINARY:=foo
+11: LIBFOO_TARGET_BINARY:=usr/bin/foo
+12:
+13: $(DL_DIR)/$(LIBFOO_SOURCE):
+14: $(call DOWNLOAD,$(LIBFOO_SITE),$(LIBFOO_SOURCE))
+15:
+16: $(LIBFOO_DIR)/.source: $(DL_DIR)/$(LIBFOO_SOURCE)
+17: $(ZCAT) $(DL_DIR)/$(LIBFOO_SOURCE) | tar -C $(BUILD_DIR) $(TAR_OPTIONS) -
+18: touch $@
+19:
+20: $(LIBFOO_DIR)/.configured: $(LIBFOO_DIR)/.source
+21: (cd $(LIBFOO_DIR); rm -rf config.cache; \
+22: $(TARGET_CONFIGURE_OPTS) \
+23: $(TARGET_CONFIGURE_ARGS) \
+24: ./configure \
+25: --target=$(GNU_TARGET_NAME) \
+26: --host=$(GNU_TARGET_NAME) \
+27: --build=$(GNU_HOST_NAME) \
+28: --prefix=/usr \
+29: --sysconfdir=/etc \
+30: )
+31: touch $@
+32:
+33: $(LIBFOO_DIR)/$(LIBFOO_BINARY): $(LIBFOO_DIR)/.configured
+34: $(MAKE) CC=$(TARGET_CC) -C $(LIBFOO_DIR)
+35:
+36: $(TARGET_DIR)/$(LIBFOO_TARGET_BINARY): $(LIBFOO_DIR)/$(LIBFOO_BINARY)
+37: $(MAKE) DESTDIR=$(TARGET_DIR) -C $(LIBFOO_DIR) install-strip
+38: rm -Rf $(TARGET_DIR)/usr/man
+39:
+40: libfoo: uclibc ncurses $(TARGET_DIR)/$(LIBFOO_TARGET_BINARY)
+41:
+42: libfoo-source: $(DL_DIR)/$(LIBFOO_SOURCE)
+43:
+44: libfoo-clean:
+45: $(MAKE) prefix=$(TARGET_DIR)/usr -C $(LIBFOO_DIR) uninstall
+46: -$(MAKE) -C $(LIBFOO_DIR) clean
+47:
+48: libfoo-dirclean:
+49: rm -rf $(LIBFOO_DIR)
+50:
+51: #############################################################
+52: #
+53: # Toplevel Makefile options
+54: #
+55: #############################################################
+56: ifeq ($(BR2_PACKAGE_LIBFOO),y)
+57: TARGETS+=libfoo
+58: endif
+------------------------
+
+First of all, this Makefile example works for a package which
+comprises a single binary executable. For other software, such as
+libraries or more complex stuff with multiple binaries, it must be
+qqadapted. For examples look at the other +*.mk+ files in the
++package+ directory.
+
+At lines 6-11, a couple of useful variables are defined:
+
+* +LIBFOO_VERSION+: The version of 'libfoo' that should be downloaded.
+
+* +LIBFOO_SOURCE+: The name of the tarball of 'libfoo' on the download
+ website or FTP site. As you can see +LIBFOO_VERSION+ is used.
+
+* +LIBFOO_SITE+: The HTTP or FTP site from which 'libfoo' archive is
+ downloaded. It must include the complete path to the directory where
+ +LIBFOO_SOURCE+ can be found.
+
+* +LIBFOO_DIR+: The directory into which the software will be
+ configured and compiled. Basically, it's a subdirectory of
+ +BUILD_DIR+ which is created upon decompression of the tarball.
+
+* +LIBFOO_BINARY+: Software binary name. As said previously, this is
+ an example for a package with a single binary.
+
+* +LIBFOO_TARGET_BINARY+: The full path of the binary inside the
+ target filesystem. Lines 13-14 define a target that downloads the
+ tarball from the remote site to the download directory (+DL_DIR+).
+
+Lines 16-18 define a target and associated rules that uncompress the
+downloaded tarball. As you can see, this target depends on the tarball
+file so that the previous target (lines 13-14) is called before
+executing the rules of the current target. Uncompressing is followed
+by 'touching' a hidden file to mark the software as having been
+uncompressed. This trick is used everywhere in a Buildroot Makefile to
+split steps (download, uncompress, configure, compile, install) while
+still having correct dependencies.
+
+Lines 20-31 define a target and associated rules that configure the
+software. It depends on the previous target (the hidden +.source+
+file) so that we are sure the software has been uncompressed. In order
+to configure the package, it basically runs the well-known
++./configure+ script. As we may be doing cross-compilation, +target+,
++host+ and +build+ arguments are given. The prefix is also set to
++/usr+, not because the software will be installed in +/usr+ on your
+host system, but because the software will be installed in + /usr+ on
+the target filesystem. Finally it creates a +.configured+ file to mark
+the software as configured.
+
+Lines 33-34 define a target and a rule that compile the software. This
+target will create the binary file in the compilation directory and
+depends on the software being already configured (hence the reference
+to the +.configured+ file). It basically runs +make+ inside the
+source directory.
+
+Lines 36-38 define a target and associated rules that install the
+software inside the target filesystem. They depend on the binary file
+in the source directory to make sure the software has been
+compiled. They use the +install-strip+ target of the software
++Makefile+ by passing a +DESTDIR+ argument so that the +Makefile+
+doesn't try to install the software in the host +/usr+ but rather in
+the target +/usr+. After the installation, the +/usr/man + directory
+inside the target filesystem is removed to save space.
+
+Line 40 defines the main target of the software — the one that
+will eventually be used by the top level +Makefile+ to download,
+compile, and then install this package. This target should first of
+all depend on all needed dependencies of the software (in our example,
+'uclibc' and 'ncurses') and also depend on the final binary. This last
+dependency will call all previous dependencies in the correct order.
+
+Line 42 defines a simple target that only downloads the code
+source. This is not used during normal operation of Buildroot, but is
+needed if you intend to download all required sources at once for
+later offline build. Note that if you add a new package, providing a
++libfoo-source+ target is 'mandatory' to support users that wish to do
+offline-builds. Furthermore, it eases checking if all package-sources
+are downloadable.
+
+Lines 44-46 define a simple target to clean the software build by
+calling the Makefile with the appropriate options. The +-clean+
+target should run +make clean+ on $(BUILD_DIR)/package-version and
+MUST uninstall all files of the package from $(STAGING_DIR) and from
+$(TARGET_DIR).
+
+Lines 48-49 define a simple target to completely remove the directory
+in which the software was uncompressed, configured and compiled. The
++-dirclean+ target MUST completely rm $(BUILD_DIR)/ package-version.
+
+Lines 51-58 add the target +libfoo+ to the list of targets to be
+compiled by Buildroot, by first checking if the configuration option
+for this package has been enabled using the configuration tool. If so,
+it then "subscribes" this package to be compiled by adding
+the package to the TARGETS global variable. The name added to the
+TARGETS global variable is the name of this package's target, as
+defined on line 40, which is used by Buildroot to download, compile,
+and then install this package.
--- /dev/null
+Adding new packages to Buildroot
+================================
+
+This section covers how new packages (userspace libraries or
+applications) can be integrated into Buildroot. It also shows how
+existing packages are integrated, which is needed for fixing issues or
+tuning their configuration.
+
+include::adding-packages-directory.txt[]
+
+include::adding-packages-gentargets.txt[]
+
+include::adding-packages-autotargets.txt[]
+
+include::adding-packages-cmaketargets.txt[]
+
+include::adding-packages-handwritten.txt[]
+
+include::adding-packages-gettext.txt[]
+
+include::adding-packages-conclusion.txt[]
--- /dev/null
+Creating your own board support
+===============================
+
+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 +MYBOARD_defconfig+.
+
+It is recommended to use as much as possible upstream versions of the
+Linux kernel and bootloaders, and to use as much as possible default
+kernel and bootloader configurations. If they are incorrect for your
+platform, 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.
--- /dev/null
+Using +ccache+ in Buildroot
+===========================
+
+http://ccache.samba.org[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+.
--- /dev/null
+Customizing the Busybox configuration
+-------------------------------------
+[[busybox-custom]]
+
+http://www.busybox.net/[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:
+
+* Do an initial compilation of Buildroot, with busybox, without
+ trying to customize it.
+
+* Invoke +make busybox-menuconfig+.
+ The nice configuration tool appears, and you can
+ customize everything.
+
+* Run the compilation of Buildroot again.
+
+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 xref:env-vars[].
+
--- /dev/null
+Customizing the Linux kernel configuration
+------------------------------------------
+
+The Linux kernel configuration can be customized just like
+xref:busybox-custom[BusyBox] and xref:uclibc-custom[uClibc] 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
+xref:env-vars[].
+
--- /dev/null
+Customizing the generated target filesystem
+-------------------------------------------
+
+There are a few ways to customize the resulting target filesystem:
+
+* Customize the target filesystem directly and rebuild the image. The
+ target filesystem is available under +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.
+
+* Create your own 'target skeleton'. You can start with the default
+ skeleton available under +fs/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. At build time, the contents of the
+ skeleton are copied to output/target before any package
+ installation.
+
+* In the Buildroot configuration, you can specify the path to a
+ post-build script, that gets called 'after' Buildroot builds all the
+ selected software, but 'before' the rootfs packages are
+ assembled. 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.
+
+* A special package, 'customize', stored in +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.
+
--- /dev/null
+Customizing the uClibc configuration
+------------------------------------
+[[uclibc-custom]]
+
+Just like xref:busybox-custom[BusyBox], http://www.uclibc.org/[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:
+
+* Do an initial compilation of Buildroot without trying to customize
+ uClibc.
+
+* Invoke +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.
+
+* Copy the +$(O)/toolchain/uclibc-VERSION/.config+ file to a different
+ place (like +toolchain/uClibc/uClibc-myconfig.config+, or
+ +board/mymanufacturer/myboard/uClibc.config+) and adjust the uClibc
+ configuration (configuration option +BR2_UCLIBC_CONFIG+) to use this
+ configuration instead of the default one.
+
+* Run the compilation of Buildroot again.
+
+Otherwise, you can simply change +toolchain/uClibc/uClibc.config+,
+without running the configuration assistant.
+
+If you want to use an existing config file for uclibc, then see
+xref:env-vars[].
+
--- /dev/null
+Customization
+=============
+
+include::customize-rootfs.txt[]
+
+include::customize-busybox-config.txt[]
+
+include::customize-uclibc-config.txt[]
+
+include::customize-kernel-config.txt[]
--- /dev/null
+Location of downloaded packages
+===============================
+
+It might be useful to know that the various tarballs that are
+downloaded by the Makefiles are all stored in the +DL_DIR+ which by
+default is the +dl+ directory. It's useful, for example, if you want
+to keep a complete version of Buildroot which is known to be working
+with the associated tarballs. This will allow you to regenerate the
+toolchain and the target filesystem with exactly the same 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>
+-----------------
--- /dev/null
+Using an external toolchain
+===========================
+
+Using an already existing toolchain is useful for different
+reasons:
+
+* you already have a toolchain that is known to work for your specific
+ CPU
+
+* you want to speed up the Buildroot build process by skipping the
+ long toolchain build part
+
+* the toolchain generation feature of Buildroot is not sufficiently
+ flexible for you (for example if you need to generate a system with
+ 'glibc' instead of 'uClibc')
+
+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:
+
+* Use a predefined external toolchain profile, and let Buildroot
+ download, extract and install the toolchain. Buildroot already knows
+ about a few CodeSourcery toolchains for ARM, PowerPC, MIPS and
+ SuperH. Just select the toolchain profile in +Toolchain+ through the
+ available ones. This is definitely the easiest solution.
+
+* Use a predefined external toolchain profile, but instead of having
+ Buildroot download and extract the toolchain, you can tell Buildroot
+ where your toolchain is already installed on your system. Just
+ select the toolchain profile in +Toolchain+ through the available
+ ones, unselect +Download toolchain automatically+, and fill the
+ +Toolchain path+ text entry with the path to your cross-compiling
+ toolchain.
+
+* Use a completely custom external toolchain. This is particularly
+ useful for toolchains generated using crosstool-NG. To do this,
+ select the +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. 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, toolchains generated by
+http://crosstool-ng.org[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
+http://www.denx.de/wiki/DULG/ELDK[ELDK] of Denx, for two reasons:
+
+* The ELDK does not contain a pure toolchain (i.e just the compiler,
+ binutils, the C and C++ libraries), but a toolchain that comes with
+ a very large set of pre-compiled libraries and programs. Therefore,
+ Buildroot cannot import the 'sysroot' of the toolchain, as it would
+ contain hundreds of megabytes of pre-compiled libraries that are
+ normally built by Buildroot.
+
+* The ELDK toolchains have a completely non-standard custom mechanism
+ to handle multiple library variants. Instead of using the standard
+ GCC 'multilib' mechanism, the ARM ELDK uses different symbolic links
+ to the compiler to differentiate between library variants (for ARM
+ soft-float and ARM VFP), and the PowerPC ELDK compiler uses a
+ +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.
--- /dev/null
+Getting Buildroot
+=================
+
+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
+---------------------
+
--- /dev/null
+How Buildroot works
+===================
+
+As mentioned above, Buildroot is basically a set of Makefiles that
+download, configure, and compile software with the correct options. It
+also includes patches for various software packages - mainly the ones
+involved in the cross-compilation tool chain (+gcc+, +binutils+ and
++uClibc+).
+
+There is basically one Makefile per software package, and they are
+named with the +.mk+ extension. Makefiles are split into three main
+sections:
+
+* *toolchain* (in the +toolchain/+ directory) contains the Makefiles
+ and associated files for all software related to the
+ cross-compilation toolchain: +binutils+, +gcc+, +gdb+,
+ +kernel-headers+ and +uClibc+.
+
+* *package* (in the +package/+ 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.
+
+* *target* (in the +target+ 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
+ is a sub-directory with the required files. There is also a
+ +default/+ directory that contains the target filesystem skeleton.
+
+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):
+
+* Create all the output directories: +staging+, +target+, +build+,
+ +stamps+, etc. in the output directory (+output/+ by default,
+ another value can be specified using +O=+)
+
+* Generate all the targets listed in the +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.
+
+* Generate all the targets listed in the +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.
+
--- /dev/null
+About Buildroot
+===============
+
+Buildroot is a set of Makefiles and patches that allows you to easily
+generate a cross-compilation toolchain, a root filesystem and a Linux
+kernel image for your target. Buildroot can be used for one, two or
+all 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.
+
+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
+http://www.gnu.org/software/libc/libc.html[GNU Libc],
+http://www.uclibc.org/[uClibc] or
+http://www.fefe.de/dietlibc/[dietlibc]). The system installed on your
+development station certainly already has a compilation toolchain that
+you can use to compile an application that runs on your system. If
+you're using a PC, your compilation toolchain runs on an x86 processor
+and generates code for an x86 processor. Under most Linux systems, the
+compilation toolchain uses the GNU libc (glibc) as the C standard
+library. This compilation toolchain is called the "host compilation
+toolchain". The machine on which it is running, and on which you're
+working, is called the "host system". The compilation toolchain is
+provided by your distribution, and Buildroot has nothing to do with it
+(other than using it to build a cross-compilation toolchain and other
+tools that are run on the development host).
+
+As said above, the compilation toolchain that comes with your system
+runs on and generates code for the processor in your host system. As
+your embedded system has a different processor, you need a
+cross-compilation toolchain - a compilation toolchain that runs on
+your host system but generates code for your target system (and target
+processor). For example, if your host system uses x86 and your target
+system uses ARM, the regular compilation toolchain on your host runs on
+x86 and generates code for x86, while the cross-compilation toolchain
+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:
+
+* The compilation toolchain on 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 that for you.
+
+* Buildroot automates the building of a root filesystem with all
+ needed tools like busybox. That makes it much easier than doing it
+ by hand.
+
+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.
+
+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.
--- /dev/null
+The Buildroot user manual
+=========================
+:toc:
+
+Buildroot usage and documentation by Thomas Petazzoni. Contributions
+from Karsten Kruse, Ned Ludd, Martin Herren and others.
+
+image::logo.png[]
+
+:leveloffset: 1
+
+include::introduction.txt[]
+
+include::getting.txt[]
+
+include::using.txt[]
+
+include::customize.txt[]
+
+include::rebuilding-packages.txt[]
+
+include::how-buildroot-works.txt[]
+
+include::using-buildroot-toolchain.txt[]
+
+include::external-toolchain.txt[]
+
+include::ccache-support.txt[]
+
+include::download-location.txt[]
+
+include::adding-packages.txt[]
--- /dev/null
+Understanding how to rebuild packages
+=====================================
+
+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 currently 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. However, implementing clean package
+removal is on the TODO-list of Buildroot developers.
+
+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.
+
+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). The
+problem is that these stamp files are not uniformly named and handled
+by the different packages, so some understanding of the particular
+package is needed.
+
+For packages relying on Buildroot packages infrastructures (see
+xref:add-packages[this section] for details), the following stamp
+files are relevant:
+
+* +output/build/packagename-version/.stamp_configured+. If removed,
+ Buildroot will trigger the recompilation of the package from the
+ configuration step (execution of +./configure+).
+
+* +output/build/packagename-version/.stamp_built+. If removed,
+ Buildroot will trigger the recompilation of the package from the
+ compilation step (execution of +make+).
+
+For other packages, an analysis of the specific 'package.mk' file is
+needed. For example, the zlib Makefile used to look like this (before
+it was converted to the generic package infrastructure):
+
+-----------------
+$(ZLIB_DIR)/.configured: $(ZLIB_DIR)/.patched
+ (cd $(ZLIB_DIR); rm -rf config.cache; \
+ [...]
+ )
+ touch $@
+
+$(ZLIB_DIR)/libz.a: $(ZLIB_DIR)/.configured
+ $(MAKE) -C $(ZLIB_DIR) all libz.a
+ touch -c $@
+-----------------
+
+If you want to trigger the reconfiguration, you need to remove
++output/build/zlib-version/.configured+. If you want to trigger only
+the recompilation, you need to remove
++output/build/zlib-version/libz.a+.
+
+Note that most packages, if not all, will progressively be ported over
+to the generic or autotools infrastructure, making it much easier to
+rebuild individual packages.
--- /dev/null
+Using the generated toolchain outside Buildroot
+===============================================
+
+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.
--- /dev/null
+Using Buildroot
+===============
+
+Configuration and general usage
+-------------------------------
+
+Buildroot has a nice configuration tool similar to the one you can
+find in the http://www.kernel.org/[Linux kernel] or in
+http://www.busybox.org/[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, so you may need to install "development" packages for
+relevant libraries used by the configuration utilities. On Debian-like
+systems, the +libncurses5-dev+ package is required to use the
+'menuconfig' interface, +libqt4-dev+ is required to use the 'xconfig'
+interface, and +libglib2.0-dev, libgtk2.0-dev and libglade2-dev+ are
+needed to use the 'gconfig' interface.
+
+For each menu entry in the configuration tool, you can find associated
+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+.
+
+This command will generally perform the following steps:
+
+* Download source files (as required)
+* Configure, build and install the cross-compiling toolchain if an
+ internal toolchain is used, or import a toolchain if an external
+ toolchain is used
+* Build/install selected target packages
+* Build a kernel image, if selected
+* Build a bootloader image, if selected
+* Create a root filesystem in selected formats
+
+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). 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, unless the
+ +development files in target filesystem+ option is selected.
+
+* +host/+ contains the installation of tools compiled for the host
+ that are needed for the proper execution of Buildroot, including the
+ cross-compilation toolchain.
+
+* +toolchain/+ contains the build directories for the various
+ components of the cross-compilation toolchain.
+
+Offline builds
+--------------
+
+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.
+
+Building out-of-tree
+--------------------
+
+Buildroot supports building out of tree with a syntax similar to the
+Linux kernel. To use it, add +O=<directory>+ to the make command line:
+
+--------------------
+ $ 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>
+--------------------
+
+Environment variables
+---------------------
+[[env-vars]]
+
+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
+* +BUSYBOX_CONFIG_FILE=<path/to/.config>+, path to
+ the Busybox configuration file
+* +BUILDROOT_DL_DIR+ to override the directory in which
+ Buildroot stores/retrieves downloaded files
+
+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
+--------------------
projects / buildroot.git / commitdiff