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 $(call GENTARGETS)) -------------------------------- The Makefile begins on line 6 to 8 with metadata information: the version of the package (+LIBFOO_VERSION+), the name of the tarball containing the package (+LIBFOO_SOURCE+) and the Internet location at which the tarball can be downloaded (+LIBFOO_SITE+). All variables must start with the same prefix, +LIBFOO_+ in this case. This prefix is always the uppercased version of the package name (see below to understand where the package name is defined). On line 9, we specify that this package wants to install something to the staging space. This is often needed for libraries, since they must install header files and other development files in the staging space. This will ensure that the commands listed in the +LIBFOO_INSTALL_STAGING_CMDS+ variable will be executed. On line 10, we specify the list of dependencies this package relies on. These dependencies are listed in terms of lower-case package names, which can be packages for the target (without the +host-+ prefix) or packages for the host (with the +host-+) prefix). Buildroot will ensure that all these packages are built and installed 'before' the current package starts its configuration. The rest of the Makefile defines what should be done at the different steps of the package configuration, compilation and installation. +LIBFOO_BUILD_CMDS+ tells what steps should be performed to build the package. +LIBFOO_INSTALL_STAGING_CMDS+ tells what steps should be performed to install the package in the staging space. +LIBFOO_INSTALL_TARGET_CMDS+ tells what steps should be performed to install the package in the target space. All these steps rely on the +$(@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 one optional argument. This argument 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)) $(eval $(call GENTARGETS,host)) ---------------------- This might be useful if the compilation of the target package requires some tools to be installed on the host. If the package name is +libfoo+, then the name of the package for the target is also +libfoo+, while the name of the package for the host is +host-libfoo+. These names should be used in the DEPENDENCIES variables of other packages, if they depend on +libfoo+ or +host-libfoo+. The call to the +GENTARGETS+ macro *must* be at the end of the +.mk+ file, after all variable definitions. For the target package, the +GENTARGETS+ uses the variables defined by the .mk file and prefixed by the uppercased package name: +LIBFOO_*+. For the host package, it uses the +HOST_LIBFOO_*+. For 'some' variables, if the +HOST_LIBFOO_+ prefixed variable doesn't exist, the package infrastructure uses the corresponding variable prefixed by +LIBFOO_+. This is done for variables that are likely to have the same value for both the target and host packages. See below for details. The list of variables that can be set in a +.mk+ file to give metadata information is (assuming the package name is +libfoo+) : * +LIBFOO_VERSION+, mandatory, must contain the version of the package. Note that if +HOST_LIBFOO_VERSION+ doesn't exist, it is assumed to be the same as +LIBFOO_VERSION+. It can also be a Subversion or Git branch or tag, for packages that are fetched directly from their revision control system. + Example: +LIBFOO_VERSION = 0.1.2+ * +LIBFOO_SOURCE+ may contain the name of the tarball of the package. If +HOST_LIBFOO_SOURCE+ is not specified, it defaults to +LIBFOO_VERSION+. If none are specified, then the value is assumed to be +packagename-$(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 ----------------------