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Diffstat (limited to 'docs/manual/adding-packages-autotargets.txt')
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diff --git a/docs/manual/adding-packages-autotargets.txt b/docs/manual/adding-packages-autotargets.txt new file mode 100644 index 000000000..cb41eadfd --- /dev/null +++ b/docs/manual/adding-packages-autotargets.txt @@ -0,0 +1,171 @@ +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. |