diff options
Diffstat (limited to 'documentation/poky-ref-manual')
| -rw-r--r-- | documentation/poky-ref-manual/ref-classes.xml | 87 |
1 files changed, 32 insertions, 55 deletions
diff --git a/documentation/poky-ref-manual/ref-classes.xml b/documentation/poky-ref-manual/ref-classes.xml index 14029559c..8eb94c268 100644 --- a/documentation/poky-ref-manual/ref-classes.xml +++ b/documentation/poky-ref-manual/ref-classes.xml @@ -6,14 +6,14 @@ <para> Class files are used to abstract common functionality and share it amongst multiple - <filename class="extension">.bb</filename> files. Any metadata usually found in a - <filename class="extension">.bb</filename> file can also be placed in a class + <filename>.bb</filename> files. Any metadata usually found in a + <filename>.bb</filename> file can also be placed in a class file. Class files are identified by the extension - <filename class="extension">.bbclass</filename> and are usually placed - in a <filename class="directory">classes/</filename> directory beneath the - <filename class="directory">meta*/</filename> directory or the directory pointed - by BUILDDIR (e.g. <filename class="directory">build/</filename>)in the same way as - <filename class="extension">.conf</filename> files in the <filename + <filename>.bbclass</filename> and are usually placed + in a <filename>classes/</filename> directory beneath the + <filename>meta*/</filename> directory or the directory pointed + by BUILDDIR (e.g. <filename>build/</filename>)in the same way as + <filename>.conf</filename> files in the <filename class="directory">conf</filename> directory. Class files are searched for in BBPATH in the same was as <filename>.conf</filename> files too. </para> @@ -28,7 +28,7 @@ <title>The base class - <filename>base.bbclass</filename></title> <para> - The base class is special in that every <filename class="extension">.bb</filename> + The base class is special in that every <filename>.bb</filename> file inherits it automatically. It contains definitions of standard basic tasks such as fetching, unpacking, configuring (empty by default), compiling (runs any Makefile present), installing (empty by default) and packaging @@ -94,54 +94,31 @@ <para> Several programs can fulfill the same or similar function and - they can be installed with the same name. For example the <command>ar</command> + be installed with the same name. + For example, the <filename>ar</filename> command is available from the "busybox", "binutils" and "elfutils" packages. - This class handles the renaming of the binaries so multiple packages - can be installed which would otherwise conflict and yet the - <command>ar</command> command still works regardless of which are installed - or subsequently removed. It renames the conflicting binary in each package + The <filename>update-alternatives.bbclass</filename> class handles renaming the + binaries so that multiple packages can be installed without conflicts. + The <filename>ar</filename> command still works regardless of which packages are installed + or subsequently removed. + The class renames the conflicting binary in each package and symlinks the highest priority binary during installation or removal of packages. - + </para> + <para> Four variables control this class: </para> - - - <variablelist> - <varlistentry> - <term>ALTERNATIVE_NAME</term> - <listitem> - <para> - Name of binary which will be replaced (<command>ar</command> in this example) - </para> - </listitem> - </varlistentry> - <varlistentry> - <term>ALTERNATIVE_LINK</term> - <listitem> - <para> - Path to resulting binary ("/bin/ar" in this example) - </para> - </listitem> - </varlistentry> - <varlistentry> - <term>ALTERNATIVE_PATH</term> - <listitem> - <para> - Path to real binary ("/usr/bin/ar.binutils" in this example) - </para> - </listitem> - </varlistentry> - <varlistentry> - <term>ALTERNATIVE_PRIORITY</term> - <listitem> - <para> - Priority of binary, the version with the most features should have the highest priority - </para> - </listitem> - </varlistentry> - </variablelist> - + <itemizedlist> + <listitem><para><filename>ALTERNATIVE_NAME</filename> ‐ The name of the + binary that is replaced (<filename>ar</filename> in this example).</para></listitem> + <listitem><para><filename>ALTERNATIVE_LINK</filename> ‐ The path to + the resulting binary (<filename>/bin/ar</filename> in this example).</para></listitem> + <listitem><para><filename>ALTERNATIVE_PATH</filename> ‐ The path to the + real binary (<filename>/usr/bin/ar.binutils</filename> in this example).</para></listitem> + <listitem><para><filename>ALTERNATIVE_PRIORITY</filename> ‐ The priority of + the binary. + The version with the most features should have the highest priority.</para></listitem> + </itemizedlist> <para> Currently, only one binary per package is supported. </para> @@ -175,7 +152,7 @@ <para> During staging Bitbake installs such scripts into the <filename class="directory">sysroots/</filename> directory. It also changes all - paths to point into the <filename class="directory">sysroots/</filename> + paths to point into the <filename>sysroots/</filename> directory so all builds which use the script will use the correct directories for the cross compiling layout. </para> @@ -218,7 +195,7 @@ </para> <para> - Result of their work are <filename class="directory">tmp/deploy/source/</filename> + Result of their work are <filename>tmp/deploy/source/</filename> subdirs with sources sorted by <glossterm><link linkend='var-LICENSE'>LICENSE</link> </glossterm> field. If recipe lists few licenses (or has entries like "Bitstream Vera") source archive is put in each license dir. @@ -322,7 +299,7 @@ </para> <para> This means that each kernel module built is packaged separately and inter-module dependencies are - created by parsing the <command>modinfo</command> output. If all modules are + created by parsing the <filename>modinfo</filename> output. If all modules are required then installing the "kernel-modules" package will install all packages with modules and various other kernel packages such as "kernel-vmlinux". </para> @@ -406,7 +383,7 @@ <para> Only the most useful/important classes are covered here but there are - others, see the <filename class="directory">meta/classes</filename> directory for the rest. + others, see the <filename>meta/classes</filename> directory for the rest. </para> </section> |