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authorScott Rifenbark <scott.m.rifenbark@intel.com>2013-02-05 09:31:54 -0600
committerRichard Purdie <richard.purdie@linuxfoundation.org>2013-02-14 17:24:03 +0000
commit1263e584752cd818d3c5dc6b45d4c5d4387e6832 (patch)
tree0e08999f12d313580ebd807ec2bb8cc8eea6fb08 /documentation/ref-manual
parent40fde06345c61ca77bb40341e048673613f9932f (diff)
downloadpoky-1263e584752cd818d3c5dc6b45d4c5d4387e6832.tar.gz
ref-manual: edits to update-alternatives.bbclass description.
Fixes YOCTO #3838 First draft of edits for this class. Removed specific variable definitions as they are now deprecated. Added a general explanation of the variable functions. Pointed user to the commented code in the actual class for details. Removed statement saying that the build system supports only one binary per package. (From yocto-docs rev: bd574f2c8a95470c5a44500b70743a6e039522b7) Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'documentation/ref-manual')
-rw-r--r--documentation/ref-manual/ref-classes.xml45
1 files changed, 23 insertions, 22 deletions
diff --git a/documentation/ref-manual/ref-classes.xml b/documentation/ref-manual/ref-classes.xml
index 2caea272a4..5e35e8946c 100644
--- a/documentation/ref-manual/ref-classes.xml
+++ b/documentation/ref-manual/ref-classes.xml
@@ -85,35 +85,36 @@
85 <title>Alternatives - <filename>update-alternatives.bbclass</filename></title> 85 <title>Alternatives - <filename>update-alternatives.bbclass</filename></title>
86 86
87 <para> 87 <para>
88 Several programs can fulfill the same or similar function and be installed with the same name. 88 This class helps the alternatives system when multiple sources provide
89 the same command.
90 This situation occurs when several programs that have the same or
91 similar function are installed with the same name.
89 For example, the <filename>ar</filename> command is available from the 92 For example, the <filename>ar</filename> command is available from the
90 <filename>busybox</filename>, <filename>binutils</filename> and 93 <filename>busybox</filename>, <filename>binutils</filename> and
91 <filename>elfutils</filename> packages. 94 <filename>elfutils</filename> packages.
92 The <filename>update-alternatives.bbclass</filename> class handles renaming the 95 The <filename>update-alternatives.bbclass</filename> class handles
93 binaries so that multiple packages can be installed without conflicts. 96 renaming the binaries so that multiple packages can be installed
94 The <filename>ar</filename> command still works regardless of which packages are installed 97 without conflicts.
95 or subsequently removed. 98 The <filename>ar</filename> command still works regardless of which
96 The class renames the conflicting binary in each package and symlinks the highest 99 packages are installed or subsequently removed.
97 priority binary during installation or removal of packages. 100 The class renames the conflicting binary in each package and symlinks
98 </para> 101 the highest priority binary during installation or removal of packages.
99 <para>
100 Four variables control this class:
101 <itemizedlist>
102 <listitem><para><filename>ALTERNATIVE_NAME</filename> &dash; The name of the
103 binary that is replaced (<filename>ar</filename> in this example).</para></listitem>
104 <listitem><para><filename>ALTERNATIVE_LINK</filename> &dash; The path to
105 the resulting binary (<filename>/bin/ar</filename> in this example).</para></listitem>
106 <listitem><para><filename>ALTERNATIVE_PATH</filename> &dash; The path to the
107 real binary (<filename>/usr/bin/ar.binutils</filename> in this example).</para></listitem>
108 <listitem><para><filename>ALTERNATIVE_PRIORITY</filename> &dash; The priority of
109 the binary.
110 The version with the most features should have the highest priority.</para></listitem>
111 </itemizedlist>
112 </para> 102 </para>
113 103
114 <para> 104 <para>
115 Currently, the OpenEmbedded build system supports only one binary per package. 105 To use this class, you need to define a number of variables.
106 These variables list alternative commands needed by a package,
107 provide pathnames for links, default links for targets, and
108 so forth.
109 For details on how to use this class, see the comments in the
110 <ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/poky/tree/meta/classes/update-alternatives.bbclass'><filename>update-alternatives.bbclass</filename></ulink>.
116 </para> 111 </para>
112
113 <note>
114 You can use the <filename>update-alternatives</filename> command
115 directly in your recipes.
116 However, this class simplifies things in most cases.
117 </note>
117</section> 118</section>
118 119
119<section id='ref-classes-update-rc.d'> 120<section id='ref-classes-update-rc.d'>