From: Scott Rifenbark Date: Tue, 5 Feb 2013 15:31:54 +0000 (-0600) Subject: ref-manual: edits to update-alternatives.bbclass description. X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1263e584752cd818d3c5dc6b45d4c5d4387e6832;p=thirdparty%2Fopenembedded%2Fopenembedded-core-contrib.git 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 Signed-off-by: Richard Purdie --- diff --git a/documentation/ref-manual/ref-classes.xml b/documentation/ref-manual/ref-classes.xml index 2caea272a48..5e35e8946cd 100644 --- a/documentation/ref-manual/ref-classes.xml +++ b/documentation/ref-manual/ref-classes.xml @@ -85,35 +85,36 @@ Alternatives - <filename>update-alternatives.bbclass</filename> - Several programs can fulfill the same or similar function and be installed with the same name. + This class helps the alternatives system when multiple sources provide + the same command. + This situation occurs when several programs that have the same or + similar function are installed with the same name. For example, the ar command is available from the busybox, binutils and elfutils packages. - The update-alternatives.bbclass class handles renaming the - binaries so that multiple packages can be installed without conflicts. - The ar 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. - - - Four variables control this class: - - ALTERNATIVE_NAME ‐ The name of the - binary that is replaced (ar in this example). - ALTERNATIVE_LINK ‐ The path to - the resulting binary (/bin/ar in this example). - ALTERNATIVE_PATH ‐ The path to the - real binary (/usr/bin/ar.binutils in this example). - ALTERNATIVE_PRIORITY ‐ The priority of - the binary. - The version with the most features should have the highest priority. - + The update-alternatives.bbclass class handles + renaming the binaries so that multiple packages can be installed + without conflicts. + The ar 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. - Currently, the OpenEmbedded build system supports only one binary per package. + To use this class, you need to define a number of variables. + These variables list alternative commands needed by a package, + provide pathnames for links, default links for targets, and + so forth. + For details on how to use this class, see the comments in the + update-alternatives.bbclass. + + + You can use the update-alternatives command + directly in your recipes. + However, this class simplifies things in most cases. +