From ed0a240e1632682ec4c33341f3e24ad71773cdfc Mon Sep 17 00:00:00 2001 From: Scott Rifenbark Date: Tue, 11 Dec 2012 12:07:58 -0600 Subject: documentation: Rename of poky-ref-manual folder to ref-manual. Changing the folder that holds the YP Reference Manual to be "ref-manual". This will help with confustion over the manual's intended purpose. (From yocto-docs rev: 1106442964b5080cb0b6b3bd3af32e9407c0f7c1) Signed-off-by: Scott Rifenbark Signed-off-by: Richard Purdie --- .../html/poky-ref-manual/ref-bitbake-parsing.html | 93 ++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 documentation/ref-manual/eclipse/html/poky-ref-manual/ref-bitbake-parsing.html (limited to 'documentation/ref-manual/eclipse/html/poky-ref-manual/ref-bitbake-parsing.html') diff --git a/documentation/ref-manual/eclipse/html/poky-ref-manual/ref-bitbake-parsing.html b/documentation/ref-manual/eclipse/html/poky-ref-manual/ref-bitbake-parsing.html new file mode 100644 index 0000000000..c86621eb38 --- /dev/null +++ b/documentation/ref-manual/eclipse/html/poky-ref-manual/ref-bitbake-parsing.html @@ -0,0 +1,93 @@ + + + +6.1. Parsing + + + + + + + +
+

+6.1. Parsing

+

+ BitBake parses configuration files, classes, and .bb files. +

+

+ The first thing BitBake does is look for the bitbake.conf file. + This file resides in the + Source Directory + within the meta/conf/ directory. + BitBake finds it by examining its + BBPATH environment + variable and looking for the meta/conf/ + directory. +

+

+ The bitbake.conf file lists other configuration + files to include from a conf/ + directory below the directories listed in BBPATH. + In general, the most important configuration file from a user's perspective + is local.conf, which contains a user's customized + settings for the OpenEmbedded build environment. + Other notable configuration files are the distribution + configuration file (set by the + DISTRO variable) + and the machine configuration file + (set by the + MACHINE variable). + The DISTRO and MACHINE BitBake environment + variables are both usually set in + the local.conf file. + Valid distribution + configuration files are available in the meta/conf/distro/ directory + and valid machine configuration + files in the meta/conf/machine/ directory. + Within the meta/conf/machine/include/ + directory are various tune-*.inc configuration files that provide common + "tuning" settings specific to and shared between particular architectures and machines. +

+

+ After the parsing of the configuration files, some standard classes are included. + The base.bbclass file is always included. + Other classes that are specified in the configuration using the + INHERIT + variable are also included. + Class files are searched for in a classes subdirectory + under the paths in BBPATH in the same way as + configuration files. +

+

+ After classes are included, the variable + BBFILES + is set, usually in + local.conf, and defines the list of places to search for + .bb files. + By default, the BBFILES variable specifies the + meta/recipes-*/ directory within Poky. + Adding extra content to BBFILES is best achieved through the use of + BitBake layers as described in the + "Understanding and + Creating Layers" section of the Yocto Project Development Manual. +

+

+ BitBake parses each .bb file in BBFILES and + stores the values of various variables. + In summary, for each .bb + file the configuration plus the base class of variables are set, followed + by the data in the .bb file + itself, followed by any inherit commands that + .bb file might contain. +

+

+ Because parsing .bb files is a time + consuming process, a cache is kept to speed up subsequent parsing. + This cache is invalid if the timestamp of the .bb + file itself changes, or if the timestamps of any of the include, + configuration or class files the .bb + file depends on changes. +

+
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