From f202838fdd1872c2a74f07c5a5d9a664780972db Mon Sep 17 00:00:00 2001 From: Scott Rifenbark Date: Mon, 12 Mar 2012 14:25:58 -0600 Subject: documentation/dev-manual/dev-manual-common-tasks.xml: Review edits Implemented Paul Eggleton's review comments for the "Understanding and Using Layers" section. (From yocto-docs rev: ec376754f63122a1bd31d47e153ee3e872aac0b5) Signed-off-by: Scott Rifenbark Signed-off-by: Richard Purdie --- .../dev-manual/dev-manual-common-tasks.xml | 63 ++++++++++++++++------ 1 file changed, 46 insertions(+), 17 deletions(-) (limited to 'documentation') diff --git a/documentation/dev-manual/dev-manual-common-tasks.xml b/documentation/dev-manual/dev-manual-common-tasks.xml index 74375c89bf..729e945153 100644 --- a/documentation/dev-manual/dev-manual-common-tasks.xml +++ b/documentation/dev-manual/dev-manual-common-tasks.xml @@ -119,7 +119,7 @@ from BBFILES into a particular layer. In this case, immediate expansion of LAYERDIR - sets BBFILES_PATTERN to the layer's path. + sets BBFILE_PATTERN to the layer's path. The BBFILE_PRIORITY variable then assigns a priority to the layer. @@ -131,9 +131,10 @@ The LAYERDIR variable expands to the directory of the current layer and requires the immediate expansion operator so that BitBake does not wait to expand the variable when it's parsing a different directory. - BitBake locates included .bbclass, configuration, - and other files using the include and require - statements by way of the BBPATH environment variable. + Through the use of the BBPATH environment variable, + BitBake locates .bbclass files, configuration + files, and files that are included with include + and require statements. For these cases, BitBake uses the first file with the matching name found in BBPATH. This is similar to the way the PATH variable is used for binaries. @@ -365,6 +366,21 @@ The following list describes the available commands: + help: + Displays general help or help on a specified command. + show-layers: + Show the current configured layers. + show-recipes: + Lists available recipes and the layers that provide them. + + show-overlayed: + Lists overlayed recipes. + A recipe is overlayed when a recipe with the same name exists in another layer + that has a higher layer priority. + + show-appends: + Lists .bbappend files and the recipe files to which + they apply. flatten: Flattens the layer configuration into a separate output directory. Flattening your layer configuration builds a "flattened" directory that contains @@ -380,22 +396,35 @@ Overridden and appended items from .bbappend files need to be cleaned up. - For example, the contents of each .bbappend end up in the + The contents of each .bbappend end up in the flattened recipe. However, if there are appended or changed variable values, you need to tidy - these up yourself. + these up yourself. + Consider the following example. + Here, the bitbake-layers command adds the line + #### bbappended ... so that you know where the following + lines originate: + + ... + DESCRIPTION = "A useful utility" + ... + EXTRA_OECONF = "--enable-something" + ... + + #### bbappended from meta-anotherlayer #### + + DESCRIPTION = "Customized utility" + EXTRA_OECONF += "--enable-somethingelse" + + Ideally, you would tidy up these utilities as follows: + + ... + DESCRIPTION = "Customized utility" + ... + EXTRA_OECONF = "--enable-something --enable-somethingelse" + ... + - help: - Displays general help or help on a specified command. - show_appends: - Lists .bbappend files and the recipe files to which - they apply. - show_layers: - Show the current configured layers. - show_overlayed: - Lists overlayed recipes. - Overlayed recipes appear in another layer that has a higher layer priority. - -- cgit v1.2.3-54-g00ecf