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author | Scott Rifenbark <scott.m.rifenbark@intel.com> | 2013-01-07 14:08:58 -0600 |
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committer | Richard Purdie <richard.purdie@linuxfoundation.org> | 2013-01-16 15:59:15 +0000 |
commit | ced75cec41d0227ef75c9765d5c0a86ddb4f21f7 (patch) | |
tree | 4dd1aff913a05984fbddd141569786ff5f3000da /documentation/kernel-dev/kernel-dev-advanced.xml | |
parent | e826a507391da71bd79bb8ab15fb340a9cc09f31 (diff) | |
download | openembedded-core-contrib-ced75cec41d0227ef75c9765d5c0a86ddb4f21f7.tar.gz |
kernel-dev: Edits to using metadata in a recipe section.
General edits to clarify the writing.
(From yocto-docs rev: 0510ab0faf81e0ac1c931863337eb217581c66ed)
Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'documentation/kernel-dev/kernel-dev-advanced.xml')
-rw-r--r-- | documentation/kernel-dev/kernel-dev-advanced.xml | 80 |
1 files changed, 43 insertions, 37 deletions
diff --git a/documentation/kernel-dev/kernel-dev-advanced.xml b/documentation/kernel-dev/kernel-dev-advanced.xml index ad46fcc8f0..a951aaec5d 100644 --- a/documentation/kernel-dev/kernel-dev-advanced.xml +++ b/documentation/kernel-dev/kernel-dev-advanced.xml @@ -77,7 +77,7 @@ to source changes. feature enablement. The BSP can be influenced from within the linux-yocto recipe. <note> - Linux kernel source that contains this Metadata is said to be + Linux kernel source that contains kernel Metadata is said to be "linux-yocto style" kernel source. A Linux kernel recipe that inherits from the <filename>linux-yocto.inc</filename> include file is said to be a @@ -91,14 +91,15 @@ to source changes. variable. This variable is typically set to the same value as the <ulink url='&YOCTO_DOCS_REF_URL;#var-MACHINE'><filename>MACHINE</filename></ulink> - variable used by BitBake (e.g. "routerstationpro" or "fri2"). - However, multiple BSPs can reuse the same <filename>KMACHINE</filename> + variable, which is used by BitBake (e.g. "routerstationpro" or "fri2"). + Multiple BSPs can reuse the same <filename>KMACHINE</filename> name if they are built using the same BSP description. + The "fri2" and "fri2-noemgd" BSP combination + in the <filename>meta-intel</filename> + layer is a good example of two BSPs using the same + <filename>KMACHINE</filename> value (i.e. "fri2"). See the <link linkend='bsp-descriptions'>BSP Descriptions</link> section for more information. - The <filename>meta-intel</filename> "fri2" and "fri2-noemgd" are good - examples of such a situation where each specifies - <filename>KMACHINE</filename> as "fri2". </para> <para> @@ -110,39 +111,43 @@ to source changes. KBRANCH_DEFAULT LINUX_KERNEL_TYPE </literallayout> - <filename>KBRANCH_DEFAULT</filename> defines the default source branch - within the Linux kernel source repository to be used to build the - Linux kernel. - It is used as the default value for <filename>KBRANCH</filename> which - may define an alternate branch, typically with a machine override, - such as: + <filename>KBRANCH_DEFAULT</filename> defines the Linux kernel source + repository's default branch to use to build the Linux kernel. + The value is used as the default for <filename>KBRANCH</filename>, which + can define an alternate branch typically with a machine override as + follows: <literallayout class='monospaced'> KBRANCH_fri2 = "standard/fri2" </literallayout> Unless you specify otherwise, <filename>KBRANCH_DEFAULT</filename> - is initialized to "master". + initializes to "master". </para> <para> <filename>LINUX_KERNEL_TYPE</filename> defines the kernel type to be - used in assembling the configuration and defaults to "standard" - if you do not specify otherwise. - Together with <filename>KMACHINE</filename>, this defines the search - arguments used by the Yocto Project Linux kernel tools to find the - appropriate description within the metadata with which to build out - the sources and configuration. + used in assembling the configuration. + If you do not specify a <filename>LINUX_KERNEL_TYPE</filename>, + it defaults to "standard". + Together with <filename>KMACHINE</filename>, + <filename>LINUX_KERNEL_TYPE</filename> defines the search + arguments used by the kernel tools to find the + appropriate description within the kernel Metadata with which to + build out the sources and configuration. The linux-yocto recipes define "standard", "tiny", and "preempt-rt" kernel types. - See section 3.3.4 for more inforation on kernel types. + See the <link linkend='kernel-types'>Kernel Types</link> section + for more inforation on kernel types. </para> <para> - During the build, the kern-tools will search for the BSP description + During the build, the kern-tools search for the BSP description file that most closely matches the <filename>KMACHINE</filename> - and <filename>LINUX_KERNEL_TYPE</filename> passed in from the + and <filename>LINUX_KERNEL_TYPE</filename> variables passed in from the recipe. - It will use the first BSP description it finds matching both variables. - Failing that it will issue a warning such as the following: + The tools use the first BSP description it finds that match + both variables. + If the tools cannot find a match, they issue a warning such as + the following: <literallayout class='monospaced'> WARNING: Can't find any BSP hardware or required configuration fragments. WARNING: Looked at meta/cfg/broken/fri2-broken/hdw_frags.txt and @@ -154,19 +159,19 @@ to source changes. </para> <para> - It will then search first for the <filename>KMACHINE</filename> and + The tools first search for the <filename>KMACHINE</filename> and then for the <filename>LINUX_KERNEL_TYPE</filename>. - If it cannot find a partial match, it will use the + If the tools cannot find a partial match, they will use the sources from the <filename>KBRANCH</filename> and any configuration specified in the <filename>SRC_URI</filename>. </para> <para> - <filename>KERNEL_FEATURES</filename> can be used to include features - (configuration fragments, patches, or both) that are not already - included by the <filename>KMACHINE</filename> and - <filename>LINUX_KERNEL_TYPE</filename> combination. - To include a feature specified as "features/netfilter.scc" for example, + You can use the <filename>KERNEL_FEATURES</filename> variable + to include features (configuration fragments, patches, or both) that + are not already included by the <filename>KMACHINE</filename> and + <filename>LINUX_KERNEL_TYPE</filename> variable combination. + For example, to include a feature specified as "features/netfilter.scc", specify: <literallayout class='monospaced'> KERNEL_FEATURES += "features/netfilter.scc" @@ -177,12 +182,13 @@ to source changes. KERNEL_FEATURES_append_qemux86 = "cfg/sound.scc" </literallayout> The value of the entries in <filename>KERNEL_FEATURES</filename> - are dependent on their location within the metadata itself. + are dependent on their location within the kernel Metadata itself. The examples here are taken from the <filename>linux-yocto-3.4</filename> repository where "features" - and "cfg" are subdirectories of the <filename>metadata</filename> - directory. - For details, see section 3.3. + and "cfg" are subdirectories within the + <filename>meta/cfg/kernel-cache</filename> directory. + For more information, see the + "<link linkend='metadata-syntax'>Metadata Syntax</link>" section. <note> The processing of the these variables has evolved some between the 0.9 and 1.3 releases of the Yocto Project and associated @@ -275,8 +281,8 @@ metadata directory. For details, see 3.3. </para> </section> -<section id='metadata-location'> - <title>Metadata Location</title> +<section id='kernel-metadata-location'> + <title>Kernel Metadata Location</title> <para> This metadata can be defined along with the Linux kernel |