summaryrefslogtreecommitdiffstats
path: root/documentation
diff options
context:
space:
mode:
Diffstat (limited to 'documentation')
-rw-r--r--documentation/kernel-dev/kernel-dev-advanced.xml98
1 files changed, 98 insertions, 0 deletions
diff --git a/documentation/kernel-dev/kernel-dev-advanced.xml b/documentation/kernel-dev/kernel-dev-advanced.xml
index 768b66450b..8a036a7d2d 100644
--- a/documentation/kernel-dev/kernel-dev-advanced.xml
+++ b/documentation/kernel-dev/kernel-dev-advanced.xml
@@ -664,6 +664,104 @@ meta/cfg/kernel-cache/ if you are creating meta-data in-tree (see 3.2.2).
664 </literallayout> 664 </literallayout>
665 </para> 665 </para>
666 666
667 <section id='configuration'>
668 <title>Configuration</title>
669
670 <para>
671 The simplest unit of metadata is the configuration-only feature.
672 It consists of one or more Linux kernel configuration parameters
673 in a configuration fragment file (<filename>.cfg</filename>)
674 and an <filename>scc</filename> file describing the fragment.
675 </para>
676
677 <para>
678 The SMP fragment included in the linux-yocto-3.4 Git repository
679 consists of the following two files:
680 <literallayout class='monospaced'>
681 cfg/smp.scc:
682 define KFEATURE_DESCRIPTION "Enable SMP"
683 kconf hardware smp.cfg
684
685 cfg/smp.cfg:
686 CONFIG_SMP=y
687 CONFIG_SCHED_SMT=y
688 </literallayout>
689 You can find information on configuration fragment files in the
690 "<ulink url='&YOCTO_DOCS_REF_URL;#creating-config-fragments'>Creating Configuration Fragments</ulink>"
691 section of the Yocto Project Development Manual and in
692 the "<link linkend='generating-configuration-files'>Generating Configuration Files</link>"
693 section earlier in this manual.
694 </para>
695
696 <para>
697 <filename>KFEATURE_DESCRIPTION</filename> provides a short
698 description of the fragment, the primary use is for higher level
699 tooling, such as the Yocto Project BSP Tools (TODO:Citation).
700 </para>
701
702 <para>
703 The <filename>kconf</filename> command is used to include the
704 actual configuration fragment in an <filename>scc</filename>
705 file, and the "hardware" keyword identifies the fragment as
706 being hardware enabling, as opposed to general policy,
707 which would use the keyword "non-hardware".
708 The distinction is made for the benefit of the configuration
709 validation tools, which will warn you if a hardware fragment
710 overrides a policy set by a non-hardware fragment.
711 </para>
712
713 <para>
714 As described in the
715 "<link linkend='generating-configuration-files'>Generating Configuration Files</link>"
716 section, the following BitBake command can be used to audit your
717 configuration:
718 <literallayout class='monospaced'>
719 $ bitbake linux-yocto -c kernel_configcheck -f
720 </literallayout>
721 The description file can include multiple <filename>kconf</filename>
722 statements, one per fragment.
723 </para>
724
725 <para>
726 Original text:
727 <literallayout class='monospaced'>
728The simplest unit of meta-data is the configuration-only feature. It consists of
729one or more Linux kernel configuration parameters in a .cfg file (as described
730in section XYZ) and an scc file describing the fragment. The SMP fragment
731included in the linux-yocto-3.4 git repository consists of the following two
732files:
733
734cfg/smp.scc:
735 define KFEATURE_DESCRIPTION "Enable SMP"
736 kconf hardware smp.cfg
737
738cfg/smp.cfg:
739 CONFIG_SMP=y
740 CONFIG_SCHED_SMT=y
741
742See 2.3.1 for details on creating configuration fragments.
743
744KFEATURE_DESCRIPTION provides a short description of the fragment, the
745primary use is for higher level tooling, such as the Yocto Project BSP Tools
746(TODO:Citation).
747
748The "kconf" command is used to include the actual configuration fragment in an
749scc file, and the "hardware" keyword identifies the fragment as being hardware
750enabling, as opposed to general policy (which would use the keyword
751"non-hardware"). The distinction is made for the benefit of the configuration
752validation tools which will warn you if a hardware fragment overrides a policy
753set by a non-hardware fragment.
754
755As described in 2.3.1, the following bitbake command can be used to audit your
756configuration:
757
758 $ bitbake linux-yocto -c kernel_configcheck -f
759
760The description file can include multiple kconf statements, one per fragment.
761 </literallayout>
762 </para>
763 </section>
764
667 765
668 766
669 767