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Diffstat (limited to 'documentation/kernel-dev/kernel-dev-advanced.xml')
-rw-r--r-- | documentation/kernel-dev/kernel-dev-advanced.xml | 74 |
1 files changed, 40 insertions, 34 deletions
diff --git a/documentation/kernel-dev/kernel-dev-advanced.xml b/documentation/kernel-dev/kernel-dev-advanced.xml index 879d3f2..4d4c850 100644 --- a/documentation/kernel-dev/kernel-dev-advanced.xml +++ b/documentation/kernel-dev/kernel-dev-advanced.xml @@ -914,47 +914,50 @@ will want to specify in the KERNEL_FEATURES variable of the Linux kernel recipe <title>Kernel Types</title> <para> - Kernel types, or <filename>ktypes</filename>, are used to - aggregate all non-hardware configuration fragments together - with any patches you want to use for all Linux kernel builds - of the specified <filename>ktype</filename>. - In short, <filename>ktypes</filename> are where you define a - high-level kernel policy. - Syntactically, however, they are no different than features - as described in the previous section. - The <filename>ktype</filename> is selected by the - <filename>LINUX_KERNEL_TYPE</filename> variable in the recipe. + A kernel type defines a high-level kernel policy by + aggregating non-hardware configuration fragments with + patches you want to use when building a Linux kernels of a + specific type. + Syntactically, kernel types are no different than features + as described in the "<link linkend='features'>Features</link>" + section. + The <filename>LINUX_KERNEL_TYPE</filename> variable in the kernel + recipe selects the kernel type. See the "<link linkend='using-kernel-metadata-in-a-recipe'>Using Kernel Metadata in a Recipe</link>" section for more information. </para> <para> - By way of example, the linux-yocto-3.4 tree defines three - <filename>ktypes</filename>: standard, tiny, and preempt-rt. + As an example, the <filename>linux-yocto-3.4</filename> + tree defines three kernel types: "standard", + "tiny", and "preempt-rt": <itemizedlist> - <listitem><para>standard: - Includes the generic Linux kernel - policy of the Yocto Project linux-yocto kernel recipes. - This includes things like which file systems, which - networking options, which core kernel features, and which + <listitem><para>"standard": + Includes the generic Linux kernel policy of the Yocto + Project linux-yocto kernel recipes. + This policy includes, among other things, which file + systems, networking options, core kernel features, and debugging and tracing options are supported. </para></listitem> - <listitem><para>preempt-rt: + <listitem><para>"preempt-rt": Applies the <filename>PREEMPT_RT</filename> patches and the configuration options required to build a real-time Linux kernel. - It inherits from standard.</para></listitem> - <listitem><para>tiny: - Independent from the standard configuration - and defines a bare minimum configuration meant to serve as a + This kernel type inherits from the "standard" kernel type. + </para></listitem> + <listitem><para>"tiny": + Defines a bare minimum configuration meant to serve as a base for very small Linux kernels. - Tiny does not currently include any source changes, but it - might in the future.</para></listitem> + The "tiny" kernel type is independent from the "standard" + configuration. + Although the "tiny" kernel type does not currently include + any source changes, it might in the future. + </para></listitem> </itemizedlist> </para> <para> - The standard kernel type is defined by + The "standard" kernel type is defined by <filename>standard.scc</filename>: <literallayout class='monospaced'> # Include this kernel type fragment to get the standard features and @@ -981,21 +984,24 @@ will want to specify in the KERNEL_FEATURES variable of the Linux kernel recipe </para> <para> - As with any <filename>scc</filename> file, a - <filename>ktype</filename> definition can aggregate other - <filename>scc</filename> files with the - <filename>include</filename> command, or directly pull in + As with any <filename>.scc</filename> file, a + kernel type definition can aggregate other + <filename>.scc</filename> files with + <filename>include</filename> commands. + These definitions can also directly pull in configuration fragments and patches with the <filename>kconf</filename> and <filename>patch</filename> commands, respectively. </para> <note> - It is not strictly necessary to create a - <filename>ktype scc</filename> file. - The BSP file can define the <filename>ktype</filename> implicitly - with a <filename>define KTYPE myktype</filename> line. See the - next section for more information. + It is not strictly necessary to create a kernel type + <filename>.scc</filename> file. + The Board Support Package (BSP) file can implicitly define + the kernel type using a <filename>define KTYPE myktype</filename> + line. + See the "<link linkend='bsp-descriptions'>BSP Descriptions</link>" + section for more information. </note> <para> |