[PATCH] ref-manual: document KERNEL_LOCALVERSION

[michael.opdenacker@bootlin.com]

From: Michael Opdenacker <michael.opdenacker@bootlin.com>

Introduced by
https://git.yoctoproject.org/poky/commit/?id=66ed174ccdf7a89cb998f503cc6b631e2d1adcc0

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
CC: Bruce Ashfield <bruce.ashfield@gmail.com>
---
 documentation/ref-manual/variables.rst | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/documentation/ref-manual/variables.rst b/documentation/ref-manual/variables.rst
index 03234d3f78..771eb91af6 100644
--- a/documentation/ref-manual/variables.rst
+++ b/documentation/ref-manual/variables.rst
@@ -2485,6 +2485,16 @@ system and gives an overview of their function and contents.
       external tools. See the :ref:`ref-classes-kernel-yocto` class in
       ``meta/classes-recipe`` to see how the variable is used.
 
+   :term:`KERNEL_LOCALVERSION`
+      This variable allows to appends a string to the version
+      of the kernel image. This corresponds to the ``CONFIG_LOCALVERSION``
+      kernel configuration parameter.
+
+      Using this variable is only useful when you are using a kernel recipe
+      inheriting the :ref:`ref-classes-kernel` class, and which doesn't
+      already set a local version. Therefore, setting this variable has no
+      impact on ``linux-yocto`` kernels.
+
    :term:`EXTERNAL_TOOLCHAIN`
       When you intend to use an
       :ref:`external toolchain <dev-manual/external-toolchain:optionally using an external toolchain>`,
-- 
2.34.1