[PATCH] ref-manual: Describe grub-efi-cfg overrides and GRUB_TITLE

["Simon A. Eugster" <simon.eu@gmail.com>]

This patch describes how to use overrides for grub-efi-cfg because that
is otherwise only clear after reading the .bbclass file. It also adds
a description for GRUB_TITLE.
---
 documentation/ref-manual/classes.rst | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/documentation/ref-manual/classes.rst b/documentation/ref-manual/classes.rst
index 761be7b545..460f94b232 100644
--- a/documentation/ref-manual/classes.rst
+++ b/documentation/ref-manual/classes.rst
@@ -987,10 +987,14 @@ introspection. This functionality is only enabled if the
 The :ref:`ref-classes-grub-efi` class provides ``grub-efi``-specific functions for
 building bootable images.
 
-This class supports several variables:
+This class supports several variables.
+The label specific override names are ``grub_LABEL``.
+To specificy an override for the label ``mylabel``, the override name is ``grub_mylabel``,
+for example ``APPEND:grub_mylabel = my-appends``.
 
 -  :term:`INITRD`: Indicates list of filesystem images to
    concatenate and use as an initial RAM disk (initrd) (optional).
+   Can be specified for each ``LABEL``.
 
 -  :term:`ROOTFS`: Indicates a filesystem image to include
    as the root filesystem (optional).
@@ -1004,6 +1008,9 @@ This class supports several variables:
 -  :term:`APPEND`: An override list of append strings for
    each ``LABEL``.
 
+-  :term:`GRUB_TITLE`: A custom title for each ```LABEL``.
+   Defaults to ``LABEL`` if it is not defined.
+
 -  :term:`GRUB_OPTS`: Additional options to add to the
    configuration (optional). Options are delimited using semi-colon
    characters (``;``).
@@ -1011,6 +1018,14 @@ This class supports several variables:
 -  :term:`GRUB_TIMEOUT`: Timeout before executing
    the default ``LABEL`` (optional).
 
+For the label ``factory``, a custom GRUB menu entry titled "Factory Install" with the additional parameter ``factory=yes``
+can be achieved as follows::
+
+  LABELS:append = "factory"
+  APPEND:grub_factory = "factory=yes"
+  GRUB_TITLE:grub_factory = "Factory Install"
+
+
 .. _ref-classes-gsettings:
 
 ``gsettings``
-- 
2.43.0