[PATCH v3] 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.

Signed-off-by: Simon A. Eugster <simon.eu@gmail.com>
---
 documentation/ref-manual/classes.rst   | 16 ++++++++++++++++
 documentation/ref-manual/variables.rst |  5 +++++
 2 files changed, 21 insertions(+)

diff --git a/documentation/ref-manual/classes.rst b/documentation/ref-manual/classes.rst
index 761be7b545..1d64ac2f28 100644
--- a/documentation/ref-manual/classes.rst
+++ b/documentation/ref-manual/classes.rst
@@ -991,6 +991,7 @@ This class supports several variables:
 
 -  :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 +1005,9 @@ 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 +1015,18 @@ This class supports several variables:
 -  :term:`GRUB_TIMEOUT`: Timeout before executing
    the default ``LABEL`` (optional).
 
+Each ``LABEL`` defined in the :term:``LABELS`` variable creates a GRUB boot
+entry, and some variables can be defined individually per ``LABEL``. The label
+specific override names are defined as ``grub_LABEL``.
+
+For example, for a label ``factory``, the override name would be
+``grub_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``
diff --git a/documentation/ref-manual/variables.rst b/documentation/ref-manual/variables.rst
index 0c5c7aab97..4eb11abede 100644
--- a/documentation/ref-manual/variables.rst
+++ b/documentation/ref-manual/variables.rst
@@ -3320,6 +3320,11 @@ system and gives an overview of their function and contents.
       :ref:`ref-classes-grub-efi` class for more information
       on how this variable is used.
 
+   :term:`GRUB_TITLE`
+      Specifies custom titles for GRUB labels defined in  :term:`LABELS`. See
+      the :ref:`ref-classes-grub-efi` class for more information on how this
+      variable is used.
+
    :term:`GTKIMMODULES_PACKAGES`
       When inheriting the :ref:`ref-classes-gtk-immodules-cache` class,
       this variable specifies the packages that contain the GTK+ input
-- 
2.43.0