[v2] ref-manual/variables.rst: document new FIT image variables

diff --git a/documentation/ref-manual/variables.rst b/documentation/ref-manual/variables.rst
index 4d8a35473..08103f7e1 100644
--- a/documentation/ref-manual/variables.rst
+++ b/documentation/ref-manual/variables.rst
@@ -3389,6 +3389,47 @@  system and gives an overview of their function and contents.
 
       This variable is used in the :ref:`ref-classes-kernel-fit-image` class.
 
+   :term:`FIT_CONF_MAPPINGS`
+      When inheriting the :ref:`ref-classes-kernel-fit-image`, the
+      :term:`FIT_CONF_MAPPINGS` variable allows specifying mappings to rename
+      configuration nodes or add extra configuration nodes for existing device
+      tree blobs (DTBs) in FIT images. This provides flexibility when a 1 to 1
+      mapping between DTB names and configuration node names does not work,
+      such as when the kernel defines a kernel specific name but the bootloader
+      uses a different name. This might be the case when maintaining
+      compatibility with existing boot scripts or bootloader configurations.
+      But there are other use cases as well.
+
+      The variable accepts a space-separated list of mapping commands:
+
+      -  ``dtb-conf:DTB_NAME:NEW_NAME``
+         Renames the configuration node for a specific DTB. The ``DTB_NAME`` is
+         the name of the DTB without its ``.dtb`` suffix.
+
+      -  ``dtb-extra-conf:DTB_NAME:EXTRA_NAME``
+         Creates an additional configuration node for an existing DTB. This is
+         useful when you need to provide alternative names for the same hardware
+         configuration to maintain compatibility with existing boot scripts or
+         bootloader configurations or just need an alias configuration name for
+         some other reason.
+
+      For example::
+
+         FIT_CONF_MAPPINGS = "\
+             dtb-extra-conf:am335x-bonegreen:bonegreen \
+             dtb-conf:am335x-boneblack:bbblack"
+
+      This generates three configuration nodes from two DTBs:
+
+      -  ``am335x-bonegreen``: the original configuration node for the
+         ``am335x-bonegreen`` device tree
+      -  ``bonegreen``: an extra configuration node for the same
+         ``am335x-bonegreen`` DTB
+      -  ``bbblack``: a renamed configuration node for the ``am335x-boneblack`` DTB
+
+      The :ref:`ref-classes-kernel-fit-image` class validates all mappings
+      and ensures they match existing DTBs.
+
    :term:`FIT_CONF_PREFIX`
       When using the :ref:`ref-classes-kernel-fit-image`, this is the prefix
       used for creating FIT configuration nodes. Its default value is "conf-".
@@ -3479,6 +3520,22 @@  system and gives an overview of their function and contents.
       The default value is set to "x509" by the
       :ref:`ref-classes-kernel-fit-image` class.
 
+   :term:`FIT_MKIMAGE_EXTRA_OPTS`
+      When inheriting the :ref:`ref-classes-kernel-fit-image`, the
+      :term:`FIT_MKIMAGE_EXTRA_OPTS` variable allows passing extra options to
+      ``mkimage`` during FIT image generation, providing flexibility for platforms
+      that require additional ``mkimage`` arguments beyond the defaults.
+
+      For example::
+
+         FIT_MKIMAGE_EXTRA_OPTS = "-B 8 -E"
+
+      This results in the ``mkimage`` command being invoked as:
+
+      .. parsed-literal::
+
+         mkimage *-B 8 -E* -f fit-image.its fitImage
+
    :term:`FIT_PAD_ALG`
       Specifies the padding algorithm used in creating the FIT Image.
       The default value is set to "pkcs-1.5" by the