diff --git a/documentation/ref-manual/classes.rst b/documentation/ref-manual/classes.rst
index 5187033f77..54a98bf24f 100644
--- a/documentation/ref-manual/classes.rst
+++ b/documentation/ref-manual/classes.rst
@@ -3426,6 +3426,8 @@ The variables used by this class are:
 -  :term:`UBOOT_FIT_USER_SETTINGS`: adds a user-specific snippet to the U-Boot
    Image Tree Source (ITS). Users can include their custom U-Boot Image Tree
    Source (ITS) snippet in this variable.
+-  :term:`UBOOT_FIT_CONF_FIRMWARE`: adds one image to the ``firmware`` property
+   of the configuration node.
 -  :term:`UBOOT_FIT_CONF_USER_LOADABLES`: adds one or more user-defined images
    to the ``loadables`` property of the configuration node.
 
diff --git a/documentation/ref-manual/variables.rst b/documentation/ref-manual/variables.rst
index 36cc78bb0a..c697bdbbb7 100644
--- a/documentation/ref-manual/variables.rst
+++ b/documentation/ref-manual/variables.rst
@@ -10439,6 +10439,15 @@ system and gives an overview of their function and contents.
 
          do_compile[depends] += "trusted-firmware-a:do_deploy"
 
+   :term:`UBOOT_FIT_CONF_FIRMWARE`
+      Adds one image to the ``firmware`` property of the configuration node of
+      the U-Boot Image Tree Source (ITS). Sets the ``firmware`` property to
+      select the image to boot first::
+
+         UBOOT_FIT_CONF_FIRMWARE = "fwa"
+
+      If not set, the first entry in "loadables" is used to boot instead.
+
    :term:`UBOOT_FIT_CONF_USER_LOADABLES`
       Adds one or more user-defined images to the ``loadables`` property of the
       configuration node of the U-Boot Image Tree Source (ITS). This variable