ref-manual/variables.rst: document SPL_DTB_BINARY

This variable is part of uboot-sign but not documented.

(From yocto-docs rev: 05eb461cb1da76ad9cbaf634da7f47447b3f6765)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/documentation/ref-manual/classes.rst b/documentation/ref-manual/classes.rst
index 748f0395c2..0f4405b98f 100644
--- a/documentation/ref-manual/classes.rst
+++ b/documentation/ref-manual/classes.rst
@@ -3166,6 +3166,9 @@ The variables used by this class are:
 -  :term:`SPL_SIGN_ENABLE`: enable signing the FIT image.
 -  :term:`SPL_SIGN_KEYDIR`: directory containing the signing keys.
 -  :term:`SPL_SIGN_KEYNAME`: base filename of the signing keys.
+-  :term:`SPL_DTB_BINARY`: Name of the SPL device tree binary. Can be set to an
+   empty string to indicate that no SPL should be created and added to the FIT
+   image.
 -  :term:`UBOOT_FIT_ADDRESS_CELLS`: ``#address-cells`` value for the FIT image.
 -  :term:`UBOOT_FIT_DESC`: description string encoded into the FIT image.
 -  :term:`UBOOT_FIT_GENERATE_KEYS`: generate the keys if they don't exist yet.