doc: capsule: Document the new mechanism to embed ESL file into dtb

Update the document to specify how the EFI Signature List(ESL) file
can be embedded into the platform's dtb as part of the U-Boot build.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

diff --git a/doc/develop/uefi/uefi.rst b/doc/develop/uefi/uefi.rst
index f27cabbcce8af2a720393161c8bd134f298c4815..68f9b332d153dc409144432a2efd692aa2fa7f48 100644 (file)
--- a/doc/develop/uefi/uefi.rst
+++ b/doc/develop/uefi/uefi.rst
@@ -562,20 +562,11 @@ and used by the steps highlighted below.
             ...
     }
 
-You can do step-4 manually with
-
-.. code-block:: console
-
-    $ dtc -@ -I dts -O dtb -o signature.dtbo signature.dts
-    $ fdtoverlay -i orig.dtb -o new.dtb -v signature.dtbo
-
-where signature.dts looks like::
-
-    &{/} {
-            signature {
-                    capsule-key = /incbin/("CRT.esl");
-            };
-    };
+You can perform step-4 through the Kconfig symbol
+CONFIG_EFI_CAPSULE_ESL_FILE. This symbol points to the esl file
+generated in step-2. Once the symbol has been populated with the path
+to the esl file, it will automatically get embedded into the
+platform's dtb as part of U-Boot build.
 
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