arm/docs: Clarify legacy DT bindings on UEFI

Since the introduction of UEFI boot for Xen, the legacy
compatible strings were not supported and the stub code
was checking only the presence of “multiboot,module” to
require the Xen UEFI configuration file or not.
The documentation was not updated to specify that behavior.

Add a phrase to docs/misc/arm/device-tree/booting.txt
to clarify it.

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>

diff --git a/docs/misc/arm/device-tree/booting.txt b/docs/misc/arm/device-tree/booting.txt
index c6a775f4e80c44472ee85ba8dbb56a6cbc8a9d4d..71895663a4deb9bc4f3503d8f4cd253f82baf7fd 100644 (file)
--- a/docs/misc/arm/device-tree/booting.txt
+++ b/docs/misc/arm/device-tree/booting.txt
@@ -51,6 +51,8 @@ Each node contains the following properties:
        Xen 4.4 supported a different set of legacy compatible strings
        which remain supported such that systems supporting both 4.4
        and later can use a single DTB.
+       However when booting Xen using UEFI, the legacy compatible
+       strings are not supported.
 
        - "xen,multiboot-module" equivalent to "multiboot,module"
        - "xen,linux-zimage"     equivalent to "multiboot,kernel"