[PATCH] docs: kbuild: add INSTALL_DTBS_PATH

[Ricardo B. Marliere]

The documentation for kbuild and makefiles is missing an explanation of
a variable important for some architectures.

Signed-off-by: Ricardo B. Marliere <ricardo@xxxxxxxxxxxx>
---
 Documentation/kbuild/kbuild.rst    | 6 ++++++
 Documentation/kbuild/makefiles.rst | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst
index bd906407e307..9c8d1d046ea5 100644
--- a/Documentation/kbuild/kbuild.rst
+++ b/Documentation/kbuild/kbuild.rst
@@ -243,6 +243,12 @@ The output directory is often set using "O=..." on the commandline.
 
 The value can be overridden in which case the default value is ignored.
 
+INSTALL_DTBS_PATH
+-----------------
+INSTALL_DTBS_PATH specifies where to install device tree blobs for
+relocations required by build roots.  This is not defined in the
+makefile but the argument can be passed to make if needed.
+
 KBUILD_ABS_SRCTREE
 --------------------------------------------------
 Kbuild uses a relative path to point to the tree when possible. For instance,
diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index e67eb261c9b0..d88d4f0f4f89 100644
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -1623,6 +1623,13 @@ INSTALL_MOD_STRIP
   INSTALL_MOD_STRIP value will be used as the option(s) to the strip
   command.
 
+INSTALL_DTBS_PATH
+  This variable specifies a prefix for relocations required by build
+  roots. It defines a place for installing the device tree blobs. Like
+  INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed
+  by the user if desired. Otherwise it defaults to the kernel install
+  path.
+
 Makefile language
 =================
 
-- 
2.42.0