Allow boards to initialize the DT at runtime.
In some boards like the Raspberry Pi the initial bootloader will pass
a DT to the kernel. When using U-Boot as such kernel, the board code in
U-Boot should be able to provide U-Boot with this, already assembled
device tree blob.
This patch introduces a new config option CONFIG_OF_BOARD to use instead
of CONFIG_OF_EMBED or CONFIG_OF_SEPARATE which will initialize the DT
from a board-specific funtion instead of bundling one with U-Boot or as
a separated file. This allows boards like the Raspberry Pi to reuse the
device tree passed from the bootcode.bin and start.elf firmware
files, including the run-time selected device tree overlays.
Signed-off-by: Alex Deymo <deymo@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/dts/Kconfig b/dts/Kconfig
index 6fe7a5b..9a06221 100644
--- a/dts/Kconfig
+++ b/dts/Kconfig
@@ -51,6 +51,14 @@
and development only and is not recommended for production devices.
Boards in the mainline U-Boot tree should not use it.
+config OF_BOARD
+ bool "Provided by the board at runtime"
+ depends on !SANDBOX
+ help
+ If this option is enabled, the device tree will be provided by
+ the board at runtime if the board supports it, instead of being
+ bundled with the image.
+
config OF_HOSTFILE
bool "Host filed DTB for DT control"
depends on SANDBOX