fdt: Avoid emitting an device tree when not needed
U-Boot always needs some sort of a device tree in the build. Some boards
never actually use this, at least in production systems, since a prior
firmware stage sets one up and passes it to U-Boot. At present the only
mechanism to do that is with custom function (OF_BOARD), but future work
will include a standard way of doing this ('standard passage').
It can be confusing to see a device tree emitted from the U-Boot build in
this situation. Add an option to drop it.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/Makefile b/Makefile
index a4f267c..074ba73 100644
--- a/Makefile
+++ b/Makefile
@@ -944,7 +944,9 @@
endif
endif
INPUTS-$(CONFIG_TPL) += tpl/u-boot-tpl.bin
-INPUTS-$(CONFIG_OF_SEPARATE) += u-boot.dtb
+
+# Allow omitting the .dtb output if it is not normally used
+INPUTS-$(CONFIG_OF_SEPARATE) += $(if $(CONFIG_OF_OMIT_DTB),dts/dt.dtb,u-boot.dtb)
ifeq ($(CONFIG_SPL_FRAMEWORK),y)
INPUTS-$(CONFIG_OF_SEPARATE) += u-boot-dtb.img
endif
@@ -1187,7 +1189,7 @@
u-boot-dtb.bin: u-boot-nodtb.bin dts/dt.dtb FORCE
$(call if_changed,cat)
-else ifeq ($(CONFIG_OF_SEPARATE),y)
+else ifeq ($(CONFIG_OF_SEPARATE).$(CONFIG_OF_OMIT_DTB),y.)
u-boot-dtb.bin: u-boot-nodtb.bin dts/dt.dtb FORCE
$(call if_changed,cat)