[PATCH V7 1/3] kbuild: Add generic rule to apply fdtoverlay

[Viresh Kumar]

From: Rob Herring <robh at kernel.org>

Add a generic rule to apply fdtoverlay in Makefile.lib, so every
platform doesn't need to carry the complex rule.

The platform's Makefile only needs to have this now:

 DTC_FLAGS_foo_base += -@
 foo-dtbs := foo_base.dtb foo_overlay1.dtbo foo_overlay2.dtbo
 overlay-y := foo.dtb

Rearrange Makefile.lib to keep DT specific stuff together.

The files from overlay-y (i.e. files generated by fdtoverlay) aren't
added to dtb-y here, as dtb-y is later used to generate .dt.yaml files
and the files in overlay-y don't have a corresponding dts file and make
dtbs_check fails for them.

Signed-off-by: Rob Herring <robh at kernel.org>
[ Viresh: Add commit log and replace dtb-y with overlay-y, handle
          CONFIG_OF_ALL_DTBS case, rearrange Makefile, don't add
	  overlay-y to dtb-y to skip dtbs_check for them. ]
Signed-off-by: Viresh Kumar <viresh.kumar at linaro.org>
---
 scripts/Makefile.lib | 39 +++++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index b00855b247e0..a6e79e3be527 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -66,23 +66,16 @@ multi-used   := $(multi-used-y) $(multi-used-m)
 real-obj-y := $(foreach m, $(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m)))
 real-obj-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)) $($(m:.o=-))),$($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)),$(m)))
 
-always-y += $(always-m)
-
-# hostprogs-always-y += foo
-# ... is a shorthand for
-# hostprogs += foo
-# always-y  += foo
-hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)
-always-y += $(hostprogs-always-y) $(hostprogs-always-m)
-
-# userprogs-always-y is likewise.
-userprogs += $(userprogs-always-y) $(userprogs-always-m)
-always-y += $(userprogs-always-y) $(userprogs-always-m)
+# Add base dtb and overlay dtbo
+dtb-y += $(foreach m,$(overlay-y), $(if $(strip $($(m:.dtb=-dtbs))),$($(m:.dtb=-dtbs)),))
+dtb-$(CONFIG_OF_ALL_DTBS) += $(foreach m,$(overlay-), $(if $(strip $($(m:.dtb=-dtbs))),$($(m:.dtb=-dtbs)),))
 
 # DTB
 # If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
 extra-y				+= $(dtb-y)
+extra-y				+= $(overlay-y)
 extra-$(CONFIG_OF_ALL_DTBS)	+= $(dtb-)
+extra-$(CONFIG_OF_ALL_DTBS)	+= $(overlay-)
 
 ifneq ($(CHECK_DTBS),)
 extra-y += $(patsubst %.dtb,%.dt.yaml, $(dtb-y))
@@ -91,6 +84,19 @@ extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-))
 extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtbo,%.dt.yaml, $(dtb-))
 endif
 
+always-y += $(always-m)
+
+# hostprogs-always-y += foo
+# ... is a shorthand for
+# hostprogs += foo
+# always-y  += foo
+hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)
+always-y += $(hostprogs-always-y) $(hostprogs-always-m)
+
+# userprogs-always-y is likewise.
+userprogs += $(userprogs-always-y) $(userprogs-always-m)
+always-y += $(userprogs-always-y) $(userprogs-always-m)
+
 # Add subdir path
 
 extra-y		:= $(addprefix $(obj)/,$(extra-y))
@@ -332,6 +338,15 @@ $(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE
 $(obj)/%.dtbo: $(src)/%.dts $(DTC) FORCE
 	$(call if_changed_dep,dtc)
 
+
+quiet_cmd_fdtoverlay = DTOVL   $@
+      cmd_fdtoverlay = $(objtree)/scripts/dtc/fdtoverlay -o $@ -i $(real-prereqs)
+
+.SECONDEXPANSION:
+
+$(obj)/%.dtb: $$(addprefix $$(obj)/,$$(%-dtbs)) FORCE
+	$(call if_changed,fdtoverlay)
+
 DT_CHECKER ?= dt-validate
 DT_BINDING_DIR := Documentation/devicetree/bindings
 # DT_TMP_SCHEMA may be overridden from Documentation/devicetree/bindings/Makefile
-- 
2.25.0.rc1.19.g042ed3e048af