Merge pull request #1104 from nmenon/dtb_build-v2

Makefile: Add ability to build dtb (v2)
diff --git a/Makefile b/Makefile
index c0fddcf..51e622e 100644
--- a/Makefile
+++ b/Makefile
@@ -125,6 +125,7 @@
 OD			:=	${CROSS_COMPILE}objdump
 NM			:=	${CROSS_COMPILE}nm
 PP			:=	${CROSS_COMPILE}gcc -E
+DTC			?=	dtc
 
 ifeq (${ARM_ARCH_MAJOR},7)
 target32-directive	= 	-target arm-none-eabi
@@ -163,6 +164,8 @@
 TF_LDFLAGS		+=	--gc-sections
 TF_LDFLAGS		+=	$(TF_LDFLAGS_$(ARCH))
 
+DTC_FLAGS		+=	-I dts -O dtb
+
 ################################################################################
 # Common sources and include directories
 ################################################################################
@@ -451,6 +454,10 @@
 endif
 endif
 
+ifdef FDT_SOURCES
+NEED_FDT := yes
+endif
+
 ################################################################################
 # Build options checks
 ################################################################################
@@ -551,7 +558,7 @@
 # Build targets
 ################################################################################
 
-.PHONY:	all msg_start clean realclean distclean cscope locate-checkpatch checkcodebase checkpatch fiptool fip fwu_fip certtool
+.PHONY:	all msg_start clean realclean distclean cscope locate-checkpatch checkcodebase checkpatch fiptool fip fwu_fip certtool dtbs
 .SUFFIXES:
 
 all: msg_start
@@ -604,6 +611,13 @@
 $(eval $(call FWU_FIP_ADD_PAYLOAD,${BL2U_PATH},--ap-fwu-cfg))
 endif
 
+# Expand build macros for the different images
+ifeq (${NEED_FDT},yes)
+$(eval $(call MAKE_DTBS,$(BUILD_PLAT)/fdts,$(FDT_SOURCES)))
+$(eval $(call MAKE_FDT))
+dtbs: $(DTBS)
+endif
+
 locate-checkpatch:
 ifndef CHECKPATCH
 	$(error "Please set CHECKPATCH to point to the Linux checkpatch.pl file, eg: CHECKPATCH=../linux/scripts/checkpatch.pl")
@@ -731,6 +745,7 @@
 	@echo "  distclean      Remove all build artifacts for all platforms"
 	@echo "  certtool       Build the Certificate generation tool"
 	@echo "  fiptool        Build the Firmware Image Package (FIP) creation tool"
+	@echo "  dtbs           Build the Flattened device tree (if required for the platform)"
 	@echo ""
 	@echo "Note: most build targets require PLAT to be set to a specific platform."
 	@echo ""
diff --git a/make_helpers/build_macros.mk b/make_helpers/build_macros.mk
index 7531f6d..e1bfbbe 100644
--- a/make_helpers/build_macros.mk
+++ b/make_helpers/build_macros.mk
@@ -336,3 +336,49 @@
 
 endef
 
+define SOURCES_TO_DTBS
+        $(notdir $(patsubst %.dts,%.dtb,$(filter %.dts,$(1))))
+endef
+
+# MAKE_FDT macro defines the targets and options to build each FDT binary
+# Arguments: (none)
+define MAKE_FDT
+        $(eval DTB_BUILD_DIR  := ${BUILD_PLAT}/fdts)
+        $(eval DTBS       := $(addprefix $(DTB_BUILD_DIR)/,$(call SOURCES_TO_DTBS,$(FDT_SOURCES))))
+        $(eval TEMP_DTB_DIRS := $(sort $(dir ${DTBS})))
+        # The $(dir ) function leaves a trailing / on the directory names
+        # Rip off the / to match directory names with make rule targets.
+        $(eval DTB_DIRS   := $(patsubst %/,%,$(TEMP_DTB_DIRS)))
+
+$(eval $(foreach objd,${DTB_DIRS},$(call MAKE_PREREQ_DIR,${objd},${BUILD_DIR})))
+
+fdt_dirs: ${DTB_DIRS}
+
+endef
+
+# MAKE_DTB generate the Flattened device tree binary (device tree binary)
+#   $(1) = output directory
+#   $(2) = input dts
+define MAKE_DTB
+
+$(eval DOBJ := $(1)/$(patsubst %.dts,%.dtb,$(notdir $(2))))
+$(eval DEP := $(patsubst %.dtb,%.d,$(DOBJ)))
+
+$(DOBJ): $(2) | fdt_dirs
+	@echo "  DTC      $$<"
+	$$(Q)$$(DTC) $$(DTC_FLAGS) -d $(DEP) -o $$@ $$<
+
+-include $(DEP)
+
+endef
+
+# MAKE_DTBS builds flattened device tree sources
+#   $(1) = output directory
+#   $(2) = list of flattened device tree source files
+define MAKE_DTBS
+        $(eval DOBJS := $(filter %.dts,$(2)))
+        $(eval REMAIN := $(filter-out %.dts,$(2)))
+        $(eval $(foreach obj,$(DOBJS),$(call MAKE_DTB,$(1),$(obj))))
+
+        $(and $(REMAIN),$(error Unexpected s present: $(REMAIN)))
+endef