[DTBO] Add support for DTBO file

all *.dts file with suffix "-overlay" into name will be managed as dtbo
file

.gitignore

@@ -19,6 +19,7 @@
 *.dt.yaml
 *.dtb
 *.dtb.S
+*.dtbo
 *.dwo
 *.elf
 *.gcno

Makefile

@@ -1353,6 +1353,9 @@ ifneq ($(dtstree),)
 %.dtb: include/config/kernel.release scripts_dtc
 	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
 
+%.dtbo: include/config/kernel.release scripts_dtc
+	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
+
 PHONY += dtbs dtbs_install dtbs_check
 dtbs: include/config/kernel.release scripts_dtc
 	$(Q)$(MAKE) $(build)=$(dtstree)

scripts/Makefile.dtbinst

@@ -18,6 +18,7 @@ include scripts/Kbuild.include
 include $(src)/Makefile
 
 dtbs    := $(addprefix $(dst)/, $(dtb-y) $(if $(CONFIG_OF_ALL_DTBS),$(dtb-)))
+dtb0s   := $(addprefix $(dst)/, $(dtbo-y) $(if $(CONFIG_OF_ALL_DTBS),$(dtbo-)))
 subdirs := $(addprefix $(obj)/, $(subdir-y) $(subdir-m))
 
 __dtbs_install: $(dtbs) $(subdirs)
@@ -29,6 +30,9 @@ quiet_cmd_dtb_install = INSTALL $@
 $(dst)/%.dtb: $(obj)/%.dtb
 	$(call cmd,dtb_install)
 
+$(dst)/%.dtbo: $(obj)/%.dtbo	
+	$(call cmd,dtb_install)
+
 PHONY += $(subdirs)
 $(subdirs):
 	$(Q)$(MAKE) $(dtbinst)=$@ dst=$(patsubst $(obj)/%,$(dst)/%,$@)

scripts/Makefile.lib

@@ -317,7 +317,7 @@ $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
 
 quiet_cmd_dtc = DTC     $@
 cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
-	$(DTC) -O $(patsubst .%,%,$(suffix $@)) -o $@ -b 0 \
+	$(DTC) -@ -O $(patsubst .%,%,$(suffix $@)) -o $@ -b 0 \
 		$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
 		-d $(depfile).dtc.tmp $(dtc-tmp) ; \
 	cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
@@ -341,6 +341,18 @@ endef
 $(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
 	$(call if_changed_rule,dtc,yaml)
 
+quiet_cmd_dtco = DTCO    $@
+cmd_dtco = mkdir -p $(dir ${dtc-tmp}) ; \
+	$(CPP) $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
+	$(DTC) -@ -H epapr -O dtb -o $@ -b 0 \
+		-i $(dir $<) $(DTC_FLAGS) \
+		-d $(depfile).dtc.tmp $(dtc-tmp) ; \
+	cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
+
+$(obj)/%.dtbo: $(src)/%-overlay.dts  $(DTCO) FORCE
+	$(call if_changed_dep,dtco,yaml)
+
+
 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
 
 # Bzip2