From 2ccecdeaa2fad8f9fd9d828e18c04c3ce2d21197 Mon Sep 17 00:00:00 2001
From: Patrick Yavitz <pyavitz@xxxxx.com>
Date: Wed, 3 Apr 2024 09:41:49 -0400
Subject: [PATCH] device tree overlay support

Signed-off-by: Patrick Yavitz <pyavitz@xxxxx.com>
---
 scripts/Makefile.lib | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 68d0134bdbf9..413f9181b763 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -348,6 +348,7 @@ ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
 DTC_FLAGS += -Wno-unit_address_vs_reg \
 	-Wno-avoid_unnecessary_addr_size \
 	-Wno-alias_paths \
+	-Wno-gpios_property \
 	-Wno-graph_child_address \
 	-Wno-simple_bus_reg
 else
@@ -362,6 +363,11 @@ DTC_FLAGS += -Wnode_name_chars_strict \
 	-Wunique_unit_address
 endif
 
+ifeq ($(CONFIG_OF_OVERLAY),y)
+# enable creation of __symbols__ node
+DTC_FLAGS += -@
+endif
+
 DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
 
 # Set -@ if the target is a base DTB that overlay is applied onto
@@ -421,6 +427,18 @@ $(obj)/%.dtb: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
 $(obj)/%.dtbo: $(src)/%.dtso $(DTC) FORCE
 	$(call if_changed_dep,dtc)
 
+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) \
+		-Wno-interrupts_property \
+		-d $(depfile).dtc.tmp $(dtc-tmp) ; \
+	cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
+
+$(obj)/%.dtbo: $(obj)/%.dts FORCE
+	$(call if_changed_dep,dtco)
+
 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
 
 # Bzip2
-- 
2.39.2