From cd37bf87dbb1632b1c40c88032b68a43722b6ea0 Mon Sep 17 00:00:00 2001
From: Patrick Yavitz <pyavitz@gmail.com>
Date: Sat, 18 Oct 2025 14:55:38 -0400
Subject: [PATCH] device tree overlay support

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

diff --git a/scripts/Makefile.dtbs b/scripts/Makefile.dtbs
index 2d321b813600..3d28c8ce09e2 100644
--- a/scripts/Makefile.dtbs
+++ b/scripts/Makefile.dtbs
@@ -96,6 +96,7 @@ 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-interrupt_map \
              -Wno-simple_bus_reg
@@ -103,6 +104,11 @@ else
 DTC_FLAGS += -Wunique_unit_address_if_enabled
 endif
 
+ifeq ($(CONFIG_OF_OVERLAY),y)
+# enable creation of __symbols__ node
+DTC_FLAGS += -@
+endif
+
 ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
 DTC_FLAGS += -Wnode_name_chars_strict \
              -Wproperty_name_chars_strict \
@@ -120,6 +126,18 @@ dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc -I $(DTC_INCLUDE) -undef -
 
 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
 
+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)
+
 quiet_cmd_dtc = DTC $(quiet_dtb_check_tag) $@
       cmd_dtc = \
 	$(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
-- 
2.43.0