From 2d6da7e23b6bdaf31be9e712adc1b4ed6352fb72 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Sun, 27 Mar 2022 21:23:49 +0200
Subject: [PATCH] build: add support for passing C preprocessor flags for DTS
 builds

Useful for adding #ifdefs based on build system provided definitions, or
for adding extra include paths

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 include/image.mk | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/image.mk b/include/image.mk
index 7acc5af61..e06b44893 100644
--- a/include/image.mk
+++ b/include/image.mk
@@ -184,6 +184,7 @@ endef
 # $(4) extra DTC flags
 define Image/BuildDTB
 	$(TARGET_CROSS)cpp -nostdinc -x assembler-with-cpp \
+		$(DTS_CPPFLAGS) \
 		-I$(DTS_DIR) \
 		-I$(DTS_DIR)/include \
 		-I$(LINUX_DIR)/include/ \