From: Bruce Ashfield <bruce.ashfield@gmail.com>
Subject: [PATCH] images/Makefile: fix cross-compilation protobuf paths

pkg-config --variable=includedir returns the host path (e.g.
/usr/include) without applying PKG_CONFIG_SYSROOT_DIR, since sysroot
prefixing only applies to -I flags from --cflags, not raw --variable
queries. The protoc --proto_path was also hardcoded to /usr/include.

Make the include dir overridable via PROTOBUF_INCLUDEDIR so cross-build
systems can pass the correct sysroot path through EXTRA_OEMAKE.

Upstream-Status: Pending

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
---
 images/Makefile | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/images/Makefile b/images/Makefile
--- a/images/Makefile
+++ b/images/Makefile
@@ -93,10 +93,11 @@ makefile-deps := Makefile $(obj)/Makefile
 #
 # Generate descriptor.pb-c.c and descriptor.pb-c.h to compile opts.proto.
 DESCRIPTOR_DIR := images/google/protobuf
-GOOGLE_INCLUDE=$(shell pkg-config protobuf --variable=includedir)/google/protobuf
+PROTOBUF_INCLUDEDIR ?= $(shell pkg-config protobuf --variable=includedir)
+GOOGLE_INCLUDE=$(PROTOBUF_INCLUDEDIR)/google/protobuf
 $(DESCRIPTOR_DIR)/descriptor.pb-c.c: $(GOOGLE_INCLUDE)/descriptor.proto
 	$(call msg-gen, $@)
-	$(Q) protoc --proto_path=/usr/include --proto_path=$(obj)/ --c_out=$(obj)/ $<
+	$(Q) protoc --proto_path=$(PROTOBUF_INCLUDEDIR) --proto_path=$(obj)/ --c_out=$(obj)/ $<
 
 cleanup-y += $(DESCRIPTOR_DIR)/descriptor.pb-c.d
