[OE-core] [PATCH] linux-dtb.inc: Run dts through the preprocessor

[Franklin S. Cooper Jr]

* In the 3.11 kernel some dts files now include C code that must first run
  through the preprocessor.
* Update building the dtb by first running the dts file through the user's
  compiler before building using the device tree compiler.
* The logic used is based on mainline u-boot dts/Makefile.

Signed-off-by: Franklin S. Cooper Jr <fcooper at ti.com>
---
 meta/recipes-kernel/linux/linux-dtb.inc |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/meta/recipes-kernel/linux/linux-dtb.inc b/meta/recipes-kernel/linux/linux-dtb.inc
index 41dd599..f1aafa2 100644
--- a/meta/recipes-kernel/linux/linux-dtb.inc
+++ b/meta/recipes-kernel/linux/linux-dtb.inc
@@ -21,7 +21,10 @@ do_install_append() {
 			DTS_BASE_NAME=`basename ${DTS_FILE} | awk -F "." '{print $1}'`
 			DTB_NAME=`echo ${KERNEL_IMAGE_BASE_NAME} | sed "s/${MACHINE}/${DTS_BASE_NAME}/g"`
 			DTB_SYMLINK_NAME=`echo ${KERNEL_IMAGE_SYMLINK_NAME} | sed "s/${MACHINE}/${DTS_BASE_NAME}/g"`
-			dtc -I dts -O dtb ${KERNEL_DEVICETREE_FLAGS} -o ${DTS_BASE_NAME} ${DTS_FILE}
+
+			cat ${DTS_FILE} | \
+				${CPP} -x assembler-with-cpp -I ./include/ -I ./arch/${ARCH}/boot/dts - | \
+				dtc ${KERNEL_DEVICETREE_FLAGS} -O dtb -o ${DTS_BASE_NAME} -i arch/${ARCH}/boot/dts/ -
 			install -m 0644 ${DTS_BASE_NAME} ${D}/${KERNEL_IMAGEDEST}/devicetree-${DTB_SYMLINK_NAME}.dtb
 		done
 	fi
-- 
1.7.0.4