Index: head/sys/tools/fdt/make_dtb.sh
===================================================================
--- head/sys/tools/fdt/make_dtb.sh	(revision 267318)
+++ head/sys/tools/fdt/make_dtb.sh	(revision 267319)
@@ -1,20 +1,20 @@
 #!/bin/sh
 #
 # $FreeBSD$
 
 # Script generates dtb file ($3) from dts source ($2) in build tree S ($1)
 S=$1
 dts="$2"
 dtb_path=$3
 
 if [ -z "$dts" ]; then
     echo "No DTS specified"
     exit 1
 fi
 
 for d in ${dts}; do
     dtb=${dtb_path}/`basename $d .dts`.dtb
     echo "converting $d -> $dtb"
-    cpp -x assembler-with-cpp -I $S/gnu/dts/include -I $S/boot/fdt/dts/${MACHINE} -I $S/gnu/dts/${MACHINE} -include $d /dev/null | 
+    cpp -P -x assembler-with-cpp -I $S/gnu/dts/include -I $S/boot/fdt/dts/${MACHINE} -I $S/gnu/dts/${MACHINE} -include $d /dev/null | 
 	dtc -O dtb -o $dtb -b 0 -p 1024 -i $S/boot/fdt/dts/${MACHINE} -i $S/gnu/dts/${MACHINE}
 done