diff --git a/qemu_multiarch_testing/parallel-build-hdc-img.sh b/qemu_multiarch_testing/parallel-build-hdc-img.sh
new file mode 100755
index 0000000..9ee54eb
--- /dev/null
+++ b/qemu_multiarch_testing/parallel-build-hdc-img.sh
@@ -0,0 +1,40 @@
+#!/bin/sh
+
+export HDBMEGS=100
+keep_hdb=false
+
+build_in_dir()
+{
+	cd "$1" || exit 1
+	rm -f hdb.img
+	nice -n10 time ./native-build.sh ../hdc.img
+	$keep_hdb || rm -f hdb.img
+	echo >&3 "Finished: $1"
+}
+
+test "$1" = "-s" && {
+	dir="$2"
+	# single mode: build one directory, show output
+	test -d "$dir" || exit 1
+	test -e "$dir/native-build.sh" || exit 1
+	build_in_dir "$dir"
+	exit $?
+}
+
+started=false
+for dir; do
+	test -d "$dir" || continue
+	test -e "$dir/native-build.sh" || continue
+	echo "Starting: $dir"
+	build_in_dir "$dir" 3>&1 </dev/null >"$dir.log" 2>&1 &
+	started=true
+done
+
+$started || {
+	echo "Give me system-image-ARCH directories on command line"
+	exit 1
+}
+
+echo "Waiting to finish"
+wait
+echo "Done, check the logs"