diff --git a/build.sh b/build.sh
index 4713fee..b193a38 100755
--- a/build.sh
+++ b/build.sh
@@ -1,7 +1,5 @@
 #!/bin/bash -e
 
-set -e
-
 function announce () {
 	echo '############################' $* >&2
 }
@@ -9,10 +7,11 @@ function announce () {
 proc=$(nproc)
 gluon_out="${HOME}/firmware"
 
-while getopts g:j:o:bv opt; do
+while getopts g:j:o:s:bv opt; do
 	case "$opt" in
 		g) gluon_path="$OPTARG" ;;
 		o) gluon_out="$OPTARG" ;;
+		s) signature="$OPTARG" ;;
 		b) export BROKEN=1 ;;
 		j) proc="$OPTARG" ;;
 		v) verbose=V=s ;;
@@ -22,6 +21,7 @@ if [ -z "${gluon_path}" ]; then
 	echo "Usage: $0 -g GLUON_PATH" >&2
 	echo "       -g GLUON_PATH   Path to a checkout of the gluon repository." >&2
 	echo "       -o OUT_PATH     Path to a checkout of the gluon repository. Default: ${gluon_out}" >&2
+	echo "       -s SIGNATURE    Sign firmware with signature" >&2
 	echo "       -b              BROKEN=1" >&2
 	echo "       -v              verbose" >&2
 	echo "       -j JOBS         Run build with -jJOBS. Default: ${proc}" >&2
@@ -29,7 +29,6 @@ if [ -z "${gluon_path}" ]; then
 fi
 
 gluon_path=$(realpath $gluon_path)
-mkdir -p ${gluon_out}
 gluon_out=$(realpath $gluon_out)
 site_path=$(realpath $(dirname $BASH_SOURCE))
 
@@ -40,12 +39,13 @@ announce FFHH SITES: $site_path >&2
 announce Building site repo and reading data >&2
 pushd $site_path > /dev/null
 make
-. info
+. ./info
 export GLUON_RELEASE
 export GLUON_BRANCH
 # get the available sites...
-sites=""
-for s in sites/*; do sites="${sites} ${s##*/}"; done
+if [ "$sites" == "" ]; then
+	for s in sites/*; do sites="${sites} ${s##*/}"; done
+fi
 announce Gluon will be built for the following sites:$sites >&2
 announce The following targets will be generated: $targets >&2
 popd >/dev/null
@@ -54,7 +54,7 @@ pushd "${gluon_path}" >/dev/null
 announce Starting make update...
 for s in $sites; do
 	export GLUON_SITEDIR="${site_path}/sites/${s}"
-	export GLUON_OUTPUTDIR="${gluon_out}/${s}/${GLUON_BRANCH}/${GLUON_RELEASE}"
+	export GLUON_OUTPUTDIR="${gluon_out}/${GLUON_RELEASE}/${GLUON_BRANCH}/${s}"
 	export GLUON_IMAGEDIR="${GLUON_OUTPUTDIR}/images"
 	export GLUON_MODULEDIR="${GLUON_OUTPUTDIR}/modules"
 	rm -rf "${GLUON_OUTPUTDIR}"
@@ -69,10 +69,21 @@ for s in $sites; do
 		fi
 	done
 	for t in $targets; do
+		announce make clean for $s/$t... >&2
+		make -j1 clean GLUON_TARGET=$t
 		announce Starting build for $s/$t... >&2
 		make -j$(nproc) GLUON_TARGET=$t $verbose
 	done
 	announce Building manifest...
 	make manifest
+	if [ -n "${signature}" ]; then
+		if [ "$GLUON_BRANCH" == "experimental" ]; then
+			announce Signing
+			"${gluon_path}/contrib/sign.sh" "${signature}" "${GLUON_IMAGEDIR}/sysupgrade/experimental.manifest"
+		else
+			echo ERROR: can only sign experimental branch >&2
+			exit 1
+		fi
+	fi
 done
 popd >/dev/null