diff --git a/config/functions b/config/functions
index 1532100303..d03b083684 100644
--- a/config/functions
+++ b/config/functions
@@ -191,6 +191,22 @@ fix_module_depends() {
   rm new.modinfo*
 }
 
+# Usage: enable_service <unit> [target]
+enable_service () {
+  local unit="$1"
+  local unit_dir="/lib/systemd/system"
+  local target="$2"
+  local target_dir=$INSTALL
+
+  [ -f "$target_dir/$unit_dir/$unit" ] || exit 1
+  [ -z "$target" ] && target=`grep '^WantedBy' $target_dir/$unit_dir/$unit | cut -f2 -d=`
+
+  if [ -n "$target" ]; then
+    mkdir -p ${target_dir}/$unit_dir/${target}.wants
+    ln -sf ../${unit} ${target_dir}/$unit_dir/${target}.wants/
+  fi
+}
+
 check_path() {
 dashes="==========================="
   if [ "${PWD##/usr}" != "${PWD}" ]; then