Implement the custom role concept

- Custom Ansible roles can be stored in the `roles/custom` directory
- The list `custom_roles` determines which roles are included

roles/custom/fvs/files/bootorder.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/bash
+#
+# fix boot order: first PXE, then Debian
+#
+set -eu
+
+cur="$(efibootmgr | grep -Ei 'BootOrder:' | \
+		     sed -E 's/^BootOrder: ([[:xdigit:]]{4}),.+$/\1/')"
+pxeip4="$(efibootmgr | grep -Ei "IP.*4" | \
+		     sed -E 's/^Boot([[:xdigit:]]{4}).+$/\1/')"
+debian="$(efibootmgr | grep -Ei "debian" | \
+		     sed -E 's/^Boot([[:xdigit:]]{4}).+$/\1/')"
+
+if [[ "$cur" != "$pxeip4" ]] && [[ -n "$pxeip4" ]] && [[ -n "$debian" ]] ; then
+    efibootmgr -o $pxeip4,$debian
+else
+    echo "Nothing to do."
+fi