Do nothing if we're debugging BIOS changes, unless forced

pack_stub

Index: pack_stub
diff --git a/pack_stub b/pack_stub
index 873188111bf16902212bc6ac54e86e30a532d78e..d871188f80e3f22ae1a0df67b4d9bdd89a4af949 100644
--- a/pack_stub
+++ b/pack_stub
@@ -108,6 +108,9 @@ case "$1" in
     TMP_DIR=""
     exit 0
     ;;
+  --force)
+    force_flag=1
+    ;;
   -h|"-?"|--help)
     echo "Shellball -- self-extract and install"
     echo ""
@@ -135,6 +138,12 @@ case "$1" in
     ;;
 esac
 
+# Do nothing if we're debugging BIOS changes, unless forced
+if [ -e /root/.leave_firmware_alone ] && [ -z "${force_flag:-}" ]; then
+  echo "WARNING: $0 is disabled"
+  exit 0
+fi
+
 # Prepare execution environment
 make_temp
 allow_temp_exec