Add --leave_firmware_alone flag for BIOS testing purposes.

scripts/image_signing/tag_image.sh

 #!/bin/bash
 
 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Script to manipulate the tag files in the output of build_image
 
 # Load common constants.  This should be the first executable line.
 # The path to common.sh should be relative to your script's location.
 . "$(dirname "$0")/common.sh"
 
 load_shflags
 
 DEFINE_string from "chromiumos_image.bin" \
   "Input file name of Chrome OS image to tag/stamp."
 DEFINE_string dev_mode "" \
   "(build-info) Tag as a developer mode build (1 to enable, 0 to disable)"
 DEFINE_string update_firmware "" \
   "(auto-update) Force updating firmware (1 to enable, 0 to disable)"
+DEFINE_string leave_firmware_alone "" \
+  "(auto-update) For BIOS development use ONLY (1 to enable, 0 to disable)"
 DEFINE_string forget_usernames "" \
   "(session-manager) Forget usernames (1 to enable, 0 to disable)"
 DEFINE_string leave_core "" \
   "(crash-reporter) Leave core dumps (1 to enable, 0 to disable)"
 DEFINE_string crosh_workarounds "" \
   "(crosh) Keep crosh (1 to keep, 0 to disable *irreversible*)"
 
 # Parameters for manipulating /etc/lsb-release.
 DEFINE_boolean remove_test_label false \
   "(build-info) Remove 'test' suffix in /etc/lsb-release"
@@ skipping 104 matching lines @@
     /root/.dev_mode \
     "${FLAGS_dev_mode}"
 
   process_tag "${do_modification}" \
     "(auto-update) update_firmware" \
     "${rootfs}" \
     /root/.force_update_firmware \
     "${FLAGS_update_firmware}"
 
   process_tag "${do_modification}" \
+    "(auto-update) leave_firmware_alone" \
+    "${rootfs}" \
+    /root/.leave_firmware_alone \
+    "${FLAGS_leave_firmware_alone}"
+
+  process_tag "${do_modification}" \
     "(session-manager) forget_usernames" \
     "${rootfs}" \
     /root/.forget_usernames \
     "${FLAGS_forget_usernames}"
 
   process_tag "${do_modification}" \
     "(crash-reporter) leave_core" \
     "${rootfs}" \
     /root/.leave_core \
     "${FLAGS_leave_core}"
@@ skipping 59 matching lines @@
   process_all_tags "${rootfs}" ${FLAGS_TRUE}
   process_all_lsb_mods "${rootfs}" ${FLAGS_TRUE}
 
   # this is supposed to be automatically done in mount_image_partition,
   # but it's no harm to explicitly make it again here.
   tag_as_needs_to_be_resigned "${rootfs}"
   echo "IMAGE IS MODIFIED. PLEASE REMEMBER TO RESIGN YOUR IMAGE."
 else
   echo "Image is not modified."
 fi