New utility to tag/stamp image

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 "$0")/common.sh"
+
+DEFINE_string from "chromiumos_image.bin" \
+  "Input file name of Chrome OS image to tag/stamp."
+DEFINE_string update_firmware "" \
+  "Tag to force updating firmware (1 to enable, 0 to disable)"
+DEFINE_string dev_mode "" \
+  "Tag for developer mode (1 to enable, 0 to disable)"
+
+# Parse command line
+FLAGS "$@" || exit 1
+eval set -- "${FLAGS_ARGV}"
+
+# Abort on error
+set -e
+
+if [ -z ${FLAGS_from} ] || [ ! -f ${FLAGS_from} ] ; then
+  echo "Error: invalid flag --from"
+  exit 1
+fi
+
+# Global variable to track if image is modified.
+g_modified=${FLAGS_FALSE}
+
+# Processes (enable, disable, or simply report) a tag file.
+# Args: DO_MODIFICATION NAME ROOT TAG_FILE ACTION
+#
+# When DO_MODIFICATION=${FLAGS_TRUE},
+#  Creates (ACTION=1) the TAG_FILE in ROOT, or
+#  removes (ACTION=0) the TAG_FILE in ROOT, then
+#  reports the status (and change) to the tag file.
+# When DO_MODIFICATION=${FLAGS_FALSE},
+#  make a dry-run and only change ${g_modified}
+function process_tag() {
+  local tag_status_text=""
+  local do_modification="$1"
+  local name="$2"
+  local root="$3"
+  local tag_file_path="$3/$4"
+  local action="$5"
+  local do_enable=${FLAGS_FALSE}
+  local do_disable=${FLAGS_FALSE}
+
+  # only 1, 0, and "" are valid params to action.
+  case "${action}" in
+    "1" )
+      do_enable=${FLAGS_TRUE}
+      ;;
+    "0" )
+      do_disable=${FLAGS_TRUE}
+      ;;
+    "" )
+      ;;
+    * )
+      echo "Error: invalid param to ${name}: ${action} (must be 1 or 0)."
+      exit 1
+      ;;
+  esac
+
+  if [ -f "${tag_file_path}" ]; then
+    tag_status_text="ENABLED"
+    if [ "${do_disable}" = ${FLAGS_TRUE} ]; then
+      # disable the tag
+      if [ "${do_modification}" = ${FLAGS_TRUE} ]; then
+        sudo rm "${tag_file_path}"
+      fi
+      g_modified=${FLAGS_TRUE}
+      tag_status_text="${tag_status_text} => disabled"
+    elif [ "${do_disable}" != ${FLAGS_FALSE} ]; then
+      # internal error
+      echo "Internal error for tag ${name}: need disable param." 1>&2
+      exit 1
+    fi
+  else
+    tag_status_text="disabled"
+    if [ "${do_enable}" = ${FLAGS_TRUE} ]; then
+      # enable the tag
+      if [ "${do_modification}" = ${FLAGS_TRUE} ]; then
+        sudo touch "${tag_file_path}"
+      fi
+      g_modified=${FLAGS_TRUE}
+      tag_status_text="${tag_status_text} => ENABLED"
+    elif [ "${do_enable}" != ${FLAGS_FALSE} ]; then
+      # internal error
+      echo "Internal error for tag ${name}: need enable param." 1>&2
+      exit 1
+    fi
+  fi
+
+  # report tag status
+  if [ "${do_modification}" != ${FLAGS_TRUE} ]; then
+    echo "${name}: ${tag_status_text}"
+  fi
+}
+
+# Iterates all tags to a given partition root.
+# Args: ROOTFS DO_MODIFICATION
+#
+# Check process_tag for the meaning of parameters.
+process_all_tags() {
+  local rootfs="$1"
+  local do_modification="$2"
+
+  process_tag "${do_modification}" \
+    "Update Firmware" \
+    "${rootfs}" \
+    /root/.force_update_firmware \
+    "${FLAGS_update_firmware}"
+
+  process_tag "${do_modification}" \
+    "Developer Mode" \
+    "${rootfs}" \
+    /root/.dev_mode \
+    "${FLAGS_dev_mode}"
+}
+
+IMAGE=$(readlink -f "${FLAGS_from}")
+if [[ -z "${IMAGE}" || ! -f "${IMAGE}" ]]; then
+  echo "Missing required argument: --from (image to update)"
+  usage
+  exit 1
+fi
+
+# First round, mount as read-only and check if we read any modification.
+rootfs=$(make_temp_dir)
+mount_image_partition_ro "${IMAGE}" 3 "${rootfs}"
+
+# we don't have tags in stateful partition yet...
+# stateful_dir=$(make_temp_dir)
+# mount_image_partition ${IMAGE} 1 ${stateful_dir}
+
+process_all_tags "${rootfs}" ${FLAGS_FALSE}
+
+if [ ${g_modified} = ${FLAGS_TRUE} ]; then
+  # remount as RW (we can't use mount -o rw,remount because of loop device)
+  sudo umount -d "${rootfs}"
+  mount_image_partition "${IMAGE}" 3 "${rootfs}"
+
+  # Second round, apply the modification to image.
+  process_all_tags "${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