make_factory_package: support using firmware updater from release rootfs

For most use case, we want to use the firmware updater from release image
rootfs. It'd be more convenient if make_factory_package extracts updater from
release image by default.

BUG=chromium-os:21512
TEST=./make_factory_package --release RELEASE --factory FACTORY --hwid none
     # success, seeing "firmware: XXXX" in output
     ./make_factory_package --release RELEASE --factory FACTORY --hwid none --firmware none
     # success, not seeing firmware in mini-omaha configuration
     ./make_factory_package --release RELEASE --factory FACTORY --hwid none --firmware FIRMWARE
     # success, seeing "firmware: XXXX" in mini-omaha configuration
     ./make_factory_package --release RELEASE --factory FACTORY --hwid none \
       --diskimg ssd.img
     # success, no firmware messages
     ./make_factory_package --release RELEASE --factory FACTORY --hwid none \
       --diskimg ssd.img --firmware FIRMWARE
     # failure as expected - firmware is not supported in --diskimg.

Change-Id: Ic368031a8a5ece89e3e7fd56e2ee4fd1143a67a7
Reviewed-on: https://gerrit.chromium.org/gerrit/10561
Tested-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Nick Sanders <nsanders@chromium.org>
Commit-Ready: Hung-Te Lin <hungte@chromium.org>

lib/cros_image_common.sh

@@ -199,6 +199,7 @@ image_mount_partition() {
   local part_num="$2"
   local mount_point="$3"
   local mount_opt="$4"
+  local mount_ext="$5"
   local offset="$(image_part_offset "$file" "$part_num")" ||
     image_die "failed to find partition #$part_num from: $file"
   local size="$(image_part_size "$file" "$part_num")" ||
@@ -211,6 +212,7 @@ image_mount_partition() {
 
   sudo mount \
     -o "loop,offset=$((offset * 512)),sizelimit=$((size * 512)),$mount_opt" \
+    $mount_ext \
     "$file" \
     "$mount_point"
 }

make_factory_package.sh

@@ -42,6 +42,7 @@ DEFINE_string factory "" \
   "Directory and file containing factory image: /path/chromiumos_test_image.bin"
 DEFINE_string firmware_updater "" \
   "Firmware updater (shellball) into the server configuration,"\
+" or leave empty (default) for the updater in release image (--release), "\
 " or '$FLAGS_NONE' to prevent running firmware updater."
 DEFINE_string hwid_updater "" \
   "The component list updater for HWID validation,"\
@@ -75,6 +76,9 @@ USAGE: $0 [flags] args
 Note environment variables with prefix MFP_ are for reserved for internal use.
 "
 
+# Internal variables
+ENABLE_FIRMWARE_UPDATER=$FLAGS_TRUE
+
 # Parse command line
 FLAGS "$@" || exit 1
 ORIGINAL_PARAMS="$@"
@@ -137,6 +141,22 @@ check_parameters() {
   check_file_param FLAGS_release ""
   check_file_param FLAGS_factory ""
 
+  # Pre-parse parameter default values
+  case "${FLAGS_firmware_updater}" in
+    $FLAGS_NONE )
+      ENABLE_FIRMWARE_UPDATER=$FLAGS_FALSE
+      ;;
+    "" )
+      # Empty value means "enable updater from rootfs" for all modes except
+      # --diskimg mode.
+      if [ -n "${FLAGS_diskimg}" ]; then
+        ENABLE_FIRMWARE_UPDATER=$FLAGS_FALSE
+      else
+        FLAGS_firmware_updater=$FLAGS_NONE
+      fi
+      ;;
+  esac
+
   # All remaining parameters must be checked:
   # install_shim, firmware, hwid_updater, complete_script.
 
@@ -259,6 +279,32 @@ prepare_release_image() {
   fi
 }
 
+# Prepares firmware updater from specified file source or release rootfs.
+prepare_firmware_updater() {
+  local image="$(readlink -f "$1")"
+  if [ -f "$FLAGS_firmware_updater" ]; then
+    return
+  fi
+
+  local fwupdater="$(mktemp --tmpdir)"
+  local temp_mount="$(mktemp -d --tmpdir)"
+  local updater_path="/usr/sbin/chromeos-firmwareupdate"
+  local src_file="$temp_mount$updater_path"
+  image_add_temp "$fwupdater"
+  image_add_temp "$temp_mount"
+
+  # 'ext2' is required to prevent accidentally modifying image
+  image_mount_partition "$image" "3" "$temp_mount" "ro" "-t ext2" ||
+    die "Cannot mount partition #3 (rootfs) in release image: $image"
+  [ -f "$src_file" ] ||
+    die "No firmware updater in release image: $image"
+  cp "$src_file" "$fwupdater" ||
+    die "Failed to copy firmware updater from release image $image."
+  image_umount_partition "$temp_mount"
+  info "Prepared firmware updater from release image: $image:3#$updater_path"
+  FLAGS_firmware_updater="$fwupdater"
+}
+
 prepare_img() {
   local outdev="$(readlink -f "$FLAGS_diskimg")"
   local sectors="$FLAGS_sectors"
@@ -711,9 +757,13 @@ main() {
 
   check_parameters
   setup_environment
-  if [ "$FLAGS_detect_release_image" = "$FLAGS_TRUE" ]; then
+
+  if [ "$FLAGS_detect_release_image" = $FLAGS_TRUE ]; then
     prepare_release_image "$FLAGS_release"
   fi
+  if [ "$ENABLE_FIRMWARE_UPDATER" = $FLAGS_TRUE ]; then
+    prepare_firmware_updater "$FLAGS_release"
+  fi
 
   if [ -n "$FLAGS_usbimg" ]; then
     generate_usbimg