Pack firmware into an image and do update in factory install (separated git).

memento_updater.sh

 #!/bin/bash
 
 # Copyright (c) 2009 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.
 
 # This is the autoupdater for Memento. When called it consults Omaha to see
 # if there's an update available. If so, it downloads it to the other
 # partition on the Memento USB stick, then alters the MBR and partitions
 # as needed so the next reboot will boot into the newly installed partition.
@@ skipping 157 matching lines @@
 
 # Find whole disk device.
 ROOT_DEV=${INSTALL_DEV%%[0-9]*}
 
 # Do some device sanity checks.
 if [ ! -b "$LOCAL_DEV" ]
 then
   log "didnt find good local device. local: $LOCAL_DEV install: $INSTALL_DEV"
   exit 1
 fi
-if [ ! -b "$INSTALL_DEV" ]
+if [ ! -b "$INSTALL_DEV" -a ! "${FLAGS_force_track}" = "firmware-channel" ]
 then
   log "didnt find good install device. local: $LOCAL_DEV install: $INSTALL_DEV"
   exit 1
 fi
 if [ "$LOCAL_DEV" == "$INSTALL_DEV" ]
 then
   log local and installation device are the same: "$LOCAL_DEV"
   exit 1
 fi
 
@@ skipping 124 matching lines @@
   POSTINST_RETURN_CODE=$?
   umount "$MOUNTPOINT"
   rmdir "$MOUNTPOINT"
 
   # If it failed, don't update MBR but just to be safe, zero out a page of
   # install device.
   abort_update_if_cmd_failed_long "$POSTINST_RETURN_CODE" "$MOUNTPOINT"/postinst
   # postinstall on new partition succeeded.
 fi
 
+if [ "${FLAGS_force_track}" = "firmware-channel" ]; then
+  log execute firmware-install script
+  INSTALL_SCRIPT="${FLAGS_dst_partition}"
+  chmod +x "${INSTALL_SCRIPT}"
+  pushd "$(dirname "${INSTALL_SCRIPT}")" > /dev/null
+  ./"${INSTALL_SCRIPT}" >> "$MEMENTO_AU_LOG"
+  popd > /dev/null
+fi
+
 if [ -z "${FLAGS_dst_partition}" ]; then
   # mark update as complete so we don't try to update again
   touch "$UPDATED_COMPLETED_FILE"
 fi
 
 # Flush linux caches; seems to be necessary
 sync
 echo 3 > /proc/sys/vm/drop_caches
 
 # tell user to reboot
 log Autoupdate applied. You should now reboot
 echo UPDATED