Factory Installer.

src/platform/memento_softwareupdate/software_update.sh

 #!/bin/sh
 
 # 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.
 
 # Called on startup as part of the init scripts. This calls forks off
 # a task which will wait some time and then check for an update.
 
 # Exit immediately if it's a dev machine
 DEVKIT_URL=$(grep ^CHROMEOS_DEVSERVER /etc/lsb-release | cut -d = -f 2-) 
 if [ -n "$DEVKIT_URL" ]; then
   exit 0
 fi
 
+# Exit immediately if it's a factory install machine
+FACTORY_INSTALL=$(grep ^FACTORY_INSTALL= /etc/lsb-release | cut -d = -f 2-)
+if [ -n "$FACTORY_INSTALL" ]; then
+  exit 0
+fi
+
 if [ -z "$1" ]; then
   SLEEP_TIME=1800  # seconds; 30 min
 else
   SLEEP_TIME="$1"
 fi
 
 # Boot after 2 min, then try every 30 min
 sleep 120  # seconds
 # Once at startup, if log file is too big, move it aside
 LOG_FILE=/var/log/softwareupdate.log
 if [ $(stat -c%s "$LOG_FILE") -gt "5242880" ]; then  # 5MB
   mv "$LOG_FILE" "$LOG_FILE".0
 fi
 while [ true ]; do
   /opt/google/memento_updater/memento_updater.sh
   sleep "$SLEEP_TIME"
 done