Clear TPM if software firmware WP is disabled

factory_install.sh

 #!/bin/sh -ex
 
-# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+# Copyright (c) 2011 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.
 
 . "$(dirname "$0")/chromeos-common.sh"
 . "/opt/google/memento_updater/memento_updater_logging.sh"
 . "/opt/google/memento_updater/find_omaha.sh"
 
 if [ $(id -u) -ne 0 ]; then
   echo "You must run this as root."
   exit 1
@@ skipping 68 matching lines @@
 
 log "Starting Factory Installer."
 
 log "Checking for Firmware Write Protect"
 
 # Only ChromeOS machines have meaninful output here.
 if crossystem hwid >/dev/null; then
   # Check for physical firmware write protect. We'll only
   # clear this stuff if the case is open.
   if [ "$(crossystem wpsw_cur)" = "0" ]; then
-    # Ensure that flash chips are in a known good state.
+    # Clear software firmware write protect.
     clear_fwwp
+  fi
 
+  # Check for software firmware write protect.  We only clear the TPM if
+  # software write protect is disabled.
+  if flashrom -p internal:bus=spi --wp-status 2>/dev/null |
+      grep -q "write protect is disabled"; then
     # Ensure that we can wipe TPM if necessary.
     clear_tpm
   fi
 fi
 
 #
 # factory_install.sh implements two operations for assembly line
 # operators: install (obviously) and reset.
 #
 # Somehow the way that operators switch between the two operations
@@ skipping 166 matching lines @@
   dd if=/dev/zero of=$DST_RELEASE
   dd if=/dev/zero of=$DST_FACTORY
   exit 1
 fi
 
 log "All done installing."
 
 sleep 3
 shutdown -r now
 sleep 1d  # sleep indefinitely to avoid respawning rather than shutting down