Modify x86 kernel command line to enable nmi watchog.

build_kernel_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.
 
 # Helper script that generates the signed kernel image
 
 # --- BEGIN COMMON.SH BOILERPLATE ---
 # Load common CrOS utilities.  Inside the chroot this file is installed in
@@ skipping 149 matching lines @@
 init=/sbin/init
 add_efi_memmap
 boot=local
 noresume
 noswap
 i915.modeset=1
 cros_secure
 kern_guid=%U
 tpm_tis.force=1
 tpm_tis.interrupts=0
+nmi_watchdog=panic,lapic
 EOF
   WORK="${WORK} ${FLAGS_working_dir}/config.txt"
 
   # We sign the image with the recovery_key, because this is what goes onto the
   # USB key. We can only boot from the USB drive in recovery mode.
   # For dev install shim, we need to use the installer keyblock instead of
   # the recovery keyblock because of the difference in flags.
   if [ ${FLAGS_use_dev_keys} -eq ${FLAGS_TRUE} ]; then
     USB_KEYBLOCK=installer_kernel.keyblock
     info "DEBUG: use dev install signing key"
@@ skipping 92 matching lines @@
   info "Cleaning up temporary files: ${WORK}"
   rm ${WORK}
   rmdir ${FLAGS_working_dir}
 fi
 
 info "Kernel partition image emitted: ${FLAGS_to}"
 
 if [[ -f ${FLAGS_rootfs_hash} ]]; then
   info "Root filesystem hash emitted: ${FLAGS_rootfs_hash}"
 fi