kernel cmdline: add dm_verity.dev_wait=1

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
 
 . "$(dirname "$0")/common.sh"
 
@@ skipping 83 matching lines @@
       base_root='/dev/${devname}${rootpart}'
     fi
     table=${table//HASH_DEV/${base_root}}
     table=${table//ROOT_DEV/${base_root}}
   fi
   verity_args="dm=\"vroot none ro,${table}\""
   info "dm-verity configuration: ${verity_args}"
 fi
 
 mkdir -p "${FLAGS_working_dir}"
+
+# Only let dm-verity block if rootfs verification is configured.
+dev_wait=0
+if [[ ${FLAGS_root} = "/dev/dm-0" ]]; then
+  dev_wait=1
+fi
+
 cat <<EOF > "${FLAGS_working_dir}/boot.config"
 root=${FLAGS_root}
 dm_verity.error_behavior=${FLAGS_verity_error_behavior}
 dm_verity.max_bios=${FLAGS_verity_max_ios}
+dm_verity.dev_wait=${dev_wait}
 ${verity_args}
 ${FLAGS_boot_args}
 EOF
 
 WORK="${WORK} ${FLAGS_working_dir}/boot.config"
 info "Emitted cross-platform boot params to ${FLAGS_working_dir}/boot.config"
 
 # FIXME: At the moment, we're working on signed images for x86 only. ARM will
 # support this before shipping, but at the moment they don't.
 if [[ "${FLAGS_arch}" = "x86" ]]; then
@@ skipping 123 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