diff options
Diffstat (limited to 'scripts/image_signing/strip_boot_from_image.sh')
-rwxr-xr-x | scripts/image_signing/strip_boot_from_image.sh | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/scripts/image_signing/strip_boot_from_image.sh b/scripts/image_signing/strip_boot_from_image.sh new file mode 100755 index 00000000..dcbdf05d --- /dev/null +++ b/scripts/image_signing/strip_boot_from_image.sh @@ -0,0 +1,65 @@ +#!/bin/bash + +# Copyright (c) 2013 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. + +# Script to remove /boot directory from an image. + +# Load common constants. This should be the first executable line. +# The path to common.sh should be relative to your script's location. +. "$(dirname "$0")/common.sh" + +load_shflags + +DEFINE_string image "chromiumos_image.bin" \ + "Input file name of Chrome OS image to strip /boot from." + +# Parse command line. +FLAGS "$@" || exit 1 +eval set -- "${FLAGS_ARGV}" + +# Abort on error. +set -e + +if [ -z "${FLAGS_image}" ] || [ ! -s "${FLAGS_image}" ] ; then + die "Error: need a valid file by --image" +fi + +# Swiped/modifed from $SRC/src/scripts/base_library/base_image_util.sh. +zero_free_space() { + local rootfs="$1" + + echo "Zeroing freespace in ${rootfs}" + # dd is a silly thing and will produce a "No space left on device" message + # that cannot be turned off and is confusing to unsuspecting victims. + ( sudo dd if=/dev/zero of="${rootfs}/filler" bs=4096 conv=fdatasync \ + status=noxfer || true ) 2>&1 | grep -v "No space left on device" + sudo rm "${rootfs}/filler" +} + + +strip_boot() { + local image=$1 + + # Mount image so we can modify it. + local rootfs_dir=$(make_temp_dir) + mount_image_partition ${image} 3 ${rootfs_dir} + + sudo rm -rf "${rootfs_dir}/boot" && + echo "/boot directory was removed." + + # To prevent the files we just removed from the FS from remaining as non- + # zero trash blocks that bloat payload sizes, need to zero them. This was + # done when the image was built, but needs to be repeated now that we've + # modified it in a non-trivial way. + zero_free_space "${rootfs_dir}" +} + + +IMAGE=$(readlink -f "${FLAGS_image}") +if [[ -z "${IMAGE}" || ! -f "${IMAGE}" ]]; then + die "Missing required argument: --from (image to update)" +fi + +strip_boot "${IMAGE}" |