Add defaults for cros_make_image_bootable.

bin/cros_make_image_bootable

 #!/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.
 #
 # Script which ensures that a given image has an up-to-date
 # kernel partition, rootfs integrity hashes, and legacy bootloader configs.
 
 # Load common constants.  This should be the first executable line.
@@ skipping 10 matching lines @@
 assert_inside_chroot
 
 set -e
 . "$(dirname "$0")/../chromeos-common.sh"  # for partoffset and partsize
 
 if [ $# -lt 2 ]; then
   echo "Usage: ${0} /PATH/TO/IMAGE IMAGE.BIN [shflags overrides]"
   exit 1
 fi
 
-BOOT_DESC_FILE="${1}/boot.desc"
-IMAGE="${1}/${2}"
+IMAGE_DIR="$(readlink -f "${1}")"
+BOOT_DESC_FILE="${IMAGE_DIR}/boot.desc"
+IMAGE="${IMAGE_DIR}/${2}"
 shift
 shift
 FLAG_OVERRIDES="${@}"
 
 if [ ! -r "${BOOT_DESC_FILE}" ]; then
   warn "${BOOT_DESC_FILE} cannot be read!"
   warn "Falling back to command line parsing"
   BOOT_DESC="${@}"
 else
   BOOT_DESC="$(cat ${BOOT_DESC_FILE} | tr -s '\n' ' ')"
@@ skipping 183 matching lines @@
     --vmlinuz="${FLAGS_rootfs_mountpoint}"/boot/vmlinuz \
     --usb_disk="${usb_disk}" \
     ${bootloader_to_flags} \
     $kernel_part
 
   trap - EXIT
   ${SCRIPTS_DIR}/mount_gpt_image.sh -u -r "${FLAGS_rootfs_mountpoint}" \
     -s "${FLAGS_statefulfs_mountpoint}"
 }
 
+# Use default of current image location if the output dir doesn't exist.
+if [ ! -d ${FLAGS_output_dir} ]; then
+  warn "Output dir not found, using ${IMAGE_DIR}."
+  FLAGS_output_dir="${IMAGE_DIR}"
+  FLAGS_rootfs_hash="${IMAGE_DIR}/rootfs.hash"
+  FLAGS_rootfs_mountpoint="${IMAGE_DIR}/rootfs_dir"
+  FLAGS_statefulfs_mountpoint="${IMAGE_DIR}/stateful_dir"
+  FLAGS_espfs_mountpoint="${IMAGE_DIR}/esp"
+fi
+
 # Create the directories if they don't exist.
 mkdir -p ${FLAGS_rootfs_mountpoint}
 mkdir -p ${FLAGS_statefulfs_mountpoint}
 mkdir -p ${FLAGS_espfs_mountpoint}
 
 make_image_bootable ${IMAGE}
 
 if [ ${FLAGS_cleanup_dirs} -eq ${FLAGS_TRUE} ]; then
   rmdir ${FLAGS_rootfs_mountpoint}
   rmdir ${FLAGS_statefulfs_mountpoint}
   rmdir ${FLAGS_espfs_mountpoint}
 fi