Allow file in --from arg

mount_gpt_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 mounts chromium os image from a device or directory
 # and creates mount points for /var and /usr/local (if in dev_mode).
 
 # --- BEGIN COMMON.SH BOILERPLATE ---
@@ skipping 33 matching lines @@
 # Flags.
 DEFINE_string board "$DEFAULT_BOARD" \
   "The board for which the image was built." b
 DEFINE_boolean read_only $FLAGS_FALSE \
   "Mount in read only mode -- skips stateful items."
 DEFINE_boolean safe $FLAGS_FALSE \
   "Mount rootfs in read only mode."
 DEFINE_boolean unmount $FLAGS_FALSE \
   "Unmount previously mounted dir." u
 DEFINE_string from "/dev/sdc" \
-  "Directory containing image or device with image on it" f
+  "Directory, image, or device with image on it" f
 DEFINE_string image "chromiumos_image.bin"\
   "Name of the bin file if a directory is specified in the from flag" i
 DEFINE_string "rootfs_mountpt" "/tmp/m" "Mount point for rootfs" "r"
 DEFINE_string "stateful_mountpt" "/tmp/s" \
     "Mount point for stateful partition" "s"
 DEFINE_string "esp_mountpt" "" \
     "Mount point for esp partition" "e"
 DEFINE_boolean most_recent ${FLAGS_FALSE} "Use the most recent image dir" m
 
 # Parse flags
 FLAGS "$@" || exit 1
 eval set -- "${FLAGS_ARGV}"
 
 # Die on error
 set -e
 
+# Check for conflicting args.
+# If --from is a block device, --image can't also be specified.
+if [ -b "${FLAGS_from}" ]; then
+  if [ "${FLAGS_image}" != "chromiumos_image.bin" ]; then
+    die "-i ${FLAGS_image} can't be used with block device ${FLAGS_from}"
+  fi
+fi
+
+# Allow --from /foo/file.bin
+if [ -f "${FLAGS_from}" ]; then
+  # If --from is specified as a file, --image cannot be also specified.
+  if [ "${FLAGS_image}" != "chromiumos_image.bin" ]; then
+    die "-i ${FLAGS_image} can't be used with --from file ${FLAGS_from}"
+  fi
+  pathname=$(dirname "${FLAGS_from}")
+  filename=$(basename "${FLAGS_from}")
+  FLAGS_image="${filename}"
+  FLAGS_from="${pathname}"
+fi
+
 # Common unmounts for either a device or directory
 function unmount_image() {
   echo "Unmounting image from ${FLAGS_stateful_mountpt}" \
       "and ${FLAGS_rootfs_mountpt}"
   # Don't die on error to force cleanup
   set +e
   # Reset symlinks in /usr/local.
   if mount | egrep ".* ${FLAGS_stateful_mountpt} .*\(rw,"; then
     setup_symlinks_on_root "/usr/local" "/var" \
       "${FLAGS_stateful_mountpt}"
@@ skipping 100 matching lines @@
 FLAGS_from=`eval readlink -f ${FLAGS_from}`
 FLAGS_rootfs_mountpt=`eval readlink -f ${FLAGS_rootfs_mountpt}`
 FLAGS_stateful_mountpt=`eval readlink -f ${FLAGS_stateful_mountpt}`
 
 # Perform desired operation.
 if [ ${FLAGS_unmount} -eq ${FLAGS_TRUE} ] ; then
   unmount_image
 else
   mount_image
 fi