Add --fast to build_image

build_image

 #!/bin/bash
 
 # Copyright (c) 2009 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 build a bootable keyfob-based chromeos system image from within
 # a chromiumos setup. This assumes that all needed packages have been built into
 # the given target's root with binary packages turned on. This script will
 # build the Chrome OS image using only pre-built binary packages.
@@ skipping 35 matching lines @@
   "Additional command line options to pass to the ARM kernel."
 DEFINE_integer rootfs_partition_size 1024 \
   "rootfs parition size in MBs."
 DEFINE_integer rootfs_size 720 \
   "rootfs filesystem size in MBs."
 DEFINE_integer statefulfs_size 1024 \
   "stateful filesystem size in MBs."
 DEFINE_boolean preserve ${FLAGS_FALSE} \
   "Attempt to preserve the previous build image if one can be found (unstable, \
 kernel/firmware not updated)"
+DEFINE_boolean fast ${FLAGS_FALSE} \
+  "Call many emerges in parallel (unstable)"
+
 
 # Parse command line.
 FLAGS "$@" || exit 1
 eval set -- "${FLAGS_ARGV}"
 
 # Only now can we die on error.  shflags functions leak non-zero error codes,
 # so will die prematurely if 'set -e' is specified before now.
 set -e
 
 if [ -z "${FLAGS_board}" ] ; then
   error "--board is required."
   exit 1
 fi
 
 if [ "${FLAGS_rootfs_size}" -gt "${FLAGS_rootfs_partition_size}" ] ; then
   error "rootfs (${FLAGS_rootfs_size} MB) is bigger than partition (${FLAGS_rootfs_partition_size} MB)."
   exit 1
 fi
 
-EMERGE_CMD="emerge"
 EMERGE_BOARD_CMD="emerge-${FLAGS_board}"
-TOP_SCRIPTS_DIR="$(dirname $0)"
-if [ -e "${TOP_SCRIPTS_DIR}/.emerge" ]; then
+if [ "${FLAGS_fast}" -eq "${FLAGS_TRUE}" ]; then
   echo "Using alternate emerge"
-  .  "${TOP_SCRIPTS_DIR}/.emerge"
+  EMERGE_BOARD_CMD="${SCRIPTS_DIR}/parallel_emerge --board=${FLAGS_board}"
 fi
 
 # Determine build version.
 . "${SCRIPTS_DIR}/chromeos_version.sh"
 
 # Use canonical path since some tools (e.g. mount) do not like symlinks.
 # Append build attempt to output directory.
 IMAGE_SUBDIR="${CHROMEOS_VERSION_STRING}-a${FLAGS_build_attempt}"
 OUTPUT_DIR="${FLAGS_output_root}/${FLAGS_board}/${IMAGE_SUBDIR}"
 
@@ skipping 522 matching lines @@
   echo "Developer image created as ${DEVELOPER_IMAGE_NAME}"
 fi
 
 print_time_elapsed
 
 echo "To copy to USB keyfob, OUTSIDE the chroot, do something like:"
 echo "  ./image_to_usb.sh --from=${OUTSIDE_OUTPUT_DIR} --to=/dev/sdX"
 echo "To convert to VMWare image, OUTSIDE the chroot, do something like:"
 echo "  ./image_to_vmware.sh --from=${OUTSIDE_OUTPUT_DIR}"
 echo "from the scripts directory where you entered the chroot."