Prototype faster build (kind of ugly)

mod_image_for_test.sh

 #!/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 modify a keyfob-based chromeos system image for testability.
 
 # Load common constants.  This should be the first executable line.
 # The path to common.sh should be relative to your script's location.
@@ skipping 21 matching lines @@
     "Location of qualified component file" d
 DEFINE_boolean yes $FLAGS_FALSE "Answer yes to all prompts" y
 DEFINE_string build_root "/build" \
     "The root location for board sysroots."
 
 
 # Parse command line
 FLAGS "$@" || exit 1
 eval set -- "${FLAGS_ARGV}"
 
+EMERGE_CMD="emerge"
+EMERGE_BOARD_CMD="emerge-${FLAGS_board}"
+if [ -e "${TOP_SCRIPTS_DIR}/.emerge" ]; then
+  .  "${TOP_SCRIPTS_DIR}/.emerge"
+fi
+
 # No board, no default and no image set then we can't find the image
 if [ -z $FLAGS_image ] && [ -z $FLAGS_board ] ; then
   setup_board_warning
   die "mod_image_for_test failed.  No board set and no image set"
 fi
 
 # We have a board name but no image set.  Use image at default location
 if [ -z $FLAGS_image ] ; then
   IMAGES_DIR="${DEFAULT_BUILD_ROOT}/images/${FLAGS_board}"
   FILENAME="chromiumos_image.bin"
@@ skipping 30 matching lines @@
 # Emerges chromeos-test onto the image.
 emerge_chromeos_test() {
   INSTALL_MASK=""
   if [[ $FLAGS_installmask -eq ${FLAGS_TRUE} ]]; then
     INSTALL_MASK="$DEFAULT_INSTALL_MASK"
   fi
 
   # Determine the root dir for test packages.
   ROOT_DEV_DIR="$ROOT_FS_DIR/usr/local"
 
-  INSTALL_MASK="$INSTALL_MASK" emerge-${FLAGS_board} \
+  INSTALL_MASK="$INSTALL_MASK" $EMERGE_BOARD_CMD \
     --root="$ROOT_DEV_DIR" --root-deps=rdeps \
     --usepkgonly chromeos-test $EMERGE_JOBS
 }
 
 
 install_autotest() {
     SYSROOT="${FLAGS_build_root}/${FLAGS_board}"
     AUTOTEST_SRC="${SYSROOT}/usr/local/autotest"
     stateful_root="${ROOT_FS_DIR}/usr/local"
     autotest_client="/autotest"
@@ skipping 46 matching lines @@
 
 # Mounts gpt image and sets up var, /usr/local and symlinks.
 "$SCRIPTS_DIR/mount_gpt_image.sh" -i "$IMAGE_NAME" -f "$IMAGE_DIR" \
   -r "$ROOT_FS_DIR" -s "$STATEFUL_DIR"
 
 if [ ${FLAGS_factory_install} -eq ${FLAGS_TRUE} ]; then
   # We don't want to emerge test packages on factory install, otherwise we run
   # out of space.
 
   # Run factory setup script to modify the image.
-  sudo emerge-${FLAGS_board} --root=$ROOT_FS_DIR --usepkgonly \
+  sudo $EMERGE_BOARD_CMD --root=$ROOT_FS_DIR --usepkgonly \
       --root-deps=rdeps --nodeps chromeos-factoryinstall
 
   # Set factory server if necessary.
   if [ "${FACTORY_SERVER}" != "" ]; then
     sudo sed -i \
       "s/CHROMEOS_AUSERVER=.*$/CHROMEOS_AUSERVER=\
 http:\/\/${FACTORY_SERVER}:8080\/update/" \
       ${ROOT_FS_DIR}/etc/lsb-release
   fi
 else
@@ skipping 18 matching lines @@
 # Let's have a look at the image just in case..
 if [ "${VERIFY}" = "true" ]; then
   pushd "${ROOT_FS_DIR}"
   bash
   popd
 fi
 
 cleanup
 trap - EXIT