Remove --build_root from all scripts except mod_image_for_pyauto.sh.

For all scripts, --build_root defaults to /build and is never used. To
remove option clutter, I've deleted this option.

The only script which still references build_root in src/scripts is
mod_image_for_pyauto.sh, which seems to support it for grabbing pyauto
dependencies from a location other than /build/*. This might conceivably
be useful, so I haven't touched that script.

BUG=chromium-os:27364
TEST=Remote trybot run. git grep for references to build_root.

Change-Id: I502f7df0123a598fc62a4ef4ed847ceb182f65b8
Reviewed-on: https://gerrit.chromium.org/gerrit/18283
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Tested-by: David James <davidjames@chromium.org>
Commit-Ready: David James <davidjames@chromium.org>

bin/cros_package_to_live

@@ -37,8 +37,6 @@ DEFINE_boolean verbose ${FLAGS_FALSE} \
 DEFINE_boolean build ${FLAGS_FALSE} "Build package before installing"
 DEFINE_string board "$DEFAULT_BOARD" \
     "Board for which the package should be built/found"
-DEFINE_string build_root "/build" \
-    "The root location for board sysroots."
 
 FLAGS "$@" || exit 1
 
@@ -79,7 +77,7 @@ if [ ${FLAGS_build} -eq ${FLAGS_TRUE} ]; then
     emerge-${FLAGS_board} $@
 fi
 
-PKGROOT="${FLAGS_build_root}/${FLAGS_board}/packages"
+PKGROOT="/build/${FLAGS_board}/packages"
 
 # Temporarily clear read-only flag on / if it is set
 remote_sh "grep '\S* / ' /proc/mounts | tail -1 | awk '{ print \$4 }' |

build_image

@@ -60,8 +60,6 @@ show_help_if_requested "$@"
 # The following options are advanced options, only available to those willing
 # to read the source code. They are not shown in help output, since they are
 # not needed for the typical developer workflow.
-DEFINE_string build_root "/build" \
-  "The root location for board sysroots."
 DEFINE_integer build_attempt 1 \
   "The build attempt for this image build."
 DEFINE_integer jobs -1 \

build_library/board_options.sh

@@ -8,7 +8,7 @@ if [ -z "${FLAGS_board}" ]; then
 fi
 
 BOARD="${FLAGS_board}"
-BOARD_ROOT="${FLAGS_build_root}/${BOARD}"
+BOARD_ROOT="/build/${BOARD}"
 
 # What cross-build are we targeting?
 . "${BOARD_ROOT}/etc/make.conf.board_setup"

common.sh

@@ -720,7 +720,7 @@ function reinterpret_path_for_chroot() {
 
 function emerge_custom_kernel() {
   local install_root="$1"
-  local root=${FLAGS_build_root}/${FLAGS_board}
+  local root=/build/${FLAGS_board}
   local tmp_pkgdir=${root}/custom-packages
 
   # Clean up any leftover state in custom directories.

image_to_usb.sh

@@ -67,8 +67,6 @@ DEFINE_boolean test_image "${FLAGS_FALSE}" \
 DEFINE_string image_name "" \
   "image base name (auto-select if empty)" \
   i
-DEFINE_string build_root "/build" \
-  "root location for board sysroots"
 DEFINE_boolean install ${FLAGS_FALSE} \
   "install to the USB/MMC device"
 DEFINE_string arch "" \
@@ -367,7 +365,7 @@ if [ -b "${FLAGS_to}" ]; then
       die "Installation must be done from inside the chroot"
     fi
 
-    "${FLAGS_build_root}/${FLAGS_board}/usr/sbin/chromeos-install" \
+    "/build/${FLAGS_board}/usr/sbin/chromeos-install" \
       --yes \
       --skip_src_removable \
       --skip_dst_removable \

mod_image_for_test.sh

@@ -26,8 +26,6 @@ DEFINE_string image "" "Location of the rootfs raw image file" i
 DEFINE_integer jobs -1 \
     "How many packages to build in parallel at maximum." j
 DEFINE_boolean yes $FLAGS_FALSE "Answer yes to all prompts" y
-DEFINE_string build_root "/build" \
-    "The root location for board sysroots."
 DEFINE_boolean fast $DEFAULT_FAST "Call many emerges in parallel"
 DEFINE_boolean inplace $FLAGS_TRUE \
     "Modify/overwrite the image $CHROMEOS_IMAGE_NAME in place.  \

setup_board

@@ -33,8 +33,6 @@ show_help_if_requested "$@"
 # The following options are advanced options, only available to those willing
 # to read the source code. They are not shown in help output, since they are
 # not needed for the typical developer workflow.
-DEFINE_string build_root "/build" \
-  "The root location for board sysroots."
 DEFINE_string board_overlay "" \
   "Location of the board overlay."
 DEFINE_string binutils_version "2.21-r4" \
@@ -525,7 +523,7 @@ case "$BOARD" in
     HOST_BOARD=false
 esac
 # Locations we will need
-BOARD_ROOT="${FLAGS_build_root}/${BOARD_VARIANT}"
+BOARD_ROOT="/build/${BOARD_VARIANT}"
 CROSSDEV_OVERLAY="/usr/local/portage/crossdev"
 CHROMIUMOS_OVERLAY="/usr/local/portage/chromiumos"
 CHROMIUMOS_CONFIG="${CHROMIUMOS_OVERLAY}/chromeos/config"
@@ -661,7 +659,6 @@ sudo ln -sf /etc/make.conf.user "${BOARD_ROOT}/etc/make.conf.user"
 # cros_choose_profile manually.
 if ! cros_choose_profile \
        --board "${FLAGS_board}" \
-       --build_root "${FLAGS_build_root}" \
        --board_overlay "${FLAGS_board_overlay}" \
        --variant "${FLAGS_variant}" \
        --profile "${FLAGS_profile}"; then