diff --git a/cros_workon_make b/cros_workon_make
new file mode 100755
index 0000000..9a469ae
--- /dev/null
+++ b/cros_workon_make
@@ -0,0 +1,147 @@
+#!/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.
+#
+# Simple wrapper script to build a cros_workon package incrementally.
+# You must already be cros_workon'ing the package in question.
+
+. /usr/share/misc/shflags || exit 1
+
+GCLIENT_ROOT="/mnt/host/source"
+DEFAULT_BOARD="$(cat "${GCLIENT_ROOT}"/src/scripts/.default_board 2>/dev/null)"
+
+info() { echo "INFO: $*"; }
+warn() { echo "WARN: $*"; }
+error() { echo "ERROR: $*"; }
+die() { error "$@"; exit 1; }
+
+DEFINE_string board "${DEFAULT_BOARD}" \
+    "Board for which to build the package."
+DEFINE_boolean test "${FLAGS_FALSE}" \
+  "Compile and run tests as well."
+DEFINE_boolean reconf "${FLAGS_FALSE}" \
+  "Re-run configure and prepare steps."
+DEFINE_boolean install "${FLAGS_FALSE}" \
+  "Incrementally build and install your package."
+DEFINE_boolean scrub "${FLAGS_FALSE}" \
+  "Blow away all in-tree files not managed by git."
+
+set -e
+# Parse command line.
+FLAGS "$@" || exit 1
+eval set -- "${FLAGS_ARGV}"
+
+if [ $# -lt 1 ]; then
+  echo "Usage: ${0} [OPTIONS] <package (read: ebuild) basename> [target args]"
+  exit 1
+fi
+
+if [ -z "${FLAGS_board}" ]; then
+  die "--board is required"
+fi
+
+if [ -n "${FLAGS_board}" ]; then
+  EBUILDCMD=ebuild-"${FLAGS_board}"
+  EMERGECMD=emerge-"${FLAGS_board}"
+  EQUERYCMD=equery-"${FLAGS_board}"
+  BOARD="${FLAGS_board}"
+fi
+
+pkg="${1}"
+shift
+if [ "${pkg}" = "." ]; then
+  if ! pkg=$(git config workon.pkg); then
+    die "workon.pkg not set in git config for this project"
+  fi
+fi
+
+unstable_suffix="9999"
+workon_name="${pkg}-${unstable_suffix}"
+pkgfile=
+
+# Find the ebuild file, ensure the caller is workon'ing the package.
+if ! pkgfile=$("${EQUERYCMD}" which "${workon_name}" 2> /dev/null); then
+  BOARD_KEYWORD="$(portageq-${FLAGS_board} envvar ARCH)"
+  if ACCEPT_KEYWORDS="~${BOARD_KEYWORD}" "${EQUERYCMD}" which "${workon_name}" \
+      > /dev/null 2>&1; then
+    die "run 'cros_workon --board ${BOARD} start ${pkg}' first!" 1>&2
+  fi
+  die "error looking up package ${pkg}"
+fi
+
+if [ "${FLAGS_scrub}" = "${FLAGS_TRUE}" ]; then
+  warn "--scrub will destroy ALL FILES unknown to git!"
+  read -p "Are you sure you want to do this? [y|N]" resp
+  if egrep -qi "^y(es)?$" <(echo -n "${resp}"); then
+    eval $(${EBUILDCMD} $(${EQUERYCMD} which ${workon_name}) info)
+    srcdir=$(readlink -m ${CROS_WORKON_SRCDIR})
+    project_path=${srcdir#${GCLIENT_ROOT}/}
+    if ! (cd "${GCLIENT_ROOT}/${project_path}" && git clean -dxf); then
+      die "Could not scrub source directory"
+    fi
+  else
+    info "Not scrubbing; exiting gracefully"
+  fi
+  exit 0
+fi
+
+# Find the portage work directory for this package.
+workpath=$(\
+    echo "${pkgfile}" | \
+        awk -F '/' '{ print $(NF-2) "/" $(NF-1) }')-"${unstable_suffix}"
+workpath="/build/${BOARD}/tmp/portage/${workpath}"
+
+# Export vars that the ebuild env needs from us.
+export SANDBOX_WRITE=~/trunk
+export CROS_WORKON_INPLACE=1
+export CROS_WORKON_MAKE_COMPILE_ARGS="$*"
+
+# The ebuild commands we run rely on portage automatically running earlier
+# phases for us.  Append in case there is something already in the env.
+FEATURES+=" -noauto"
+export FEATURES
+
+# Vars that we want to pass through for the user.
+PASS_THROUGH_VARS=(
+  # cros-workon.eclass vars.
+  CROS_WORKON_MAKE_COMPILE_ARGS
+  # Common test vars.
+  GTEST_ARGS
+  # Platform eclass vars.
+  P2_TEST_FILTER
+  P2_VMODULE
+)
+
+# Determine if we're going to do tests, set up commands appropriately.
+to_do="compile"
+if [ "${FLAGS_test}" = "${FLAGS_TRUE}" ]; then
+  to_do="test"
+  FEATURES+=" test"
+  rm -f "${workpath}/.tested"
+fi
+
+workdir="${workpath}/work/${workon_name}"
+if [ ! -h "${workdir}" ]; then
+  warn "Cleaning up stale workdir: ${workdir}"
+  FLAGS_reconf="${FLAGS_TRUE}"  # To force symlinking in the user's src dir.
+fi
+
+if [ "${FLAGS_install}" = "${FLAGS_TRUE}" ]; then
+  exec "${EMERGECMD}" --nodeps "${pkg}"
+fi
+
+clean=
+if [ "${FLAGS_reconf}" = "${FLAGS_TRUE}" ]; then
+  clean="clean"
+else
+  rm -f "${workpath}/.compiled"
+  envf="${workpath}/temp/environment"
+  for v in ${PASS_THROUGH_VARS[@]}; do
+    # We delete it independently in case the var wasn't set initially.
+    sed -i -e "/^declare .. ${v}=/d" "${envf}"
+    printf 'declare -x %s="%s"\n' "${v}" "${!v}" >> "${envf}"
+  done
+fi
+exec "${EBUILDCMD}" "${pkgfile}" ${clean} "${to_do}"