diff --git a/build_test.bash b/build_test.bash
new file mode 100755
index 0000000..f833366
--- /dev/null
+++ b/build_test.bash
@@ -0,0 +1,34 @@
+#!/bin/bash -eu
+#
+# Copyright 2017 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#
+# This file is used in our continous build infrastructure to run a variety of
+# tests related to the build system.
+#
+# Currently, it's used to build and run multiproduct_kati, so it'll attempt
+# to build ninja files for every product in the tree. I expect this to
+# evolve as we find interesting things to test or track performance for.
+#
+
+# To track how long we took to startup. %N isn't supported on Darwin, but
+# that's detected in the Go code, which skips calculating the startup time.
+export TRACE_BEGIN_SOONG=$(date +%s%N)
+
+export TOP=$(cd $(dirname ${BASH_SOURCE[0]})/../..; PWD= /bin/pwd)
+source "${TOP}/build/soong/cmd/microfactory/microfactory.bash"
+
+build_go multiproduct_kati android/soong/cmd/multiproduct_kati
+exec "$(getoutdir)/multiproduct_kati" "$@"
diff --git a/cmd/microfactory/microfactory.bash b/cmd/microfactory/microfactory.bash
new file mode 100644
index 0000000..7489fe3
--- /dev/null
+++ b/cmd/microfactory/microfactory.bash
@@ -0,0 +1,88 @@
+# Copyright 2017 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Set of utility functions to build and run go code with microfactory
+#
+# Inputs:
+#  ${TOP}: The top of the android source tree
+#  ${OUT_DIR}: The output directory location (defaults to ${TOP}/out)
+#  ${OUT_DIR_COMMON_BASE}: Change the default out directory to
+#    ${OUT_DIR_COMMON_BASE}/$(basename ${TOP})
+
+# Ensure GOROOT is set to the in-tree version.
+case $(uname) in
+    Linux)
+        export GOROOT="${TOP}/prebuilts/go/linux-x86/"
+        ;;
+    Darwin)
+        export GOROOT="${TOP}/prebuilts/go/darwin-x86/"
+        ;;
+    *) echo "unknown OS:" $(uname) >&2 && exit 1;;
+esac
+
+# Find the output directory
+function getoutdir
+{
+    local out_dir="${OUT_DIR-}"
+    if [ -z "${out_dir}" ]; then
+        if [ "${OUT_DIR_COMMON_BASE-}" ]; then
+            out_dir="${OUT_DIR_COMMON_BASE}/$(basename ${TOP})"
+        else
+            out_dir="${TOP}/out"
+        fi
+    fi
+    echo "${out_dir}"
+}
+
+# Bootstrap microfactory from source if necessary and use it to build the
+# requested binary.
+#
+# Arguments:
+#  $1: name of the requested binary
+#  $2: package name
+function build_go
+{
+    # Increment when microfactory changes enough that it cannot rebuild itself.
+    # For example, if we use a new command line argument that doesn't work on older versions.
+    local mf_version=2
+
+    local mf_src="${TOP}/build/soong/cmd/microfactory"
+
+    local out_dir=$(getoutdir)
+    local mf_bin="${out_dir}/microfactory_$(uname)"
+    local mf_version_file="${out_dir}/.microfactory_$(uname)_version"
+    local built_bin="${out_dir}/$1"
+    local from_src=1
+
+    if [ -f "${mf_bin}" ] && [ -f "${mf_version_file}" ]; then
+        if [ "${mf_version}" -eq "$(cat "${mf_version_file}")" ]; then
+            from_src=0
+        fi
+    fi
+
+    local mf_cmd
+    if [ $from_src -eq 1 ]; then
+        mf_cmd="${GOROOT}/bin/go run ${mf_src}/microfactory.go"
+    else
+        mf_cmd="${mf_bin}"
+    fi
+
+    ${mf_cmd} -s "${mf_src}" -b "${mf_bin}" \
+            -pkg-path "android/soong=${TOP}/build/soong" -trimpath "${TOP}/build/soong" \
+            -o "${built_bin}" $2
+
+    if [ $from_src -eq 1 ]; then
+        echo "${mf_version}" >"${mf_version_file}"
+    fi
+}
diff --git a/soong_ui.bash b/soong_ui.bash
index e3997cf..105af9f 100755
--- a/soong_ui.bash
+++ b/soong_ui.bash
@@ -15,7 +15,7 @@
 # limitations under the License.
 
 # To track how long we took to startup. %N isn't supported on Darwin, but
-# that's detected in the Go code, and skip calculating the startup time.
+# that's detected in the Go code, which skips calculating the startup time.
 export TRACE_BEGIN_SOONG=$(date +%s%N)
 
 # Function to find top of the source tree (if $TOP isn't set) by walking up the
@@ -47,63 +47,8 @@
     fi
 }
 
-# Bootstrap microfactory from source if necessary and use it to build the
-# soong_ui binary, then run soong_ui.
-function run_go
-{
-    # Increment when microfactory changes enough that it cannot rebuild itself.
-    # For example, if we use a new command line argument that doesn't work on older versions.
-    local mf_version=2
-
-    local mf_src="${TOP}/build/soong/cmd/microfactory"
-
-    local out_dir="${OUT_DIR-}"
-    if [ -z "${out_dir}" ]; then
-        if [ "${OUT_DIR_COMMON_BASE-}" ]; then
-            out_dir="${OUT_DIR_COMMON_BASE}/$(basename ${TOP})"
-        else
-            out_dir="${TOP}/out"
-        fi
-    fi
-
-    local mf_bin="${out_dir}/microfactory_$(uname)"
-    local mf_version_file="${out_dir}/.microfactory_$(uname)_version"
-    local soong_ui_bin="${out_dir}/soong_ui"
-    local from_src=1
-
-    if [ -f "${mf_bin}" ] && [ -f "${mf_version_file}" ]; then
-        if [ "${mf_version}" -eq "$(cat "${mf_version_file}")" ]; then
-            from_src=0
-        fi
-    fi
-
-    local mf_cmd
-    if [ $from_src -eq 1 ]; then
-        mf_cmd="${GOROOT}/bin/go run ${mf_src}/microfactory.go"
-    else
-        mf_cmd="${mf_bin}"
-    fi
-
-    ${mf_cmd} -s "${mf_src}" -b "${mf_bin}" \
-            -pkg-path "android/soong=${TOP}/build/soong" -trimpath "${TOP}/build/soong" \
-            -o "${soong_ui_bin}" android/soong/cmd/soong_ui
-
-    if [ $from_src -eq 1 ]; then
-        echo "${mf_version}" >"${mf_version_file}"
-    fi
-
-    exec "${out_dir}/soong_ui" "$@"
-}
-
 export TOP=$(gettop)
-case $(uname) in
-    Linux)
-        export GOROOT="${TOP}/prebuilts/go/linux-x86/"
-        ;;
-    Darwin)
-        export GOROOT="${TOP}/prebuilts/go/darwin-x86/"
-        ;;
-    *) echo "unknown OS:" $(uname) >&2 && exit 1;;
-esac
+source build/soong/cmd/microfactory/microfactory.bash
 
-run_go "$@"
+build_go soong_ui android/soong/cmd/soong_ui
+exec "$(getoutdir)/soong_ui" "$@"