auto import from //depot/cupcake/@135843
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
new file mode 100644
index 0000000..e38a803
--- /dev/null
+++ b/core/version_defaults.mk
@@ -0,0 +1,84 @@
+#
+# Copyright (C) 2008 The Android Open Source Project
+#
+# 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.
+#
+
+#
+# Handle various build version information.
+#
+# Guarantees that the following are defined:
+# PLATFORM_VERSION
+# PLATFORM_SDK_VERSION
+# BUILD_ID
+# BUILD_NUMBER
+#
+
+# Look for an optional file containing overrides of the defaults,
+# but don't cry if we don't find it. We could just use -include, but
+# the build.prop target also wants INTERNAL_BUILD_ID_MAKEFILE to be set
+# if the file exists.
+#
+INTERNAL_BUILD_ID_MAKEFILE := $(wildcard $(BUILD_SYSTEM)/build_id.mk)
+ifneq "" "$(INTERNAL_BUILD_ID_MAKEFILE)"
+ include $(INTERNAL_BUILD_ID_MAKEFILE)
+endif
+
+ifeq "" "$(PLATFORM_VERSION)"
+ # This is the canonical definition of the platform version,
+ # which is the version that we reveal to the end user.
+ # Update this value when the platform version changes (rather
+ # than overriding it somewhere else). Can be an arbitrary string.
+ PLATFORM_VERSION := 1.5
+endif
+
+ifeq "" "$(PLATFORM_SDK_VERSION)"
+ # This is the canonical definition of the SDK version, which defines
+ # the set of APIs and functionality available in the platform. This is
+ # a single integer, that increases monotonically as updates to the SDK
+ # are released.
+ PLATFORM_SDK_VERSION := 3
+endif
+
+ifeq "" "$(BUILD_ID)"
+ # Used to signify special builds. E.g., branches and/or releases,
+ # like "M5-RC7". Can be an arbitrary string, but must be a single
+ # word and a valid file name.
+ #
+ # If there is no BUILD_ID set, make it obvious.
+ BUILD_ID := UNKNOWN
+endif
+
+ifeq "" "$(BUILD_NUMBER)"
+ # BUILD_NUMBER should be set to the source control value that
+ # represents the current state of the source code. E.g., a
+ # perforce changelist number or a git hash. Can be an arbitrary string
+ # (to allow for source control that uses something other than numbers),
+ # but must be a single word and a valid file name.
+ #
+ # If no BUILD_NUMBER is set, create a useful "I am an engineering build
+ # from this date/time" value. Make it start with a non-digit so that
+ # anyone trying to parse it as an integer will probably get "0".
+ BUILD_NUMBER := eng.$(USER).$(shell date +%Y%m%d.%H%M%S)
+endif
+
+ifeq "true" "$(DISPLAY_BUILD_NUMBER)"
+ # if the build_id.mk has this defined, then BUILD_ID is updated with
+ # the BUILD_NUMBER as well. For development branches, this will be
+ # set, but release branches this will not be set.
+ BUILD_DISPLAY_ID := "$(BUILD_ID).$(BUILD_NUMBER)"
+else
+ BUILD_DISPLAY_ID := "$(BUILD_ID)"
+endif
+
+