diff --git a/core/base_rules.mk b/core/base_rules.mk
index 0ad797a881..f0cbdca8c7 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -235,7 +235,8 @@ endif
 ###########################################################
 #TODO: pull this into java.make once host and target are combined
 
-java_sources := $(addprefix $(TOP_DIR)$(LOCAL_PATH)/, $(filter %.java,$(LOCAL_SRC_FILES))) $(aidl_java_sources) $(logtags_java_sources)
+java_sources := $(addprefix $(TOP_DIR)$(LOCAL_PATH)/, $(filter %.java,$(LOCAL_SRC_FILES))) $(aidl_java_sources) $(logtags_java_sources) \
+                $(filter %.java,$(LOCAL_GENERATED_SOURCES))
 all_java_sources := $(java_sources) $(addprefix $($(my_prefix)OUT_COMMON_INTERMEDIATES)/, $(filter %.java,$(LOCAL_INTERMEDIATE_SOURCES)))
 
 ## Java resources #########################################
diff --git a/core/main.mk b/core/main.mk
index cd7e718a95..6eb167b144 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -687,8 +687,21 @@ droidcore: files \
 # The actual files built by the droidcore target changes depending
 # on the build variant.
 .PHONY: droid tests
-droid tests: droidcore
+ifeq ($(strip $(is_unbundled_app_build)),true)
+unbundled_build_modules :=
+ifdef UNBUNDLED_APPS
+unbundled_build_modules := $(UNBUNDLED_APPS)
+else # UNBUNDLED_APPS
+# Otherwise we build all modules in the source tree.
+unbundled_build_modules := $(sort $(call get-tagged-modules,$(ALL_MODULE_TAGS)))
+endif # UNBUNDLED_APPS
+droid: $(unbundled_build_modules)
+else # is_unbundled_app_build
+droid: droidcore
+endif # is_unbundled_app_build
+tests: droidcore
 
+ifneq ($(strip $(is_unbundled_app_build)),true)
 $(call dist-for-goals, droid, \
 	$(INTERNAL_UPDATE_PACKAGE_TARGET) \
 	$(INTERNAL_OTA_PACKAGE_TARGET) \
@@ -713,6 +726,15 @@ $(call dist-for-goals, droid, \
  )
 endif
 
+else # is_unbundled_app_build
+# dist the unbundled app.
+ifdef UNBUNDLED_APPS
+  $(call dist-for-goals,droid, \
+    $(foreach m,$(UNBUNDLED_APPS),$(ALL_MODULES.$(m).INSTALLED)) \
+  )
+endif # UNBUNDLED_APPS
+endif # is_unbundled_app_build
+
 .PHONY: docs
 docs: $(ALL_DOCS)
 
diff --git a/core/package.mk b/core/package.mk
index 24807f9e4c..d5de77b265 100644
--- a/core/package.mk
+++ b/core/package.mk
@@ -304,6 +304,10 @@ PACKAGES.$(LOCAL_PACKAGE_NAME).CERTIFICATE := $(certificate)
 # Define the rule to build the actual package.
 $(LOCAL_BUILT_MODULE): $(AAPT) | $(ZIPALIGN)
 $(LOCAL_BUILT_MODULE): PRIVATE_JNI_SHARED_LIBRARIES := $(jni_shared_libraries)
+ifeq ($(strip $(is_unbundled_app_build)),true)
+    # Include all resources for unbundled apps.
+    $(LOCAL_BUILT_MODULE): PRODUCT_AAPT_CONFIG :=
+endif
 $(LOCAL_BUILT_MODULE): $(all_res_assets) $(jni_shared_libraries) $(full_android_manifest)
 	@echo "target Package: $(PRIVATE_MODULE) ($@)"
 	$(create-empty-package)
diff --git a/core/product.mk b/core/product.mk
index eca98ed725..38d11482f1 100644
--- a/core/product.mk
+++ b/core/product.mk
@@ -29,13 +29,13 @@ $(shell test -d device && find device -maxdepth 6 -name AndroidProducts.mk) \
 endef
 
 #
-# Returns the sorted concatenation of all PRODUCT_MAKEFILES
-# variables set in all AndroidProducts.mk files.
-# $(call ) isn't necessary.
+# Returns the sorted concatenation of PRODUCT_MAKEFILES
+# variables set in the given AndroidProducts.mk files.
+# $(1): the list of AndroidProducts.mk files.
 #
-define get-all-product-makefiles
+define get-product-makefiles
 $(sort \
-  $(foreach f,$(_find-android-products-files), \
+  $(foreach f,$(1), \
     $(eval PRODUCT_MAKEFILES :=) \
     $(eval LOCAL_DIR := $(patsubst %/,%,$(dir $(f)))) \
     $(eval include $(f)) \
@@ -46,6 +46,15 @@ $(sort \
  )
 endef
 
+#
+# Returns the sorted concatenation of all PRODUCT_MAKEFILES
+# variables set in all AndroidProducts.mk files.
+# $(call ) isn't necessary.
+#
+define get-all-product-makefiles
+$(call get-product-makefiles,$(_find-android-products-files))
+endef
+
 #
 # Functions for including product makefiles
 #
diff --git a/core/product_config.mk b/core/product_config.mk
index ffb8d27a8c..e86b04073d 100644
--- a/core/product_config.mk
+++ b/core/product_config.mk
@@ -148,6 +148,27 @@ $(goal_name): $(MAKECMDGOALS)
 endif
 # else: Use the value set in the environment or buildspec.mk.
 
+# ---------------------------------------------------------------
+# Provide "APP-<appname>" targets, which lets you build
+# an unbundled app.
+#
+unbundled_goals := $(strip $(filter APP-%,$(MAKECMDGOALS)))
+ifdef unbundled_goals
+  ifneq ($(words $(unbundled_goals)),1)
+    $(error Only one APP-* goal may be specified; saw "$(unbundled_goals)"))
+  endif
+  UNBUNDLED_APPS := $(strip $(subst -, ,$(patsubst APP-%,%,$(unbundled_goals))))
+  ifneq ($(filter $(DEFAULT_GOAL),$(MAKECMDGOALS)),)
+    MAKECMDGOALS := $(patsubst $(unbundled_goals),,$(MAKECMDGOALS))
+  else
+    MAKECMDGOALS := $(patsubst $(unbundled_goals),$(DEFAULT_GOAL),$(MAKECMDGOALS))
+  endif
+  is_unbundled_app_build := true
+
+.PHONY: $(unbundled_goals)
+$(unbundled_goals): $(MAKECMDGOALS)
+endif # unbundled_goals
+
 # ---------------------------------------------------------------
 # Include the product definitions.
 # We need to do this to translate TARGET_PRODUCT into its
@@ -157,12 +178,18 @@ include $(BUILD_SYSTEM)/node_fns.mk
 include $(BUILD_SYSTEM)/product.mk
 include $(BUILD_SYSTEM)/device.mk
 
-# Read in all of the product definitions specified by the AndroidProducts.mk
-# files in the tree.
-#
-#TODO: when we start allowing direct pointers to product files,
-#    guarantee that they're in this list.
-$(call import-products, $(get-all-product-makefiles))
+ifeq ($(strip $(is_unbundled_app_build)),true)
+  # An unbundled app build needs only the core product makefiles.
+  $(call import-products,$(call get-product-makefiles,\
+      $(SRC_TARGET_DIR)/product/AndroidProducts.mk))
+else
+  # Read in all of the product definitions specified by the AndroidProducts.mk
+  # files in the tree.
+  #
+  #TODO: when we start allowing direct pointers to product files,
+  #    guarantee that they're in this list.
+  $(call import-products, $(get-all-product-makefiles))
+endif # is_unbundled_app_build
 $(check-all-products)
 #$(dump-products)
 #$(error done)
diff --git a/target/product/AndroidProducts.mk b/target/product/AndroidProducts.mk
index be874c6e0b..df2fca1b92 100644
--- a/target/product/AndroidProducts.mk
+++ b/target/product/AndroidProducts.mk
@@ -25,6 +25,12 @@
 # it includes.
 #
 
+ifeq ($(strip $(is_unbundled_app_build)),true)
+# An unbundled app build needs only generic.mk.
+PRODUCT_MAKEFILES := \
+    $(LOCAL_DIR)/core.mk \
+    $(LOCAL_DIR)/generic.mk
+else
 PRODUCT_MAKEFILES := \
     $(LOCAL_DIR)/core.mk \
     $(LOCAL_DIR)/generic.mk \
@@ -32,3 +38,4 @@ PRODUCT_MAKEFILES := \
     $(LOCAL_DIR)/full.mk \
     $(LOCAL_DIR)/sdk.mk \
     $(LOCAL_DIR)/sim.mk
+endif