diff --git a/core/Makefile b/core/Makefile
index c5e30c2..af233f1 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -590,6 +590,14 @@
 INTERNAL_USERIMAGES_DEPS := $(MKEXTUSERIMG) $(MAKE_EXT4FS)
 INTERNAL_USERIMAGES_BINARY_PATHS := $(sort $(dir $(INTERNAL_USERIMAGES_DEPS)))
 
+# Calculate size of all files for device image and report on filesizes
+# $(1): src directory
+define calculate-userimage-ext-size
+  @echo Calculating image size...
+  @find $(1) -type f | xargs du -k | sort -gr > $(PRODUCT_OUT)/imagesize-report.txt
+  @du -s -h -k $(1)
+endef
+
 # $(1): src directory
 # $(2): output file
 # $(3): mount point
@@ -738,6 +746,7 @@
 # $(1): output file
 define build-systemimage-target
     @echo "Target system fs image: $(1)"
+    $(call calculate-userimage-ext-size,$(TARGET_OUT))
     $(call build-userimage-ext-target,$(TARGET_OUT),$(1),system,$(INTERNAL_USERIMAGES_EXT_VARIANT),$(BOARD_SYSTEMIMAGE_PARTITION_SIZE))
 endef
 
diff --git a/core/prebuilt.mk b/core/prebuilt.mk
index 07ecf64..bd4d91f 100644
--- a/core/prebuilt.mk
+++ b/core/prebuilt.mk
@@ -16,16 +16,6 @@
 $(error dont use LOCAL_PREBUILT_JAVA_LIBRARIES anymore LOCAL_PATH=$(LOCAL_PATH))
 endif
 
-ifneq ($(filter APPS,$(LOCAL_MODULE_CLASS)),)
-ifeq (true,$(WITH_DEXPREOPT))
-ifeq (,$(TARGET_BUILD_APPS))
-ifndef LOCAL_DEX_PREOPT
-LOCAL_DEX_PREOPT := true
-endif
-endif
-endif
-endif
-
 ifeq ($(LOCAL_STRIP_MODULE),true)
   ifdef LOCAL_IS_HOST_MODULE
     $(error Cannot strip host module LOCAL_PATH=$(LOCAL_PATH))
@@ -55,20 +45,8 @@
 
 # Ensure that prebuilt .apks have been aligned.
 ifneq ($(filter APPS,$(LOCAL_MODULE_CLASS)),)
-ifeq ($(LOCAL_DEX_PREOPT),true)
-# Make sure the boot jars get dexpreopt-ed first
-$(built_module): $(DEXPREOPT_BOOT_ODEXS) | $(DEXPREOPT) $(DEXOPT) $(AAPT)
-endif
 $(built_module) : $(LOCAL_PATH)/$(LOCAL_SRC_FILES) | $(ZIPALIGN)
 	$(transform-prebuilt-to-target-with-zipalign)
-ifeq ($(LOCAL_DEX_PREOPT),true)
-	$(hide) rm -f $(patsubst %.apk,%.odex,$@)
-	$(call dexpreopt-one-file,$@,$(patsubst %.apk,%.odex,$@))
-	$(call dexpreopt-remove-classes.dex,$@)
-
-built_odex := $(basename $(built_module)).odex
-$(built_odex): $(built_module)
-endif
 else
 ifneq ($(LOCAL_PREBUILT_STRIP_COMMENTS),)
 $(built_module) : $(LOCAL_PATH)/$(LOCAL_SRC_FILES)