diff --git a/core/Makefile b/core/Makefile
index c9e64f8..d150ec3 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -406,6 +406,9 @@
 	$(hide) echo ro.vendor.build.date=`$(DATE_FROM_FILE)`>>$@
 	$(hide) echo ro.vendor.build.date.utc=`$(DATE_FROM_FILE) +%s`>>$@
 	$(hide) echo ro.vendor.build.fingerprint="$(BUILD_FINGERPRINT_FROM_FILE)">>$@
+	$(hide) echo ro.vendor.product.cpu.abilist="$(TARGET_CPU_ABI_LIST)">>$@
+	$(hide) echo ro.vendor.product.cpu.abilist32="$(TARGET_CPU_ABI_LIST_32_BIT)">>$@
+	$(hide) echo ro.vendor.product.cpu.abilist64="$(TARGET_CPU_ABI_LIST_64_BIT)">>$@
 	$(hide) TARGET_DEVICE="$(TARGET_DEVICE)" \
 			PRODUCT_NAME="$(TARGET_PRODUCT)" \
 			PRODUCT_BRAND="$(PRODUCT_BRAND)" \
@@ -2374,18 +2377,18 @@
   system/extras/verity/build_verity_metadata.py \
   system/extras/ext4_utils/mke2fs.conf \
   external/avb/test/data/testkey_rsa4096.pem \
-  $(shell find system/update_engine/scripts -name \*.pyc -prune -o -type f -print | sort) \
-  $(shell find build/target/product/security -type f -name \*.x509.pem -o -name \*.pk8 -o \
-      -name verity_key | sort) \
-  $(shell find device $(wildcard vendor) -type f -name \*.pk8 -o -name verifiedboot\* -o \
-      -name \*.x509.pem -o -name oem\*.prop | sort)
+  $(sort $(shell find system/update_engine/scripts -name \*.pyc -prune -o -type f -print)) \
+  $(sort $(shell find build/target/product/security -type f -name \*.x509.pem -o -name \*.pk8 -o \
+      -name verity_key)) \
+  $(sort $(shell find device $(wildcard vendor) -type f -name \*.pk8 -o -name verifiedboot\* -o \
+      -name \*.x509.pem -o -name oem\*.prop))
 
 OTATOOLS_RELEASETOOLS := \
-  $(shell find build/make/tools/releasetools -name \*.pyc -prune -o -type f | sort)
+  $(sort $(shell find build/make/tools/releasetools -name \*.pyc -prune -o -type f))
 
 ifeq (true,$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT))
 OTATOOLS_DEPS += \
-  $(shell find external/vboot_reference/tests/devkeys -type f | sort)
+  $(sort $(shell find external/vboot_reference/tests/devkeys -type f))
 endif
 
 $(BUILT_OTATOOLS_PACKAGE): $(OTATOOLS) $(OTATOOLS_DEPS) $(OTATOOLS_RELEASETOOLS) | $(ACP)
diff --git a/core/aux_config.mk b/core/aux_config.mk
index bdae86a..6a5cd63 100644
--- a/core/aux_config.mk
+++ b/core/aux_config.mk
@@ -154,7 +154,7 @@
 config_roots := $(wildcard device vendor)
 all_configs :=
 ifdef config_roots
-all_configs := $(shell find $(config_roots) -maxdepth 4 -name '*$(variant_sfx)' -o -name '*$(os_sfx)' | sort)
+all_configs := $(sort $(shell find $(config_roots) -maxdepth 4 -name '*$(variant_sfx)' -o -name '*$(os_sfx)'))
 endif
 all_os_configs := $(filter %$(os_sfx),$(all_configs))
 all_variant_configs := $(filter %$(variant_sfx),$(all_configs))
diff --git a/core/base_rules.mk b/core/base_rules.mk
index 3ff3bd3..bbcf202 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -654,6 +654,9 @@
 ALL_MODULES.$(my_register_name).TARGET_REQUIRED := \
     $(strip $(ALL_MODULES.$(my_register_name).TARGET_REQUIRED)\
         $(LOCAL_TARGET_REQUIRED_MODULES))
+ALL_MODULES.$(my_register_name).HOST_REQUIRED := \
+    $(strip $(ALL_MODULES.$(my_register_name).HOST_REQUIRED)\
+        $(LOCAL_HOST_REQUIRED_MODULES))
 ALL_MODULES.$(my_register_name).EVENT_LOG_TAGS := \
     $(ALL_MODULES.$(my_register_name).EVENT_LOG_TAGS) $(event_log_tags)
 ALL_MODULES.$(my_register_name).MAKEFILE := \
diff --git a/core/clang/versions.mk b/core/clang/versions.mk
index f3a206a..1e41f92 100644
--- a/core/clang/versions.mk
+++ b/core/clang/versions.mk
@@ -1,4 +1,4 @@
 ## Clang/LLVM release versions.
 
-LLVM_PREBUILTS_VERSION ?= clang-4393122
+LLVM_PREBUILTS_VERSION ?= clang-4579689
 LLVM_PREBUILTS_BASE ?= prebuilts/clang/host
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index 7d3fa75..c3694ab2 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -98,6 +98,7 @@
 LOCAL_GTEST:=true
 LOCAL_HAL_STATIC_LIBRARIES:=
 LOCAL_HEADER_LIBRARIES:=
+LOCAL_HOST_REQUIRED_MODULES:=
 LOCAL_INIT_RC:=
 LOCAL_INSTALLED_MODULE:=
 LOCAL_INSTALLED_MODULE_STEM:=
@@ -435,6 +436,13 @@
 LOCAL_WHOLE_STATIC_LIBRARIES_32:=
 LOCAL_WHOLE_STATIC_LIBRARIES_64:=
 
+# Robolectric variables
+LOCAL_INSTRUMENT_SOURCE_DIRS :=
+LOCAL_ROBOTEST_FAILURE_FATAL :=
+LOCAL_ROBOTEST_FILES :=
+LOCAL_ROBOTEST_TIMEOUT :=
+LOCAL_TEST_PACKAGE :=
+
 # Aux specific variables
 LOCAL_AUX_ARCH :=
 LOCAL_AUX_CPU :=
diff --git a/core/config.mk b/core/config.mk
index a32e9f2..e9b5d4c 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -837,12 +837,6 @@
   DEFAULT_SYSTEM_DEV_CERTIFICATE := build/target/product/security/testkey
 endif
 
-FRAMEWORK_MANIFEST_INPUT_FILES := system/libhidl/manifest.xml
-ifdef DEVICE_FRAMEWORK_MANIFEST_FILE
-  FRAMEWORK_MANIFEST_INPUT_FILES += $(DEVICE_FRAMEWORK_MANIFEST_FILE)
-endif
-$(KATI_obsolete_var DEVICE_FRAMEWORK_MANIFEST_FILE,No one should ever need to use this.)
-
 BUILD_NUMBER_FROM_FILE := $$(cat $(OUT_DIR)/build_number.txt)
 BUILD_DATETIME_FROM_FILE := $$(cat $(OUT_DIR)/build_date.txt)
 
@@ -959,8 +953,8 @@
     $(wildcard $(HISTORICAL_SDK_VERSIONS_ROOT)/*/android_system.jar)))) \
     $(TARGET_AVAILABLE_SDK_VERSIONS)
 
-# We don't have prebuilt test_current SDK yet.
-TARGET_AVAILABLE_SDK_VERSIONS := test_current $(TARGET_AVAILABLE_SDK_VERSIONS)
+# We don't have prebuilt test_current and core_current SDK yet.
+TARGET_AVAILABLE_SDK_VERSIONS := test_current core_current $(TARGET_AVAILABLE_SDK_VERSIONS)
 
 TARGET_SDK_VERSIONS_WITHOUT_JAVA_18_SUPPORT := $(call numbers_less_than,24,$(TARGET_AVAILABLE_SDK_VERSIONS))
 TARGET_SDK_VERSIONS_WITHOUT_JAVA_19_SUPPORT := $(call numbers_less_than,27,$(TARGET_AVAILABLE_SDK_VERSIONS))
diff --git a/core/dpi_specific_apk.mk b/core/dpi_specific_apk.mk
index e29cde7..f32daf5 100644
--- a/core/dpi_specific_apk.mk
+++ b/core/dpi_specific_apk.mk
@@ -18,7 +18,7 @@
 $(built_dpi_apk): PRIVATE_ASSET_DIR := $(LOCAL_ASSET_DIR)
 $(built_dpi_apk): PRIVATE_AAPT_INCLUDES := $(all_library_res_package_exports)
 $(built_dpi_apk): PRIVATE_RESOURCE_LIST := $(all_res_assets)
-ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
+ifneq (,$(filter-out current system_current test_current core_current, $(LOCAL_SDK_VERSION)))
 $(built_dpi_apk): PRIVATE_DEFAULT_APP_TARGET_SDK := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
 else
 $(built_dpi_apk): PRIVATE_DEFAULT_APP_TARGET_SDK := $(DEFAULT_APP_TARGET_SDK)
diff --git a/core/droiddoc.mk b/core/droiddoc.mk
index 176a01d..25b591c 100644
--- a/core/droiddoc.mk
+++ b/core/droiddoc.mk
@@ -71,19 +71,16 @@
   else ifeq ($(LOCAL_SDK_VERSION)$(TARGET_BUILD_APPS),test_current)
     LOCAL_JAVA_LIBRARIES := android_test_stubs_current $(LOCAL_JAVA_LIBRARIES)
     $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, android_test_stubs_current)
+  else ifeq ($(LOCAL_SDK_VERSION)$(TARGET_BUILD_APPS),core_current)
+    LOCAL_JAVA_LIBRARIES := core.current.stubs $(LOCAL_JAVA_LIBRARIES)
+    $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, core.current.stubs)
   else
-    ifneq (,$(call has-system-sdk-version,$(LOCAL_SDK_VERSION)))
-      ifeq (,$(TARGET_BUILD_APPS))
-        LOCAL_JAVA_LIBRARIES := system_sdk_v$(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION)) $(LOCAL_JAVA_LIBRARIES)
-        $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, system_sdk_v$(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION)))
-      else
-        LOCAL_JAVA_LIBRARIES := sdk_v$(LOCAL_SDK_VERSION) $(LOCAL_JAVA_LIBRARIES)
-        $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, sdk_v$(LOCAL_SDK_VERSION))
-      endif
-    else
-      LOCAL_JAVA_LIBRARIES := sdk_v$(LOCAL_SDK_VERSION) $(LOCAL_JAVA_LIBRARIES)
-      $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, sdk_v$(LOCAL_SDK_VERSION))
-    endif
+    # core_<ver> is subset of <ver>. Instead of defining a prebuilt lib for core_<ver>,
+    # use the stub for <ver> when building for apps.
+    _version := $(patsubst core_%,%,$(LOCAL_SDK_VERSION))
+    LOCAL_JAVA_LIBRARIES := sdk_v$(_version) $(LOCAL_JAVA_LIBRARIES)
+    $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, sdk_v$(_version))
+    _version :=
   endif
 else
   LOCAL_JAVA_LIBRARIES := core-oj core-libart ext framework $(LOCAL_JAVA_LIBRARIES)
diff --git a/core/host_dalvik_java_library.mk b/core/host_dalvik_java_library.mk
index 1ff9b91..7bae696 100644
--- a/core/host_dalvik_java_library.mk
+++ b/core/host_dalvik_java_library.mk
@@ -193,7 +193,7 @@
 
 endif # !LOCAL_IS_STATIC_JAVA_LIBRARY
 
-ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
+ifneq (,$(filter-out current system_current test_current core_current, $(LOCAL_SDK_VERSION)))
   my_default_app_target_sdk := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
   my_sdk_version := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
 else
diff --git a/core/java.mk b/core/java.mk
index 6f5dce4..5945fae 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -125,7 +125,7 @@
 else
   ifneq (,$(LOCAL_SDK_VERSION))
     # Set target-api for LOCAL_SDK_VERSIONs other than current.
-    ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
+    ifneq (,$(filter-out current system_current test_current core_current, $(LOCAL_SDK_VERSION)))
       renderscript_target_api := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
     endif
   endif  # LOCAL_SDK_VERSION is set
@@ -150,7 +150,7 @@
 renderscript_flags += $(LOCAL_RENDERSCRIPT_FLAGS)
 
 # prepend the RenderScript system include path
-ifneq ($(filter-out current system_current test_current,$(LOCAL_SDK_VERSION))$(if $(TARGET_BUILD_APPS),$(filter current system_current test_current,$(LOCAL_SDK_VERSION))),)
+ifneq ($(filter-out current system_current test_current core_current,$(LOCAL_SDK_VERSION))$(if $(TARGET_BUILD_APPS),$(filter current system_current test_current,$(LOCAL_SDK_VERSION))),)
 # if a numeric LOCAL_SDK_VERSION, or current LOCAL_SDK_VERSION with TARGET_BUILD_APPS
 LOCAL_RENDERSCRIPT_INCLUDES := \
     $(HISTORICAL_SDK_VERSIONS_ROOT)/renderscript/clang-include \
@@ -266,7 +266,7 @@
 
 aidl_preprocess_import :=
 ifdef LOCAL_SDK_VERSION
-ifneq ($(filter current system_current test_current, $(LOCAL_SDK_VERSION)$(TARGET_BUILD_APPS)),)
+ifneq ($(filter current system_current test_current core_current, $(LOCAL_SDK_VERSION)$(TARGET_BUILD_APPS)),)
   # LOCAL_SDK_VERSION is current and no TARGET_BUILD_APPS
   aidl_preprocess_import := $(TARGET_OUT_COMMON_INTERMEDIATES)/framework.aidl
 else
@@ -610,7 +610,7 @@
 my_proguard_sdk_raise :=
 ifdef LOCAL_SDK_VERSION
 ifdef TARGET_BUILD_APPS
-ifeq (,$(filter current system_current test_current, $(LOCAL_SDK_VERSION)))
+ifeq (,$(filter current system_current test_current core_current, $(LOCAL_SDK_VERSION)))
   my_proguard_sdk_raise := $(call java-lib-header-files, sdk_vcurrent)
 endif
 else
@@ -806,7 +806,7 @@
 
 endif  # full_classes_jar is defined
 
-ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
+ifneq (,$(filter-out current system_current test_current core_current, $(LOCAL_SDK_VERSION)))
   my_default_app_target_sdk := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
   my_sdk_version := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
 else
diff --git a/core/java_common.mk b/core/java_common.mk
index ac8b0d2..3a5c5c6 100644
--- a/core/java_common.mk
+++ b/core/java_common.mk
@@ -258,17 +258,15 @@
       full_java_bootclasspath_libs := $(call java-lib-header-files,android_system_stubs_current)
     else ifeq ($(LOCAL_SDK_VERSION)$(TARGET_BUILD_APPS),test_current)
       full_java_bootclasspath_libs := $(call java-lib-header-files,android_test_stubs_current)
+    else ifeq ($(LOCAL_SDK_VERSION)$(TARGET_BUILD_APPS),core_current)
+      full_java_bootclasspath_libs := $(call java-lib-header-files,core.current.stubs)
     else
-      ifneq (,$(call has-system-sdk-version,$(LOCAL_SDK_VERSION)))
-        ifeq (,$(TARGET_BUILD_APPS))
-          full_java_bootclasspath_libs := $(call java-lib-header-files,system_sdk_v$(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION)))
-        else
-          full_java_bootclasspath_libs := $(call java-lib-header-files,sdk_v$(LOCAL_SDK_VERSION))
-        endif
-      else
-        full_java_bootclasspath_libs := $(call java-lib-header-files,sdk_v$(LOCAL_SDK_VERSION))
-      endif
-    endif # current, system_current, system_${VER} or test_current
+      # core_<ver> is subset of <ver>. Instead of defining a prebuilt lib for core_<ver>,
+      # use the stub for <ver> when building for apps.
+      _version := $(patsubst core_%,%,$(LOCAL_SDK_VERSION))
+      full_java_bootclasspath_libs := $(call java-lib-header-files,sdk_v$(_version))
+      _version :=
+    endif # current, system_current, system_${VER}, test_current or core_current
   endif # LOCAL_SDK_VERSION
 
   ifneq ($(LOCAL_NO_STANDARD_LIBRARIES),true)
@@ -460,19 +458,23 @@
 ifeq ($(LOCAL_SDK_VERSION),system_current)
 my_link_type := java:system
 my_warn_types := java:platform
-my_allowed_types := java:sdk java:system
+my_allowed_types := java:sdk java:system java:core
 else ifneq (,$(call has-system-sdk-version,$(LOCAL_SDK_VERSION)))
 my_link_type := java:system
 my_warn_types := java:platform
-my_allowed_types := java:sdk java:system
+my_allowed_types := java:sdk java:system java:core
+else ifeq ($(LOCAL_SDK_VERSION),core_current)
+my_link_type := java:core
+my_warn_types :=
+my_allowed_types := java:core
 else ifneq ($(LOCAL_SDK_VERSION),)
 my_link_type := java:sdk
 my_warn_types := java:system java:platform
-my_allowed_types := java:sdk
+my_allowed_types := java:sdk java:core
 else
 my_link_type := java:platform
 my_warn_types :=
-my_allowed_types := java:sdk java:system java:platform
+my_allowed_types := java:sdk java:system java:platform java:core
 endif
 
 ifdef LOCAL_AAPT2_ONLY
diff --git a/core/main.mk b/core/main.mk
index 38e9bd1..4d43295 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -610,6 +610,31 @@
 endef
 $(call add-all-host-to-target-required-modules-deps)
 
+# Sets up dependencies such that whenever a target module is installed,
+# any host modules listed in $(ALL_MODULES.$(m).HOST_REQUIRED) will also be installed
+define add-all-target-to-host-required-modules-deps
+$(foreach m,$(ALL_MODULES), \
+  $(eval req_mods := $(ALL_MODULES.$(m).HOST_REQUIRED))\
+  $(if $(req_mods), \
+    $(eval req_files := )\
+    $(foreach req_mod,$(req_mods), \
+      $(eval req_file := $(filter $(HOST_OUT)/%, $(call module-installed-files,$(req_mod)))) \
+      $(if $(strip $(req_file)),\
+        ,\
+        $(error $(m).LOCAL_HOST_REQUIRED_MODULES : illegal value $(req_mod) : not a host module. If you want to specify target modules to be required to be installed along with your target module, add those module names to LOCAL_REQUIRED_MODULES instead)\
+      )\
+      $(eval req_files := $(req_files)$(space)$(req_file))\
+    )\
+    $(eval req_files := $(strip $(req_files)))\
+    $(eval mod_files := $(filter $(TARGET_OUT_ROOT)/%, $(call module-installed-files,$(m))))\
+    $(eval mod_files := $(filter-out $(req_files),$(mod_files)))\
+    $(if $(mod_files),\
+      $(eval $(call add-required-deps, $(mod_files),$(req_files))) \
+    )\
+  )\
+)
+endef
+$(call add-all-target-to-host-required-modules-deps)
 
 t_m :=
 h_m :=
diff --git a/core/package_internal.mk b/core/package_internal.mk
index 4890966..d7944bb 100644
--- a/core/package_internal.mk
+++ b/core/package_internal.mk
@@ -394,7 +394,7 @@
 else
 ifneq (,$(LOCAL_SDK_VERSION))
 # Set target-api for LOCAL_SDK_VERSIONs other than current.
-ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
+ifneq (,$(filter-out current system_current test_current core_current, $(LOCAL_SDK_VERSION)))
 renderscript_target_api := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
 endif
 endif  # LOCAL_SDK_VERSION is set
diff --git a/core/prebuilt_internal.mk b/core/prebuilt_internal.mk
index ea7fd03..cb1d401 100644
--- a/core/prebuilt_internal.mk
+++ b/core/prebuilt_internal.mk
@@ -546,6 +546,8 @@
 my_link_type := java:system
 else ifneq (,$(call has-system-sdk-version,$(LOCAL_SDK_VERSION)))
 my_link_type := java:system
+else ifeq ($(LOCAL_SDK_VERSION),core_current)
+my_link_type := java:core
 else ifneq ($(LOCAL_SDK_VERSION),)
 my_link_type := java:sdk
 else
diff --git a/core/soong_app_prebuilt.mk b/core/soong_app_prebuilt.mk
index 65aabff..c553c4c 100644
--- a/core/soong_app_prebuilt.mk
+++ b/core/soong_app_prebuilt.mk
@@ -78,15 +78,15 @@
 ifeq ($(LOCAL_SDK_VERSION),system_current)
 my_link_type := java:system
 my_warn_types := java:platform
-my_allowed_types := java:sdk java:system
+my_allowed_types := java:sdk java:system java:core
 else ifneq ($(LOCAL_SDK_VERSION),)
 my_link_type := java:sdk
 my_warn_types := java:system java:platform
-my_allowed_types := java:sdk
+my_allowed_types := java:sdk java:core
 else
 my_link_type := java:platform
 my_warn_types :=
-my_allowed_types := java:sdk java:system java:platform
+my_allowed_types := java:sdk java:system java:platform java:core
 endif
 
 my_link_deps :=
diff --git a/core/soong_java_prebuilt.mk b/core/soong_java_prebuilt.mk
index 5c2d768..f3ed376 100644
--- a/core/soong_java_prebuilt.mk
+++ b/core/soong_java_prebuilt.mk
@@ -90,19 +90,23 @@
 ifeq ($(LOCAL_SDK_VERSION),system_current)
 my_link_type := java:system
 my_warn_types := java:platform
-my_allowed_types := java:sdk java:system
+my_allowed_types := java:sdk java:system java:core
 else ifneq (,$(call has-system-sdk-version,$(LOCAL_SDK_VERSION)))
 my_link_type := java:system
 my_warn_types := java:platform
-my_allowed_types := java:sdk java:system
+my_allowed_types := java:sdk java:system java:core
+else ifeq ($(LOCAL_SDK_VERSION),core_current)
+my_link_type := java:core
+my_warn_types :=
+my_allowed_types := java:core
 else ifneq ($(LOCAL_SDK_VERSION),)
 my_link_type := java:sdk
 my_warn_types := java:system java:platform
-my_allowed_types := java:sdk
+my_allowed_types := java:sdk java:core
 else
 my_link_type := java:platform
 my_warn_types :=
-my_allowed_types := java:sdk java:system java:platform
+my_allowed_types := java:sdk java:system java:platform java:core
 endif
 
 my_link_deps :=
diff --git a/core/static_java_library.mk b/core/static_java_library.mk
index aa1f0fa..c1478f1 100644
--- a/core/static_java_library.mk
+++ b/core/static_java_library.mk
@@ -156,7 +156,7 @@
 else
 ifneq (,$(LOCAL_SDK_VERSION))
 # Set target-api for LOCAL_SDK_VERSIONs other than current.
-ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
+ifneq (,$(filter-out current system_current test_current core_current, $(LOCAL_SDK_VERSION)))
 renderscript_target_api := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
 endif
 endif  # LOCAL_SDK_VERSION is set
diff --git a/target/board/Android.mk b/target/board/Android.mk
index 9b2620c..7fe45eb 100644
--- a/target/board/Android.mk
+++ b/target/board/Android.mk
@@ -52,65 +52,3 @@
 include $(BUILD_PREBUILT)
 BUILT_VENDOR_MANIFEST := $(LOCAL_BUILT_MODULE)
 endif
-
-# VNDK Version in device compatibility matrix and framework manifest
-ifeq ($(BOARD_VNDK_VERSION),current)
-VINTF_VNDK_VERSION := $(PLATFORM_VNDK_VERSION)
-else
-VINTF_VNDK_VERSION := $(BOARD_VNDK_VERSION)
-endif
-
-# Device Compatibility Matrix
-ifdef DEVICE_MATRIX_FILE
-include $(CLEAR_VARS)
-LOCAL_MODULE        := device_compatibility_matrix.xml
-LOCAL_MODULE_STEM   := compatibility_matrix.xml
-LOCAL_MODULE_CLASS  := ETC
-LOCAL_MODULE_PATH   := $(TARGET_OUT_VENDOR)/etc/vintf
-
-GEN := $(local-generated-sources-dir)/compatibility_matrix.xml
-
-$(GEN): PRIVATE_VINTF_VNDK_VERSION := $(VINTF_VNDK_VERSION)
-$(GEN): $(DEVICE_MATRIX_FILE) $(HOST_OUT_EXECUTABLES)/assemble_vintf
-	REQUIRED_VNDK_VERSION=$(PRIVATE_VINTF_VNDK_VERSION) \
-	BOARD_SYSTEMSDK_VERSIONS="$(BOARD_SYSTEMSDK_VERSIONS)" \
-		$(HOST_OUT_EXECUTABLES)/assemble_vintf -i $< -o $@
-
-LOCAL_PREBUILT_MODULE_FILE := $(GEN)
-include $(BUILD_PREBUILT)
-BUILT_VENDOR_MATRIX := $(LOCAL_BUILT_MODULE)
-endif
-
-# Framework Manifest
-include $(CLEAR_VARS)
-LOCAL_MODULE        := framework_manifest.xml
-LOCAL_MODULE_STEM   := manifest.xml
-LOCAL_MODULE_CLASS  := ETC
-LOCAL_MODULE_PATH   := $(TARGET_OUT)/etc/vintf
-
-GEN := $(local-generated-sources-dir)/manifest.xml
-
-$(GEN): PRIVATE_FLAGS :=
-
-ifeq ($(PRODUCT_ENFORCE_VINTF_MANIFEST),true)
-ifdef BUILT_VENDOR_MATRIX
-$(GEN): $(BUILT_VENDOR_MATRIX)
-$(GEN): PRIVATE_FLAGS += -c "$(BUILT_VENDOR_MATRIX)"
-endif
-endif
-
-$(GEN): PRIVATE_VINTF_VNDK_VERSION := $(VINTF_VNDK_VERSION)
-$(GEN): PRIVATE_FRAMEWORK_MANIFEST_INPUT_FILES := $(FRAMEWORK_MANIFEST_INPUT_FILES)
-$(GEN): $(FRAMEWORK_MANIFEST_INPUT_FILES) $(HOST_OUT_EXECUTABLES)/assemble_vintf
-	BOARD_SEPOLICY_VERS=$(BOARD_SEPOLICY_VERS) \
-	PROVIDED_VNDK_VERSIONS="$(PRIVATE_VINTF_VNDK_VERSION) $(PRODUCT_EXTRA_VNDK_VERSIONS)" \
-	PLATFORM_SYSTEMSDK_VERSIONS="$(PLATFORM_SYSTEMSDK_VERSIONS)" \
-		$(HOST_OUT_EXECUTABLES)/assemble_vintf \
-		-i $(call normalize-path-list,$(PRIVATE_FRAMEWORK_MANIFEST_INPUT_FILES)) \
-		-o $@ $(PRIVATE_FLAGS)
-
-LOCAL_PREBUILT_MODULE_FILE := $(GEN)
-include $(BUILD_PREBUILT)
-BUILT_SYSTEM_MANIFEST := $(LOCAL_BUILT_MODULE)
-
-VINTF_VNDK_VERSION :=
diff --git a/target/product/core.mk b/target/product/core.mk
index cab8d97..bbc2b75 100644
--- a/target/product/core.mk
+++ b/target/product/core.mk
@@ -56,6 +56,7 @@
     StorageManager \
     Telecom \
     TeleService \
+    Traceur \
     VpnDialogs \
     vr \
     MmsService
diff --git a/target/product/core_64_bit_only.mk b/target/product/core_64_bit_only.mk
new file mode 100644
index 0000000..72d30f5
--- /dev/null
+++ b/target/product/core_64_bit_only.mk
@@ -0,0 +1,30 @@
+#
+# Copyright (C) 2014 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.
+#
+
+# Inherit from this product for devices that support only 64-bit apps using:
+# $(call inherit-product, $(SRC_TARGET_DIR)/product/core_64_bit_only.mk)
+# The inheritance for this must come before the inheritance chain that leads
+# to core_minimal.mk.
+
+# Copy the 64-bit zygote startup script
+PRODUCT_COPY_FILES += system/core/rootdir/init.zygote64.rc:root/init.zygote64.rc
+
+# Set the zygote property to select the 64-bit script.
+# This line must be parsed before the one in core_minimal.mk
+PRODUCT_DEFAULT_PROPERTY_OVERRIDES += ro.zygote=zygote64
+
+TARGET_SUPPORTS_32_BIT_APPS := false
+TARGET_SUPPORTS_64_BIT_APPS := true
diff --git a/tools/releasetools/check_ota_package_signature.py b/tools/releasetools/check_ota_package_signature.py
index b5e9d8b..3cac90a 100755
--- a/tools/releasetools/check_ota_package_signature.py
+++ b/tools/releasetools/check_ota_package_signature.py
@@ -154,22 +154,18 @@
   print('Verifying A/B OTA payload signatures...')
 
   # Dump pubkey from the certificate.
-  pubkey = common.MakeTempFile(prefix="key-", suffix=".key")
-  cmd = ['openssl', 'x509', '-pubkey', '-noout', '-in', cert, '-out', pubkey]
-  proc = common.Run(cmd, stdout=subprocess.PIPE)
-  stdoutdata, _ = proc.communicate()
-  assert proc.returncode == 0, \
-      'Failed to dump public key from certificate: %s\n%s' % (cert, stdoutdata)
+  pubkey = common.MakeTempFile(prefix="key-", suffix=".pem")
+  with open(pubkey, 'wb') as pubkey_fp:
+    pubkey_fp.write(common.ExtractPublicKey(cert))
 
-  package_dir = tempfile.mkdtemp(prefix='package-')
-  common.OPTIONS.tempfiles.append(package_dir)
+  package_dir = common.MakeTempDir(prefix='package-')
 
   # Signature verification with delta_generator.
   payload_file = package_zip.extract('payload.bin', package_dir)
   cmd = ['delta_generator',
          '--in_file=' + payload_file,
          '--public_key=' + pubkey]
-  proc = common.Run(cmd, stdout=subprocess.PIPE)
+  proc = common.Run(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
   stdoutdata, _ = proc.communicate()
   assert proc.returncode == 0, \
       'Failed to verify payload with delta_generator: %s\n%s' % (package,
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index d0ee6ae..16600ed 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -25,6 +25,7 @@
 import re
 import shlex
 import shutil
+import string
 import subprocess
 import sys
 import tempfile
@@ -34,6 +35,7 @@
 from hashlib import sha1, sha256
 
 import blockimgdiff
+import sparse_img
 
 class Options(object):
   def __init__(self):
@@ -124,6 +126,11 @@
   return subprocess.Popen(args, **kwargs)
 
 
+def RoundUpTo4K(value):
+  rounded_up = value + 4095
+  return rounded_up - (rounded_up % 4096)
+
+
 def CloseInheritedPipes():
   """ Gmake in MAC OS has file descriptor (PIPE) leak. We close those fds
   before doing other work."""
@@ -618,6 +625,56 @@
   return tmp, zipfile.ZipFile(filename, "r")
 
 
+def GetSparseImage(which, tmpdir, input_zip):
+  """Returns a SparseImage object suitable for passing to BlockImageDiff.
+
+  This function loads the specified sparse image from the given path, and
+  performs additional processing for OTA purpose. For example, it always adds
+  block 0 to clobbered blocks list. It also detects files that cannot be
+  reconstructed from the block list, for whom we should avoid applying imgdiff.
+
+  Args:
+    which: The partition name, which must be "system" or "vendor".
+    tmpdir: The directory that contains the prebuilt image and block map file.
+    input_zip: The target-files ZIP archive.
+
+  Returns:
+    A SparseImage object, with file_map info loaded.
+  """
+  assert which in ("system", "vendor")
+
+  path = os.path.join(tmpdir, "IMAGES", which + ".img")
+  mappath = os.path.join(tmpdir, "IMAGES", which + ".map")
+
+  # The image and map files must have been created prior to calling
+  # ota_from_target_files.py (since LMP).
+  assert os.path.exists(path) and os.path.exists(mappath)
+
+  # In ext4 filesystems, block 0 might be changed even being mounted R/O. We add
+  # it to clobbered_blocks so that it will be written to the target
+  # unconditionally. Note that they are still part of care_map. (Bug: 20939131)
+  clobbered_blocks = "0"
+
+  image = sparse_img.SparseImage(path, mappath, clobbered_blocks)
+
+  # block.map may contain less blocks, because mke2fs may skip allocating blocks
+  # if they contain all zeros. We can't reconstruct such a file from its block
+  # list. Tag such entries accordingly. (Bug: 65213616)
+  for entry in image.file_map:
+    # "/system/framework/am.jar" => "SYSTEM/framework/am.jar".
+    arcname = string.replace(entry, which, which.upper(), 1)[1:]
+    # Skip artificial names, such as "__ZERO", "__NONZERO-1".
+    if arcname not in input_zip.namelist():
+      continue
+
+    info = input_zip.getinfo(arcname)
+    ranges = image.file_map[entry]
+    if RoundUpTo4K(info.file_size) > ranges.size() * 4096:
+      ranges.extra['incomplete'] = True
+
+  return image
+
+
 def GetKeyPasswords(keylist):
   """Given a list of keys, prompt the user to enter passwords for
   those which require them.  Return a {key: password} dict.  password
@@ -1747,6 +1804,31 @@
   cert = "".join(cert).decode('base64')
   return cert
 
+
+def ExtractPublicKey(cert):
+  """Extracts the public key (PEM-encoded) from the given certificate file.
+
+  Args:
+    cert: The certificate filename.
+
+  Returns:
+    The public key string.
+
+  Raises:
+    AssertionError: On non-zero return from 'openssl'.
+  """
+  # The behavior with '-out' is different between openssl 1.1 and openssl 1.0.
+  # While openssl 1.1 writes the key into the given filename followed by '-out',
+  # openssl 1.0 (both of 1.0.1 and 1.0.2) doesn't. So we collect the output from
+  # stdout instead.
+  cmd = ['openssl', 'x509', '-pubkey', '-noout', '-in', cert]
+  proc = Run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+  pubkey, stderrdata = proc.communicate()
+  assert proc.returncode == 0, \
+      'Failed to dump public key from certificate: %s\n%s' % (cert, stderrdata)
+  return pubkey
+
+
 def MakeRecoveryPatch(input_dir, output_sink, recovery_img, boot_img,
                       info_dict=None):
   """Generate a binary patch that creates the recovery image starting
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index 95b7303..cd497b2 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -92,6 +92,24 @@
       first, so that any changes made to the system partition are done
       using the new recovery (new kernel, etc.).
 
+  --include_secondary
+      Additionally include the payload for secondary slot images (default:
+      False). Only meaningful when generating A/B OTAs.
+
+      By default, an A/B OTA package doesn't contain the images for the
+      secondary slot (e.g. system_other.img). Specifying this flag allows
+      generating a separate payload that will install secondary slot images.
+
+      Such a package needs to be applied in a two-stage manner, with a reboot
+      in-between. During the first stage, the updater applies the primary
+      payload only. Upon finishing, it reboots the device into the newly updated
+      slot. It then continues to install the secondary payload to the inactive
+      slot, but without switching the active slot at the end (needs the matching
+      support in update_engine, i.e. SWITCH_SLOT_ON_REBOOT flag).
+
+      Due to the special install procedure, the secondary payload will be always
+      generated as a full payload.
+
   --block
       Generate a block-based OTA for non-A/B device. We have deprecated the
       support for file-based OTA since O. Block-based OTA will be used by
@@ -140,7 +158,6 @@
 
 import common
 import edify_generator
-import sparse_img
 
 if sys.hexversion < 0x02070000:
   print("Python 2.7 or newer is required.", file=sys.stderr)
@@ -160,6 +177,7 @@
 if OPTIONS.worker_threads == 0:
   OPTIONS.worker_threads = 1
 OPTIONS.two_step = False
+OPTIONS.include_secondary = False
 OPTIONS.no_signing = False
 OPTIONS.block_based = True
 OPTIONS.updater_binary = None
@@ -360,6 +378,133 @@
     return out_file
 
 
+class Payload(object):
+  """Manages the creation and the signing of an A/B OTA Payload."""
+
+  PAYLOAD_BIN = 'payload.bin'
+  PAYLOAD_PROPERTIES_TXT = 'payload_properties.txt'
+  SECONDARY_PAYLOAD_BIN = 'secondary/payload.bin'
+  SECONDARY_PAYLOAD_PROPERTIES_TXT = 'secondary/payload_properties.txt'
+
+  def __init__(self):
+    # The place where the output from the subprocess should go.
+    self._log_file = sys.stdout if OPTIONS.verbose else subprocess.PIPE
+    self.payload_file = None
+    self.payload_properties = None
+
+  def Generate(self, target_file, source_file=None, additional_args=None):
+    """Generates a payload from the given target-files zip(s).
+
+    Args:
+      target_file: The filename of the target build target-files zip.
+      source_file: The filename of the source build target-files zip; or None if
+          generating a full OTA.
+      additional_args: A list of additional args that should be passed to
+          brillo_update_payload script; or None.
+    """
+    if additional_args is None:
+      additional_args = []
+
+    payload_file = common.MakeTempFile(prefix="payload-", suffix=".bin")
+    cmd = ["brillo_update_payload", "generate",
+           "--payload", payload_file,
+           "--target_image", target_file]
+    if source_file is not None:
+      cmd.extend(["--source_image", source_file])
+    cmd.extend(additional_args)
+    p = common.Run(cmd, stdout=self._log_file, stderr=subprocess.STDOUT)
+    stdoutdata, _ = p.communicate()
+    assert p.returncode == 0, \
+        "brillo_update_payload generate failed: {}".format(stdoutdata)
+
+    self.payload_file = payload_file
+    self.payload_properties = None
+
+  def Sign(self, payload_signer):
+    """Generates and signs the hashes of the payload and metadata.
+
+    Args:
+      payload_signer: A PayloadSigner() instance that serves the signing work.
+
+    Raises:
+      AssertionError: On any failure when calling brillo_update_payload script.
+    """
+    assert isinstance(payload_signer, PayloadSigner)
+
+    # 1. Generate hashes of the payload and metadata files.
+    payload_sig_file = common.MakeTempFile(prefix="sig-", suffix=".bin")
+    metadata_sig_file = common.MakeTempFile(prefix="sig-", suffix=".bin")
+    cmd = ["brillo_update_payload", "hash",
+           "--unsigned_payload", self.payload_file,
+           "--signature_size", "256",
+           "--metadata_hash_file", metadata_sig_file,
+           "--payload_hash_file", payload_sig_file]
+    p1 = common.Run(cmd, stdout=self._log_file, stderr=subprocess.STDOUT)
+    p1.communicate()
+    assert p1.returncode == 0, "brillo_update_payload hash failed"
+
+    # 2. Sign the hashes.
+    signed_payload_sig_file = payload_signer.Sign(payload_sig_file)
+    signed_metadata_sig_file = payload_signer.Sign(metadata_sig_file)
+
+    # 3. Insert the signatures back into the payload file.
+    signed_payload_file = common.MakeTempFile(prefix="signed-payload-",
+                                              suffix=".bin")
+    cmd = ["brillo_update_payload", "sign",
+           "--unsigned_payload", self.payload_file,
+           "--payload", signed_payload_file,
+           "--signature_size", "256",
+           "--metadata_signature_file", signed_metadata_sig_file,
+           "--payload_signature_file", signed_payload_sig_file]
+    p1 = common.Run(cmd, stdout=self._log_file, stderr=subprocess.STDOUT)
+    p1.communicate()
+    assert p1.returncode == 0, "brillo_update_payload sign failed"
+
+    # 4. Dump the signed payload properties.
+    properties_file = common.MakeTempFile(prefix="payload-properties-",
+                                          suffix=".txt")
+    cmd = ["brillo_update_payload", "properties",
+           "--payload", signed_payload_file,
+           "--properties_file", properties_file]
+    p1 = common.Run(cmd, stdout=self._log_file, stderr=subprocess.STDOUT)
+    p1.communicate()
+    assert p1.returncode == 0, "brillo_update_payload properties failed"
+
+    if OPTIONS.wipe_user_data:
+      with open(properties_file, "a") as f:
+        f.write("POWERWASH=1\n")
+
+    self.payload_file = signed_payload_file
+    self.payload_properties = properties_file
+
+  def WriteToZip(self, output_zip, secondary=False):
+    """Writes the payload to the given zip.
+
+    Args:
+      output_zip: The output ZipFile instance.
+      secondary: Whether the payload should be packed as secondary payload
+          (default: False).
+    """
+    assert self.payload_file is not None
+    assert self.payload_properties is not None
+
+    if secondary:
+      payload_arcname = Payload.SECONDARY_PAYLOAD_BIN
+      payload_properties_arcname = Payload.SECONDARY_PAYLOAD_PROPERTIES_TXT
+    else:
+      payload_arcname = Payload.PAYLOAD_BIN
+      payload_properties_arcname = Payload.PAYLOAD_PROPERTIES_TXT
+
+    # Add the signed payload file and properties into the zip. In order to
+    # support streaming, we pack them as ZIP_STORED. So these entries can be
+    # read directly with the offset and length pairs.
+    common.ZipWrite(output_zip, self.payload_file, arcname=payload_arcname,
+                    compress_type=zipfile.ZIP_STORED)
+    common.ZipWrite(output_zip, self.payload_properties,
+                    arcname=payload_properties_arcname,
+                    compress_type=zipfile.ZIP_STORED)
+
+
 def SignOutput(temp_zip_name, output_zip_name):
   pw = OPTIONS.key_passwords[OPTIONS.package_key]
 
@@ -452,31 +597,6 @@
         source_info.GetBuildProp("ro.build.thumbprint"))
 
 
-def GetImage(which, tmpdir):
-  """Returns an image object suitable for passing to BlockImageDiff.
-
-  'which' partition must be "system" or "vendor". A prebuilt image and file
-  map must already exist in tmpdir.
-  """
-
-  assert which in ("system", "vendor")
-
-  path = os.path.join(tmpdir, "IMAGES", which + ".img")
-  mappath = os.path.join(tmpdir, "IMAGES", which + ".map")
-
-  # The image and map files must have been created prior to calling
-  # ota_from_target_files.py (since LMP).
-  assert os.path.exists(path) and os.path.exists(mappath)
-
-  # Bug: http://b/20939131
-  # In ext4 filesystems, block 0 might be changed even being mounted
-  # R/O. We add it to clobbered_blocks so that it will be written to the
-  # target unconditionally. Note that they are still part of care_map.
-  clobbered_blocks = "0"
-
-  return sparse_img.SparseImage(path, mappath, clobbered_blocks)
-
-
 def AddCompatibilityArchiveIfTrebleEnabled(target_zip, output_zip, target_info,
                                            source_info=None):
   """Adds compatibility info into the output zip if it's Treble-enabled target.
@@ -662,7 +782,7 @@
   # has the effect of writing new data from the package to the entire
   # partition, but lets us reuse the updater code that writes incrementals to
   # do it.
-  system_tgt = GetImage("system", OPTIONS.input_tmp)
+  system_tgt = common.GetSparseImage("system", OPTIONS.input_tmp, input_zip)
   system_tgt.ResetFileMap()
   system_diff = common.BlockDifference("system", system_tgt, src=None)
   system_diff.WriteScript(script, output_zip)
@@ -673,7 +793,7 @@
   if HasVendorPartition(input_zip):
     script.ShowProgress(0.1, 0)
 
-    vendor_tgt = GetImage("vendor", OPTIONS.input_tmp)
+    vendor_tgt = common.GetSparseImage("vendor", OPTIONS.input_tmp, input_zip)
     vendor_tgt.ResetFileMap()
     vendor_diff = common.BlockDifference("vendor", vendor_tgt)
     vendor_diff.WriteScript(script, output_zip)
@@ -778,6 +898,10 @@
       'post-build' : target_info.fingerprint,
       'post-build-incremental' : target_info.GetBuildProp(
           'ro.build.version.incremental'),
+      'post-sdk-level' : target_info.GetBuildProp(
+          'ro.build.version.sdk'),
+      'post-security-patch-level' : target_info.GetBuildProp(
+          'ro.build.version.security_patch'),
   }
 
   if target_info.is_ab:
@@ -846,8 +970,8 @@
   target_recovery = common.GetBootableImage(
       "/tmp/recovery.img", "recovery.img", OPTIONS.target_tmp, "RECOVERY")
 
-  system_src = GetImage("system", OPTIONS.source_tmp)
-  system_tgt = GetImage("system", OPTIONS.target_tmp)
+  system_src = common.GetSparseImage("system", OPTIONS.source_tmp, source_zip)
+  system_tgt = common.GetSparseImage("system", OPTIONS.target_tmp, target_zip)
 
   blockimgdiff_version = max(
       int(i) for i in target_info.get("blockimgdiff_versions", "1").split(","))
@@ -872,8 +996,8 @@
   if HasVendorPartition(target_zip):
     if not HasVendorPartition(source_zip):
       raise RuntimeError("can't generate incremental that adds /vendor")
-    vendor_src = GetImage("vendor", OPTIONS.source_tmp)
-    vendor_tgt = GetImage("vendor", OPTIONS.target_tmp)
+    vendor_src = common.GetSparseImage("vendor", OPTIONS.source_tmp, source_zip)
+    vendor_tgt = common.GetSparseImage("vendor", OPTIONS.target_tmp, target_zip)
 
     # Check first block of vendor partition for remount R/W only if
     # disk type is ext4
@@ -919,7 +1043,7 @@
   if OPTIONS.two_step:
     if not source_info.get("multistage_support"):
       assert False, "two-step packages not supported by this build"
-    fs = OPTIONS.source_info_dict["fstab"]["/misc"]
+    fs = source_info["fstab"]["/misc"]
     assert fs.fs_type.upper() == "EMMC", \
         "two-step packages only supported on devices with EMMC /misc partitions"
     bcb_dev = {"bcb_dev" : fs.device}
@@ -1049,7 +1173,6 @@
   if OPTIONS.wipe_user_data:
     script.Print("Erasing user data...")
     script.FormatPartition("/data")
-    metadata["ota-wipe"] = "yes"
 
   if OPTIONS.two_step:
     script.AppendExtra("""
@@ -1069,6 +1192,47 @@
   WriteMetadata(metadata, output_zip)
 
 
+def GetTargetFilesZipForSecondaryImages(input_file):
+  """Returns a target-files.zip file for generating secondary payload.
+
+  Although the original target-files.zip already contains secondary slot
+  images (i.e. IMAGES/system_other.img), we need to rename the files to the
+  ones without _other suffix. Note that we cannot instead modify the names in
+  META/ab_partitions.txt, because there are no matching partitions on device.
+
+  For the partitions that don't have secondary images, the ones for primary
+  slot will be used. This is to ensure that we always have valid boot, vbmeta,
+  bootloader images in the inactive slot.
+
+  Args:
+    input_file: The input target-files.zip file.
+
+  Returns:
+    The filename of the target-files.zip for generating secondary payload.
+  """
+  target_file = common.MakeTempFile(prefix="targetfiles-", suffix=".zip")
+  target_zip = zipfile.ZipFile(target_file, 'w', allowZip64=True)
+
+  input_tmp, input_zip = common.UnzipTemp(input_file, UNZIP_PATTERN)
+  for info in input_zip.infolist():
+    unzipped_file = os.path.join(input_tmp, *info.filename.split('/'))
+    if info.filename == 'IMAGES/system_other.img':
+      common.ZipWrite(target_zip, unzipped_file, arcname='IMAGES/system.img')
+
+    # Primary images and friends need to be skipped explicitly.
+    elif info.filename in ('IMAGES/system.img',
+                           'IMAGES/system.map'):
+      pass
+
+    elif info.filename.startswith(('META/', 'IMAGES/')):
+      common.ZipWrite(target_zip, unzipped_file, arcname=info.filename)
+
+  common.ZipClose(input_zip)
+  common.ZipClose(target_zip)
+
+  return target_file
+
+
 def WriteABOTAPackageWithBrilloScript(target_file, output_file,
                                       source_file=None):
   """Generate an Android OTA package that has A/B update payload."""
@@ -1123,12 +1287,6 @@
       value += ' ' * (expected_length - len(value))
     return value
 
-  # The place where the output from the subprocess should go.
-  log_file = sys.stdout if OPTIONS.verbose else subprocess.PIPE
-
-  # Get the PayloadSigner to be used in step 3.
-  payload_signer = PayloadSigner()
-
   # Stage the output zip package for package signing.
   temp_zip_file = tempfile.NamedTemporaryFile()
   output_zip = zipfile.ZipFile(temp_zip_file, "w",
@@ -1144,73 +1302,27 @@
   # Metadata to comply with Android OTA package format.
   metadata = GetPackageMetadata(target_info, source_info)
 
-  # 1. Generate payload.
-  payload_file = common.MakeTempFile(prefix="payload-", suffix=".bin")
-  cmd = ["brillo_update_payload", "generate",
-         "--payload", payload_file,
-         "--target_image", target_file]
-  if source_file is not None:
-    cmd.extend(["--source_image", source_file])
-  p1 = common.Run(cmd, stdout=log_file, stderr=subprocess.STDOUT)
-  p1.communicate()
-  assert p1.returncode == 0, "brillo_update_payload generate failed"
+  # Generate payload.
+  payload = Payload()
+  payload.Generate(target_file, source_file)
 
-  # 2. Generate hashes of the payload and metadata files.
-  payload_sig_file = common.MakeTempFile(prefix="sig-", suffix=".bin")
-  metadata_sig_file = common.MakeTempFile(prefix="sig-", suffix=".bin")
-  cmd = ["brillo_update_payload", "hash",
-         "--unsigned_payload", payload_file,
-         "--signature_size", "256",
-         "--metadata_hash_file", metadata_sig_file,
-         "--payload_hash_file", payload_sig_file]
-  p1 = common.Run(cmd, stdout=log_file, stderr=subprocess.STDOUT)
-  p1.communicate()
-  assert p1.returncode == 0, "brillo_update_payload hash failed"
+  # Sign the payload.
+  payload_signer = PayloadSigner()
+  payload.Sign(payload_signer)
 
-  # 3. Sign the hashes and insert them back into the payload file.
-  # 3a. Sign the payload hash.
-  signed_payload_sig_file = payload_signer.Sign(payload_sig_file)
+  # Write the payload into output zip.
+  payload.WriteToZip(output_zip)
 
-  # 3b. Sign the metadata hash.
-  signed_metadata_sig_file = payload_signer.Sign(metadata_sig_file)
-
-  # 3c. Insert the signatures back into the payload file.
-  signed_payload_file = common.MakeTempFile(prefix="signed-payload-",
-                                            suffix=".bin")
-  cmd = ["brillo_update_payload", "sign",
-         "--unsigned_payload", payload_file,
-         "--payload", signed_payload_file,
-         "--signature_size", "256",
-         "--metadata_signature_file", signed_metadata_sig_file,
-         "--payload_signature_file", signed_payload_sig_file]
-  p1 = common.Run(cmd, stdout=log_file, stderr=subprocess.STDOUT)
-  p1.communicate()
-  assert p1.returncode == 0, "brillo_update_payload sign failed"
-
-  # 4. Dump the signed payload properties.
-  properties_file = common.MakeTempFile(prefix="payload-properties-",
-                                        suffix=".txt")
-  cmd = ["brillo_update_payload", "properties",
-         "--payload", signed_payload_file,
-         "--properties_file", properties_file]
-  p1 = common.Run(cmd, stdout=log_file, stderr=subprocess.STDOUT)
-  p1.communicate()
-  assert p1.returncode == 0, "brillo_update_payload properties failed"
-
-  if OPTIONS.wipe_user_data:
-    with open(properties_file, "a") as f:
-      f.write("POWERWASH=1\n")
-    metadata["ota-wipe"] = "yes"
-
-  # Add the signed payload file and properties into the zip. In order to
-  # support streaming, we pack payload.bin, payload_properties.txt and
-  # care_map.txt as ZIP_STORED. So these entries can be read directly with
-  # the offset and length pairs.
-  common.ZipWrite(output_zip, signed_payload_file, arcname="payload.bin",
-                  compress_type=zipfile.ZIP_STORED)
-  common.ZipWrite(output_zip, properties_file,
-                  arcname="payload_properties.txt",
-                  compress_type=zipfile.ZIP_STORED)
+  # Generate and include the secondary payload that installs secondary images
+  # (e.g. system_other.img).
+  if OPTIONS.include_secondary:
+    # We always include a full payload for the secondary slot, even when
+    # building an incremental OTA. See the comments for "--include_secondary".
+    secondary_target_file = GetTargetFilesZipForSecondaryImages(target_file)
+    secondary_payload = Payload()
+    secondary_payload.Generate(secondary_target_file)
+    secondary_payload.Sign(payload_signer)
+    secondary_payload.WriteToZip(output_zip, secondary=True)
 
   # If dm-verity is supported for the device, copy contents of care_map
   # into A/B OTA package.
@@ -1221,6 +1333,8 @@
     namelist = target_zip.namelist()
     if care_map_path in namelist:
       care_map_data = target_zip.read(care_map_path)
+      # In order to support streaming, care_map.txt needs to be packed as
+      # ZIP_STORED.
       common.ZipWriteStr(output_zip, "care_map.txt", care_map_data,
                          compress_type=zipfile.ZIP_STORED)
     else:
@@ -1308,6 +1422,8 @@
                          "integers are allowed." % (a, o))
     elif o in ("-2", "--two_step"):
       OPTIONS.two_step = True
+    elif o == "--include_secondary":
+      OPTIONS.include_secondary = True
     elif o == "--no_signing":
       OPTIONS.no_signing = True
     elif o == "--verify":
@@ -1347,6 +1463,7 @@
                                  "extra_script=",
                                  "worker_threads=",
                                  "two_step",
+                                 "include_secondary",
                                  "no_signing",
                                  "block",
                                  "binary=",
diff --git a/tools/releasetools/rangelib.py b/tools/releasetools/rangelib.py
index 87380a5..8af61c3 100644
--- a/tools/releasetools/rangelib.py
+++ b/tools/releasetools/rangelib.py
@@ -25,6 +25,7 @@
 
   def __init__(self, data=None):
     self.monotonic = False
+    self._extra = {}
     if isinstance(data, str):
       self._parse_internal(data)
     elif data:
@@ -56,6 +57,10 @@
   def __repr__(self):
     return '<RangeSet("' + self.to_string() + '")>'
 
+  @property
+  def extra(self):
+    return self._extra
+
   @classmethod
   def parse(cls, text):
     """Parse a text string consisting of a space-separated list of
diff --git a/tools/releasetools/sign_target_files_apks.py b/tools/releasetools/sign_target_files_apks.py
index 7a1126c..1f9a3ca 100755
--- a/tools/releasetools/sign_target_files_apks.py
+++ b/tools/releasetools/sign_target_files_apks.py
@@ -538,10 +538,7 @@
             " as payload verification key.\n\n")
 
     print("Using %s for payload verification." % (mapped_keys[0],))
-    cmd = common.Run(
-        ["openssl", "x509", "-pubkey", "-noout", "-in", mapped_keys[0]],
-        stdout=subprocess.PIPE)
-    pubkey, _ = cmd.communicate()
+    pubkey = common.ExtractPublicKey(mapped_keys[0])
     common.ZipWriteStr(
         output_tf_zip,
         "SYSTEM/etc/update_engine/update-payload-key.pub.pem",
diff --git a/tools/releasetools/test_common.py b/tools/releasetools/test_common.py
index 8fb4600..6da286c 100644
--- a/tools/releasetools/test_common.py
+++ b/tools/releasetools/test_common.py
@@ -21,8 +21,10 @@
 from hashlib import sha1
 
 import common
+import test_utils
 import validate_target_files
 
+
 KiB = 1024
 MiB = 1024 * KiB
 GiB = 1024 * MiB
@@ -474,6 +476,18 @@
     with zipfile.ZipFile(target_files, 'r') as input_zip:
       self.assertRaises(ValueError, common.ReadApkCerts, input_zip)
 
+  def test_ExtractPublicKey(self):
+    testdata_dir = test_utils.get_testdata_dir()
+    cert = os.path.join(testdata_dir, 'testkey.x509.pem')
+    pubkey = os.path.join(testdata_dir, 'testkey.pubkey.pem')
+    with open(pubkey, 'rb') as pubkey_fp:
+      self.assertEqual(pubkey_fp.read(), common.ExtractPublicKey(cert))
+
+  def test_ExtractPublicKey_invalidInput(self):
+    testdata_dir = test_utils.get_testdata_dir()
+    wrong_input = os.path.join(testdata_dir, 'testkey.pk8')
+    self.assertRaises(AssertionError, common.ExtractPublicKey, wrong_input)
+
 
 class InstallRecoveryScriptFormatTest(unittest.TestCase):
   """Checks the format of install-recovery.sh.
diff --git a/tools/releasetools/test_ota_from_target_files.py b/tools/releasetools/test_ota_from_target_files.py
index fa6655b..6edf80c 100644
--- a/tools/releasetools/test_ota_from_target_files.py
+++ b/tools/releasetools/test_ota_from_target_files.py
@@ -15,20 +15,44 @@
 #
 
 import copy
+import os
 import os.path
 import unittest
+import zipfile
 
 import common
+import test_utils
 from ota_from_target_files import (
-    _LoadOemDicts, BuildInfo, GetPackageMetadata, PayloadSigner,
+    _LoadOemDicts, BuildInfo, GetPackageMetadata,
+    GetTargetFilesZipForSecondaryImages, Payload, PayloadSigner,
     WriteFingerprintAssertion)
 
 
-def get_testdata_dir():
-  """Returns the testdata dir, in relative to the script dir."""
-  # The script dir is the one we want, which could be different from pwd.
-  current_dir = os.path.dirname(os.path.realpath(__file__))
-  return os.path.join(current_dir, 'testdata')
+def construct_target_files(secondary=False):
+  """Returns a target-files.zip file for generating OTA packages."""
+  target_files = common.MakeTempFile(prefix='target_files-', suffix='.zip')
+  with zipfile.ZipFile(target_files, 'w') as target_files_zip:
+    # META/update_engine_config.txt
+    target_files_zip.writestr(
+        'META/update_engine_config.txt',
+        "PAYLOAD_MAJOR_VERSION=2\nPAYLOAD_MINOR_VERSION=4\n")
+
+    # META/ab_partitions.txt
+    ab_partitions = ['boot', 'system', 'vendor']
+    target_files_zip.writestr(
+        'META/ab_partitions.txt',
+        '\n'.join(ab_partitions))
+
+    # Create dummy images for each of them.
+    for partition in ab_partitions:
+      target_files_zip.writestr('IMAGES/' + partition + '.img',
+                                os.urandom(len(partition)))
+
+    if secondary:
+      target_files_zip.writestr('IMAGES/system_other.img',
+                                os.urandom(len("system_other")))
+
+  return target_files
 
 
 class MockScriptWriter(object):
@@ -318,6 +342,8 @@
           'ro.product.device' : 'product-device',
           'ro.build.fingerprint' : 'build-fingerprint-target',
           'ro.build.version.incremental' : 'build-version-incremental-target',
+          'ro.build.version.sdk' : '27',
+          'ro.build.version.security_patch' : '2017-12-01',
           'ro.build.date.utc' : '1500000000',
       },
   }
@@ -327,6 +353,8 @@
           'ro.product.device' : 'product-device',
           'ro.build.fingerprint' : 'build-fingerprint-source',
           'ro.build.version.incremental' : 'build-version-incremental-source',
+          'ro.build.version.sdk' : '25',
+          'ro.build.version.security_patch' : '2016-12-01',
           'ro.build.date.utc' : '1400000000',
       },
   }
@@ -349,6 +377,8 @@
             'ota-required-cache' : '0',
             'post-build' : 'build-fingerprint-target',
             'post-build-incremental' : 'build-version-incremental-target',
+            'post-sdk-level' : '27',
+            'post-security-patch-level' : '2017-12-01',
             'post-timestamp' : '1500000000',
             'pre-device' : 'product-device',
         },
@@ -367,6 +397,8 @@
             'ota-required-cache' : '0',
             'post-build' : 'build-fingerprint-target',
             'post-build-incremental' : 'build-version-incremental-target',
+            'post-sdk-level' : '27',
+            'post-security-patch-level' : '2017-12-01',
             'post-timestamp' : '1500000000',
             'pre-device' : 'product-device',
             'pre-build' : 'build-fingerprint-source',
@@ -382,6 +414,8 @@
             'ota-type' : 'BLOCK',
             'post-build' : 'build-fingerprint-target',
             'post-build-incremental' : 'build-version-incremental-target',
+            'post-sdk-level' : '27',
+            'post-security-patch-level' : '2017-12-01',
             'post-timestamp' : '1500000000',
             'pre-device' : 'product-device',
         },
@@ -397,6 +431,8 @@
             'ota-type' : 'BLOCK',
             'post-build' : 'build-fingerprint-target',
             'post-build-incremental' : 'build-version-incremental-target',
+            'post-sdk-level' : '27',
+            'post-security-patch-level' : '2017-12-01',
             'post-timestamp' : '1500000000',
             'pre-device' : 'product-device',
             'pre-build' : 'build-fingerprint-source',
@@ -414,6 +450,8 @@
             'ota-wipe' : 'yes',
             'post-build' : 'build-fingerprint-target',
             'post-build-incremental' : 'build-version-incremental-target',
+            'post-sdk-level' : '27',
+            'post-security-patch-level' : '2017-12-01',
             'post-timestamp' : '1500000000',
             'pre-device' : 'product-device',
         },
@@ -457,6 +495,8 @@
             'ota-wipe' : 'yes',
             'post-build' : 'build-fingerprint-target',
             'post-build-incremental' : 'build-version-incremental-target',
+            'post-sdk-level' : '27',
+            'post-security-patch-level' : '2017-12-01',
             'pre-device' : 'product-device',
             'pre-build' : 'build-fingerprint-source',
             'pre-build-incremental' : 'build-version-incremental-source',
@@ -479,6 +519,8 @@
             'ota-type' : 'BLOCK',
             'post-build' : 'build-fingerprint-target',
             'post-build-incremental' : 'build-version-incremental-target',
+            'post-sdk-level' : '27',
+            'post-security-patch-level' : '2017-12-01',
             'post-timestamp' : '1500000001',
             'pre-device' : 'product-device',
             'pre-build' : 'build-fingerprint-source',
@@ -486,6 +528,21 @@
         },
         metadata)
 
+  def test_GetTargetFilesZipForSecondaryImages(self):
+    input_file = construct_target_files(secondary=True)
+    target_file = GetTargetFilesZipForSecondaryImages(input_file)
+
+    with zipfile.ZipFile(target_file) as verify_zip:
+      namelist = verify_zip.namelist()
+
+    self.assertIn('META/ab_partitions.txt', namelist)
+    self.assertIn('IMAGES/boot.img', namelist)
+    self.assertIn('IMAGES/system.img', namelist)
+    self.assertIn('IMAGES/vendor.img', namelist)
+
+    self.assertNotIn('IMAGES/system_other.img', namelist)
+    self.assertNotIn('IMAGES/system.map', namelist)
+
 
 class PayloadSignerTest(unittest.TestCase):
 
@@ -493,7 +550,7 @@
   SIGNED_SIGFILE = 'signed-sigfile.bin'
 
   def setUp(self):
-    self.testdata_dir = get_testdata_dir()
+    self.testdata_dir = test_utils.get_testdata_dir()
     self.assertTrue(os.path.exists(self.testdata_dir))
 
     common.OPTIONS.payload_signer = None
@@ -564,3 +621,159 @@
 
     verify_file = os.path.join(self.testdata_dir, self.SIGNED_SIGFILE)
     self._assertFilesEqual(verify_file, signed_file)
+
+
+class PayloadTest(unittest.TestCase):
+
+  def setUp(self):
+    self.testdata_dir = test_utils.get_testdata_dir()
+    self.assertTrue(os.path.exists(self.testdata_dir))
+
+    common.OPTIONS.wipe_user_data = False
+    common.OPTIONS.payload_signer = None
+    common.OPTIONS.payload_signer_args = None
+    common.OPTIONS.package_key = os.path.join(self.testdata_dir, 'testkey')
+    common.OPTIONS.key_passwords = {
+        common.OPTIONS.package_key : None,
+    }
+
+  def tearDown(self):
+    common.Cleanup()
+
+  @staticmethod
+  def _create_payload_full(secondary=False):
+    target_file = construct_target_files(secondary)
+    payload = Payload()
+    payload.Generate(target_file)
+    return payload
+
+  @staticmethod
+  def _create_payload_incremental():
+    target_file = construct_target_files()
+    source_file = construct_target_files()
+    payload = Payload()
+    payload.Generate(target_file, source_file)
+    return payload
+
+  def test_Generate_full(self):
+    payload = self._create_payload_full()
+    self.assertTrue(os.path.exists(payload.payload_file))
+
+  def test_Generate_incremental(self):
+    payload = self._create_payload_incremental()
+    self.assertTrue(os.path.exists(payload.payload_file))
+
+  def test_Generate_additionalArgs(self):
+    target_file = construct_target_files()
+    source_file = construct_target_files()
+    payload = Payload()
+    # This should work the same as calling payload.Generate(target_file,
+    # source_file).
+    payload.Generate(
+        target_file, additional_args=["--source_image", source_file])
+    self.assertTrue(os.path.exists(payload.payload_file))
+
+  def test_Generate_invalidInput(self):
+    target_file = construct_target_files()
+    common.ZipDelete(target_file, 'IMAGES/vendor.img')
+    payload = Payload()
+    self.assertRaises(AssertionError, payload.Generate, target_file)
+
+  def test_Sign_full(self):
+    payload = self._create_payload_full()
+    payload.Sign(PayloadSigner())
+
+    output_file = common.MakeTempFile(suffix='.zip')
+    with zipfile.ZipFile(output_file, 'w') as output_zip:
+      payload.WriteToZip(output_zip)
+
+    import check_ota_package_signature
+    check_ota_package_signature.VerifyAbOtaPayload(
+        os.path.join(self.testdata_dir, 'testkey.x509.pem'),
+        output_file)
+
+  def test_Sign_incremental(self):
+    payload = self._create_payload_incremental()
+    payload.Sign(PayloadSigner())
+
+    output_file = common.MakeTempFile(suffix='.zip')
+    with zipfile.ZipFile(output_file, 'w') as output_zip:
+      payload.WriteToZip(output_zip)
+
+    import check_ota_package_signature
+    check_ota_package_signature.VerifyAbOtaPayload(
+        os.path.join(self.testdata_dir, 'testkey.x509.pem'),
+        output_file)
+
+  def test_Sign_withDataWipe(self):
+    common.OPTIONS.wipe_user_data = True
+    payload = self._create_payload_full()
+    payload.Sign(PayloadSigner())
+
+    with open(payload.payload_properties) as properties_fp:
+      self.assertIn("POWERWASH=1", properties_fp.read())
+
+  def test_Sign_badSigner(self):
+    """Tests that signing failure can be captured."""
+    payload = self._create_payload_full()
+    payload_signer = PayloadSigner()
+    payload_signer.signer_args.append('bad-option')
+    self.assertRaises(AssertionError, payload.Sign, payload_signer)
+
+  def test_WriteToZip(self):
+    payload = self._create_payload_full()
+    payload.Sign(PayloadSigner())
+
+    output_file = common.MakeTempFile(suffix='.zip')
+    with zipfile.ZipFile(output_file, 'w') as output_zip:
+      payload.WriteToZip(output_zip)
+
+    with zipfile.ZipFile(output_file) as verify_zip:
+      # First make sure we have the essential entries.
+      namelist = verify_zip.namelist()
+      self.assertIn(Payload.PAYLOAD_BIN, namelist)
+      self.assertIn(Payload.PAYLOAD_PROPERTIES_TXT, namelist)
+
+      # Then assert these entries are stored.
+      for entry_info in verify_zip.infolist():
+        if entry_info.filename not in (Payload.PAYLOAD_BIN,
+                                       Payload.PAYLOAD_PROPERTIES_TXT):
+          continue
+        self.assertEqual(zipfile.ZIP_STORED, entry_info.compress_type)
+
+  def test_WriteToZip_unsignedPayload(self):
+    """Unsigned payloads should not be allowed to be written to zip."""
+    payload = self._create_payload_full()
+
+    output_file = common.MakeTempFile(suffix='.zip')
+    with zipfile.ZipFile(output_file, 'w') as output_zip:
+      self.assertRaises(AssertionError, payload.WriteToZip, output_zip)
+
+    # Also test with incremental payload.
+    payload = self._create_payload_incremental()
+
+    output_file = common.MakeTempFile(suffix='.zip')
+    with zipfile.ZipFile(output_file, 'w') as output_zip:
+      self.assertRaises(AssertionError, payload.WriteToZip, output_zip)
+
+  def test_WriteToZip_secondary(self):
+    payload = self._create_payload_full(secondary=True)
+    payload.Sign(PayloadSigner())
+
+    output_file = common.MakeTempFile(suffix='.zip')
+    with zipfile.ZipFile(output_file, 'w') as output_zip:
+      payload.WriteToZip(output_zip, secondary=True)
+
+    with zipfile.ZipFile(output_file) as verify_zip:
+      # First make sure we have the essential entries.
+      namelist = verify_zip.namelist()
+      self.assertIn(Payload.SECONDARY_PAYLOAD_BIN, namelist)
+      self.assertIn(Payload.SECONDARY_PAYLOAD_PROPERTIES_TXT, namelist)
+
+      # Then assert these entries are stored.
+      for entry_info in verify_zip.infolist():
+        if entry_info.filename not in (
+            Payload.SECONDARY_PAYLOAD_BIN,
+            Payload.SECONDARY_PAYLOAD_PROPERTIES_TXT):
+          continue
+        self.assertEqual(zipfile.ZIP_STORED, entry_info.compress_type)
diff --git a/tools/releasetools/test_utils.py b/tools/releasetools/test_utils.py
new file mode 100644
index 0000000..ec53731
--- /dev/null
+++ b/tools/releasetools/test_utils.py
@@ -0,0 +1,28 @@
+#
+# Copyright (C) 2018 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.
+#
+
+"""
+Utils for running unittests.
+"""
+
+import os.path
+
+
+def get_testdata_dir():
+  """Returns the testdata dir, in relative to the script dir."""
+  # The script dir is the one we want, which could be different from pwd.
+  current_dir = os.path.dirname(os.path.realpath(__file__))
+  return os.path.join(current_dir, 'testdata')
diff --git a/tools/releasetools/testdata/testkey.pubkey.pem b/tools/releasetools/testdata/testkey.pubkey.pem
new file mode 100644
index 0000000..418ae60
--- /dev/null
+++ b/tools/releasetools/testdata/testkey.pubkey.pem
@@ -0,0 +1,9 @@
+-----BEGIN PUBLIC KEY-----
+MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAvjvyO2LwWgmQNyq7z+xK
+04eg0t3AL4y2NhpAAOzVnFyCArFcFjLTGQDDvkbZP6N12O6+dwJoPLntnm9A+VnP
+IFFRHg0HUWSbHM+Qk8Jgv2/2AVkAUj5J1r9t4X+2WI0eRzJP15Zjn68pQKGmcyci
+ry0gbvmYvXL2ZUmTm56DmEfCUCRIY2IGJ/CcMnFeItVU0LxKsV5Mlt5BO0Vv/CV4
+EaiOLwyCnoZuUhYto7dHlO/47v/H9zhkJC54OA1dkD38EPgO5GnfhGFSNXQRmJDT
+XrFgd6O+QO4yUNX8lYP10MzimUpItZa05t68NADqwYl3T7nWzvuC9r4IqZDyPf21
+TQIDAQAB
+-----END PUBLIC KEY-----
diff --git a/tools/releasetools/validate_target_files.py b/tools/releasetools/validate_target_files.py
index b590392..1b3eb73 100755
--- a/tools/releasetools/validate_target_files.py
+++ b/tools/releasetools/validate_target_files.py
@@ -29,35 +29,17 @@
 import sys
 
 import common
-import sparse_img
-
-
-def _GetImage(which, tmpdir):
-  assert which in ('system', 'vendor')
-
-  path = os.path.join(tmpdir, 'IMAGES', which + '.img')
-  mappath = os.path.join(tmpdir, 'IMAGES', which + '.map')
-
-  # Map file must exist (allowed to be empty).
-  assert os.path.exists(path) and os.path.exists(mappath)
-
-  clobbered_blocks = '0'
-  return sparse_img.SparseImage(path, mappath, clobbered_blocks)
 
 
 def _ReadFile(file_name, unpacked_name, round_up=False):
   """Constructs and returns a File object. Rounds up its size if needed."""
 
-  def RoundUpTo4K(value):
-    rounded_up = value + 4095
-    return rounded_up - (rounded_up % 4096)
-
   assert os.path.exists(unpacked_name)
   with open(unpacked_name, 'r') as f:
     file_data = f.read()
   file_size = len(file_data)
   if round_up:
-    file_size_rounded_up = RoundUpTo4K(file_size)
+    file_size_rounded_up = common.RoundUpTo4K(file_size)
     file_data += '\0' * (file_size_rounded_up - file_size)
   return common.File(file_name, file_data)
 
@@ -79,33 +61,28 @@
 
   def CheckAllFiles(which):
     logging.info('Checking %s image.', which)
-    image = _GetImage(which, input_tmp)
+    image = common.GetSparseImage(which, input_tmp, input_zip)
     prefix = '/' + which
     for entry in image.file_map:
+      # Skip entries like '__NONZERO-0'.
       if not entry.startswith(prefix):
         continue
 
       # Read the blocks that the file resides. Note that it will contain the
       # bytes past the file length, which is expected to be padded with '\0's.
       ranges = image.file_map[entry]
+
+      incomplete = ranges.extra.get('incomplete', False)
+      if incomplete:
+        logging.warning('Skipping %s that has incomplete block list', entry)
+        continue
+
       blocks_sha1 = image.RangeSha1(ranges)
 
       # The filename under unpacked directory, such as SYSTEM/bin/sh.
       unpacked_name = os.path.join(
           input_tmp, which.upper(), entry[(len(prefix) + 1):])
       unpacked_file = _ReadFile(entry, unpacked_name, True)
-      file_size = unpacked_file.size
-
-      # block.map may contain less blocks, because mke2fs may skip allocating
-      # blocks if they contain all zeros. We can't reconstruct such a file from
-      # its block list. (Bug: 65213616)
-      if file_size > ranges.size() * 4096:
-        logging.warning(
-            'Skipping %s that has less blocks: file size %d-byte,'
-            ' ranges %s (%d-byte)', entry, file_size, ranges,
-            ranges.size() * 4096)
-        continue
-
       file_sha1 = unpacked_file.sha1
       assert blocks_sha1 == file_sha1, \
           'file: %s, range: %s, blocks_sha1: %s, file_sha1: %s' % (