diff --git a/core/Makefile b/core/Makefile
index f788abd..d85bd76 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -934,6 +934,17 @@
 $(INTERNAL_VENDOR_RAMDISK_TARGET): $(MKBOOTFS) $(INTERNAL_VENDOR_RAMDISK_FILES) | $(COMPRESSION_COMMAND_DEPS)
 	$(MKBOOTFS) -d $(TARGET_OUT) $(TARGET_VENDOR_RAMDISK_OUT) $(PRIVATE_ADDITIONAL_DIR) | $(COMPRESSION_COMMAND) > $@
 
+INSTALLED_FILES_FILE_VENDOR_RAMDISK := $(PRODUCT_OUT)/installed-files-vendor-ramdisk.txt
+INSTALLED_FILES_JSON_VENDOR_RAMDISK := $(INSTALLED_FILES_FILE_VENDOR_RAMDISK:.txt=.json)
+$(INSTALLED_FILES_FILE_VENDOR_RAMDISK): .KATI_IMPLICIT_OUTPUTS := $(INSTALLED_FILES_JSON_VENDOR_RAMDISK)
+$(INSTALLED_FILES_FILE_VENDOR_RAMDISK): $(INTERNAL_VENDOR_RAMDISK_TARGET)
+$(INSTALLED_FILES_FILE_VENDOR_RAMDISK): $(INTERNAL_VENDOR_RAMDISK_FILES) $(FILESLIST) $(FILESLIST_UTIL)
+	echo Installed file list: $@
+	mkdir -p $(dir $@)
+	rm -f $@
+	$(hide) $(FILESLIST) $(TARGET_VENDOR_RAMDISK_OUT) > $(@:.txt=.json)
+	$(hide) $(FILESLIST_UTIL) -c $(@:.txt=.json) > $@
+
 ifdef BOARD_INCLUDE_DTB_IN_BOOTIMG
   INTERNAL_VENDOR_BOOTIMAGE_ARGS += --dtb $(INSTALLED_DTBIMAGE_TARGET)
 endif
diff --git a/core/base_rules.mk b/core/base_rules.mk
index adf61f1..dbd8930 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -274,6 +274,12 @@
   endif
 endif
 
+ifeq ($(LOCAL_IS_UNIT_TEST),true)
+  ifeq ($(LOCAL_IS_HOST_MODULE),true)
+    LOCAL_COMPATIBILITY_SUITE += host-unit-tests
+  endif
+endif
+
 ifeq ($(my_module_path),)
   install_path_var := $(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)OUT$(partition_tag)_$(LOCAL_MODULE_CLASS)
   ifeq (true,$(LOCAL_PRIVILEGED_MODULE))
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index 6e1cb68..6909275 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -130,6 +130,7 @@
 LOCAL_IS_FUZZ_TARGET:=
 LOCAL_IS_HOST_MODULE:=
 LOCAL_IS_RUNTIME_RESOURCE_OVERLAY:=
+LOCAL_IS_UNIT_TEST:=
 LOCAL_JACK_CLASSPATH:=
 LOCAL_JACK_COVERAGE_EXCLUDE_FILTER:=
 LOCAL_JACK_COVERAGE_INCLUDE_FILTER:=
diff --git a/core/definitions.mk b/core/definitions.mk
index daac652..8219f82 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -107,7 +107,7 @@
 # All tests that should be skipped in presubmit check.
 ALL_DISABLED_PRESUBMIT_TESTS :=
 
-# All compatibility suites mentioned in LOCAL_COMPATIBILITY_SUITES
+# All compatibility suites mentioned in LOCAL_COMPATIBILITY_SUITE
 ALL_COMPATIBILITY_SUITES :=
 
 # All compatibility suite files to dist.
@@ -2404,6 +2404,7 @@
 	$(1) \
 	$(HOST_INIT_VERIFIER) \
 	$(call intermediates-dir-for,ETC,passwd_system)/passwd_system \
+	$(call intermediates-dir-for,ETC,passwd_system_ext)/passwd_system_ext \
 	$(call intermediates-dir-for,ETC,passwd_vendor)/passwd_vendor \
 	$(call intermediates-dir-for,ETC,passwd_odm)/passwd_odm \
 	$(call intermediates-dir-for,ETC,passwd_product)/passwd_product \
@@ -2414,6 +2415,7 @@
 	$(call intermediates-dir-for,ETC,odm_property_contexts)/odm_property_contexts
 	$(hide) $(HOST_INIT_VERIFIER) \
 	  -p $(call intermediates-dir-for,ETC,passwd_system)/passwd_system \
+	  -p $(call intermediates-dir-for,ETC,passwd_system_ext)/passwd_system_ext \
 	  -p $(call intermediates-dir-for,ETC,passwd_vendor)/passwd_vendor \
 	  -p $(call intermediates-dir-for,ETC,passwd_odm)/passwd_odm \
 	  -p $(call intermediates-dir-for,ETC,passwd_product)/passwd_product \
diff --git a/core/java_host_unit_test_config_template.xml b/core/java_host_unit_test_config_template.xml
new file mode 100644
index 0000000..ff300da
--- /dev/null
+++ b/core/java_host_unit_test_config_template.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2020 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.
+-->
+<!-- This test config file is auto-generated. -->
+<configuration description="Runs {MODULE}">
+    <option name="test-suite-tag" value="apct" />
+    <option name="test-suite-tag" value="apct-unit-tests" />
+
+    {EXTRA_CONFIGS}
+
+    <test class="com.android.tradefed.testtype.IsolatedHostTest" >
+        <option name="jar" value="{MODULE}.jar" />
+    </test>
+</configuration>
diff --git a/core/main.mk b/core/main.mk
index 9b19761..d8a0443 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -1625,6 +1625,8 @@
     $(INSTALLED_FILES_JSON_RAMDISK) \
     $(INSTALLED_FILES_FILE_DEBUG_RAMDISK) \
     $(INSTALLED_FILES_JSON_DEBUG_RAMDISK) \
+    $(INSTALLED_FILES_FILE_VENDOR_RAMDISK) \
+    $(INSTALLED_FILES_JSON_VENDOR_RAMDISK) \
     $(INSTALLED_FILES_FILE_VENDOR_DEBUG_RAMDISK) \
     $(INSTALLED_FILES_JSON_VENDOR_DEBUG_RAMDISK) \
     $(INSTALLED_FILES_FILE_ROOT) \
@@ -1639,6 +1641,7 @@
 
 ifeq ($(SOONG_COLLECT_JAVA_DEPS), true)
   $(call dist-for-goals, dist_files, $(SOONG_OUT_DIR)/module_bp_java_deps.json)
+  $(call dist-for-goals, dist_files, $(PRODUCT_OUT)/module-info.json)
 endif
 
 .PHONY: apps_only
@@ -1773,6 +1776,8 @@
       $(INSTALLED_FILES_JSON_RAMDISK) \
       $(INSTALLED_FILES_FILE_DEBUG_RAMDISK) \
       $(INSTALLED_FILES_JSON_DEBUG_RAMDISK) \
+      $(INSTALLED_FILES_FILE_VENDOR_RAMDISK) \
+      $(INSTALLED_FILES_JSON_VENDOR_RAMDISK) \
       $(INSTALLED_FILES_FILE_VENDOR_DEBUG_RAMDISK) \
       $(INSTALLED_FILES_JSON_VENDOR_DEBUG_RAMDISK) \
       $(INSTALLED_DEBUG_RAMDISK_TARGET) \
diff --git a/core/product.mk b/core/product.mk
index 666e390..5f06141 100644
--- a/core/product.mk
+++ b/core/product.mk
@@ -120,7 +120,7 @@
 # The resoure configuration options to use for this product.
 _product_list_vars += PRODUCT_LOCALES
 _product_list_vars += PRODUCT_AAPT_CONFIG
-_product_list_vars += PRODUCT_AAPT_PREF_CONFIG
+_product_single_value_vars += PRODUCT_AAPT_PREF_CONFIG
 _product_list_vars += PRODUCT_AAPT_PREBUILT_DPI
 _product_list_vars += PRODUCT_HOST_PACKAGES
 _product_list_vars += PRODUCT_PACKAGES
@@ -209,7 +209,7 @@
 _product_list_vars += PRODUCT_SOONG_NAMESPACES
 
 _product_list_vars += PRODUCT_DEFAULT_WIFI_CHANNELS
-_product_list_vars += PRODUCT_DEFAULT_DEV_CERTIFICATE
+_product_single_value_vars += PRODUCT_DEFAULT_DEV_CERTIFICATE
 _product_list_vars += PRODUCT_MAINLINE_SEPOLICY_DEV_CERTIFICATES
 _product_list_vars += PRODUCT_RESTRICT_VENDOR_FILES
 
@@ -233,7 +233,7 @@
 # List of system_server jars delivered via apex. Format = <apex name>:<jar name>.
 _product_list_vars += PRODUCT_UPDATABLE_SYSTEM_SERVER_JARS
 # If true, then suboptimal order of system server jars does not cause an error.
-_product_list_vars += PRODUCT_BROKEN_SUBOPTIMAL_ORDER_OF_SYSTEM_SERVER_JARS
+_product_single_value_vars += PRODUCT_BROKEN_SUBOPTIMAL_ORDER_OF_SYSTEM_SERVER_JARS
 
 # Additional system server jars to be appended at the end of the common list.
 # This is necessary to avoid jars reordering due to makefile inheritance order.
@@ -258,13 +258,13 @@
 
 # Per-module dex-preopt configs.
 _product_list_vars += PRODUCT_DEX_PREOPT_MODULE_CONFIGS
-_product_list_vars += PRODUCT_DEX_PREOPT_DEFAULT_COMPILER_FILTER
+_product_single_value_vars += PRODUCT_DEX_PREOPT_DEFAULT_COMPILER_FILTER
 _product_list_vars += PRODUCT_DEX_PREOPT_DEFAULT_FLAGS
-_product_list_vars += PRODUCT_DEX_PREOPT_BOOT_FLAGS
-_product_list_vars += PRODUCT_DEX_PREOPT_PROFILE_DIR
-_product_list_vars += PRODUCT_DEX_PREOPT_GENERATE_DM_FILES
-_product_list_vars += PRODUCT_DEX_PREOPT_NEVER_ALLOW_STRIPPING
-_product_list_vars += PRODUCT_DEX_PREOPT_RESOLVE_STARTUP_STRINGS
+_product_single_value_vars += PRODUCT_DEX_PREOPT_BOOT_FLAGS
+_product_single_value_vars += PRODUCT_DEX_PREOPT_PROFILE_DIR
+_product_single_value_vars += PRODUCT_DEX_PREOPT_GENERATE_DM_FILES
+_product_single_value_vars += PRODUCT_DEX_PREOPT_NEVER_ALLOW_STRIPPING
+_product_single_value_vars += PRODUCT_DEX_PREOPT_RESOLVE_STARTUP_STRINGS
 
 # Boot image options.
 _product_single_value_vars += \
@@ -272,7 +272,7 @@
     PRODUCT_DEX_PREOPT_BOOT_IMAGE_PROFILE_LOCATION \
     PRODUCT_USES_DEFAULT_ART_CONFIG \
 
-_product_list_vars += PRODUCT_SYSTEM_SERVER_COMPILER_FILTER
+_product_single_value_vars += PRODUCT_SYSTEM_SERVER_COMPILER_FILTER
 # Per-module sanitizer configs
 _product_list_vars += PRODUCT_SANITIZER_MODULE_CONFIGS
 _product_single_value_vars += PRODUCT_SYSTEM_BASE_FS_PATH
diff --git a/core/soong_config.mk b/core/soong_config.mk
index 809a4d6..06b5555 100644
--- a/core/soong_config.mk
+++ b/core/soong_config.mk
@@ -1,7 +1,3 @@
-SOONG := $(SOONG_OUT_DIR)/soong
-SOONG_BOOTSTRAP := $(SOONG_OUT_DIR)/.soong.bootstrap
-SOONG_BUILD_NINJA := $(SOONG_OUT_DIR)/build.ninja
-SOONG_IN_MAKE := $(SOONG_OUT_DIR)/.soong.in_make
 SOONG_MAKEVARS_MK := $(SOONG_OUT_DIR)/make_vars-$(TARGET_PRODUCT).mk
 SOONG_VARIABLES := $(SOONG_OUT_DIR)/soong.variables
 SOONG_ANDROID_MK := $(SOONG_OUT_DIR)/Android-$(TARGET_PRODUCT).mk
diff --git a/core/tasks/host_init_verifier.mk b/core/tasks/host_init_verifier.mk
new file mode 100644
index 0000000..bdf996c
--- /dev/null
+++ b/core/tasks/host_init_verifier.mk
@@ -0,0 +1,56 @@
+#
+# Copyright (C) 2020 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.
+#
+
+host_init_verifier_output := $(PRODUCT_OUT)/host_init_verifier_output.txt
+
+$(host_init_verifier_output): \
+    $(INSTALLED_SYSTEMIMAGE_TARGET) \
+    $(INSTALLED_SYSTEM_EXTIMAGE_TARGET) \
+    $(INSTALLED_VENDORIMAGE_TARGET) \
+    $(INSTALLED_ODMIMAGE_TARGET) \
+    $(INSTALLED_PRODUCTIMAGE_TARGET) \
+    $(call intermediates-dir-for,ETC,passwd_system)/passwd_system \
+    $(call intermediates-dir-for,ETC,passwd_system_ext)/passwd_system_ext \
+    $(call intermediates-dir-for,ETC,passwd_vendor)/passwd_vendor \
+    $(call intermediates-dir-for,ETC,passwd_odm)/passwd_odm \
+    $(call intermediates-dir-for,ETC,passwd_product)/passwd_product \
+    $(call intermediates-dir-for,ETC,plat_property_contexts)/plat_property_contexts \
+    $(call intermediates-dir-for,ETC,system_ext_property_contexts)/system_ext_property_contexts \
+    $(call intermediates-dir-for,ETC,product_property_contexts)/product_property_contexts \
+    $(call intermediates-dir-for,ETC,vendor_property_contexts)/vendor_property_contexts \
+    $(call intermediates-dir-for,ETC,odm_property_contexts)/odm_property_contexts
+
+# Run host_init_verifier on the partition staging directories.
+$(host_init_verifier_output): $(HOST_INIT_VERIFIER)
+	$(HOST_INIT_VERIFIER) \
+		-p $(call intermediates-dir-for,ETC,passwd_system)/passwd_system \
+		-p $(call intermediates-dir-for,ETC,passwd_system_ext)/passwd_system_ext \
+		-p $(call intermediates-dir-for,ETC,passwd_vendor)/passwd_vendor \
+		-p $(call intermediates-dir-for,ETC,passwd_odm)/passwd_odm \
+		-p $(call intermediates-dir-for,ETC,passwd_product)/passwd_product \
+		--property-contexts=$(call intermediates-dir-for,ETC,plat_property_contexts)/plat_property_contexts \
+		--property-contexts=$(call intermediates-dir-for,ETC,system_ext_property_contexts)/system_ext_property_contexts \
+		--property-contexts=$(call intermediates-dir-for,ETC,product_property_contexts)/product_property_contexts \
+		--property-contexts=$(call intermediates-dir-for,ETC,vendor_property_contexts)/vendor_property_contexts \
+		--property-contexts=$(call intermediates-dir-for,ETC,odm_property_contexts)/odm_property_contexts \
+		--out_system $(PRODUCT_OUT)/$(TARGET_COPY_OUT_SYSTEM) \
+		--out_system_ext $(PRODUCT_OUT)/$(TARGET_COPY_OUT_SYSTEM_EXT) \
+		--out_vendor $(PRODUCT_OUT)/$(TARGET_COPY_OUT_VENDOR) \
+		--out_odm $(PRODUCT_OUT)/$(TARGET_COPY_OUT_ODM) \
+		--out_product $(PRODUCT_OUT)/$(TARGET_COPY_OUT_PRODUCT) \
+		> $@
+
+$(call dist-for-goals,droidcore,$(host_init_verifier_output))
diff --git a/core/tasks/platform_availability_check.mk b/core/tasks/platform_availability_check.mk
index 7ce6b40..1524758 100644
--- a/core/tasks/platform_availability_check.mk
+++ b/core/tasks/platform_availability_check.mk
@@ -17,6 +17,9 @@
 # Check whether there is any module that isn't available for platform
 # is installed to the platform.
 
+# Skip for unbundled builds that don't produce a platform image.
+ifeq (,$(TARGET_BUILD_UNBUNDLED))
+
 # Filter FAKE and NON_INSTALLABLE modules out and then collect those are not
 # available for platform
 _modules_not_available_for_platform := \
@@ -41,7 +44,7 @@
 # Don't error out immediately when ALLOW_MISSING_DEPENDENCIES is set.
 # Instead, add a dependency on a rule that prints the error message.
   define not_available_for_platform_rule
-    not_installable_file := $(patsubst $(OUT_DIR)/%,$(OUT_DIR)/NOT_AVAILABLE_FOR_PLATFORM/%,$(1)))
+    not_installable_file := $(patsubst $(OUT_DIR)/%,$(OUT_DIR)/NOT_AVAILABLE_FOR_PLATFORM/%,$(1))
     $(1): $$(not_installable_file)
     $$(not_installable_file):
 	$(call echo-error,$(2),Module is requested to be installed but is not \
@@ -54,3 +57,5 @@
     $(foreach i,$(filter-out $(HOST_OUT)/%,$(ALL_MODULES.$(m).INSTALLED)),\
       $(eval $(call not_available_for_platform_rule,$(i),$(m)))))
 endif
+
+endif
diff --git a/rbesetup.sh b/rbesetup.sh
index 0182bfd..410ed86 100644
--- a/rbesetup.sh
+++ b/rbesetup.sh
@@ -66,6 +66,7 @@
   unset USE_GOMA
   export USE_RBE="true"
   export RBE_CXX_EXEC_STRATEGY="remote_local_fallback"
+  export RBE_use_unified_cas_ops="true"
   export RBE_JAVAC=1
   export RBE_R8=1
   export RBE_D8=1
diff --git a/target/product/cfi-common.mk b/target/product/cfi-common.mk
index 6d81a87..623a9a8 100644
--- a/target/product/cfi-common.mk
+++ b/target/product/cfi-common.mk
@@ -17,6 +17,7 @@
 # This is a set of common components to enable CFI for (across
 # compatible product configs)
 PRODUCT_CFI_INCLUDE_PATHS :=  \
+    device/generic/goldfish/wifi/wpa_supplicant_8_lib \
     device/google/cuttlefish/guest/libs/wpa_supplicant_8_lib \
     device/google/wahoo/wifi_offload \
     external/tinyxml2 \
diff --git a/target/product/generic_x86.mk b/target/product/generic_x86.mk
index 0274b5b..eeb8216 100644
--- a/target/product/generic_x86.mk
+++ b/target/product/generic_x86.mk
@@ -17,7 +17,7 @@
 # This is a generic phone product that isn't specialized for a specific device.
 # It includes the base Android platform.
 
-include $(SRC_TARGET_DIR)/product/generic.mk
+$(call inherit-product, $(SRC_TARGET_DIR)/product/generic.mk)
 
 # Overrides
 PRODUCT_BRAND := generic_x86
diff --git a/target/product/sdk_phone_x86.mk b/target/product/sdk_phone_x86.mk
index 63671dc..9096ff3 100644
--- a/target/product/sdk_phone_x86.mk
+++ b/target/product/sdk_phone_x86.mk
@@ -50,8 +50,8 @@
 $(call inherit-product, $(SRC_TARGET_DIR)/board/emulator_x86/device.mk)
 
 # Define the host tools and libs that are parts of the SDK.
--include sdk/build/product_sdk.mk
--include development/build/product_sdk.mk
+$(call inherit-product-if-exists, sdk/build/product_sdk.mk)
+$(call inherit-product-if-exists, development/build/product_sdk.mk)
 
 # Overrides
 PRODUCT_BRAND := Android
diff --git a/target/product/sdk_phone_x86_64.mk b/target/product/sdk_phone_x86_64.mk
index c5a6245..161043b 100644
--- a/target/product/sdk_phone_x86_64.mk
+++ b/target/product/sdk_phone_x86_64.mk
@@ -51,8 +51,8 @@
 $(call inherit-product, $(SRC_TARGET_DIR)/board/emulator_x86_64/device.mk)
 
 # Define the host tools and libs that are parts of the SDK.
--include sdk/build/product_sdk.mk
--include development/build/product_sdk.mk
+$(call inherit-product-if-exists, sdk/build/product_sdk.mk)
+$(call inherit-product-if-exists, development/build/product_sdk.mk)
 
 # Overrides
 PRODUCT_BRAND := Android
diff --git a/target/product/virtual_ab_ota.mk b/target/product/virtual_ab_ota.mk
new file mode 120000
index 0000000..16f7329
--- /dev/null
+++ b/target/product/virtual_ab_ota.mk
@@ -0,0 +1 @@
+virtual_ab_ota/launch.mk
\ No newline at end of file
diff --git a/target/product/virtual_ab_ota/README.md b/target/product/virtual_ab_ota/README.md
new file mode 100644
index 0000000..c1d0d7d
--- /dev/null
+++ b/target/product/virtual_ab_ota/README.md
@@ -0,0 +1,14 @@
+# Virtual A/B makefiles
+
+Devices that uses Virtual A/B must inherit from one of the makefiles in this directory.
+
+## Structure
+
+```
+launch.mk
+  |- retrofit.mk
+  |- plus_non_ab.mk
+  |- compression.mk
+
+compression_retrofit.mk
+```
diff --git a/target/product/virtual_ab_ota_retrofit_compression.mk b/target/product/virtual_ab_ota/compression.mk
similarity index 91%
rename from target/product/virtual_ab_ota_retrofit_compression.mk
rename to target/product/virtual_ab_ota/compression.mk
index 8059f75..2251187 100644
--- a/target/product/virtual_ab_ota_retrofit_compression.mk
+++ b/target/product/virtual_ab_ota/compression.mk
@@ -14,9 +14,8 @@
 # limitations under the License.
 #
 
-$(call inherit-product, $(SRC_TARGET_DIR)/product/virtual_ab_ota_retrofit.mk)
+$(call inherit-product, $(SRC_TARGET_DIR)/product/virtual_ab_ota/launch.mk)
 
 PRODUCT_VENDOR_PROPERTIES += ro.virtual_ab.compression.enabled=true
 
-PRODUCT_PACKAGES += snapuserd_ramdisk
-
+PRODUCT_PACKAGES += snapuserd.vendor_ramdisk snapuserd
diff --git a/target/product/virtual_ab_ota_retrofit_compression.mk b/target/product/virtual_ab_ota/compression_retrofit.mk
similarity index 66%
copy from target/product/virtual_ab_ota_retrofit_compression.mk
copy to target/product/virtual_ab_ota/compression_retrofit.mk
index 8059f75..b34e3f1 100644
--- a/target/product/virtual_ab_ota_retrofit_compression.mk
+++ b/target/product/virtual_ab_ota/compression_retrofit.mk
@@ -14,9 +14,11 @@
 # limitations under the License.
 #
 
-$(call inherit-product, $(SRC_TARGET_DIR)/product/virtual_ab_ota_retrofit.mk)
-
 PRODUCT_VENDOR_PROPERTIES += ro.virtual_ab.compression.enabled=true
 
-PRODUCT_PACKAGES += snapuserd_ramdisk
-
+# For devices that are not GKI-capable (eg do not have vendor_boot),
+# snapuserd.ramdisk is included rather than snapuserd.vendor_ramdisk.
+# When using virtual_ab_ota_compression_retrofit.mk, either
+# virtual_ab_ota.mk or virtual_ab_ota_retrofit.mk must be inherited
+# as well.
+PRODUCT_PACKAGES += snapuserd.ramdisk snapuserd
diff --git a/target/product/virtual_ab_ota.mk b/target/product/virtual_ab_ota/launch.mk
similarity index 100%
rename from target/product/virtual_ab_ota.mk
rename to target/product/virtual_ab_ota/launch.mk
diff --git a/target/product/virtual_ab_ota_plus_non_ab.mk b/target/product/virtual_ab_ota/plus_non_ab.mk
similarity index 97%
rename from target/product/virtual_ab_ota_plus_non_ab.mk
rename to target/product/virtual_ab_ota/plus_non_ab.mk
index 99a10ed..820fa1e 100644
--- a/target/product/virtual_ab_ota_plus_non_ab.mk
+++ b/target/product/virtual_ab_ota/plus_non_ab.mk
@@ -14,7 +14,7 @@
 # limitations under the License.
 #
 
-$(call inherit-product, $(SRC_TARGET_DIR)/product/virtual_ab_ota.mk)
+$(call inherit-product, $(SRC_TARGET_DIR)/product/virtual_ab_ota/launch.mk)
 
 PRODUCT_OTA_FORCE_NON_AB_PACKAGE := true
 
diff --git a/target/product/virtual_ab_ota_retrofit.mk b/target/product/virtual_ab_ota/retrofit.mk
similarity index 97%
rename from target/product/virtual_ab_ota_retrofit.mk
rename to target/product/virtual_ab_ota/retrofit.mk
index 3416a4f..93b42b7 100644
--- a/target/product/virtual_ab_ota_retrofit.mk
+++ b/target/product/virtual_ab_ota/retrofit.mk
@@ -14,7 +14,7 @@
 # limitations under the License.
 #
 
-$(call inherit-product, $(SRC_TARGET_DIR)/product/virtual_ab_ota.mk)
+$(call inherit-product, $(SRC_TARGET_DIR)/product/virtual_ab_ota/launch.mk)
 
 PRODUCT_VIRTUAL_AB_OTA_RETROFIT := true
 
diff --git a/target/product/virtual_ab_ota_compression.mk b/target/product/virtual_ab_ota_compression.mk
deleted file mode 100644
index eef3c33..0000000
--- a/target/product/virtual_ab_ota_compression.mk
+++ /dev/null
@@ -1,21 +0,0 @@
-#
-# Copyright (C) 2020 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.
-#
-
-$(call inherit-product, $(SRC_TARGET_DIR)/product/virtual_ab_ota.mk)
-
-PRODUCT_VENDOR_PROPERTIES += ro.virtual_ab.compression.enabled=true
-
-PRODUCT_PACKAGES += snapuserd_ramdisk snapuserd
diff --git a/target/product/virtual_ab_ota_plus_non_ab.mk b/target/product/virtual_ab_ota_plus_non_ab.mk
new file mode 120000
index 0000000..4979957
--- /dev/null
+++ b/target/product/virtual_ab_ota_plus_non_ab.mk
@@ -0,0 +1 @@
+virtual_ab_ota/plus_non_ab.mk
\ No newline at end of file
diff --git a/target/product/virtual_ab_ota_retrofit.mk b/target/product/virtual_ab_ota_retrofit.mk
new file mode 120000
index 0000000..1e16ca8
--- /dev/null
+++ b/target/product/virtual_ab_ota_retrofit.mk
@@ -0,0 +1 @@
+virtual_ab_ota/retrofit.mk
\ No newline at end of file
diff --git a/tools/fs_config/fs_config_generator.py b/tools/fs_config/fs_config_generator.py
index 940a398..098fde6 100755
--- a/tools/fs_config/fs_config_generator.py
+++ b/tools/fs_config/fs_config_generator.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 """Generates config files for Android file system properties.
 
 This script is used for generating configuration files for configuring
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 0683678..149deda 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -217,6 +217,25 @@
 def SetHostToolLocation(tool_name, location):
   OPTIONS.host_tools[tool_name] = location
 
+def FindHostToolPath(tool_name):
+  """Finds the path to the host tool.
+
+  Args:
+    tool_name: name of the tool to find
+  Returns:
+    path to the tool if found under either one of the host_tools map or under
+    the same directory as this binary is located at. If not found, tool_name
+    is returned.
+  """
+  if tool_name in OPTIONS.host_tools:
+    return OPTIONS.host_tools[tool_name]
+
+  my_dir = os.path.dirname(os.path.realpath(sys.argv[0]))
+  tool_path = os.path.join(my_dir, tool_name)
+  if os.path.exists(tool_path):
+    return tool_path
+
+  return tool_name
 
 def Run(args, verbose=None, **kwargs):
   """Creates and returns a subprocess.Popen object.
@@ -240,12 +259,10 @@
   if 'universal_newlines' not in kwargs:
     kwargs['universal_newlines'] = True
 
-  # If explicitly set host tool location before, use that location to avoid
-  # PATH violation. Make a copy of args in case client relies on the content
-  # of args later.
-  if args and args[0] in OPTIONS.host_tools:
+  if args:
+    # Make a copy of args in case client relies on the content of args later.
     args = args[:]
-    args[0] = OPTIONS.host_tools[args[0]]
+    args[0] = FindHostToolPath(args[0])
 
   # Don't log any if caller explicitly says so.
   if verbose:
diff --git a/tools/releasetools/merge_target_files.py b/tools/releasetools/merge_target_files.py
index ba9e740..b1b4a16 100755
--- a/tools/releasetools/merge_target_files.py
+++ b/tools/releasetools/merge_target_files.py
@@ -456,6 +456,12 @@
     # false in the partial builds to prevent duplicate building of super.img.
     merged_dict['build_super_partition'] = 'true'
 
+  # If AVB is enabled then ensure that we build vbmeta.img.
+  # Partial builds with AVB enabled may set PRODUCT_BUILD_VBMETA_IMAGE=false to
+  # skip building an incomplete vbmeta.img.
+  if merged_dict.get('avb_enable') == 'true':
+    merged_dict['avb_building_vbmeta_image'] = 'true'
+
   # Replace <image>_selinux_fc values with framework or vendor file_contexts.bin
   # depending on which dictionary the key came from.
   # Only the file basename is required because all selinux_fc properties are
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index ce36508..6b82d32 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -269,6 +269,7 @@
 OPTIONS.skip_postinstall = False
 OPTIONS.skip_compatibility_check = False
 OPTIONS.disable_fec_computation = False
+OPTIONS.disable_verity_computation = False
 OPTIONS.partial = None
 OPTIONS.custom_images = {}
 
@@ -402,6 +403,8 @@
       cmd.extend(["--source_image", source_file])
       if OPTIONS.disable_fec_computation:
         cmd.extend(["--disable_fec_computation", "true"])
+      if OPTIONS.disable_verity_computation:
+        cmd.extend(["--disable_verity_computation", "true"])
     cmd.extend(additional_args)
     self._Run(cmd)
 
@@ -1038,6 +1041,7 @@
       # TODO(zhangkelvin) Remove this once FEC on VABC is supported
       logger.info("Virtual AB Compression enabled, disabling FEC")
       OPTIONS.disable_fec_computation = True
+      OPTIONS.disable_verity_computation = True
   else:
     assert "ab_partitions" in OPTIONS.info_dict, \
         "META/ab_partitions.txt is required for ab_update."
@@ -1087,7 +1091,7 @@
   additional_args += ["--max_timestamp", max_timestamp]
 
   if SupportsMainlineGkiUpdates(source_file):
-    logger.info("Detected build with mainline GKI, include full boot image.")
+    logger.warn("Detected build with mainline GKI, include full boot image.")
     additional_args.extend(["--full_boot", "true"])
 
   payload.Generate(
@@ -1228,6 +1232,8 @@
       OPTIONS.output_metadata_path = a
     elif o == "--disable_fec_computation":
       OPTIONS.disable_fec_computation = True
+    elif o == "--disable_verity_computation":
+      OPTIONS.disable_verity_computation = True
     elif o == "--force_non_ab":
       OPTIONS.force_non_ab = True
     elif o == "--boot_variable_file":
@@ -1276,6 +1282,7 @@
                                  "skip_compatibility_check",
                                  "output_metadata_path=",
                                  "disable_fec_computation",
+                                 "disable_verity_computation",
                                  "force_non_ab",
                                  "boot_variable_file=",
                                  "partial=",