diff --git a/core/main.mk b/core/main.mk
index 16e70eb..2ef17a2 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -898,6 +898,9 @@
   # by the appropriate product definition file, which was included
   # by product_config.mk.
   product_MODULES := $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_PACKAGES)
+ifdef BOARD_VNDK_VERSION
+  product_MODULES += vndk_package
+endif
   # Filter out the overridden packages before doing expansion
   product_MODULES := $(filter-out $(foreach p, $(product_MODULES), \
       $(PACKAGES.$(p).OVERRIDES)), $(product_MODULES))
diff --git a/target/board/generic/BoardConfig.mk b/target/board/generic/BoardConfig.mk
index 9bf3c8b..ee1bde5 100644
--- a/target/board/generic/BoardConfig.mk
+++ b/target/board/generic/BoardConfig.mk
@@ -27,18 +27,11 @@
 BOARD_USES_GENERIC_AUDIO := true
 TARGET_BOOTLOADER_BOARD_NAME := goldfish_$(TARGET_ARCH)
 
+TARGET_USES_64_BIT_BINDER := true
+
 # no hardware camera
 USE_CAMERA_STUB := true
 
-# Enable dex-preoptimization to speed up the first boot sequence
-# of an SDK AVD. Note that this operation only works on Linux for now
-ifeq ($(HOST_OS),linux)
-  ifeq ($(WITH_DEXPREOPT),)
-    WITH_DEXPREOPT := true
-    WITH_DEXPREOPT_BOOT_IMG_AND_SYSTEM_SERVER_ONLY := false
-  endif
-endif
-
 TARGET_USES_HWC2 := true
 NUM_FRAMEBUFFER_SURFACE_BUFFERS := 3
 
@@ -51,7 +44,8 @@
 USE_OPENGL_RENDERER := true
 
 TARGET_USERIMAGES_USE_EXT4 := true
-BOARD_SYSTEMIMAGE_PARTITION_SIZE := 2147483648  # 2 GB
+# Partition size is default 1.5GB (1536MB) for 64 bits projects
+BOARD_SYSTEMIMAGE_PARTITION_SIZE := 1610612736
 BOARD_USERDATAIMAGE_PARTITION_SIZE := 576716800
 TARGET_COPY_OUT_VENDOR := vendor
 # ~100 MB vendor image. Please adjust system image / vendor image sizes
@@ -65,6 +59,13 @@
 BOARD_SEPOLICY_DIRS += build/target/board/generic/sepolicy
 BOARD_PROPERTY_OVERRIDES_SPLIT_ENABLED := true
 
+ifneq (,$(filter userdebug eng,$(TARGET_BUILD_VARIANT)))
+# GSI is always userdebug and needs a couple of properties taking precedence
+# over those set by the vendor.
+TARGET_SYSTEM_PROP := build/make/target/board/treble_system.prop
+endif
+BOARD_VNDK_VERSION := current
+
 # Enable A/B update
 TARGET_NO_RECOVERY := true
 BOARD_BUILD_SYSTEM_ROOT_IMAGE := true
diff --git a/target/board/generic/device.mk b/target/board/generic/device.mk
index e18c165..d2f6310 100644
--- a/target/board/generic/device.mk
+++ b/target/board/generic/device.mk
@@ -23,9 +23,26 @@
 
 PRODUCT_COPY_FILES := \
     device/generic/goldfish/data/etc/apns-conf.xml:system/etc/apns-conf.xml \
-    device/generic/goldfish/camera/media_profiles.xml:system/etc/media_profiles.xml \
-    frameworks/av/media/libstagefright/data/media_codecs_google_audio.xml:system/etc/media_codecs_google_audio.xml \
-    frameworks/av/media/libstagefright/data/media_codecs_google_telephony.xml:system/etc/media_codecs_google_telephony.xml \
-    frameworks/av/media/libstagefright/data/media_codecs_google_video.xml:system/etc/media_codecs_google_video.xml \
-    device/generic/goldfish/camera/media_codecs.xml:system/etc/media_codecs.xml \
+    device/generic/goldfish/camera/media_profiles.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_profiles.xml \
+    frameworks/av/media/libstagefright/data/media_codecs_google_audio.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_codecs_google_audio.xml \
+    frameworks/av/media/libstagefright/data/media_codecs_google_telephony.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_codecs_google_telephony.xml \
+    frameworks/av/media/libstagefright/data/media_codecs_google_video.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_codecs_google_video.xml \
+    device/generic/goldfish/camera/media_codecs.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_codecs.xml \
     hardware/libhardware_legacy/audio/audio_policy.conf:system/etc/audio_policy.conf
+
+# minimal configuration for audio policy.
+PRODUCT_COPY_FILES += \
+    frameworks/av/services/audiopolicy/config/audio_policy_configuration_generic.xml:system/etc/audio_policy_configuration.xml \
+    frameworks/av/services/audiopolicy/config/primary_audio_policy_configuration.xml:system/etc/primary_audio_policy_configuration.xml \
+    frameworks/av/services/audiopolicy/config/r_submix_audio_policy_configuration.xml:system/etc/r_submix_audio_policy_configuration.xml \
+    frameworks/av/services/audiopolicy/config/audio_policy_volumes.xml:system/etc/audio_policy_volumes.xml \
+    frameworks/av/services/audiopolicy/config/default_volume_tables.xml:system/etc/default_volume_tables.xml \
+
+# NFC:
+#   Provide default libnfc-nci.conf file for devices that does not have one in
+#   vendor/etc because aosp system image (of aosp_$arch products) is going to
+#   be used as GSI.
+#   May need to remove the following for newly launched devices in P since this
+#   NFC configuration file should be in vendor/etc, instead of system/etc
+PRODUCT_COPY_FILES += \
+    device/generic/common/nfc/libnfc-nci.conf:system/etc/libnfc-nci.conf
diff --git a/target/board/generic_arm64/BoardConfig.mk b/target/board/generic_arm64/BoardConfig.mk
index dbdec90..ee4103d 100644
--- a/target/board/generic_arm64/BoardConfig.mk
+++ b/target/board/generic_arm64/BoardConfig.mk
@@ -61,15 +61,6 @@
 # no hardware camera
 USE_CAMERA_STUB := true
 
-# Enable dex-preoptimization to speed up the first boot sequence
-# of an SDK AVD. Note that this operation only works on Linux for now
-ifeq ($(HOST_OS),linux)
-  ifeq ($(WITH_DEXPREOPT),)
-    WITH_DEXPREOPT := true
-    WITH_DEXPREOPT_BOOT_IMG_AND_SYSTEM_SERVER_ONLY := false
-  endif
-endif
-
 TARGET_USES_HWC2 := true
 NUM_FRAMEBUFFER_SURFACE_BUFFERS := 3
 
@@ -82,7 +73,8 @@
 USE_OPENGL_RENDERER := true
 
 TARGET_USERIMAGES_USE_EXT4 := true
-BOARD_SYSTEMIMAGE_PARTITION_SIZE := 2684354560  # 2.5 GB
+# Partition size is default 1.5GB (1536MB) for 64 bits projects
+BOARD_SYSTEMIMAGE_PARTITION_SIZE := 1610612736
 BOARD_USERDATAIMAGE_PARTITION_SIZE := 576716800
 TARGET_COPY_OUT_VENDOR := vendor
 # ~100 MB vendor image. Please adjust system image / vendor image sizes
@@ -96,6 +88,24 @@
 BOARD_PROPERTY_OVERRIDES_SPLIT_ENABLED := true
 BOARD_SEPOLICY_DIRS += build/target/board/generic/sepolicy
 
+ifneq (,$(filter userdebug eng,$(TARGET_BUILD_VARIANT)))
+# GSI is always userdebug and needs a couple of properties taking precedence
+# over those set by the vendor.
+TARGET_SYSTEM_PROP := build/make/target/board/treble_system.prop
+endif
+BOARD_VNDK_VERSION := current
+
+# Emulator system image is going to be used as GSI and some vendor still hasn't
+# cleaned up all device specific directories under root!
+
+# TODO(jiyong) These might be SoC specific.
+BOARD_ROOT_EXTRA_FOLDERS += firmware firmware/radio persist
+BOARD_ROOT_EXTRA_SYMLINKS := /vendor/lib/dsp:/dsp
+
+# TODO(b/36764215): remove this setting when the generic system image
+# no longer has QCOM-specific directories under /.
+BOARD_SEPOLICY_DIRS += build/target/board/generic_arm64_ab/sepolicy
+
 # Enable A/B update
 TARGET_NO_RECOVERY := true
 BOARD_BUILD_SYSTEM_ROOT_IMAGE := true
diff --git a/target/board/generic_arm64/device.mk b/target/board/generic_arm64/device.mk
index ca287eb..8d62f4b 100644
--- a/target/board/generic_arm64/device.mk
+++ b/target/board/generic_arm64/device.mk
@@ -23,11 +23,28 @@
 
 PRODUCT_COPY_FILES := \
     device/generic/goldfish/data/etc/apns-conf.xml:system/etc/apns-conf.xml \
-    device/generic/goldfish/camera/media_profiles.xml:system/etc/media_profiles.xml \
-    frameworks/av/media/libstagefright/data/media_codecs_google_audio.xml:system/etc/media_codecs_google_audio.xml \
-    frameworks/av/media/libstagefright/data/media_codecs_google_telephony.xml:system/etc/media_codecs_google_telephony.xml \
-    frameworks/av/media/libstagefright/data/media_codecs_google_video.xml:system/etc/media_codecs_google_video.xml \
-    device/generic/goldfish/camera/media_codecs.xml:system/etc/media_codecs.xml
+    device/generic/goldfish/camera/media_profiles.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_profiles.xml \
+    frameworks/av/media/libstagefright/data/media_codecs_google_audio.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_codecs_google_audio.xml \
+    frameworks/av/media/libstagefright/data/media_codecs_google_telephony.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_codecs_google_telephony.xml \
+    frameworks/av/media/libstagefright/data/media_codecs_google_video.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_codecs_google_video.xml \
+    device/generic/goldfish/camera/media_codecs.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_codecs.xml
+
+# minimal configuration for audio policy.
+PRODUCT_COPY_FILES += \
+    frameworks/av/services/audiopolicy/config/audio_policy_configuration_generic.xml:system/etc/audio_policy_configuration.xml \
+    frameworks/av/services/audiopolicy/config/primary_audio_policy_configuration.xml:system/etc/primary_audio_policy_configuration.xml \
+    frameworks/av/services/audiopolicy/config/r_submix_audio_policy_configuration.xml:system/etc/r_submix_audio_policy_configuration.xml \
+    frameworks/av/services/audiopolicy/config/audio_policy_volumes.xml:system/etc/audio_policy_volumes.xml \
+    frameworks/av/services/audiopolicy/config/default_volume_tables.xml:system/etc/default_volume_tables.xml \
+
+# NFC:
+#   Provide default libnfc-nci.conf file for devices that does not have one in
+#   vendor/etc because aosp system image (of aosp_$arch products) is going to
+#   be used as GSI.
+#   May need to remove the following for newly launched devices in P since this
+#   NFC configuration file should be in vendor/etc, instead of system/etc
+PRODUCT_COPY_FILES += \
+    device/generic/common/nfc/libnfc-nci.conf:system/etc/libnfc-nci.conf
 
 # Adjust the Dalvik heap to be appropriate for a tablet.
 $(call inherit-product-if-exists, frameworks/base/build/tablet-dalvik-heap.mk)
diff --git a/target/board/generic_x86/device.mk b/target/board/generic_x86/device.mk
index 24c39a5..7b6fa3c 100644
--- a/target/board/generic_x86/device.mk
+++ b/target/board/generic_x86/device.mk
@@ -29,6 +29,23 @@
     frameworks/av/media/libstagefright/data/media_codecs_google_video.xml:system/etc/media_codecs_google_video.xml \
     device/generic/goldfish/camera/media_codecs.xml:system/etc/media_codecs.xml
 
+# minimal configuration for audio policy.
+PRODUCT_COPY_FILES += \
+    frameworks/av/services/audiopolicy/config/audio_policy_configuration_generic.xml:system/etc/audio_policy_configuration.xml \
+    frameworks/av/services/audiopolicy/config/primary_audio_policy_configuration.xml:system/etc/primary_audio_policy_configuration.xml \
+    frameworks/av/services/audiopolicy/config/r_submix_audio_policy_configuration.xml:system/etc/r_submix_audio_policy_configuration.xml \
+    frameworks/av/services/audiopolicy/config/audio_policy_volumes.xml:system/etc/audio_policy_volumes.xml \
+    frameworks/av/services/audiopolicy/config/default_volume_tables.xml:system/etc/default_volume_tables.xml \
+
+# NFC:
+#   Provide default libnfc-nci.conf file for devices that does not have one in
+#   vendor/etc because aosp system image (of aosp_$arch products) is going to
+#   be used as GSI.
+#   May need to remove the following for newly launched devices in P since this
+#   NFC configuration file should be in vendor/etc, instead of system/etc
+PRODUCT_COPY_FILES += \
+    device/generic/common/nfc/libnfc-nci.conf:system/etc/libnfc-nci.conf
+
 PRODUCT_PACKAGES := \
     audio.primary.goldfish \
     vibrator.goldfish
diff --git a/target/board/generic_x86_64/device.mk b/target/board/generic_x86_64/device.mk
index 24c39a5..7b6fa3c 100755
--- a/target/board/generic_x86_64/device.mk
+++ b/target/board/generic_x86_64/device.mk
@@ -29,6 +29,23 @@
     frameworks/av/media/libstagefright/data/media_codecs_google_video.xml:system/etc/media_codecs_google_video.xml \
     device/generic/goldfish/camera/media_codecs.xml:system/etc/media_codecs.xml
 
+# minimal configuration for audio policy.
+PRODUCT_COPY_FILES += \
+    frameworks/av/services/audiopolicy/config/audio_policy_configuration_generic.xml:system/etc/audio_policy_configuration.xml \
+    frameworks/av/services/audiopolicy/config/primary_audio_policy_configuration.xml:system/etc/primary_audio_policy_configuration.xml \
+    frameworks/av/services/audiopolicy/config/r_submix_audio_policy_configuration.xml:system/etc/r_submix_audio_policy_configuration.xml \
+    frameworks/av/services/audiopolicy/config/audio_policy_volumes.xml:system/etc/audio_policy_volumes.xml \
+    frameworks/av/services/audiopolicy/config/default_volume_tables.xml:system/etc/default_volume_tables.xml \
+
+# NFC:
+#   Provide default libnfc-nci.conf file for devices that does not have one in
+#   vendor/etc because aosp system image (of aosp_$arch products) is going to
+#   be used as GSI.
+#   May need to remove the following for newly launched devices in P since this
+#   NFC configuration file should be in vendor/etc, instead of system/etc
+PRODUCT_COPY_FILES += \
+    device/generic/common/nfc/libnfc-nci.conf:system/etc/libnfc-nci.conf
+
 PRODUCT_PACKAGES := \
     audio.primary.goldfish \
     vibrator.goldfish
diff --git a/target/product/aosp_arm.mk b/target/product/aosp_arm.mk
index 820e392..c66f954 100644
--- a/target/product/aosp_arm.mk
+++ b/target/product/aosp_arm.mk
@@ -22,7 +22,7 @@
 # see copy file rules in core/Makefile
 PRODUCT_COPY_FILES += \
     development/sys-img/advancedFeatures.ini.arm:advancedFeatures.ini \
-    prebuilts/qemu-kernel/arm/3.18/kernel-qemu2:kernel-ranchu \
+    prebuilts/qemu-kernel/arm64/3.18/kernel-qemu2:kernel-ranchu-64 \
     device/generic/goldfish/fstab.ranchu.arm:$(TARGET_COPY_OUT_VENDOR)/etc/fstab.ranchu
 
 include $(SRC_TARGET_DIR)/product/full.mk
diff --git a/target/product/aosp_arm64.mk b/target/product/aosp_arm64.mk
index 1231609..e7378d5 100644
--- a/target/product/aosp_arm64.mk
+++ b/target/product/aosp_arm64.mk
@@ -30,6 +30,14 @@
     prebuilts/qemu-kernel/arm64/3.18/kernel-qemu2:kernel-ranchu \
     device/generic/goldfish/fstab.ranchu.arm:$(TARGET_COPY_OUT_VENDOR)/etc/fstab.ranchu
 
+# Copy different zygote settings for vendor.img to select by setting property
+# ro.zygote=zygote64_32 or ro.zygote=zygote32_64:
+#   1. 64-bit primary, 32-bit secondary OR
+#   2. 32-bit primary, 64-bit secondary
+# init.zygote64_32.rc is in the core_64_bit.mk below
+PRODUCT_COPY_FILES += \
+    system/core/rootdir/init.zygote32_64.rc:root/init.zygote32_64.rc
+
 $(call inherit-product, $(SRC_TARGET_DIR)/product/core_64_bit.mk)
 $(call inherit-product, $(SRC_TARGET_DIR)/product/aosp_base_telephony.mk)
 $(call inherit-product, $(SRC_TARGET_DIR)/board/generic_arm64/device.mk)
diff --git a/target/product/aosp_x86_64.mk b/target/product/aosp_x86_64.mk
index 086a76f..b1ed44e 100644
--- a/target/product/aosp_x86_64.mk
+++ b/target/product/aosp_x86_64.mk
@@ -27,6 +27,14 @@
     device/generic/goldfish/data/etc/encryptionkey.img:encryptionkey.img \
     prebuilts/qemu-kernel/x86_64/4.4/kernel-qemu2:kernel-ranchu
 
+# Copy different zygote settings for vendor.img to select by setting property
+# ro.zygote=zygote64_32 or ro.zygote=zygote32_64:
+#   1. 64-bit primary, 32-bit secondary OR
+#   2. 32-bit primary, 64-bit secondary
+# init.zygote64_32.rc is in the core_64_bit.mk below
+PRODUCT_COPY_FILES += \
+    system/core/rootdir/init.zygote32_64.rc:root/init.zygote32_64.rc
+
 $(call inherit-product, $(SRC_TARGET_DIR)/product/core_64_bit.mk)
 $(call inherit-product, $(SRC_TARGET_DIR)/product/aosp_base_telephony.mk)
 $(call inherit-product, $(SRC_TARGET_DIR)/board/generic_x86_64/device.mk)
diff --git a/target/product/full_base.mk b/target/product/full_base.mk
index 7aac435..777d6c7 100644
--- a/target/product/full_base.mk
+++ b/target/product/full_base.mk
@@ -37,6 +37,20 @@
     PhaseBeam \
     PhotoTable
 
+# Bluetooth:
+#   audio.a2dp.default is a system module. Generic system image includes
+#   audio.a2dp.default to support A2DP if board has the capability.
+PRODUCT_PACKAGES += \
+    audio.a2dp.default
+
+# Net:
+#   Vendors can use the platform-provided network configuration utilities (ip,
+#   iptable, etc.) to configure the Linux networking stack, but these utilities
+#   do not yet include a HIDL interface wrapper. This is a solution on
+#   Android O.
+PRODUCT_PACKAGES += \
+    netutils-wrapper-1.0
+
 # Additional settings used in all AOSP builds
 PRODUCT_PROPERTY_OVERRIDES := \
     ro.config.ringtone=Ring_Synth_04.ogg \
diff --git a/target/product/sdk_phone_armv7.mk b/target/product/sdk_phone_armv7.mk
index 09e5c75..73c42c3 100644
--- a/target/product/sdk_phone_armv7.mk
+++ b/target/product/sdk_phone_armv7.mk
@@ -22,7 +22,7 @@
 # see copy file rules in core/Makefile
 PRODUCT_COPY_FILES += \
     development/sys-img/advancedFeatures.ini.arm:advancedFeatures.ini \
-    prebuilts/qemu-kernel/arm/3.18/kernel-qemu2:kernel-ranchu \
+    prebuilts/qemu-kernel/arm64/3.18/kernel-qemu2:kernel-ranchu-64 \
     device/generic/goldfish/fstab.ranchu.arm:$(TARGET_COPY_OUT_VENDOR)/etc/fstab.ranchu
 
 $(call inherit-product, $(SRC_TARGET_DIR)/product/sdk_base.mk)
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index fd8a130..14d0ca4 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -966,17 +966,18 @@
 
 
 COMMON_DOCSTRING = """
-  -p  (--path)  <dir>
-      Prepend <dir>/bin to the list of places to search for binaries
-      run by this script, and expect to find jars in <dir>/framework.
+Global options
+
+  -p  (--path) <dir>
+      Prepend <dir>/bin to the list of places to search for binaries run by this
+      script, and expect to find jars in <dir>/framework.
 
   -s  (--device_specific) <file>
-      Path to the python module containing device-specific
-      releasetools code.
+      Path to the Python module containing device-specific releasetools code.
 
-  -x  (--extra)  <key=value>
-      Add a key/value pair to the 'extras' dict, which device-specific
-      extension code may look at.
+  -x  (--extra) <key=value>
+      Add a key/value pair to the 'extras' dict, which device-specific extension
+      code may look at.
 
   -v  (--verbose)
       Show command lines being executed.
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index fba9119..b6c26bf 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -15,39 +15,80 @@
 # limitations under the License.
 
 """
-Given a target-files zipfile, produces an OTA package that installs
-that build.  An incremental OTA is produced if -i is given, otherwise
-a full OTA is produced.
+Given a target-files zipfile, produces an OTA package that installs that build.
+An incremental OTA is produced if -i is given, otherwise a full OTA is produced.
 
-Usage:  ota_from_target_files [flags] input_target_files output_ota_package
+Usage:  ota_from_target_files [options] input_target_files output_ota_package
 
-  -k (--package_key) <key> Key to use to sign the package (default is
-      the value of default_system_dev_certificate from the input
-      target-files's META/misc_info.txt, or
-      "build/target/product/security/testkey" if that value is not
-      specified).
+Common options that apply to both of non-A/B and A/B OTAs
+
+  --downgrade
+      Intentionally generate an incremental OTA that updates from a newer build
+      to an older one (based on timestamp comparison). "post-timestamp" will be
+      replaced by "ota-downgrade=yes" in the metadata file. A data wipe will
+      always be enforced, so "ota-wipe=yes" will also be included in the
+      metadata file. The update-binary in the source build will be used in the
+      OTA package, unless --binary flag is specified. Please also check the doc
+      for --override_timestamp below.
+
+  -i  (--incremental_from) <file>
+      Generate an incremental OTA using the given target-files zip as the
+      starting build.
+
+  -k  (--package_key) <key>
+      Key to use to sign the package (default is the value of
+      default_system_dev_certificate from the input target-files's
+      META/misc_info.txt, or "build/target/product/security/testkey" if that
+      value is not specified).
 
       For incremental OTAs, the default value is based on the source
       target-file, not the target build.
 
-  -i  (--incremental_from)  <file>
-      Generate an incremental OTA using the given target-files zip as
-      the starting build.
+  --override_timestamp
+      Intentionally generate an incremental OTA that updates from a newer build
+      to an older one (based on timestamp comparison), by overriding the
+      timestamp in package metadata. This differs from --downgrade flag: we know
+      for sure this is NOT an actual downgrade case, but two builds are cut in a
+      reverse order. A legit use case is that we cut a new build C (after having
+      A and B), but want to enfore an update path of A -> C -> B.  Specifying
+      --downgrade may not help since that would enforce a data wipe for C -> B
+      update. The value of "post-timestamp" will be set to the newer timestamp
+      plus one, so that the package can be pushed and applied.
 
-  --full_radio
-      When generating an incremental OTA, always include a full copy of
-      radio image. This option is only meaningful when -i is specified,
-      because a full radio is always included in a full OTA if applicable.
+  --wipe_user_data
+      Generate an OTA package that will wipe the user data partition when
+      installed.
+
+Non-A/B OTA specific options
+
+  -b  (--binary) <file>
+      Use the given binary as the update-binary in the output package, instead
+      of the binary in the build's target_files. Use for development only.
+
+  --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
+      default for all non-A/B devices. Keeping this flag here to not break
+      existing callers.
+
+  -e  (--extra_script) <file>
+      Insert the contents of file at the end of the update script.
 
   --full_bootloader
       Similar to --full_radio. When generating an incremental OTA, always
       include a full copy of bootloader image.
 
-  --verify
-      Remount and verify the checksums of the files written to the system and
-      vendor (if used) partitions. Non-A/B incremental OTAs only.
+  --full_radio
+      When generating an incremental OTA, always include a full copy of radio
+      image. This option is only meaningful when -i is specified, because a full
+      radio is always included in a full OTA if applicable.
 
-  -o  (--oem_settings)  <main_file[,additional_files...]>
+  --log_diff <file>
+      Generate a log file that shows the differences in the source and target
+      builds for an incremental package. This option is only meaningful when -i
+      is specified.
+
+  -o  (--oem_settings) <main_file[,additional_files...]>
       Comma seperated list of files used to specify the expected OEM-specific
       properties on the OEM partition of the intended device. Multiple expected
       values can be used by providing multiple files. Only the first dict will
@@ -55,42 +96,29 @@
       OEM-specific properties.
 
   --oem_no_mount
-      For devices with OEM-specific properties but without an OEM partition,
-      do not mount the OEM partition in the updater-script. This should be
-      very rarely used, since it's expected to have a dedicated OEM partition
-      for OEM-specific properties. Only meaningful when -o is specified.
+      For devices with OEM-specific properties but without an OEM partition, do
+      not mount the OEM partition in the updater-script. This should be very
+      rarely used, since it's expected to have a dedicated OEM partition for
+      OEM-specific properties. Only meaningful when -o is specified.
 
-  --wipe_user_data
-      Generate an OTA package that will wipe the user data partition
-      when installed.
+  --stash_threshold <float>
+      Specify the threshold that will be used to compute the maximum allowed
+      stash size (defaults to 0.8).
 
-  --downgrade
-      Intentionally generate an incremental OTA that updates from a newer
-      build to an older one (based on timestamp comparison). "post-timestamp"
-      will be replaced by "ota-downgrade=yes" in the metadata file. A data
-      wipe will always be enforced, so "ota-wipe=yes" will also be included in
-      the metadata file. The update-binary in the source build will be used in
-      the OTA package, unless --binary flag is specified. Please also check the
-      doc for --override_timestamp below.
+  -t  (--worker_threads) <int>
+      Specify the number of worker-threads that will be used when generating
+      patches for incremental updates (defaults to 3).
 
-  --override_timestamp
-      Intentionally generate an incremental OTA that updates from a newer
-      build to an older one (based on timestamp comparison), by overriding the
-      timestamp in package metadata. This differs from --downgrade flag: we
-      know for sure this is NOT an actual downgrade case, but two builds are
-      cut in a reverse order. A legit use case is that we cut a new build C
-      (after having A and B), but want to enfore an update path of A -> C -> B.
-      Specifying --downgrade may not help since that would enforce a data wipe
-      for C -> B update. The value of "post-timestamp" will be set to the newer
-      timestamp plus one, so that the package can be pushed and applied.
-
-  -e  (--extra_script)  <file>
-      Insert the contents of file at the end of the update script.
+  --verify
+      Verify the checksums of the updated system and vendor (if any) partitions.
+      Non-A/B incremental OTAs only.
 
   -2  (--two_step)
-      Generate a 'two-step' OTA package, where recovery is updated
-      first, so that any changes made to the system partition are done
-      using the new recovery (new kernel, etc.).
+      Generate a 'two-step' OTA package, where recovery is updated first, so
+      that any changes made to the system partition are done using the new
+      recovery (new kernel, etc.).
+
+A/B OTA specific options
 
   --include_secondary
       Additionally include the payload for secondary slot images (default:
@@ -110,30 +138,6 @@
       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
-      default for all non-A/B devices. Keeping this flag here to not break
-      existing callers.
-
-  -b  (--binary)  <file>
-      Use the given binary as the update-binary in the output package,
-      instead of the binary in the build's target_files.  Use for
-      development only.
-
-  -t  (--worker_threads) <int>
-      Specifies the number of worker-threads that will be used when
-      generating patches for incremental updates (defaults to 3).
-
-  --stash_threshold <float>
-      Specifies the threshold that will be used to compute the maximum
-      allowed stash size (defaults to 0.8).
-
-  --log_diff <file>
-      Generate a log file that shows the differences in the source and target
-      builds for an incremental package. This option is only meaningful when
-      -i is specified.
-
   --payload_signer <signer>
       Specify the signer when signing the payload and metadata for A/B OTAs.
       By default (i.e. without this flag), it calls 'openssl pkeyutl' to sign