diff --git a/core/Makefile b/core/Makefile
index 2df67e9..875162a 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -2657,12 +2657,12 @@
 endif
 
 INTERNAL_AVB_PARTITIONS_IN_CHAINED_VBMETA_IMAGES := \
-    $(BOARD_AVB_VBMETA_MAINLINE) \
+    $(BOARD_AVB_VBMETA_SYSTEM) \
     $(BOARD_AVB_VBMETA_VENDOR)
 
 # Not allowing the same partition to appear in multiple groups.
 ifneq ($(words $(sort $(INTERNAL_AVB_PARTITIONS_IN_CHAINED_VBMETA_IMAGES))),$(words $(INTERNAL_AVB_PARTITIONS_IN_CHAINED_VBMETA_IMAGES)))
-  $(error BOARD_AVB_VBMETA_MAINLINE and BOARD_AVB_VBMETA_VENDOR cannot have duplicates)
+  $(error BOARD_AVB_VBMETA_SYSTEM and BOARD_AVB_VBMETA_VENDOR cannot have duplicates)
 endif
 
 BOOT_FOOTER_ARGS := BOARD_AVB_BOOT_ADD_HASH_FOOTER_ARGS
@@ -2675,7 +2675,7 @@
 ODM_FOOTER_ARGS := BOARD_AVB_ODM_ADD_HASHTREE_FOOTER_ARGS
 
 # Helper function that checks and sets required build variables for an AVB chained partition.
-# $(1): the partition to enable AVB chain, e.g., boot or system or vbmeta_mainline.
+# $(1): the partition to enable AVB chain, e.g., boot or system or vbmeta_system.
 define _check-and-set-avb-chain-args
 $(eval part := $(1))
 $(eval PART=$(call to-upper,$(part)))
@@ -2698,7 +2698,7 @@
     --chain_partition $(part):$($(_rollback_index_location)):$(AVB_CHAIN_KEY_DIR)/$(part).avbpubkey)
 
 # Set rollback_index via footer args for non-chained vbmeta image. Chained vbmeta image will pick up
-# the index via a separate flag (e.g. BOARD_AVB_VBMETA_MAINLINE_ROLLBACK_INDEX).
+# the index via a separate flag (e.g. BOARD_AVB_VBMETA_SYSTEM_ROLLBACK_INDEX).
 $(if $(filter $(part),$(part:vbmeta_%=%)),\
     $(eval _footer_args := $(PART)_FOOTER_ARGS) \
     $(eval $($(_footer_args)) += --rollback_index $($(_rollback_index))))
@@ -2750,9 +2750,9 @@
 $(eval $(call check-and-set-avb-args,recovery))
 endif
 
-# Not using INSTALLED_VBMETA_MAINLINEIMAGE_TARGET as it won't be set yet.
-ifdef BOARD_AVB_VBMETA_MAINLINE
-$(eval $(call check-and-set-avb-args,vbmeta_mainline))
+# Not using INSTALLED_VBMETA_SYSTEMIMAGE_TARGET as it won't be set yet.
+ifdef BOARD_AVB_VBMETA_SYSTEM
+$(eval $(call check-and-set-avb-args,vbmeta_system))
 endif
 
 ifdef BOARD_AVB_VBMETA_VENDOR
@@ -2772,12 +2772,12 @@
 endif
 
 BOARD_AVB_MAKE_VBMETA_IMAGE_ARGS += --padding_size 4096
-BOARD_AVB_MAKE_VBMETA_MAINLINE_IMAGE_ARGS += --padding_size 4096
+BOARD_AVB_MAKE_VBMETA_SYSTEM_IMAGE_ARGS += --padding_size 4096
 BOARD_AVB_MAKE_VBMETA_VENDOR_IMAGE_ARGS += --padding_size 4096
 
 ifeq (eng,$(filter eng, $(TARGET_BUILD_VARIANT)))
 BOARD_AVB_MAKE_VBMETA_IMAGE_ARGS += --set_hashtree_disabled_flag
-BOARD_AVB_MAKE_VBMETA_MAINLINE_IMAGE_ARGS += --set_hashtree_disabled_flag
+BOARD_AVB_MAKE_VBMETA_SYSTEM_IMAGE_ARGS += --set_hashtree_disabled_flag
 BOARD_AVB_MAKE_VBMETA_VENDOR_IMAGE_ARGS += --set_hashtree_disabled_flag
 endif
 
@@ -2785,9 +2785,9 @@
 BOARD_AVB_MAKE_VBMETA_IMAGE_ARGS += --rollback_index $(BOARD_AVB_ROLLBACK_INDEX)
 endif
 
-ifdef BOARD_AVB_VBMETA_MAINLINE_ROLLBACK_INDEX
-BOARD_AVB_MAKE_VBMETA_MAINLINE_IMAGE_ARGS += \
-    --rollback_index $(BOARD_AVB_VBMETA_MAINLINE_ROLLBACK_INDEX)
+ifdef BOARD_AVB_VBMETA_SYSTEM_ROLLBACK_INDEX
+BOARD_AVB_MAKE_VBMETA_SYSTEM_IMAGE_ARGS += \
+    --rollback_index $(BOARD_AVB_VBMETA_SYSTEM_ROLLBACK_INDEX)
 endif
 
 ifdef BOARD_AVB_VBMETA_VENDOR_ROLLBACK_INDEX
@@ -2821,9 +2821,9 @@
   $(if $(BOARD_AVB_RECOVERY_KEY_PATH),\
     $(hide) $(AVBTOOL) extract_public_key --key $(BOARD_AVB_RECOVERY_KEY_PATH) \
       --output $(1)/recovery.avbpubkey)
-  $(if $(BOARD_AVB_VBMETA_MAINLINE_KEY_PATH),\
-    $(hide) $(AVBTOOL) extract_public_key --key $(BOARD_AVB_VBMETA_MAINLINE_KEY_PATH) \
-        --output $(1)/vbmeta_mainline.avbpubkey)
+  $(if $(BOARD_AVB_VBMETA_SYSTEM_KEY_PATH),\
+    $(hide) $(AVBTOOL) extract_public_key --key $(BOARD_AVB_VBMETA_SYSTEM_KEY_PATH) \
+        --output $(1)/vbmeta_system.avbpubkey)
   $(if $(BOARD_AVB_VBMETA_VENDOR_KEY_PATH),\
     $(hide) $(AVBTOOL) extract_public_key --key $(BOARD_AVB_VBMETA_VENDOR_KEY_PATH) \
         --output $(1)/vbmeta_vendor.avbpubkey)
@@ -2831,11 +2831,11 @@
 
 # Builds a chained VBMeta image. This VBMeta image will contain the descriptors for the partitions
 # specified in BOARD_AVB_VBMETA_<NAME>. The built VBMeta image will be included into the top-level
-# vbmeta image as a chained partition. For example, if a target defines `BOARD_AVB_VBMETA_MAINLINE
-# := system product_services`, `vbmeta_mainline.img` will be created that includes the descriptors
-# for `system.img` and `product_services.img`. `vbmeta_mainline.img` itself will be included into
+# vbmeta image as a chained partition. For example, if a target defines `BOARD_AVB_VBMETA_SYSTEM
+# := system product_services`, `vbmeta_system.img` will be created that includes the descriptors
+# for `system.img` and `product_services.img`. `vbmeta_system.img` itself will be included into
 # `vbmeta.img` as a chained partition.
-# $(1): VBMeta image name, such as "vbmeta_mainline", "vbmeta_vendor" etc.
+# $(1): VBMeta image name, such as "vbmeta_system", "vbmeta_vendor" etc.
 # $(2): Output filename.
 define build-chained-vbmeta-image
   $(call pretty,"Target chained vbmeta image: $@")
@@ -2847,13 +2847,13 @@
       --output $@
 endef
 
-ifdef BOARD_AVB_VBMETA_MAINLINE
-INSTALLED_VBMETA_MAINLINEIMAGE_TARGET := $(PRODUCT_OUT)/vbmeta_mainline.img
-$(INSTALLED_VBMETA_MAINLINEIMAGE_TARGET): \
+ifdef BOARD_AVB_VBMETA_SYSTEM
+INSTALLED_VBMETA_SYSTEMIMAGE_TARGET := $(PRODUCT_OUT)/vbmeta_system.img
+$(INSTALLED_VBMETA_SYSTEMIMAGE_TARGET): \
 		$(AVBTOOL) \
-		$(call images-for-partitions,$(BOARD_AVB_VBMETA_MAINLINE)) \
-		$(BOARD_AVB_VBMETA_MAINLINE_KEY_PATH)
-	$(call build-chained-vbmeta-image,vbmeta_mainline)
+		$(call images-for-partitions,$(BOARD_AVB_VBMETA_SYSTEM)) \
+		$(BOARD_AVB_VBMETA_SYSTEM_KEY_PATH)
+	$(call build-chained-vbmeta-image,vbmeta_system)
 endif
 
 ifdef BOARD_AVB_VBMETA_VENDOR
@@ -2891,9 +2891,9 @@
 		$(INSTALLED_ODMIMAGE_TARGET) \
 		$(INSTALLED_DTBOIMAGE_TARGET) \
 		$(INSTALLED_RECOVERYIMAGE_TARGET) \
-		$(INSTALLED_VBMETA_MAINLINEIMAGE_TARGET) \
+		$(INSTALLED_VBMETA_SYSTEMIMAGE_TARGET) \
 		$(INSTALLED_VBMETA_VENDORIMAGE_TARGET) \
-		$(BOARD_AVB_VBMETA_MAINLINE_KEY_PATH) \
+		$(BOARD_AVB_VBMETA_SYSTEM_KEY_PATH) \
 		$(BOARD_AVB_VBMETA_VENDOR_KEY_PATH) \
 		$(BOARD_AVB_KEY_PATH)
 	$(build-vbmetaimage-target)
@@ -2939,18 +2939,20 @@
   --metadata-size 65536 \
   --metadata-slots $(if $(1),2,1) \
   --device-size $(BOARD_SUPER_PARTITION_SIZE) \
-  $(foreach name,$(BOARD_SUPER_PARTITION_PARTITION_LIST), \
-    --partition $(name)$(1):readonly:$(if $(2),$(call read-size-of-partitions,$(name)),0) \
-    $(if $(2), --image $(name)$(1)=$(call images-for-partitions,$(name))) \
-    $(if $(1), --partition $(name)_b:readonly:0) \
-  )
+  $(foreach group,$(BOARD_SUPER_PARTITION_GROUPS), \
+    --group $(group):$(BOARD_$(call to-upper,$(group))_SIZE) \
+    $(foreach name,$(BOARD_$(call to-upper,$(group))_PARTITION_LIST), \
+      --partition $(name)$(1):readonly:$(if $(2),$(call read-size-of-partitions,$(name)),0):$(group) \
+      $(if $(2), --image $(name)$(1)=$(call images-for-partitions,$(name))) \
+      $(if $(1), --partition $(name)_b:readonly:0:$(group)) \
+  ))
 endef
 
 # $(1): output image path
 # $(2): slot A suffix (_a or empty)
 # $(3): include images or not (true or empty)
 define build-superimage-target
-  $(HOST_OUT_EXECUTABLES)/lpmake \
+  $(LPMAKE) \
     $(call build-superimage-target-args,$(2),$(3)) \
     --output $(1)
 endef
@@ -3520,16 +3522,16 @@
 	$(hide) echo "avb_recovery_algorithm=$(BOARD_AVB_RECOVERY_ALGORITHM)" >> $(zip_root)/META/misc_info.txt
 	$(hide) echo "avb_recovery_rollback_index_location=$(BOARD_AVB_RECOVERY_ROLLBACK_INDEX_LOCATION)" >> $(zip_root)/META/misc_info.txt
 endif # BOARD_AVB_RECOVERY_KEY_PATH
-ifneq (,$(strip $(BOARD_AVB_VBMETA_MAINLINE)))
-	$(hide) echo "avb_vbmeta_mainline=$(BOARD_AVB_VBMETA_MAINLINE)" >> $(zip_root)/META/misc_info.txt
-	$(hide) echo "avb_vbmeta_mainline_args=$(BOARD_AVB_MAKE_VBMETA_MAINLINE_IMAGE_ARGS)" >> $(zip_root)/META/misc_info.txt
-	$(hide) echo "avb_vbmeta_mainline_key_path=$(BOARD_AVB_VBMETA_MAINLINE_KEY_PATH)" >> $(zip_root)/META/misc_info.txt
-	$(hide) echo "avb_vbmeta_mainline_algorithm=$(BOARD_AVB_VBMETA_MAINLINE_ALGORITHM)" >> $(zip_root)/META/misc_info.txt
-	$(hide) echo "avb_vbmeta_mainline_rollback_index_location=$(BOARD_AVB_VBMETA_MAINLINE_ROLLBACK_INDEX_LOCATION)" >> $(zip_root)/META/misc_info.txt
-endif # BOARD_AVB_VBMETA_MAINLINE
+ifneq (,$(strip $(BOARD_AVB_VBMETA_SYSTEM)))
+	$(hide) echo "avb_vbmeta_system=$(BOARD_AVB_VBMETA_SYSTEM)" >> $(zip_root)/META/misc_info.txt
+	$(hide) echo "avb_vbmeta_system_args=$(BOARD_AVB_MAKE_VBMETA_SYSTEM_IMAGE_ARGS)" >> $(zip_root)/META/misc_info.txt
+	$(hide) echo "avb_vbmeta_system_key_path=$(BOARD_AVB_VBMETA_SYSTEM_KEY_PATH)" >> $(zip_root)/META/misc_info.txt
+	$(hide) echo "avb_vbmeta_system_algorithm=$(BOARD_AVB_VBMETA_SYSTEM_ALGORITHM)" >> $(zip_root)/META/misc_info.txt
+	$(hide) echo "avb_vbmeta_system_rollback_index_location=$(BOARD_AVB_VBMETA_SYSTEM_ROLLBACK_INDEX_LOCATION)" >> $(zip_root)/META/misc_info.txt
+endif # BOARD_AVB_VBMETA_SYSTEM
 ifneq (,$(strip $(BOARD_AVB_VBMETA_VENDOR)))
 	$(hide) echo "avb_vbmeta_vendor=$(BOARD_AVB_VBMETA_VENDOR)" >> $(zip_root)/META/misc_info.txt
-	$(hide) echo "avb_vbmeta_vendor_args=$(BOARD_AVB_MAKE_VBMETA_MAINLINE_IMAGE_ARGS)" >> $(zip_root)/META/misc_info.txt
+	$(hide) echo "avb_vbmeta_vendor_args=$(BOARD_AVB_MAKE_VBMETA_SYSTEM_IMAGE_ARGS)" >> $(zip_root)/META/misc_info.txt
 	$(hide) echo "avb_vbmeta_vendor_key_path=$(BOARD_AVB_VBMETA_VENDOR_KEY_PATH)" >> $(zip_root)/META/misc_info.txt
 	$(hide) echo "avb_vbmeta_vendor_algorithm=$(BOARD_AVB_VBMETA_VENDOR_ALGORITHM)" >> $(zip_root)/META/misc_info.txt
 	$(hide) echo "avb_vbmeta_vendor_rollback_index_location=$(BOARD_AVB_VBMETA_VENDOR_ROLLBACK_INDEX_LOCATION)" >> $(zip_root)/META/misc_info.txt
diff --git a/core/android_manifest.mk b/core/android_manifest.mk
index 8e8bfec..8608ca1 100644
--- a/core/android_manifest.mk
+++ b/core/android_manifest.mk
@@ -72,8 +72,15 @@
     my_manifest_fixer_flags += --uses-non-sdk-api
 endif
 $(fixed_android_manifest): PRIVATE_MANIFEST_FIXER_FLAGS := $(my_manifest_fixer_flags)
+# These two libs are added as optional dependencies (<uses-library> with
+# android:required set to false). This is because they haven't existed in pre-P
+# devices, but classes in them were in bootclasspath jars, etc. So making them
+# hard dependencies (andriod:required=true) would prevent apps from being
+# installed to such legacy devices.
+$(fixed_android_manifest): PRIVATE_OPTIONAL_SDK_LIB_NAMES := android.test.base android.test.mock
 $(fixed_android_manifest): $(MANIFEST_FIXER)
 $(fixed_android_manifest): $(main_android_manifest)
+	echo $(PRIVATE_OPTIONAL_SDK_LIB_NAMES) | tr ' ' '\n' > $(PRIVATE_EXPORTED_SDK_LIBS_FILE).optional
 	@echo "Fix manifest: $@"
 	$(MANIFEST_FIXER) \
 	  --minSdkVersion $(PRIVATE_MIN_SDK_VERSION) \
@@ -81,5 +88,8 @@
           --raise-min-sdk-version \
 	  $(PRIVATE_MANIFEST_FIXER_FLAGS) \
 	  $(if (PRIVATE_EXPORTED_SDK_LIBS_FILE),\
-	    $$(cat $(PRIVATE_EXPORTED_SDK_LIBS_FILE) | sort -u | sed -e 's/^/\ --uses-library\ /' | tr '\n' ' ')) \
+	    $$(cat $(PRIVATE_EXPORTED_SDK_LIBS_FILE) | grep -v -f $(PRIVATE_EXPORTED_SDK_LIBS_FILE).optional | sort -u | sed -e 's/^/\ --uses-library\ /' | tr '\n' ' ') \
+	    $$(cat $(PRIVATE_EXPORTED_SDK_LIBS_FILE) | grep -f $(PRIVATE_EXPORTED_SDK_LIBS_FILE).optional | sort -u | sed -e 's/^/\ --optional-uses-library\ /' | tr '\n' ' ') \
+	   ) \
 	  $< $@
+	rm $(PRIVATE_EXPORTED_SDK_LIBS_FILE).optional
diff --git a/core/config.mk b/core/config.mk
index b9174b3..bf834b2 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -958,7 +958,6 @@
     requirements := \
         PRODUCT_USE_DYNAMIC_PARTITION_SIZE \
         PRODUCT_BUILD_SUPER_PARTITION \
-        PRODUCT_USE_FASTBOOTD \
 
     $(foreach req,$(requirements),$(if $(filter false,$($(req))),\
         $(error PRODUCT_USE_LOGICAL_PARTITIONS requires $(req) to be true)))
diff --git a/core/product.mk b/core/product.mk
index ef1a709..f9f8d60 100644
--- a/core/product.mk
+++ b/core/product.mk
@@ -209,7 +209,6 @@
     PRODUCT_ARTIFACT_PATH_REQUIREMENT_WHITELIST \
     PRODUCT_USE_DYNAMIC_PARTITION_SIZE \
     PRODUCT_BUILD_SUPER_PARTITION \
-    PRODUCT_USE_FASTBOOTD \
     PRODUCT_FORCE_PRODUCT_MODULES_TO_SYSTEM_PARTITION \
 
 define dump-product
diff --git a/core/product_config.mk b/core/product_config.mk
index 7cbea91..27af09e 100644
--- a/core/product_config.mk
+++ b/core/product_config.mk
@@ -525,10 +525,6 @@
     $(strip $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_BUILD_SUPER_PARTITION)),\
     $(PRODUCT_USE_LOGICAL_PARTITIONS))
 .KATI_READONLY := PRODUCT_BUILD_SUPER_PARTITION
-PRODUCT_USE_FASTBOOTD := $(or \
-    $(strip $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_USE_FASTBOOTD)),\
-    $(PRODUCT_USE_LOGICAL_PARTITIONS))
-.KATI_READONLY := PRODUCT_USE_FASTBOOTD
 
 # List of modules that should be forcefully unmarked from being LOCAL_PRODUCT_MODULE, and hence
 # installed on /system directory by default.
diff --git a/target/product/base_system.mk b/target/product/base_system.mk
index 11f5fe4..57e981f 100644
--- a/target/product/base_system.mk
+++ b/target/product/base_system.mk
@@ -85,9 +85,9 @@
     incidentd \
     incident_helper \
     incident_report \
-    init \
     init.environ.rc \
     init.rc \
+    init_system \
     input \
     installd \
     iorapd \
diff --git a/target/product/base_vendor.mk b/target/product/base_vendor.mk
index 1b25f27..9bb45d1 100644
--- a/target/product/base_vendor.mk
+++ b/target/product/base_vendor.mk
@@ -34,6 +34,7 @@
     fs_config_dirs_nonsystem \
     gralloc.default \
     group \
+    init_vendor \
     libbundlewrapper \
     libclearkeycasplugin \
     libdownmix \
diff --git a/target/product/mainline_system.mk b/target/product/mainline_system.mk
index 8d0611f..192e9b1 100644
--- a/target/product/mainline_system.mk
+++ b/target/product/mainline_system.mk
@@ -40,6 +40,10 @@
 PRODUCT_PACKAGES += \
     netutils-wrapper-1.0 \
 
+# Charger images
+PRODUCT_PACKAGES += \
+    charger_res_images \
+
 # system_other support
 PRODUCT_PACKAGES += \
     cppreopts.sh \
@@ -62,10 +66,8 @@
 _my_whitelist := $(_base_mk_whitelist)
 
 # Both /system and / are in system.img when PRODUCT_SHIPPING_API_LEVEL>=28.
-# Though we do have a new ramdisk partition for logical partitions.
 _my_paths := \
   $(TARGET_COPY_OUT_ROOT) \
   $(TARGET_COPY_OUT_SYSTEM) \
-  $(TARGET_COPY_OUT_RAMDISK) \
 
 $(call require-artifacts-in-path, $(_my_paths), $(_my_whitelist))
diff --git a/tools/atree/files.cpp b/tools/atree/files.cpp
index d5c8a97..b90f8b3 100644
--- a/tools/atree/files.cpp
+++ b/tools/atree/files.cpp
@@ -81,7 +81,7 @@
                     state = TEXT;
                     break;
                 }
-                // otherwise fall-through to TEXT case
+                [[fallthrough]];
             case TEXT:
                 if (state != IN_QUOTE && isspace(*p)) {
                     if (q != p) {
diff --git a/tools/releasetools/add_img_to_target_files.py b/tools/releasetools/add_img_to_target_files.py
index 2fa5f52..1b1ec20 100755
--- a/tools/releasetools/add_img_to_target_files.py
+++ b/tools/releasetools/add_img_to_target_files.py
@@ -399,7 +399,7 @@
     partitions: A dict that's keyed by partition names with image paths as
         values. Only valid partition names are accepted, as listed in
         common.AVB_PARTITIONS.
-    name: Name of the VBMeta partition, e.g. 'vbmeta', 'vbmeta_mainline'.
+    name: Name of the VBMeta partition, e.g. 'vbmeta', 'vbmeta_system'.
     needed_partitions: Partitions whose descriptors should be included into the
         generated VBMeta image.
 
@@ -832,15 +832,15 @@
     # chained VBMeta image plus the chained VBMeta images themselves.
     vbmeta_partitions = common.AVB_PARTITIONS[:]
 
-    vbmeta_mainline = OPTIONS.info_dict.get("avb_vbmeta_mainline", "").strip()
-    if vbmeta_mainline:
-      banner("vbmeta_mainline")
+    vbmeta_system = OPTIONS.info_dict.get("avb_vbmeta_system", "").strip()
+    if vbmeta_system:
+      banner("vbmeta_system")
       AddVBMeta(
-          output_zip, partitions, "vbmeta_mainline", vbmeta_mainline.split())
+          output_zip, partitions, "vbmeta_system", vbmeta_system.split())
       vbmeta_partitions = [
           item for item in vbmeta_partitions
-          if item not in vbmeta_mainline.split()]
-      vbmeta_partitions.append("vbmeta_mainline")
+          if item not in vbmeta_system.split()]
+      vbmeta_partitions.append("vbmeta_system")
 
     vbmeta_vendor = OPTIONS.info_dict.get("avb_vbmeta_vendor", "").strip()
     if vbmeta_vendor: