diff --git a/CleanSpec.mk b/CleanSpec.mk
index ac25996..3f1721f 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -622,6 +622,9 @@
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/lib*/libicu*)
 
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/target/common/obj/framework.aidl)
+
+# Clean up adb_debug.propr
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/etc/adb_debug.prop)
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************
diff --git a/core/Makefile b/core/Makefile
index 8a960b6..e8e592a 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -1936,6 +1936,106 @@
 endif
 
 # -----------------------------------------------------------------
+# the debug ramdisk, which is the original ramdisk plus additional
+# files: force_debuggable, adb_debug.prop and userdebug sepolicy.
+# When /force_debuggable is present, /init will load userdebug sepolicy
+# and property files to allow adb root, if the device is unlocked.
+
+ifdef BUILDING_RAMDISK_IMAGE
+BUILT_DEBUG_RAMDISK_TARGET := $(PRODUCT_OUT)/ramdisk-debug.img
+INSTALLED_DEBUG_RAMDISK_TARGET := $(BUILT_DEBUG_RAMDISK_TARGET)
+
+INTERNAL_DEBUG_RAMDISK_FILES := $(filter $(TARGET_DEBUG_RAMDISK_OUT)/%, \
+    $(ALL_GENERATED_SOURCES) \
+    $(ALL_DEFAULT_INSTALLED_MODULES))
+
+# Note: TARGET_DEBUG_RAMDISK_OUT will be $(PRODUCT_OUT)/debug_ramdisk/first_stage_ramdisk,
+# if BOARD_USES_RECOVERY_AS_BOOT is true. Otherwise, it will be $(PRODUCT_OUT)/debug_ramdisk.
+# But the root dir of the ramdisk to build is always $(PRODUCT_OUT)/debug_ramdisk.
+my_debug_ramdisk_root_dir := $(PRODUCT_OUT)/debug_ramdisk
+
+INSTALLED_FILES_FILE_DEBUG_RAMDISK := $(PRODUCT_OUT)/installed-files-ramdisk-debug.txt
+INSTALLED_FILES_JSON_DEBUG_RAMDISK := $(INSTALLED_FILES_FILE_DEBUG_RAMDISK:.txt=.json)
+$(INSTALLED_FILES_FILE_DEBUG_RAMDISK): .KATI_IMPLICIT_OUTPUTS := $(INSTALLED_FILES_JSON_DEBUG_RAMDISK)
+$(INSTALLED_FILES_FILE_DEBUG_RAMDISK): DEBUG_RAMDISK_ROOT_DIR := $(my_debug_ramdisk_root_dir)
+
+# Cannot just depend on INTERNAL_DEBUG_RAMDISK_FILES like other INSTALLED_FILES_FILE_* rules.
+# Because ramdisk-debug.img will rsync from either ramdisk.img or ramdisk-recovery.img.
+# Need to depend on the built ramdisk-debug.img, to get a complete list of the installed files.
+$(INSTALLED_FILES_FILE_DEBUG_RAMDISK) : $(INSTALLED_DEBUG_RAMDISK_TARGET)
+$(INSTALLED_FILES_FILE_DEBUG_RAMDISK) : $(INTERNAL_DEBUG_RAMDISK_FILES) $(FILESLIST)
+	echo Installed file list: $@
+	mkdir -p $(dir $@)
+	rm -f $@
+	$(FILESLIST) $(DEBUG_RAMDISK_ROOT_DIR) > $(@:.txt=.json)
+	build/make/tools/fileslist_util.py -c $(@:.txt=.json) > $@
+
+# ramdisk-debug.img will rsync the content from either ramdisk.img or ramdisk-recovery.img,
+# depending on whether BOARD_USES_RECOVERY_AS_BOOT is set or not.
+ifeq ($(BOARD_USES_RECOVERY_AS_BOOT),true)
+my_debug_ramdisk_sync_dir := $(TARGET_RECOVERY_ROOT_OUT)
+else
+my_debug_ramdisk_sync_dir := $(TARGET_RAMDISK_OUT)
+endif # BOARD_USES_RECOVERY_AS_BOOT
+
+$(INSTALLED_DEBUG_RAMDISK_TARGET): DEBUG_RAMDISK_SYNC_DIR := $(my_debug_ramdisk_sync_dir)
+$(INSTALLED_DEBUG_RAMDISK_TARGET): DEBUG_RAMDISK_ROOT_DIR := $(my_debug_ramdisk_root_dir)
+# We should have just depended on ramdisk.img or ramdisk-recovery.img.
+# But ramdisk-recovery.img is not a make target, so let's depend on the boot.img directly.
+$(INSTALLED_DEBUG_RAMDISK_TARGET): $(INSTALLED_BOOTIMAGE_TARGET)
+$(INSTALLED_DEBUG_RAMDISK_TARGET): $(MKBOOTFS) $(INTERNAL_DEBUG_RAMDISK_FILES) | $(MINIGZIP)
+	$(call pretty,"Target debug ram disk: $@")
+	mkdir -p $(TARGET_DEBUG_RAMDISK_OUT)
+	touch $(TARGET_DEBUG_RAMDISK_OUT)/force_debuggable
+	rsync -a $(DEBUG_RAMDISK_SYNC_DIR)/* $(DEBUG_RAMDISK_ROOT_DIR)
+	$(MKBOOTFS) -d $(TARGET_OUT) $(DEBUG_RAMDISK_ROOT_DIR) | $(MINIGZIP) > $@
+
+.PHONY: ramdisk_debug-nodeps
+ramdisk_debug-nodeps: DEBUG_RAMDISK_SYNC_DIR := $(my_debug_ramdisk_sync_dir)
+ramdisk_debug-nodeps: DEBUG_RAMDISK_ROOT_DIR := $(my_debug_ramdisk_root_dir)
+ramdisk_debug-nodeps: $(MKBOOTFS) | $(MINIGZIP)
+	echo "make $@: ignoring dependencies"
+	mkdir -p $(TARGET_DEBUG_RAMDISK_OUT)
+	touch $(TARGET_DEBUG_RAMDISK_OUT)/force_debuggable
+	rsync -a $(DEBUG_RAMDISK_SYNC_DIR)/* $(DEBUG_RAMDISK_ROOT_DIR)
+	$(MKBOOTFS) -d $(TARGET_OUT) $(DEBUG_RAMDISK_ROOT_DIR) | $(MINIGZIP) > $(INSTALLED_DEBUG_RAMDISK_TARGET)
+
+my_debug_ramdisk_sync_dir :=
+my_debug_ramdisk_root_dir :=
+
+endif # BUILDING_RAMDISK_IMAGE
+
+# -----------------------------------------------------------------
+# the boot-debug.img, which is the kernel plus ramdisk-debug.img
+#
+# Note: it's intentional to skip signing for boot-debug.img, because it
+# can only be used if the device is unlocked with verification error.
+ifneq ($(strip $(TARGET_NO_KERNEL)),true)
+
+INSTALLED_DEBUG_BOOTIMAGE_TARGET := $(PRODUCT_OUT)/boot-debug.img
+
+# Replace ramdisk.img in $(MKBOOTIMG) ARGS with ramdisk-debug.img to build boot-debug.img
+ifeq ($(BOARD_USES_RECOVERY_AS_BOOT),true)
+INTERNAL_DEBUG_BOOTIMAGE_ARGS := $(subst $(recovery_ramdisk),$(INSTALLED_DEBUG_RAMDISK_TARGET), $(INTERNAL_RECOVERYIMAGE_ARGS))
+else
+INTERNAL_DEBUG_BOOTIMAGE_ARGS := $(subst $(INSTALLED_RAMDISK_TARGET),$(INSTALLED_DEBUG_RAMDISK_TARGET), $(INTERNAL_BOOTIMAGE_ARGS))
+endif
+
+# Depends on original boot.img and ramdisk-debug.img, to build the new boot-debug.img
+$(INSTALLED_DEBUG_BOOTIMAGE_TARGET): $(MKBOOTIMG) $(INSTALLED_BOOTIMAGE_TARGET) $(INSTALLED_DEBUG_RAMDISK_TARGET)
+	$(call pretty,"Target boot debug image: $@")
+	$(MKBOOTIMG) $(INTERNAL_DEBUG_BOOTIMAGE_ARGS) $(INTERNAL_MKBOOTIMG_VERSION_ARGS) $(BOARD_MKBOOTIMG_ARGS) --output $@
+	$(call assert-max-image-size,$@,$(BOARD_BOOTIMAGE_PARTITION_SIZE))
+
+.PHONY: bootimage_debug-nodeps
+bootimage_debug-nodeps: $(MKBOOTIMG)
+	echo "make $@: ignoring dependencies"
+	$(MKBOOTIMG) $(INTERNAL_DEBUG_BOOTIMAGE_ARGS) $(INTERNAL_MKBOOTIMG_VERSION_ARGS) $(BOARD_MKBOOTIMG_ARGS) --output $(INSTALLED_DEBUG_BOOTIMAGE_TARGET)
+	$(call assert-max-image-size,$(INSTALLED_DEBUG_BOOTIMAGE_TARGET),$(BOARD_BOOTIMAGE_PARTITION_SIZE))
+
+endif # TARGET_NO_KERNEL
+
+# -----------------------------------------------------------------
 # system image
 #
 # Remove overridden packages from $(ALL_PDK_FUSION_FILES)
diff --git a/core/board_config.mk b/core/board_config.mk
index dcfed9d..2580a33 100644
--- a/core/board_config.mk
+++ b/core/board_config.mk
@@ -241,6 +241,12 @@
 endif
 
 ###########################################
+# Now we can substitute with the real value of TARGET_COPY_OUT_DEBUG_RAMDISK
+ifeq ($(BOARD_USES_RECOVERY_AS_BOOT),true)
+TARGET_COPY_OUT_DEBUG_RAMDISK := debug_ramdisk/first_stage_ramdisk
+endif
+
+###########################################
 # Configure whether we're building the system image
 BUILDING_SYSTEM_IMAGE := true
 ifeq ($(PRODUCT_BUILD_SYSTEM_IMAGE),)
diff --git a/core/config.mk b/core/config.mk
index 386c64e..94928a2 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -1178,7 +1178,9 @@
     onod odmimage-nodeps \
     systemotherimage-nodeps \
     ramdisk-nodeps \
+    ramdisk_debug-nodeps \
     bootimage-nodeps \
+    bootimage_debug-nodeps \
     recoveryimage-nodeps \
     vbmetaimage-nodeps \
     product-graph dump-products
diff --git a/core/envsetup.mk b/core/envsetup.mk
index 7b90334..46edc0e 100644
--- a/core/envsetup.mk
+++ b/core/envsetup.mk
@@ -225,6 +225,7 @@
 TARGET_COPY_OUT_ASAN := $(TARGET_COPY_OUT_DATA)/asan
 TARGET_COPY_OUT_OEM := oem
 TARGET_COPY_OUT_RAMDISK := ramdisk
+TARGET_COPY_OUT_DEBUG_RAMDISK := debug_ramdisk
 TARGET_COPY_OUT_ROOT := root
 TARGET_COPY_OUT_RECOVERY := recovery
 # The directory used for optional partitions depend on the BoardConfig, so
@@ -838,6 +839,7 @@
 
 TARGET_RAMDISK_OUT := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_RAMDISK)
 TARGET_RAMDISK_OUT_UNSTRIPPED := $(TARGET_OUT_UNSTRIPPED)
+TARGET_DEBUG_RAMDISK_OUT := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_DEBUG_RAMDISK)
 
 TARGET_ROOT_OUT := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_ROOT)
 TARGET_ROOT_OUT_BIN := $(TARGET_ROOT_OUT)/bin
diff --git a/core/main.mk b/core/main.mk
index 590bfcc..af26705 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -1429,6 +1429,9 @@
 .PHONY: ramdisk
 ramdisk: $(INSTALLED_RAMDISK_TARGET)
 
+.PHONY: ramdisk_debug
+ramdisk_debug: $(INSTALLED_DEBUG_RAMDISK_TARGET)
+
 .PHONY: systemtarball
 systemtarball: $(INSTALLED_SYSTEMTARBALL_TARGET)
 
@@ -1475,6 +1478,9 @@
 .PHONY: bootimage
 bootimage: $(INSTALLED_BOOTIMAGE_TARGET)
 
+.PHONY: bootimage_debug
+bootimage_debug: $(INSTALLED_DEBUG_BOOTIMAGE_TARGET)
+
 .PHONY: vbmetaimage
 vbmetaimage: $(INSTALLED_VBMETAIMAGE_TARGET)
 
@@ -1487,6 +1493,8 @@
     $(INSTALLED_SYSTEMIMAGE_TARGET) \
     $(INSTALLED_RAMDISK_TARGET) \
     $(INSTALLED_BOOTIMAGE_TARGET) \
+    $(INSTALLED_DEBUG_RAMDISK_TARGET) \
+    $(INSTALLED_DEBUG_BOOTIMAGE_TARGET) \
     $(INSTALLED_RECOVERYIMAGE_TARGET) \
     $(INSTALLED_VBMETAIMAGE_TARGET) \
     $(INSTALLED_USERDATAIMAGE_TARGET) \
@@ -1511,6 +1519,8 @@
     $(INSTALLED_FILES_JSON_SYSTEMOTHER) \
     $(INSTALLED_FILES_FILE_RAMDISK) \
     $(INSTALLED_FILES_JSON_RAMDISK) \
+    $(INSTALLED_FILES_FILE_DEBUG_RAMDISK) \
+    $(INSTALLED_FILES_JSON_DEBUG_RAMDISK) \
     $(INSTALLED_FILES_FILE_ROOT) \
     $(INSTALLED_FILES_JSON_ROOT) \
     $(INSTALLED_FILES_FILE_RECOVERY) \
@@ -1631,6 +1641,10 @@
     $(call dist-for-goals, droidcore, \
       $(INSTALLED_FILES_FILE_RAMDISK) \
       $(INSTALLED_FILES_JSON_RAMDISK) \
+      $(INSTALLED_FILES_FILE_DEBUG_RAMDISK) \
+      $(INSTALLED_FILES_JSON_DEBUG_RAMDISK) \
+      $(INSTALLED_DEBUG_RAMDISK_TARGET) \
+      $(INSTALLED_DEBUG_BOOTIMAGE_TARGET) \
     )
   endif
 
diff --git a/core/notice_files.mk b/core/notice_files.mk
index e687ab2..c314734 100644
--- a/core/notice_files.mk
+++ b/core/notice_files.mk
@@ -38,6 +38,8 @@
 endif
 endif
 
+installed_notice_file :=
+
 ifdef notice_file
 
 ifdef my_register_name
@@ -71,12 +73,17 @@
       endif
       module_installed_filename := \
           $(patsubst $(PRODUCT_OUT)/%,%,$($(my_prefix)OUT_JAVA_LIBRARIES))/$(module_leaf)
+    else ifeq ($(LOCAL_MODULE_CLASS),ETC)
+      # ETC modules may be uninstallable, yet still have a NOTICE file. e.g. apex components
+      module_installed_filename :=
     else
       $(error Cannot determine where to install NOTICE file for $(LOCAL_MODULE))
     endif # JAVA_LIBRARIES
   endif # STATIC_LIBRARIES
 endif
 
+ifdef module_installed_filename
+
 # In case it's actually a host file
 module_installed_filename := $(patsubst $(HOST_OUT)/%,%,$(module_installed_filename))
 module_installed_filename := $(patsubst $(HOST_CROSS_OUT)/%,%,$(module_installed_filename))
@@ -110,10 +117,8 @@
 endif  # JAVA_LIBRARIES
 endif  # TARGET_BUILD_APPS
 
-else
-# NOTICE file does not exist
-installed_notice_file :=
-endif
+endif  # module_installed_filename
+endif  # notice_file
 
 # Create a predictable, phony target to build this notice file.
 # Define it even if the notice file doesn't exist so that other
diff --git a/target/product/gsi/adb_debug.prop b/target/product/gsi/adb_debug.prop
deleted file mode 100644
index 37e2f2d..0000000
--- a/target/product/gsi/adb_debug.prop
+++ /dev/null
@@ -1,12 +0,0 @@
-# Note: This file will be loaded with highest priority to override
-# other system properties, if a special ramdisk with "/force_debuggable"
-# is used and the device is unlocked.
-
-# Disable adb authentication to allow test automation on user build GSI
-ro.adb.secure=0
-
-# Allow 'adb root' on user build GSI
-ro.debuggable=1
-
-# Introduce this property to indicate that init has loaded adb_debug.prop
-ro.force.debuggable=1
diff --git a/target/product/gsi_common.mk b/target/product/gsi_common.mk
index 2c978ab..c38dd80 100644
--- a/target/product/gsi_common.mk
+++ b/target/product/gsi_common.mk
@@ -50,13 +50,13 @@
 PRODUCT_ARTIFACT_PATH_REQUIREMENT_WHITELIST += \
     system/etc/init/config/skip_mount.cfg \
     system/etc/init/init.gsi.rc \
-    system/etc/adb_debug.prop \
 
 # Exclude all files under system/product and system/product_services
 PRODUCT_ARTIFACT_PATH_REQUIREMENT_WHITELIST += \
     system/product/% \
     system/product_services/%
 
+
 # Split selinux policy
 PRODUCT_FULL_TREBLE_OVERRIDE := true
 
@@ -92,7 +92,3 @@
 #   Provide a libnfc-nci.conf to GSI product
 PRODUCT_COPY_FILES += \
     device/generic/common/nfc/libnfc-nci.conf:$(TARGET_COPY_OUT_PRODUCT)/etc/libnfc-nci.conf
-
-# Allow 'adb root' on user build GSI
-PRODUCT_COPY_FILES += \
-    build/make/target/product/gsi/adb_debug.prop:$(TARGET_COPY_OUT_SYSTEM)/etc/adb_debug.prop
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 3e2a113..495fec3 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -93,9 +93,11 @@
 # Values for "certificate" in apkcerts that mean special things.
 SPECIAL_CERT_STRINGS = ("PRESIGNED", "EXTERNAL")
 
-# The partitions allowed to be signed by AVB (Android verified boot 2.0).
-AVB_PARTITIONS = ('boot', 'recovery', 'system', 'vendor', 'product',
-                  'product_services', 'dtbo', 'odm')
+# The partitions allowed to be signed by AVB (Android Verified Boot 2.0). Note
+# that system_other is not in the list because we don't want to include its
+# descriptor into vbmeta.img.
+AVB_PARTITIONS = ('boot', 'dtbo', 'odm', 'product', 'product_services',
+                  'recovery', 'system', 'vendor')
 
 # Partitions that should have their care_map added to META/care_map.pb
 PARTITIONS_WITH_CARE_MAP = ('system', 'vendor', 'product', 'product_services',
diff --git a/tools/releasetools/sign_target_files_apks.py b/tools/releasetools/sign_target_files_apks.py
index 64e7ca8..9aa9499 100755
--- a/tools/releasetools/sign_target_files_apks.py
+++ b/tools/releasetools/sign_target_files_apks.py
@@ -602,6 +602,13 @@
         print("    Rewriting AVB public key of system_other in /product")
         common.ZipWrite(output_tf_zip, public_key, filename)
 
+    # Should NOT sign boot-debug.img.
+    elif filename in (
+        "BOOT/RAMDISK/force_debuggable",
+        "RECOVERY/RAMDISK/force_debuggable"
+        "RECOVERY/RAMDISK/first_stage_ramdisk/force_debuggable"):
+      raise common.ExternalError("debuggable boot.img cannot be signed")
+
     # A non-APK file; copy it verbatim.
     else:
       common.ZipWriteStr(output_tf_zip, out_info, data)