diff --git a/CleanSpec.mk b/CleanSpec.mk
index 0634fad..f5f2a14 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -617,6 +617,8 @@
 # Clean up bufferhub files
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/bin/hw/android.frameworks.bufferhub@1.0-service)
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/etc/init/android.frameworks.bufferhub@1.0-service.rc)
+
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/super.img)
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************
diff --git a/core/Makefile b/core/Makefile
index 24cc4bd..db2ddc4 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -2165,7 +2165,7 @@
 #   libicuuc.so
 #   libnativehelper.so  - cf_x86_phone-userdebug builds get this in system/lib/arm
 #   libprofile.so
-#   libsigchain.so
+#   libsigchain.so  - cf_x86_phone-userdebug builds get this in system/lib/arm
 #   libtombstoned_client.so
 APEX_MODULE_LIBS= \
   libadbconnection.so \
@@ -4426,7 +4426,7 @@
 endef
 
 ifneq (true,$(PRODUCT_RETROFIT_DYNAMIC_PARTITIONS))
-INSTALLED_SUPERIMAGE_TARGET := $(PRODUCT_OUT)/super.img
+INSTALLED_SUPERIMAGE_TARGET := $(call intermediates-dir-for,PACKAGING,super.img)/super.img
 $(INSTALLED_SUPERIMAGE_TARGET): extracted_input_target_files := $(patsubst %.zip,%,$(BUILT_TARGET_FILES_PACKAGE))
 $(INSTALLED_SUPERIMAGE_TARGET): $(LPMAKE) $(BUILT_TARGET_FILES_PACKAGE) $(BUILD_SUPER_IMAGE)
 	$(call pretty,"Target super fs image: $@")
diff --git a/core/base_rules.mk b/core/base_rules.mk
index f477eda..d5055d4 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -224,15 +224,15 @@
 ifdef LOCAL_IS_HOST_MODULE
   partition_tag :=
 else
-ifeq (true,$(LOCAL_VENDOR_MODULE))
+ifeq (true,$(strip $(LOCAL_VENDOR_MODULE)))
   partition_tag := _VENDOR
-else ifeq (true,$(LOCAL_OEM_MODULE))
+else ifeq (true,$(strip $(LOCAL_OEM_MODULE)))
   partition_tag := _OEM
-else ifeq (true,$(LOCAL_ODM_MODULE))
+else ifeq (true,$(strip $(LOCAL_ODM_MODULE)))
   partition_tag := _ODM
-else ifeq (true,$(LOCAL_PRODUCT_MODULE))
+else ifeq (true,$(strip $(LOCAL_PRODUCT_MODULE)))
   partition_tag := _PRODUCT
-else ifeq (true,$(LOCAL_PRODUCT_SERVICES_MODULE))
+else ifeq (true,$(strip $(LOCAL_PRODUCT_SERVICES_MODULE)))
   partition_tag := _PRODUCT_SERVICES
 else ifeq (NATIVE_TESTS,$(LOCAL_MODULE_CLASS))
   partition_tag := _DATA
diff --git a/core/build_rro_package.mk b/core/build_rro_package.mk
index c3daf6e..a6921d5 100644
--- a/core/build_rro_package.mk
+++ b/core/build_rro_package.mk
@@ -16,11 +16,11 @@
 endif
 
 partition :=
-ifeq ($(LOCAL_ODM_MODULE),true)
+ifeq ($(strip $(LOCAL_ODM_MODULE)),true)
   partition := $(TARGET_OUT_ODM)
-else ifeq ($(LOCAL_VENDOR_MODULE),true)
+else ifeq ($(strip $(LOCAL_VENDOR_MODULE)),true)
   partition := $(TARGET_OUT_VENDOR)
-else ifeq ($(LOCAL_PRODUCT_SERVICES_MODULE),true)
+else ifeq ($(strip $(LOCAL_PRODUCT_SERVICES_MODULE)),true)
   partition := $(TARGET_OUT_PRODUCT_SERVICES)
 else
   partition := $(TARGET_OUT_PRODUCT)
diff --git a/target/product/base_system.mk b/target/product/base_system.mk
index e55124b..c3a7516 100644
--- a/target/product/base_system.mk
+++ b/target/product/base_system.mk
@@ -167,7 +167,6 @@
     libradio_metadata \
     librtp_jni \
     libsensorservice \
-    libsigchain \
     libskia \
     libsonic \
     libsonivox \
@@ -278,7 +277,6 @@
 PRODUCT_HOST_PACKAGES += \
     BugReport \
     adb \
-    adbd \
     art-tools \
     atest \
     bcc \
@@ -295,9 +293,7 @@
     minigzip \
     mke2fs \
     resize2fs \
-    selinux_policy_system \
     sgdisk \
-    shell_and_utilities_system \
     sqlite3 \
     tinyplay \
     tune2fs \
@@ -316,11 +312,11 @@
 $(error TARGET_CORE_JARS is empty; cannot initialize PRODUCT_BOOT_JARS variable)
 endif
 
-# The order matters
+# The order matters for runtime class lookup performance.
 PRODUCT_BOOT_JARS := \
     $(TARGET_CORE_JARS) \
-    ext \
     framework \
+    ext \
     telephony-common \
     voip-common \
     ims-common \
diff --git a/target/product/gsi_common.mk b/target/product/gsi_common.mk
index 5e73e63..2c978ab 100644
--- a/target/product/gsi_common.mk
+++ b/target/product/gsi_common.mk
@@ -31,7 +31,6 @@
 # The mainline checking whitelist, should be clean up
 PRODUCT_ARTIFACT_PATH_REQUIREMENT_WHITELIST += \
     system/app/messaging/messaging.apk \
-    system/app/PhotoTable/PhotoTable.apk \
     system/app/WAPPushManager/WAPPushManager.apk \
     system/bin/healthd \
     system/etc/init/healthd.rc \
diff --git a/target/product/mainline.mk b/target/product/mainline.mk
index 59bad98..7900cdf 100644
--- a/target/product/mainline.mk
+++ b/target/product/mainline.mk
@@ -14,10 +14,24 @@
 # limitations under the License.
 #
 
-# Makefile including the mainline system image, and the relevant AOSP portions
-# for the other partitions.
+# This makefile is intended to serve as a base for completely AOSP based
+# mainline devices, It contain the mainline system partition and sensible
+# defaults for the product and vendor partition.
 $(call inherit-product, $(SRC_TARGET_DIR)/product/mainline_system.mk)
+
 $(call inherit-product, $(SRC_TARGET_DIR)/product/handheld_vendor.mk)
 $(call inherit-product, $(SRC_TARGET_DIR)/product/handheld_product.mk)
 $(call inherit-product, $(SRC_TARGET_DIR)/product/telephony_vendor.mk)
 $(call inherit-product, $(SRC_TARGET_DIR)/product/telephony_product.mk)
+
+$(call inherit-product, frameworks/base/data/sounds/AllAudio.mk)
+
+PRODUCT_PROPERTY_OVERRIDES += \
+    ro.config.ringtone=Ring_Synth_04.ogg \
+    ro.com.android.dataroaming=true \
+
+PRODUCT_PACKAGES += \
+    PhotoTable \
+    WallpaperPicker \
+
+PRODUCT_COPY_FILES += device/sample/etc/apns-full-conf.xml:$(TARGET_COPY_OUT_PRODUCT)/etc/apns-conf.xml
diff --git a/tools/releasetools/merge_target_files.py b/tools/releasetools/merge_target_files.py
index 3c6bfbf..3b72551 100755
--- a/tools/releasetools/merge_target_files.py
+++ b/tools/releasetools/merge_target_files.py
@@ -47,6 +47,9 @@
   --rebuild_recovery
       Rebuild the recovery patch used by non-A/B devices and write it to the
       system image.
+
+  --keep-tmp
+      Keep tempoary files for debugging purposes.
 """
 
 from __future__ import print_function
@@ -296,6 +299,37 @@
       output.write('%s\n' % partition)
 
 
+def append_recovery_to_filesystem_config(output_target_files_temp_dir):
+  """Perform special processing for META/filesystem_config.txt
+
+  This function appends recovery information to META/filesystem_config.txt
+  so that recovery patch regeneration will succeed.
+
+  Args:
+    output_target_files_temp_dir: The name of a directory that will be used
+    to create the output target files package after all the special cases
+    are processed. We find filesystem_config.txt here.
+  """
+
+  filesystem_config_txt = os.path.join(
+      output_target_files_temp_dir,
+      'META',
+      'filesystem_config.txt')
+
+  with open(filesystem_config_txt, 'a') as f:
+    # TODO(bpeckham) this data is hard coded. It should be generated
+    # programmatically.
+    f.write(
+        'system/bin/install-recovery.sh 0 0 750 '
+        'selabel=u:object_r:install_recovery_exec:s0 capabilities=0x0\n')
+    f.write(
+        'system/recovery-from-boot.p 0 0 644 '
+        'selabel=u:object_r:system_file:s0 capabilities=0x0\n')
+    f.write(
+        'system/etc/recovery.img 0 0 440 '
+        'selabel=u:object_r:install_recovery_exec:s0 capabilities=0x0\n')
+
+
 def process_misc_info_txt(
     system_target_files_temp_dir,
     other_target_files_temp_dir,
@@ -454,7 +488,9 @@
     system_target_files_temp_dir,
     other_target_files_temp_dir,
     output_target_files_temp_dir,
-    system_misc_info_keys):
+    system_misc_info_keys,
+    rebuild_recovery
+):
   """Perform special-case processing for certain target files items.
 
   Certain files in the output target files package require special-case
@@ -476,12 +512,20 @@
 
     system_misc_info_keys: A list of keys to obtain from the system instance
     of META/misc_info.txt. The remaining keys from the other instance.
+
+    rebuild_recovery: If true, rebuild the recovery patch used by non-A/B
+    devices and write it to the system image.
   """
 
-  process_ab_partitions_txt(
-      system_target_files_temp_dir=system_target_files_temp_dir,
-      other_target_files_temp_dir=other_target_files_temp_dir,
-      output_target_files_temp_dir=output_target_files_temp_dir)
+  if 'ab_update' in system_misc_info_keys:
+    process_ab_partitions_txt(
+        system_target_files_temp_dir=system_target_files_temp_dir,
+        other_target_files_temp_dir=other_target_files_temp_dir,
+        output_target_files_temp_dir=output_target_files_temp_dir)
+
+  if rebuild_recovery:
+    append_recovery_to_filesystem_config(
+        output_target_files_temp_dir=output_target_files_temp_dir)
 
   process_misc_info_txt(
       system_target_files_temp_dir=system_target_files_temp_dir,
@@ -599,7 +643,8 @@
       system_target_files_temp_dir=system_target_files_temp_dir,
       other_target_files_temp_dir=other_target_files_temp_dir,
       output_target_files_temp_dir=output_target_files_temp_dir,
-      system_misc_info_keys=system_misc_info_keys)
+      system_misc_info_keys=system_misc_info_keys,
+      rebuild_recovery=rebuild_recovery)
 
   # Regenerate IMAGES in the temporary directory.
 
@@ -704,7 +749,7 @@
       OPTIONS.output_target_files = a
     elif o == '--rebuild_recovery':
       OPTIONS.rebuild_recovery = True
-    elif o == '--keep_tmp':
+    elif o == '--keep-tmp':
       OPTIONS.keep_tmp = True
     else:
       return False
@@ -720,7 +765,7 @@
           'other-item-list=',
           'output-target-files=',
           'rebuild_recovery',
-          "keep_tmp",
+          'keep-tmp',
       ],
       extra_option_handler=option_handler)
 
diff --git a/tools/releasetools/sign_target_files_apks.py b/tools/releasetools/sign_target_files_apks.py
index d3e9ea1..c482a49 100755
--- a/tools/releasetools/sign_target_files_apks.py
+++ b/tools/releasetools/sign_target_files_apks.py
@@ -383,24 +383,24 @@
 
   Args:
     apex_data: Raw APEX data.
-    payload_key: The path to payload signing key (w/o extension).
+    payload_key: The path to payload signing key (w/ extension).
     container_key: The path to container signing key (w/o extension).
     container_pw: The matching password of the container_key, or None.
     codename_to_api_level_map: A dict that maps from codename to API level.
     signing_args: Additional args to be passed to the payload signer.
 
   Returns:
-    (signed_apex, payload_key_name): signed_apex is the path to the signed APEX
-        file; payload_key_name is a str of the payload signing key name (e.g.
-        com.android.tzdata).
+    The path to the signed APEX file.
   """
   apex_file = common.MakeTempFile(prefix='apex-', suffix='.apex')
   with open(apex_file, 'wb') as apex_fp:
     apex_fp.write(apex_data)
 
   APEX_PAYLOAD_IMAGE = 'apex_payload.img'
+  APEX_PUBKEY = 'apex_pubkey'
 
-  # 1. Extract and sign the APEX_PAYLOAD_IMAGE entry with the given payload_key.
+  # 1a. Extract and sign the APEX_PAYLOAD_IMAGE entry with the given
+  # payload_key.
   payload_dir = common.MakeTempDir(prefix='apex-payload-')
   with zipfile.ZipFile(apex_file) as apex_fd:
     payload_file = apex_fd.extract(APEX_PAYLOAD_IMAGE, payload_dir)
@@ -414,9 +414,14 @@
       payload_info['Salt'],
       signing_args)
 
+  # 1b. Update the embedded payload public key.
+  payload_public_key = common.ExtractAvbPublicKey(payload_key)
+
   common.ZipDelete(apex_file, APEX_PAYLOAD_IMAGE)
+  common.ZipDelete(apex_file, APEX_PUBKEY)
   apex_zip = zipfile.ZipFile(apex_file, 'a')
   common.ZipWrite(apex_zip, payload_file, arcname=APEX_PAYLOAD_IMAGE)
+  common.ZipWrite(apex_zip, payload_public_key, arcname=APEX_PUBKEY)
   common.ZipClose(apex_zip)
 
   # 2. Align the files at page boundary (same as in apexer).
@@ -440,7 +445,7 @@
       codename_to_api_level_map=codename_to_api_level_map,
       extra_signapk_args=extra_signapk_args)
 
-  return (signed_apex, payload_info['apex.key'])
+  return signed_apex
 
 
 def ProcessTargetFiles(input_tf_zip, output_tf_zip, misc_info,
@@ -454,10 +459,6 @@
        if GetApkFileInfo(i.filename, compressed_extension, [])[0]])
   system_root_image = misc_info.get("system_root_image") == "true"
 
-  # A dict of APEX payload public keys that should be updated, i.e. the files
-  # under '/system/etc/security/apex/'.
-  updated_apex_payload_keys = {}
-
   for info in input_tf_zip.infolist():
     filename = info.filename
     if filename.startswith("IMAGES/"):
@@ -511,7 +512,7 @@
         print("           : %-*s payload   (%s)" % (
             maxsize, name, payload_key))
 
-        (signed_apex, payload_key_name) = SignApex(
+        signed_apex = SignApex(
             data,
             payload_key,
             container_key,
@@ -519,7 +520,6 @@
             codename_to_api_level_map,
             OPTIONS.avb_extra_args.get('apex'))
         common.ZipWrite(output_tf_zip, signed_apex, filename)
-        updated_apex_payload_keys[payload_key_name] = payload_key
 
       else:
         print(
@@ -606,34 +606,6 @@
     else:
       common.ZipWriteStr(output_tf_zip, out_info, data)
 
-  # Copy or update APEX payload public keys.
-  for info in input_tf_zip.infolist():
-    filename = info.filename
-    if (os.path.dirname(filename) != 'SYSTEM/etc/security/apex' or
-        filename == 'SYSTEM/etc/security/apex/'):
-      continue
-
-    name = os.path.basename(filename)
-
-    # Copy the keys for PRESIGNED APEXes.
-    if name not in updated_apex_payload_keys:
-      data = input_tf_zip.read(filename)
-      common.ZipWriteStr(output_tf_zip, info, data)
-      continue
-
-    key_path = updated_apex_payload_keys[name]
-    if not os.path.exists(key_path) and not key_path.endswith('.pem'):
-      key_path = '{}.pem'.format(key_path)
-    assert os.path.exists(key_path), \
-        'Failed to find public key file {} for APEX {}'.format(
-            updated_apex_payload_keys[name], name)
-
-    print('Replacing APEX payload public key for {} with {}'.format(
-        name, key_path))
-
-    public_key = common.ExtractAvbPublicKey(key_path)
-    common.ZipWrite(output_tf_zip, public_key, arcname=filename)
-
   if OPTIONS.replace_ota_keys:
     ReplaceOtaKeys(input_tf_zip, output_tf_zip, misc_info)