diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index ca7401b..da799db 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -189,7 +189,7 @@
     #  It must be of the form "YYYY-MM-DD" on production devices.
     #  It must match one of the Android Security Patch Level strings of the Public Security Bulletins.
     #  If there is no $PLATFORM_SECURITY_PATCH set, keep it empty.
-      PLATFORM_SECURITY_PATCH := 2017-12-01
+      PLATFORM_SECURITY_PATCH := 2018-01-05
 endif
 
 ifndef PLATFORM_BASE_OS
diff --git a/target/board/generic/sepolicy/hal_gnss_default.te b/target/board/generic/sepolicy/hal_gnss_default.te
index ddc68cc..0dd3d03 100644
--- a/target/board/generic/sepolicy/hal_gnss_default.te
+++ b/target/board/generic/sepolicy/hal_gnss_default.te
@@ -1 +1,3 @@
-vndbinder_use(hal_gnss_default);
+#============= hal_gnss_default ==============
+allow hal_gnss_default vndbinder_device:chr_file { ioctl open read write };
+
diff --git a/target/board/generic/sepolicy/hal_graphics_composer_default.te b/target/board/generic/sepolicy/hal_graphics_composer_default.te
index 40ecda6..034bdef 100644
--- a/target/board/generic/sepolicy/hal_graphics_composer_default.te
+++ b/target/board/generic/sepolicy/hal_graphics_composer_default.te
@@ -1 +1,3 @@
-vndbinder_use(hal_graphics_composer_default);
+#============= hal_graphics_composer_default ==============
+allow hal_graphics_composer_default vndbinder_device:chr_file { ioctl open read write };
+
diff --git a/target/board/treble_common.mk b/target/board/treble_common.mk
index 253d8ef..1ba6726 100644
--- a/target/board/treble_common.mk
+++ b/target/board/treble_common.mk
@@ -30,7 +30,10 @@
 TARGET_NO_KERNEL := true
 
 # system.img is always ext4 with sparse option
+# GSI also includes make_f2fs to support userdata parition in f2fs
+# for some devices
 TARGET_USERIMAGES_USE_EXT4 := true
+TARGET_USERIMAGES_USE_F2FS := true
 TARGET_USERIMAGES_SPARSE_EXT_DISABLED := false
 TARGET_USES_MKE2FS := true
 
diff --git a/target/product/emulator.mk b/target/product/emulator.mk
index 58245cb..13b8f28 100644
--- a/target/product/emulator.mk
+++ b/target/product/emulator.mk
@@ -110,8 +110,8 @@
     vndk-sp
 
 PRODUCT_COPY_FILES += \
-    device/generic/goldfish/init.ranchu-core.sh:$(TARGET_COPY_OUT_VENDOR)/bin/init.ranchu-core.sh \
-    device/generic/goldfish/init.ranchu-net.sh:$(TARGET_COPY_OUT_VENDOR)/bin/init.ranchu-net.sh \
+    device/generic/goldfish/init.ranchu-core.sh:vendor/bin/init.ranchu-core.sh \
+    device/generic/goldfish/init.ranchu-net.sh:vendor/bin/init.ranchu-net.sh \
     device/generic/goldfish/init.ranchu.rc:root/init.ranchu.rc \
     device/generic/goldfish/fstab.ranchu:root/fstab.ranchu \
     device/generic/goldfish/fstab.ranchu.early:root/fstab.ranchu.early \
diff --git a/target/product/go_defaults_common.mk b/target/product/go_defaults_common.mk
index fbb9567..ca58c1d 100644
--- a/target/product/go_defaults_common.mk
+++ b/target/product/go_defaults_common.mk
@@ -55,3 +55,10 @@
 PRODUCT_PROPERTY_OVERRIDES += dalvik.vm.heapgrowthlimit=128m
 PRODUCT_PROPERTY_OVERRIDES += dalvik.vm.heapsize=256m
 
+# Do not generate libartd.
+PRODUCT_ART_TARGET_INCLUDE_DEBUG_BUILD := false
+
+# Strip the local variable table and the local variable type table to reduce
+# the size of the system image. This has no bearing on stack traces, but will
+# leave less information available via JDWP.
+PRODUCT_MINIMIZE_JAVA_DEBUG_INFO := true
diff --git a/target/product/sdk_base.mk b/target/product/sdk_base.mk
index a641be3..75a63e6 100644
--- a/target/product/sdk_base.mk
+++ b/target/product/sdk_base.mk
@@ -92,7 +92,7 @@
 	frameworks/base/data/sounds/effects/VideoRecord.ogg:system/media/audio/ui/VideoRecord.ogg \
 	frameworks/base/data/sounds/effects/VideoStop.ogg:system/media/audio/ui/VideoStop.ogg \
 	device/generic/goldfish/data/etc/handheld_core_hardware.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/handheld_core_hardware.xml \
-	device/generic/goldfish/camera/media_profiles.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_profiles.xml \
+	device/generic/goldfish/camera/media_profiles.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_profiles_V1_0.xml \
 	frameworks/av/media/libstagefright/data/media_codecs_google_audio.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_codecs_google_audio.xml \
 	frameworks/av/media/libstagefright/data/media_codecs_google_telephony.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_codecs_google_telephony.xml \
 	device/generic/goldfish/camera/media_codecs_google_video.xml:$(TARGET_COPY_OUT_VENDOR)/etc/media_codecs_google_video.xml \
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index 60aa84e..63af8b0 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -1122,6 +1122,11 @@
          "--target_image", target_file]
   if source_file is not None:
     cmd.extend(["--source_image", source_file])
+  if OPTIONS.downgrade:
+    max_timestamp = GetBuildProp("ro.build.date.utc", OPTIONS.source_info_dict)
+  else:
+    max_timestamp = metadata["post-timestamp"]
+  cmd.extend(["--max_timestamp", max_timestamp])
   p1 = common.Run(cmd, stdout=log_file, stderr=subprocess.STDOUT)
   p1.communicate()
   assert p1.returncode == 0, "brillo_update_payload generate failed"