diff --git a/core/apidiff.mk b/core/apidiff.mk
index 1a7467d..42a1d34 100644
--- a/core/apidiff.mk
+++ b/core/apidiff.mk
@@ -57,8 +57,13 @@
     LOCAL_JAVA_LIBRARIES := android_test_stubs_current $(LOCAL_JAVA_LIBRARIES)
     $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, android_test_stubs_current)
   else
-    LOCAL_JAVA_LIBRARIES := sdk_v$(LOCAL_SDK_VERSION) $(LOCAL_JAVA_LIBRARIES)
-    $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, sdk_v$(LOCAL_SDK_VERSION))
+    ifneq (,$(call has-system-sdk-version,$(LOCAL_SDK_VERSION)))
+      LOCAL_JAVA_LIBRARIES := system_sdk_v$(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION)) $(LOCAL_JAVA_LIBRARIES)
+      $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, system_sdk_v$(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION)))
+    else
+      LOCAL_JAVA_LIBRARIES := sdk_v$(LOCAL_SDK_VERSION) $(LOCAL_JAVA_LIBRARIES)
+      $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, sdk_v$(LOCAL_SDK_VERSION))
+    endif
   endif
 else
   LOCAL_JAVA_LIBRARIES := core-oj core-libart ext framework $(LOCAL_JAVA_LIBRARIES)
diff --git a/core/base_rules.mk b/core/base_rules.mk
index 592650d..3663d51 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -86,6 +86,7 @@
 endif
 
 include $(BUILD_SYSTEM)/local_vndk.mk
+include $(BUILD_SYSTEM)/local_vsdk.mk
 
 my_module_tags := $(LOCAL_MODULE_TAGS)
 ifeq ($(my_host_cross),true)
diff --git a/core/binary.mk b/core/binary.mk
index e54edbe..0a88ca8 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -806,7 +806,7 @@
 ifneq (,$(LOCAL_SDK_VERSION))
 # Set target-api for LOCAL_SDK_VERSIONs other than current.
 ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
-renderscript_target_api := $(LOCAL_SDK_VERSION)
+renderscript_target_api := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
 endif
 endif  # LOCAL_SDK_VERSION is set
 endif  # LOCAL_RENDERSCRIPT_TARGET_API is set
diff --git a/core/config.mk b/core/config.mk
index a4aa930..e0c79d7 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -880,6 +880,11 @@
     $(patsubst $(HISTORICAL_SDK_VERSIONS_ROOT)/%/android.jar,%, \
     $(wildcard $(HISTORICAL_SDK_VERSIONS_ROOT)/*/android.jar)))
 
+TARGET_AVAILABLE_SDK_VERSIONS := $(addprefix system_,$(call numerically_sort,\
+    $(patsubst $(HISTORICAL_SDK_VERSIONS_ROOT)/%/android_system.jar,%, \
+    $(wildcard $(HISTORICAL_SDK_VERSIONS_ROOT)/*/android_system.jar)))) \
+    $(TARGET_AVAILABLE_SDK_VERSIONS)
+
 # We don't have prebuilt test_current SDK yet.
 TARGET_AVAILABLE_SDK_VERSIONS := test_current $(TARGET_AVAILABLE_SDK_VERSIONS)
 
diff --git a/core/definitions.mk b/core/definitions.mk
index 9491412..b850bb8 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -3395,3 +3395,22 @@
   $(eval ALL_MODULES.$(enforce_rro_source_module).REQUIRED += $(enforce_rro_module)) \
 )
 endef
+
+###########################################################
+## Find system_$(VER) in LOCAL_SDK_VERSION
+##
+## $(1): LOCAL_SDK_VERSION
+###########################################################
+define has-system-sdk-version
+$(filter system_%,$(1))
+endef
+
+###########################################################
+## Get numerical version in LOCAL_SDK_VERSION
+##
+## $(1): LOCAL_SDK_VERSION
+###########################################################
+define get-numeric-sdk-version
+$(filter-out current,\
+  $(if $(call has-system-sdk-version,$(1)),$(patsubst system_%,%,$(1)),$(1)))
+endef
diff --git a/core/dpi_specific_apk.mk b/core/dpi_specific_apk.mk
index ac5c4a9..e29cde7 100644
--- a/core/dpi_specific_apk.mk
+++ b/core/dpi_specific_apk.mk
@@ -19,7 +19,7 @@
 $(built_dpi_apk): PRIVATE_AAPT_INCLUDES := $(all_library_res_package_exports)
 $(built_dpi_apk): PRIVATE_RESOURCE_LIST := $(all_res_assets)
 ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
-$(built_dpi_apk): PRIVATE_DEFAULT_APP_TARGET_SDK := $(LOCAL_SDK_VERSION)
+$(built_dpi_apk): PRIVATE_DEFAULT_APP_TARGET_SDK := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
 else
 $(built_dpi_apk): PRIVATE_DEFAULT_APP_TARGET_SDK := $(DEFAULT_APP_TARGET_SDK)
 endif
diff --git a/core/droiddoc.mk b/core/droiddoc.mk
index 2bac984..778a631 100644
--- a/core/droiddoc.mk
+++ b/core/droiddoc.mk
@@ -72,8 +72,13 @@
     LOCAL_JAVA_LIBRARIES := android_test_stubs_current $(LOCAL_JAVA_LIBRARIES)
     $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, android_test_stubs_current)
   else
-    LOCAL_JAVA_LIBRARIES := sdk_v$(LOCAL_SDK_VERSION) $(LOCAL_JAVA_LIBRARIES)
-    $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, sdk_v$(LOCAL_SDK_VERSION))
+    ifneq (,$(call has-system-sdk-version,$(LOCAL_SDK_VERSION)))
+      LOCAL_JAVA_LIBRARIES := system_sdk_v$(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION)) $(LOCAL_JAVA_LIBRARIES)
+      $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, system_sdk_v$(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION)))
+    else
+      LOCAL_JAVA_LIBRARIES := sdk_v$(LOCAL_SDK_VERSION) $(LOCAL_JAVA_LIBRARIES)
+      $(full_target): PRIVATE_BOOTCLASSPATH := $(call java-lib-files, sdk_v$(LOCAL_SDK_VERSION))
+    endif
   endif
 else
   LOCAL_JAVA_LIBRARIES := core-oj core-libart ext framework $(LOCAL_JAVA_LIBRARIES)
diff --git a/core/host_dalvik_java_library.mk b/core/host_dalvik_java_library.mk
index a522f0b..1b3f967 100644
--- a/core/host_dalvik_java_library.mk
+++ b/core/host_dalvik_java_library.mk
@@ -186,8 +186,8 @@
 endif # !LOCAL_IS_STATIC_JAVA_LIBRARY
 
 ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
-  my_default_app_target_sdk := $(LOCAL_SDK_VERSION)
-  my_sdk_version := $(LOCAL_SDK_VERSION)
+  my_default_app_target_sdk := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
+  my_sdk_version := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
 else
   my_default_app_target_sdk := $(DEFAULT_APP_TARGET_SDK)
   my_sdk_version := $(PLATFORM_SDK_VERSION)
diff --git a/core/java.mk b/core/java.mk
index 45d5678..99dc9fc 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -135,7 +135,7 @@
   ifneq (,$(LOCAL_SDK_VERSION))
     # Set target-api for LOCAL_SDK_VERSIONs other than current.
     ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
-      renderscript_target_api := $(LOCAL_SDK_VERSION)
+      renderscript_target_api := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
     endif
   endif  # LOCAL_SDK_VERSION is set
 endif  # LOCAL_RENDERSCRIPT_TARGET_API is set
@@ -820,8 +820,8 @@
 endif  # full_classes_jar is defined
 
 ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
-  my_default_app_target_sdk := $(LOCAL_SDK_VERSION)
-  my_sdk_version := $(LOCAL_SDK_VERSION)
+  my_default_app_target_sdk := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
+  my_sdk_version := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
 else
   my_default_app_target_sdk := $(DEFAULT_APP_TARGET_SDK)
   my_sdk_version := $(PLATFORM_SDK_VERSION)
diff --git a/core/java_common.mk b/core/java_common.mk
index 4dd0de6..59c5e34 100644
--- a/core/java_common.mk
+++ b/core/java_common.mk
@@ -229,8 +229,12 @@
     else ifeq ($(LOCAL_SDK_VERSION)$(TARGET_BUILD_APPS),test_current)
       full_java_bootclasspath_libs := $(call java-lib-header-files,android_test_stubs_current)
     else
-      full_java_bootclasspath_libs := $(call java-lib-header-files,sdk_v$(LOCAL_SDK_VERSION))
-    endif # current, system_current, or test_current
+      ifneq (,$(call has-system-sdk-version,$(LOCAL_SDK_VERSION)))
+        full_java_bootclasspath_libs := $(call java-lib-header-files,system_sdk_v$(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION)))
+      else
+        full_java_bootclasspath_libs := $(call java-lib-header-files,sdk_v$(LOCAL_SDK_VERSION))
+      endif
+    endif # current, system_current, system_${VER} or test_current
   endif # LOCAL_SDK_VERSION
 
   ifneq ($(LOCAL_NO_STANDARD_LIBRARIES),true)
@@ -404,6 +408,10 @@
 my_link_type := java:system
 my_warn_types := java:platform
 my_allowed_types := java:sdk java:system
+else ifneq (,$(call has-system-sdk-version,$(LOCAL_SDK_VERSION)))
+my_link_type := java:system
+my_warn_types := java:platform
+my_allowed_types := java:sdk java:system
 else ifneq ($(LOCAL_SDK_VERSION),)
 my_link_type := java:sdk
 my_warn_types := java:system java:platform
diff --git a/core/local_vsdk.mk b/core/local_vsdk.mk
new file mode 100644
index 0000000..f798d47
--- /dev/null
+++ b/core/local_vsdk.mk
@@ -0,0 +1,19 @@
+
+ifdef BOARD_VSDK_VERSION
+# Set LOCAL_SDK_VERSION to system_current, If LOCAL_SDK_VERSION is not defined and LOCAL_VENDOR_MODULE is true
+  _is_vendor_app :=
+  ifneq (,$(filter true,$(LOCAL_VENDOR_MODULE) $(LOCAL_ODM_MODULE) $(LOCAL_OEM_MODULE) $(LOCAL_PROPRIETARY_MODULE)))
+    _is_vendor_app := true
+  else
+    ifneq (,$(filter $(TARGET_OUT_VENDOR)%,$(LOCAL_MODULE_PATH) $(LOCAL_MODULE_PATH_32) $(LOCAL_MODULE_PATH_64)))
+      _is_vendor_app := true
+    endif
+  endif
+  ifneq (,$(filter JAVA_LIBRARIES APPS,$(LOCAL_MODULE_CLASS)))
+    ifndef LOCAL_SDK_VERSION
+      ifeq ($(_is_vendor_app),true)
+        LOCAL_SDK_VERSION := system_current
+      endif
+    endif
+  endif
+endif
diff --git a/core/package_internal.mk b/core/package_internal.mk
index 6337131..282bcad 100644
--- a/core/package_internal.mk
+++ b/core/package_internal.mk
@@ -389,7 +389,7 @@
 ifneq (,$(LOCAL_SDK_VERSION))
 # Set target-api for LOCAL_SDK_VERSIONs other than current.
 ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
-renderscript_target_api := $(LOCAL_SDK_VERSION)
+renderscript_target_api := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
 endif
 endif  # LOCAL_SDK_VERSION is set
 endif  # LOCAL_RENDERSCRIPT_TARGET_API is set
diff --git a/core/prebuilt_internal.mk b/core/prebuilt_internal.mk
index 6b7f150..2a9ad1f 100644
--- a/core/prebuilt_internal.mk
+++ b/core/prebuilt_internal.mk
@@ -540,6 +540,8 @@
 
 ifeq ($(LOCAL_SDK_VERSION),system_current)
 my_link_type := java:system
+else ifneq (,$(call has-system-sdk-version,$(LOCAL_SDK_VERSION)))
+my_link_type := java:system
 else ifneq ($(LOCAL_SDK_VERSION),)
 my_link_type := java:sdk
 else
diff --git a/core/soong_java_prebuilt.mk b/core/soong_java_prebuilt.mk
index ccbe745..14fe73e 100644
--- a/core/soong_java_prebuilt.mk
+++ b/core/soong_java_prebuilt.mk
@@ -79,6 +79,10 @@
 my_link_type := java:system
 my_warn_types := java:platform
 my_allowed_types := java:sdk java:system
+else ifneq (,$(call has-system-sdk-version,$(LOCAL_SDK_VERSION)))
+my_link_type := java:system
+my_warn_types := java:platform
+my_allowed_types := java:sdk java:system
 else ifneq ($(LOCAL_SDK_VERSION),)
 my_link_type := java:sdk
 my_warn_types := java:system java:platform
diff --git a/core/static_java_library.mk b/core/static_java_library.mk
index dd54135..ae606dd 100644
--- a/core/static_java_library.mk
+++ b/core/static_java_library.mk
@@ -160,7 +160,7 @@
 ifneq (,$(LOCAL_SDK_VERSION))
 # Set target-api for LOCAL_SDK_VERSIONs other than current.
 ifneq (,$(filter-out current system_current test_current, $(LOCAL_SDK_VERSION)))
-renderscript_target_api := $(LOCAL_SDK_VERSION)
+renderscript_target_api := $(call get-numeric-sdk-version,$(LOCAL_SDK_VERSION))
 endif
 endif  # LOCAL_SDK_VERSION is set
 endif  # LOCAL_RENDERSCRIPT_TARGET_API is set