diff --git a/core/binary.mk b/core/binary.mk
index 0582920..b14d8b8 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -1570,28 +1570,22 @@
 ## Define PRIVATE_ variables from global vars
 ###########################################################
 ifndef LOCAL_IS_HOST_MODULE
+
 ifdef LOCAL_USE_VNDK
-my_target_global_c_includes := \
-    $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)PROJECT_INCLUDES)
-my_target_global_c_system_includes := \
-    $(TARGET_OUT_HEADERS) \
-    $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)PROJECT_SYSTEM_INCLUDES)
+  my_target_global_c_includes :=
+  my_target_global_c_system_includes := $(TARGET_OUT_HEADERS)
 else ifdef LOCAL_SDK_VERSION
-my_target_global_c_includes :=
-my_target_global_c_system_includes := $(my_ndk_stl_include_path) $(my_ndk_sysroot_include)
+  my_target_global_c_includes :=
+  my_target_global_c_system_includes := $(my_ndk_stl_include_path) $(my_ndk_sysroot_include)
 else ifdef BOARD_VNDK_VERSION
-my_target_global_c_includes := $(SRC_HEADERS) \
-    $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)PROJECT_INCLUDES) \
+  my_target_global_c_includes := $(SRC_HEADERS) \
     $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)C_INCLUDES)
-my_target_global_c_system_includes := $(SRC_SYSTEM_HEADERS) \
-    $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)PROJECT_SYSTEM_INCLUDES) \
+  my_target_global_c_system_includes := $(SRC_SYSTEM_HEADERS) \
     $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)C_SYSTEM_INCLUDES)
 else
-my_target_global_c_includes := $(SRC_HEADERS) \
-    $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)PROJECT_INCLUDES) \
+  my_target_global_c_includes := $(SRC_HEADERS) \
     $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)C_INCLUDES)
-my_target_global_c_system_includes := $(SRC_SYSTEM_HEADERS) $(TARGET_OUT_HEADERS) \
-    $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)PROJECT_SYSTEM_INCLUDES) \
+  my_target_global_c_system_includes := $(SRC_SYSTEM_HEADERS) $(TARGET_OUT_HEADERS) \
     $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)C_SYSTEM_INCLUDES)
 endif
 
@@ -1674,9 +1668,22 @@
 ####################################################
 ## Import includes
 ####################################################
+imported_includes :=
+
+ifdef LOCAL_USE_VNDK
+  imported_includes += $(call intermediates-dir-for,HEADER_LIBRARIES,device_kernel_headers,$(my_kind),,$(LOCAL_2ND_ARCH_VAR_PREFIX),$(my_host_cross))
+else ifdef LOCAL_SDK_VERSION
+  # Apps shouldn't need device-specific kernel headers
+else ifdef BOARD_VNDK_VERSION
+  # For devices building with the VNDK, only the VNDK gets device-specific kernel headers by default
+  # In soong, it's entirely opt-in
+else
+  # For older non-VNDK builds, continue adding in kernel headers to everything like we used to
+  imported_includes += $(call intermediates-dir-for,HEADER_LIBRARIES,device_kernel_headers,$(my_kind),,$(LOCAL_2ND_ARCH_VAR_PREFIX),$(my_host_cross))
+endif
+
 imported_includes := $(strip \
-    $(if $(LOCAL_USE_VNDK),\
-      $(call intermediates-dir-for,HEADER_LIBRARIES,device_kernel_headers,$(my_kind),,$(LOCAL_2ND_ARCH_VAR_PREFIX),$(my_host_cross))) \
+    $(imported_includes) \
     $(foreach l, $(installed_shared_library_module_names), \
       $(call intermediates-dir-for,SHARED_LIBRARIES,$(l),$(my_kind),,$(LOCAL_2ND_ARCH_VAR_PREFIX),$(my_host_cross))) \
     $(foreach l, $(my_static_libraries) $(my_whole_static_libraries), \
diff --git a/core/config.mk b/core/config.mk
index 69e2b5c..8910c11 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -135,6 +135,12 @@
   LOCAL_IS_AUX_MODULE \
   ,AUX support has been removed)
 $(KATI_obsolete_var HOST_OUT_TEST_CONFIG TARGET_OUT_TEST_CONFIG LOCAL_TEST_CONFIG_OPTIONS)
+$(KATI_obsolete_var \
+  TARGET_PROJECT_INCLUDES \
+  2ND_TARGET_PROJECT_INCLUDES \
+  TARGET_PROJECT_SYSTEM_INCLUDES \
+  2ND_TARGET_PROJECT_SYSTEM_INCLUDES \
+  ,Project include variables have been removed)
 
 # Used to force goals to build.  Only use for conditionally defined goals.
 .PHONY: FORCE
@@ -1057,16 +1063,6 @@
 RELATIVE_PWD :=
 endif
 
-TARGET_PROJECT_INCLUDES :=
-TARGET_PROJECT_SYSTEM_INCLUDES := \
-		$(TARGET_DEVICE_KERNEL_HEADERS) $(TARGET_BOARD_KERNEL_HEADERS) \
-		$(TARGET_PRODUCT_KERNEL_HEADERS)
-
-ifdef TARGET_2ND_ARCH
-$(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_PROJECT_INCLUDES := $(TARGET_PROJECT_INCLUDES)
-$(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_PROJECT_SYSTEM_INCLUDES := $(TARGET_PROJECT_SYSTEM_INCLUDES)
-endif
-
 # Flags for DEX2OAT
 first_non_empty_of_three = $(if $(1),$(1),$(if $(2),$(2),$(3)))
 DEX2OAT_TARGET_ARCH := $(TARGET_ARCH)
diff --git a/core/soong_config.mk b/core/soong_config.mk
index f0b6be8..18949be 100644
--- a/core/soong_config.mk
+++ b/core/soong_config.mk
@@ -121,7 +121,7 @@
 $(call add_json_bool, ArtUseReadBarrier,                 $(call invert_bool,$(filter false,$(PRODUCT_ART_USE_READ_BARRIER))))
 $(call add_json_bool, Binder32bit,                       $(BINDER32BIT))
 $(call add_json_str,  BtConfigIncludeDir,                $(BOARD_BLUETOOTH_BDROID_BUILDCFG_INCLUDE_DIR))
-$(call add_json_list, DeviceKernelHeaders,               $(TARGET_PROJECT_SYSTEM_INCLUDES))
+$(call add_json_list, DeviceKernelHeaders,               $(TARGET_DEVICE_KERNEL_HEADERS) $(TARGET_BOARD_KERNEL_HEADERS) $(TARGET_PRODUCT_KERNEL_HEADERS))
 $(call add_json_bool, DevicePrefer32BitApps,             $(filter true,$(TARGET_PREFER_32_BIT_APPS)))
 $(call add_json_bool, DevicePrefer32BitExecutables,      $(filter true,$(TARGET_PREFER_32_BIT_EXECUTABLES)))
 $(call add_json_str,  DeviceVndkVersion,                 $(BOARD_VNDK_VERSION))
diff --git a/core/tasks/boot_jars_package_check.mk b/core/tasks/boot_jars_package_check.mk
index cbaa682..02d7212 100644
--- a/core/tasks/boot_jars_package_check.mk
+++ b/core/tasks/boot_jars_package_check.mk
@@ -26,7 +26,7 @@
 # Convert the colon-separated components <apex>:<jar> to <jar>.<apex> names
 # (e.g. com.android.media:updatable-media -> updatable-media.com.android.media).
 # Special cases:
-#   - for the "platform" apex drop the .<apex> suffix
+#   - for the "platform" or "system_ext" apex drop the .<apex> suffix
 #   - for the ART apex select release variant
 boot_jars := $(foreach pair,$(PRODUCT_BOOT_JARS) $(PRODUCT_UPDATABLE_BOOT_JARS), \
   $(eval apex := $(call word-colon,1,$(pair))) \
@@ -34,6 +34,7 @@
   $(eval q := :) \
   $(eval sfx := $(q).$(apex)$(q)) \
   $(eval sfx := $(subst $(q).platform$(q),$(q)$(q),$(sfx))) \
+  $(eval sfx := $(subst $(q).system_ext$(q),$(q)$(q),$(sfx))) \
   $(eval sfx := $(subst $(q).com.android.art$(q),$(q).com.android.art.release$(q),$(sfx))) \
   $(eval sfx := $(patsubst $(q)%$(q),%,$(sfx))) \
   $(jar)$(sfx))
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index cdb10fa..1abf5a5 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -361,10 +361,13 @@
     self.oem_dicts = oem_dicts
 
     self._is_ab = info_dict.get("ab_update") == "true"
-    self._oem_props = info_dict.get("oem_fingerprint_properties")
 
-    if self._oem_props:
-      assert oem_dicts, "OEM source required for this build"
+    # Skip _oem_props if oem_dicts is None to use BuildInfo in
+    # sign_target_files_apks
+    if self.oem_dicts:
+      self._oem_props = info_dict.get("oem_fingerprint_properties")
+    else:
+      self._oem_props = None
 
     def check_fingerprint(fingerprint):
       if (" " in fingerprint or any(ord(ch) > 127 for ch in fingerprint)):
diff --git a/tools/releasetools/sign_apex.py b/tools/releasetools/sign_apex.py
index b0128dc..fb947f4 100755
--- a/tools/releasetools/sign_apex.py
+++ b/tools/releasetools/sign_apex.py
@@ -35,6 +35,10 @@
   -e  (--extra_apks)  <name,name,...=key>
       Add extra APK name/key pairs. This is useful to sign the apk files in the
       apex payload image.
+
+  --codename_to_api_level_map Q:29,R:30,...
+      A Mapping of codename to api level.  This is useful to provide sdk targeting
+      information to APK Signer.
 """
 
 import logging
@@ -48,7 +52,7 @@
 
 
 def SignApexFile(avbtool, apex_file, payload_key, container_key, no_hashtree,
-                 apk_keys=None, signing_args=None):
+                 apk_keys=None, signing_args=None, codename_to_api_level_map=None):
   """Signs the given apex file."""
   with open(apex_file, 'rb') as input_fp:
     apex_data = input_fp.read()
@@ -59,7 +63,7 @@
       payload_key=payload_key,
       container_key=container_key,
       container_pw=None,
-      codename_to_api_level_map=None,
+      codename_to_api_level_map=codename_to_api_level_map,
       no_hashtree=no_hashtree,
       apk_keys=apk_keys,
       signing_args=signing_args)
@@ -82,6 +86,13 @@
       options['payload_key'] = a
     elif o == '--payload_extra_args':
       options['payload_extra_args'] = a
+    elif o == '--codename_to_api_level_map':
+      versions = a.split(",")
+      for v in versions:
+        key, value = v.split(":")
+        if 'codename_to_api_level_map' not in options:
+          options['codename_to_api_level_map'] = {}
+        options['codename_to_api_level_map'].update({key: value})
     elif o in ("-e", "--extra_apks"):
       names, key = a.split("=")
       names = names.split(",")
@@ -98,6 +109,7 @@
       extra_opts='e:',
       extra_long_opts=[
           'avbtool=',
+          'codename_to_api_level_map=',
           'container_key=',
           'payload_extra_args=',
           'payload_key=',
@@ -119,7 +131,9 @@
       options['container_key'],
       no_hashtree=False,
       apk_keys=options.get('extra_apks', {}),
-      signing_args=options.get('payload_extra_args'))
+      signing_args=options.get('payload_extra_args'),
+      codename_to_api_level_map=options.get(
+          'codename_to_api_level_map', {}))
   shutil.copyfile(signed_apex, args[1])
   logger.info("done.")
 
diff --git a/tools/releasetools/test_check_target_files_vintf.py b/tools/releasetools/test_check_target_files_vintf.py
index 79f9018..d326229 100644
--- a/tools/releasetools/test_check_target_files_vintf.py
+++ b/tools/releasetools/test_check_target_files_vintf.py
@@ -35,20 +35,20 @@
     'SYSTEM_EXT/etc/build.prop': '',
 
     # Non-empty files
-    'SYSTEM/compatibility_matrix.xml':"""
-        <compatibility-matrix version="1.0" type="framework">
+    'SYSTEM/etc/vintf/compatibility_matrix.1.xml':"""
+        <compatibility-matrix version="1.0" level="1" type="framework">
             <sepolicy>
                 <sepolicy-version>0.0</sepolicy-version>
                 <kernel-sepolicy-version>0</kernel-sepolicy-version>
             </sepolicy>
         </compatibility-matrix>""",
     'SYSTEM/manifest.xml':
-        '<manifest version="1.0" type="framework" />',
+        '<manifest version="1.0" type="framework"/>',
     'VENDOR/build.prop': 'ro.product.first_api_level=29\n',
     'VENDOR/compatibility_matrix.xml':
         '<compatibility-matrix version="1.0" type="device" />',
-    'VENDOR/manifest.xml':
-        '<manifest version="1.0" type="device"/>',
+    'VENDOR/etc/vintf/manifest.xml':
+        '<manifest version="1.0" target-level="1" type="device"/>',
     'META/misc_info.txt':
         'recovery_api_version=3\nfstab_version=2\nvintf_enforce=true\n',
 }
@@ -140,6 +140,6 @@
   def test_CheckVintf_bad_xml(self):
     test_dir = self.prepare_test_dir('does-not-exist')
     write_string_to_file('not an XML',
-                         os.path.join(test_dir, 'VENDOR/manifest.xml'))
+                         os.path.join(test_dir, 'VENDOR/etc/vintf/manifest.xml'))
     # Should raise an error because a file has invalid format.
     self.assertRaises(common.ExternalError, CheckVintf, test_dir)
diff --git a/tools/releasetools/test_common.py b/tools/releasetools/test_common.py
index f1971d3..665eb51 100644
--- a/tools/releasetools/test_common.py
+++ b/tools/releasetools/test_common.py
@@ -176,10 +176,6 @@
     self.assertEqual('brand3/product-name/device3:build-thumbprint',
                      target_info.fingerprint)
 
-    # Missing oem_dict should be rejected.
-    self.assertRaises(AssertionError, common.BuildInfo,
-                      self.TEST_INFO_DICT_USES_OEM_PROPS, None)
-
   def test_init_badFingerprint(self):
     info_dict = copy.deepcopy(self.TEST_INFO_DICT)
     info_dict['build.prop']['ro.build.fingerprint'] = 'bad fingerprint'
diff --git a/tools/releasetools/testdata/vintf/kernel/SYSTEM/compatibility_matrix.xml b/tools/releasetools/testdata/vintf/kernel/SYSTEM/etc/vintf/compatibility_matrix.1.xml
similarity index 74%
rename from tools/releasetools/testdata/vintf/kernel/SYSTEM/compatibility_matrix.xml
rename to tools/releasetools/testdata/vintf/kernel/SYSTEM/etc/vintf/compatibility_matrix.1.xml
index ed46b6b..a92dd6e 100644
--- a/tools/releasetools/testdata/vintf/kernel/SYSTEM/compatibility_matrix.xml
+++ b/tools/releasetools/testdata/vintf/kernel/SYSTEM/etc/vintf/compatibility_matrix.1.xml
@@ -1,4 +1,4 @@
-<compatibility-matrix version="1.0" type="framework">
+<compatibility-matrix version="1.0" level="1" type="framework">
     <kernel version="4.14.1" />
     <sepolicy>
         <sepolicy-version>0.0</sepolicy-version>
diff --git a/tools/releasetools/testdata/vintf/matrix_incompat/SYSTEM/compatibility_matrix.xml b/tools/releasetools/testdata/vintf/matrix_incompat/SYSTEM/etc/vintf/compatibility_matrix.1.xml
similarity index 71%
rename from tools/releasetools/testdata/vintf/matrix_incompat/SYSTEM/compatibility_matrix.xml
rename to tools/releasetools/testdata/vintf/matrix_incompat/SYSTEM/etc/vintf/compatibility_matrix.1.xml
index 5d891fa..1700e21 100644
--- a/tools/releasetools/testdata/vintf/matrix_incompat/SYSTEM/compatibility_matrix.xml
+++ b/tools/releasetools/testdata/vintf/matrix_incompat/SYSTEM/etc/vintf/compatibility_matrix.1.xml
@@ -1,4 +1,4 @@
-<compatibility-matrix version="1.0" type="framework">
+<compatibility-matrix version="1.0" level="1" type="framework">
     <sepolicy>
         <sepolicy-version>1.0</sepolicy-version>
         <kernel-sepolicy-version>0</kernel-sepolicy-version>
diff --git a/tools/releasetools/testdata/vintf/sku_compat/SYSTEM/compatibility_matrix.xml b/tools/releasetools/testdata/vintf/sku_compat/SYSTEM/etc/vintf/compatibility_matrix.1.xml
similarity index 85%
rename from tools/releasetools/testdata/vintf/sku_compat/SYSTEM/compatibility_matrix.xml
rename to tools/releasetools/testdata/vintf/sku_compat/SYSTEM/etc/vintf/compatibility_matrix.1.xml
index 19a9b6a..22272fd 100644
--- a/tools/releasetools/testdata/vintf/sku_compat/SYSTEM/compatibility_matrix.xml
+++ b/tools/releasetools/testdata/vintf/sku_compat/SYSTEM/etc/vintf/compatibility_matrix.1.xml
@@ -1,4 +1,4 @@
-<compatibility-matrix version="1.0" type="framework">
+<compatibility-matrix version="1.0" level="1" type="framework">
     <hal format="hidl" optional="false">
         <name>foo</name>
         <version>1.0</version>
diff --git a/tools/releasetools/testdata/vintf/sku_incompat/SYSTEM/compatibility_matrix.xml b/tools/releasetools/testdata/vintf/sku_incompat/SYSTEM/etc/vintf/compatibility_matrix.1.xml
similarity index 85%
rename from tools/releasetools/testdata/vintf/sku_incompat/SYSTEM/compatibility_matrix.xml
rename to tools/releasetools/testdata/vintf/sku_incompat/SYSTEM/etc/vintf/compatibility_matrix.1.xml
index e0e0d6c..1a3fc43 100644
--- a/tools/releasetools/testdata/vintf/sku_incompat/SYSTEM/compatibility_matrix.xml
+++ b/tools/releasetools/testdata/vintf/sku_incompat/SYSTEM/etc/vintf/compatibility_matrix.1.xml
@@ -1,4 +1,4 @@
-<compatibility-matrix version="1.0" type="framework">
+<compatibility-matrix version="1.0" level="1" type="framework">
     <hal format="hidl" optional="false">
         <name>foo</name>
         <version>1.1</version>