diff --git a/target/board/BoardConfigGsiCommon.mk b/target/board/BoardConfigGsiCommon.mk
index dfa103a..a52bb80 100644
--- a/target/board/BoardConfigGsiCommon.mk
+++ b/target/board/BoardConfigGsiCommon.mk
@@ -1,14 +1,14 @@
 # BoardConfigGsiCommon.mk
 #
 # Common compile-time definitions for GSI
+# Builds upon the mainline config.
 #
 
-# The generic product target doesn't have any hardware-specific pieces.
-TARGET_NO_BOOTLOADER := true
-TARGET_NO_KERNEL := true
+include build/make/target/board/BoardConfigMainlineCommon.mk
 
-# GSIs always use ext4.
-TARGET_USERIMAGES_USE_EXT4 := true
+# This flag is set by mainline but isn't desired for GSI.
+BOARD_USES_SYSTEM_OTHER_ODEX :=
+
 # GSIs are historically released in sparse format.
 # Some vendors' bootloaders don't work properly with raw format images. So
 # we explicit specify this need below (even though it's the current default).
@@ -40,14 +40,6 @@
 # over those set by the vendor.
 TARGET_SYSTEM_PROP := build/make/target/board/gsi_system.prop
 endif
-BOARD_VNDK_VERSION := current
-
-# system-as-root is mandatory from Android P
-TARGET_NO_RECOVERY := true
-BOARD_BUILD_SYSTEM_ROOT_IMAGE := true
-
-# 64 bits binder interface is mandatory from Android P
-TARGET_USES_64_BIT_BINDER := true
 
 # Android generic system image always create metadata partition
 BOARD_USES_METADATA_PARTITION := true
@@ -56,6 +48,3 @@
 # The partition size doesn't matter, just to make build pass.
 BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE := ext4
 BOARD_CACHEIMAGE_PARTITION_SIZE := 16777216
-
-# Audio: must using XML format for Treblized devices
-USE_XML_AUDIO_POLICY_CONF := 1
diff --git a/target/board/BoardConfigMainlineCommon.mk b/target/board/BoardConfigMainlineCommon.mk
new file mode 100644
index 0000000..1cbe2e0
--- /dev/null
+++ b/target/board/BoardConfigMainlineCommon.mk
@@ -0,0 +1,25 @@
+# BoardConfigMainlineCommon.mk
+#
+# Common compile-time definitions for mainline images.
+
+# The generic product target doesn't have any hardware-specific pieces.
+TARGET_NO_BOOTLOADER := true
+TARGET_NO_KERNEL := true
+
+TARGET_USERIMAGES_USE_EXT4 := true
+
+# system-as-root is mandatory from Android P
+TARGET_NO_RECOVERY := true
+BOARD_BUILD_SYSTEM_ROOT_IMAGE := true
+
+BOARD_VNDK_VERSION := current
+
+# Required flag for non-64 bit devices from P.
+TARGET_USES_64_BIT_BINDER := true
+
+# Puts odex files on system_other, as well as causing dex files not to get
+# stripped from APKs.
+BOARD_USES_SYSTEM_OTHER_ODEX := true
+
+# Audio: must using XML format for Treblized devices
+USE_XML_AUDIO_POLICY_CONF := 1
diff --git a/target/board/mainline_arm64/BoardConfig.mk b/target/board/mainline_arm64/BoardConfig.mk
index 936c5a0..521d976 100644
--- a/target/board/mainline_arm64/BoardConfig.mk
+++ b/target/board/mainline_arm64/BoardConfig.mk
@@ -24,8 +24,4 @@
 TARGET_2ND_CPU_ABI2 := armeabi
 TARGET_2ND_CPU_VARIANT := generic
 
-# Puts odex files on system_other, as well as causing dex files not to get
-# stripped from APKs.
-BOARD_USES_SYSTEM_OTHER_ODEX := true
-
-include build/make/target/board/BoardConfigGsiCommon.mk
+include build/make/target/board/BoardConfigMainlineCommon.mk