diff --git a/core/pdk_fusion_modules.mk b/core/pdk_fusion_modules.mk
new file mode 100644
index 0000000..369ecbb
--- /dev/null
+++ b/core/pdk_fusion_modules.mk
@@ -0,0 +1,75 @@
+# Auto-generate module defitions from platform.zip.
+# We use these rules to rebuild .odex files of the .jar/.apk inside the platform.zip.
+#
+
+pdk_dexpreopt_config_mk := $(TARGET_OUT_INTERMEDIATES)/pdk_dexpreopt_config.mk
+
+$(shell rm -f $(pdk_dexpreopt_config_mk) && mkdir -p $(dir $(pdk_dexpreopt_config_mk)) && \
+        unzip -qo $(PDK_FUSION_PLATFORM_ZIP) -d $(dir $(pdk_dexpreopt_config_mk)) pdk_dexpreopt_config.mk 2>/dev/null)
+
+-include $(pdk_dexpreopt_config_mk)
+
+# Define a PDK prebuilt module that comes from platform.zip.
+# Must be called with $(eval)
+define prebuilt-pdk-java-module
+include $(CLEAR_VARS)
+LOCAL_MODULE:=$(1)
+LOCAL_MODULE_CLASS:=$(2)
+# Use LOCAL_PREBUILT_MODULE_FILE instead of LOCAL_SRC_FILES so we don't need to deal with LOCAL_PATH.
+LOCAL_PREBUILT_MODULE_FILE:=$(3)
+LOCAL_DEX_PREOPT:=$(4)
+LOCAL_MULTILIB:=$(5)
+LOCAL_DEX_PREOPT_FLAGS:=$(6)
+LOCAL_BUILT_MODULE_STEM:=$(7)
+LOCAL_MODULE_SUFFIX:=$(suffix $(7))
+LOCAL_PRIVILEGED_MODULE:=$(8)
+LOCAL_PROPRIETARY_MODULE:=$(9)
+LOCAL_MODULE_TARGET_ARCH:=$(10)
+LOCAL_REPLACE_PREBUILT_APK_INSTALLED:=$(11)
+LOCAL_CERTIFICATE:=PRESIGNED
+include $(BUILD_PREBUILT)
+
+# The source prebuilts are extracted in the rule of _pdk_fusion_stamp.
+# Use a touch rule to establish the dependency.
+$(3) $(11) : $(_pdk_fusion_stamp)
+	$(hide) if [ ! -f $$@ ]; then \
+	  echo 'Error: $$@ does not exist. Check your platform.zip.' 1>&2; \
+	  exit 1; \
+	fi
+	$(hide) touch $$@
+endef
+
+##### Java libraries.
+# Only set up rules for modules that aren't built from source.
+pdk_prebuilt_libraries := $(foreach l,$(PDK.DEXPREOPT.JAVA_LIBRARIES),\
+  $(if $(MODULE.TARGET.JAVA_LIBRARIES.$(l)),,$(l)))
+
+$(foreach l,$(pdk_prebuilt_libraries), $(eval \
+  $(call prebuilt-pdk-java-module,\
+    $(l),\
+    JAVA_LIBRARIES,\
+    $(_pdk_fusion_intermediates)/$(PDK.DEXPREOPT.$(l).SRC),\
+    $(PDK.DEXPREOPT.$(l).DEX_PREOPT),\
+    $(PDK.DEXPREOPT.$(l).MULTILIB),\
+    $(PDK.DEXPREOPT.$(l).DEX_PREOPT_FLAGS),\
+    javalib.jar,\
+    )))
+
+###### Apps.
+pdk_prebuilt_apps := $(foreach a,$(PDK.DEXPREOPT.APPS),\
+  $(if $(MODULE.TARGET.APPS.$(a)),,$(a)))
+
+$(foreach a,$(pdk_prebuilt_apps), $(eval \
+  $(call prebuilt-pdk-java-module,\
+    $(a),\
+    APPS,\
+    $(_pdk_fusion_intermediates)/$(PDK.DEXPREOPT.$(a).SRC),\
+    $(PDK.DEXPREOPT.$(a).DEX_PREOPT),\
+    $(PDK.DEXPREOPT.$(a).MULTILIB),\
+    $(PDK.DEXPREOPT.$(a).DEX_PREOPT_FLAGS),\
+    package.apk,\
+    $(PDK.DEXPREOPT.$(a).PRIVILEGED_MODULE),\
+    $(PDK.DEXPREOPT.$(a).PROPRIETARY_MODULE),\
+    $(PDK.DEXPREOPT.$(a).TARGET_ARCH),\
+    $(_pdk_fusion_intermediates)/$(PDK.DEXPREOPT.$(a).STRIPPED_SRC),\
+    )))