Want to compile external/libffi into system, could you tell me which files need to be modified? Please advice!

Trying the following changes out/soong/Android - evk_8mq. Mk, but in the out/soong/. Intermediates/external/not generates libffi directory,

The include $(CLEAR_VARS)
LOCAL_PATH:=external/libffi
The LOCAL_MODULE: libffi=
LOCAL_MODULE_CLASS:=SHARED_LIBRARIES
LOCAL_PREBUILT_MODULE_FILE:=out/soong/intermediates/external/libffi libffi/android_arm64_armv8 - a_cortex - a53_core_shared/libffi. So
LOCAL_MODULE_TARGET_ARCH:=arm64
LOCAL_NOTICE_FILE:=external/libffi/NOTICE
LOCAL_SHARED_LIBRARIES:=libc libm libdl
LOCAL_STATIC_LIBRARIES:=libc++ _static libclang_rt. Builtins aarch64 - android libatomic libgcc_stripped
LOCAL_SOONG_LINK_TYPE:=native: platform
LOCAL_SOONG_TOC:=out/soong/intermediates/external/libffi libffi/android_arm64_armv8 - a_cortex - a53_core_shared/libffi. So. The toc
LOCAL_SOONG_UNSTRIPPED_BINARY:=out/soong/intermediates/external/libffi/libffi/android_arm64_armv8 - a_cortex - a53_core_shared unstripped/libffi. So
LOCAL_EXPORT_CFLAGS:=- Iexternal libffi/Linux - arm64 - Iout/soong/. Intermediates/external/libffi ffi_header/gen
LOCAL_EXPORT_C_INCLUDE_DEPS:=out/soong/intermediates/external/libffi/ffi_header/gen/ffi_gen. H
LOCAL_ADDITIONAL_DEPENDENCIES:=
LOCAL_BUILT_MODULE_STEM:=$(LOCAL_MODULE). So
LOCAL_MODULE_SUFFIX:=. So
LOCAL_MODULE_PATH:=$(OUT_DIR)/target/product/evk_8mq/system/lib64
LOCAL_MODULE_STEM:=libffi
LOCAL_UNINSTALLABLE_MODULE:=false
The include $(BUILD_SYSTEM)/soong_cc_prebuilt. Mk