diff --git a/Makefile b/Makefile
index c92b2733..ff44d22f 100644
--- a/Makefile
+++ b/Makefile
@@ -15,71 +15,56 @@
 # specific language governing permissions and limitations
 # under the License.
 
-OPTEE_PATH        ?= $(OPTEE_DIR)
-OPTEE_BUILD_PATH  ?= $(OPTEE_PATH)/build
-OPTEE_OS_PATH     ?= $(OPTEE_PATH)/optee_os
-OPTEE_CLIENT_PATH ?= $(OPTEE_PATH)/optee_client
-
-CCACHE ?= $(shell which ccache)
+ifneq ($V,1)
+	q := @
+	echo := @echo
+else
+	q :=
+	echo := @:
+endif
 
 EXAMPLES = $(wildcard examples/*)
 EXAMPLES_INSTALL = $(EXAMPLES:%=%-install)
 EXAMPLES_CLEAN  = $(EXAMPLES:%=%-clean)
 
 ifneq ($(ARCH), arm)
-	VENDOR := qemu_v8.mk
-	AARCH_CROSS_COMPILE := $(OPTEE_PATH)/toolchains/aarch64/bin/aarch64-linux-gnu-
-	HOST_TARGET := aarch64-unknown-linux-gnu
-	TA_TARGET := aarch64-unknown-linux-gnu
+	CROSS_COMPILE ?= aarch64-linux-gnu-
+	TARGET := aarch64-unknown-linux-gnu
 else
-	VENDOR := qemu.mk
-	ARCH_CROSS_COMPILE := $(OPTEE_PATH)/toolchains/aarch32/bin/arm-linux-gnueabihf-
-	HOST_TARGET := arm-unknown-linux-gnueabihf
-	TA_TARGET := arm-unknown-linux-gnueabihf
+	CROSS_COMPILE ?= arm-linux-gnueabihf-
+	TARGET := arm-unknown-linux-gnueabihf
 endif
 
-all: toolchains optee-os optee-client examples
-optee: toolchains optee-os optee-client
-
-toolchains:
-	make -C $(OPTEE_BUILD_PATH) -f $(VENDOR) toolchains
-
-optee-os:
-	make -C $(OPTEE_BUILD_PATH) -f $(VENDOR) optee-os
+export ARCH
 
-OPTEE_CLIENT_FLAGS ?= CROSS_COMPILE="$(CCACHE) $(AARCH_CROSS_COMPILE)" \
-	CFG_TEE_BENCHMARK=n \
-	CFG_TA_TEST_PATH=y \
-	WITH_TEEACL=0
-
-optee-client:
-	make -C $(OPTEE_CLIENT_PATH) $(OPTEE_CLIENT_FLAGS)
+.PHONY: all
+ifneq ($(wildcard $(TA_DEV_KIT_DIR)/host_include/conf.mk),)
+all: examples examples-install
+else
+all:
+	$(q)echo "TA_DEV_KIT_DIR is not correctly defined" && false
+endif
 
-examples: $(EXAMPLES) toolchains optee-os optee-client
+examples: $(EXAMPLES)
 $(EXAMPLES):
-	make -C $@
+	$(q)make -C $@ CROSS_COMPILE=$(CROSS_COMPILE) TA_DEV_KIT_DIR=$(TA_DEV_KIT_DIR) \
+		OPTEE_CLIENT_EXPORT=$(OPTEE_CLIENT_EXPORT)
 
 examples-install: $(EXAMPLES_INSTALL)
-$(EXAMPLES_INSTALL):
-	install -D $(@:%-install=%)/host/target/$(HOST_TARGET)/release/$(@:examples/%-install=%) -t out/host/
-	install -D $(@:%-install=%)/ta/target/$(TA_TARGET)/release/*.ta -t out/ta/
-	if [ -d "$(@:%-install=%)/plugin/target/" ]; then \
-		install -D $(@:%-install=%)/plugin/target/$(HOST_TARGET)/release/*.plugin.so -t out/plugin/; \
+$(EXAMPLES_INSTALL): examples
+	install -D $(@:%-install=%)/host/target/$(TARGET)/release/$(@:examples/%-install=%) -t out/host/
+	install -D $(@:%-install=%)/ta/target/$(TARGET)/release/*.ta -t out/ta/
+	$(q)if [ -d "$(@:%-install=%)/plugin/target/" ]; then \
+		install -D $(@:%-install=%)/plugin/target/$(TARGET)/release/*.plugin.so -t out/plugin/; \
 	fi
 
-optee-os-clean:
-	make -C $(OPTEE_OS_PATH) O=out/arm clean
-
-optee-client-clean:
-	make -C $(OPTEE_CLIENT_PATH) $(OPTEE_CLIENT_CLEAN_FLAGS) clean
-
 examples-clean: $(EXAMPLES_CLEAN) out-clean
 $(EXAMPLES_CLEAN):
-	make -C $(@:-clean=) clean
+	$(q)make -C $(@:-clean=) clean
 
 out-clean:
 	rm -rf out
 
-.PHONY: clean optee-os-clean optee-client-clean $(EXAMPLES) $(EXAMPLES_CLEAN)
+.PHONY: clean $(EXAMPLES) $(EXAMPLES_CLEAN)
 
-clean: optee-os-clean optee-client-clean $(EXAMPLES_CLEAN)
+clean: $(EXAMPLES_CLEAN)
diff --git a/environment b/environment
deleted file mode 100644
index 3216d099..00000000
--- a/environment
+++ /dev/null
@@ -1,41 +0,0 @@
-# Licensed to the Apache Software Foundation (ASF) under one
-# or more contributor license agreements.  See the NOTICE file
-# distributed with this work for additional information
-# regarding copyright ownership.  The ASF licenses this file
-# to you under the Apache License, Version 2.0 (the
-# "License"); you may not use this file except in compliance
-# with the License.  You may obtain a copy of the License at
-#
-#   http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing,
-# software distributed under the License is distributed on an
-# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-# KIND, either express or implied.  See the License for the
-# specific language governing permissions and limitations
-# under the License.
-
-export RUST_TARGET_PATH="$(pwd)"
-export RUST_COMPILER_RT_ROOT=$RUST_TARGET_PATH/rust/rust/src/llvm-project/compiler-rt
-if [ -z "$OPTEE_DIR" ]
-then
-  export OPTEE_DIR="$(pwd)/optee"
-fi
-export OPTEE_OS_DIR="$OPTEE_DIR/optee_os"
-export OPTEE_CLIENT_DIR="$OPTEE_DIR/optee_client/out"
-export OPTEE_CLIENT_INCLUDE="$OPTEE_DIR/optee_client/out/export/usr/include"
-if [ "$ARCH" = "arm" ]
-then
-  export ARCH="arm"
-  export PATH=$PATH:$OPTEE_DIR/toolchains/aarch32/bin
-  export VENDOR="qemu.mk"
-  export OPTEE_OS_INCLUDE="$OPTEE_DIR/optee_os/out/arm/export-ta_arm32/include"
-  export CC=$OPTEE_DIR/toolchains/aarch32/bin/arm-linux-gnueabihf-gcc
-else
-  # export ARCH="aarch64" # comment this because currently optee_os cannot be compiled in the aarch64 target
-  unset ARCH
-  export PATH=$PATH:$OPTEE_DIR/toolchains/aarch64/bin
-  export VENDOR="qemu_v8.mk"
-  export OPTEE_OS_INCLUDE="$OPTEE_DIR/optee_os/out/arm/export-ta_arm64/include"
-  export CC=$OPTEE_DIR/toolchains/aarch64/bin/aarch64-linux-gnu-gcc
-fi
diff --git a/setup.sh b/setup.sh
index fda0e089..7e439d1f 100755
--- a/setup.sh
+++ b/setup.sh
@@ -38,52 +38,3 @@ fi
 # rustup-wrapped command to trigger installation. We've arbitrarily chosen
 # "cargo --version" since it has no other effect.
 cargo --version >/dev/null
-
-########################################################
-# initialize submodules: optee_os / optee_client / build
-OPTEE_RELEASE_VERSION=3.20.0
-
-if [[ -z "$OPTEE_DIR" ]] || [[ "$OPTEE_DIR" == "$(pwd)/optee" ]]
-then
-	OPTEE_DIR="$(pwd)/optee"
-	echo "optee dir: $OPTEE_DIR"
-	OPTEE_SUBMODULES=(optee_os optee_client build)
-
-	if [ ! -d "$OPTEE_DIR" ]
-	then
-		mkdir "$OPTEE_DIR"
-	else
-		rm -r "$OPTEE_DIR"/*
-	fi
-
-	# download optee release
-	echo "Downloading optee release..."
-	for submodule in ${OPTEE_SUBMODULES[*]}
-	do
-		echo "Downloading $submodule..."
-		curl --retry 5 -s -S \
-			-L "https://github.com/OP-TEE/$submodule/archive/refs/tags/$OPTEE_RELEASE_VERSION.tar.gz" \
-			-o "$OPTEE_DIR/$OPTEE_RELEASE_VERSION.tar.gz"
-		if [ ! $? -eq 0 ]
-		then
-			rm "$OPTEE_DIR/$OPTEE_RELEASE_VERSION.tar.gz" && \
-				echo "Download failed" && \
-				exit 1
-		fi
-		echo "Uncompressing $submodule..."
-		mkdir -p "$OPTEE_DIR/$submodule" && \
-			tar zxf "$OPTEE_DIR/$OPTEE_RELEASE_VERSION.tar.gz" \
-			-C "$OPTEE_DIR/$submodule" --strip-components 1
-		if [ ! $? -eq 0 ]
-		then
-			rm "$OPTEE_DIR/$OPTEE_RELEASE_VERSION.tar.gz" && \
-				rm -r "$OPTEE_DIR/$submodule" && \
-				echo "Downloaded file is damaged" && \
-				exit 1
-		fi
-		rm "$OPTEE_DIR/$OPTEE_RELEASE_VERSION.tar.gz"
-	done
-	echo "Download finished"
-else
-	echo "OPTEE_DIR has been set, omit to download optee submodules"
-fi