These are step-by-step instructions for using the Android NDK to build Arm NN. They have been tested on a clean installation of Ubuntu 18.04 and 20.04, and should also work with other OS versions. The instructions show how to build the Arm NN core library and its dependencies.
For ease of use there is a shell script version of this guide located in the scripts directory called build_android_ndk_guide.sh. Run the script with a -h flag to see the command line parameters.
The shell script version of this guide (build_android_ndk_guide.sh) also provides user the option to use the Arm NN and ComputeLibrary available in your BASE_DIR, instead of downloading a new version. BASE_DIR is path to the script file, which is armnn/scripts/.
First, we need to specify the Android version and the directories you want to build Arm NN in and to install some applications required to build Arm NN and its dependencies.
export ANDROID_API=30 export WORKING_DIR=$HOME/armnn-devenv export NDK_DIR=$WORKING_DIR/android-ndk-r25 export NDK_TOOLCHAIN_ROOT=$NDK_DIR/toolchains/llvm/prebuilt/linux-x86_64 export PATH=$NDK_TOOLCHAIN_ROOT/bin/:$PATH
You may want to append the above export variables commands to your ~/.bashrc
(or ~/.bash_profile
in macOS).
The ANDROID_API variable should be set to the Android API version number you are using. For example, "30" for Android R. The WORKING_DIR can be any directory you have write permissions to.
Git is required to obtain Arm NN. If this has not been already installed then install it using:
sudo apt install git
Arm Compute Library requires SCons. If this has not been already installed then install it using:
sudo apt install scons
CMake is required to build Arm NN and its dependencies. If this has not been already installed then install it using:
sudo apt install cmake
Download the Android NDK from the official website:
mkdir -p $WORKING_DIR cd $WORKING_DIR # For Mac OS, change the NDK download link accordingly. wget https://dl.google.com/android/repository/android-ndk-r25-linux.zip unzip android-ndk-r25-linux.zip
With Android NDK-25, you no longer need to use the make_standalone_toolchain script to create a toolchain for a specific version of Android. Android's current preference is for you to just specify the architecture and operating system while setting the compiler and just use the ndk directory.
Cmake 3.19rc3 or later is required to build Arm NN. If you are using Ubuntu 20.04 the command given in Initial Setup should install a usable version. If you're using Ubuntu 18.04 you may need to compile cmake yourself.
cd $WORKING_DIR sudo apt-get install libssl-dev wget https://github.com/Kitware/CMake/releases/download/v3.19.0-rc3/cmake-3.19.0-rc3.tar.gz tar -zxvf cmake-3.19.0-rc3.tar.gz cd cmake-3.19.0-rc3 ./bootstrap --prefix=$WORKING_DIR/cmake/install make all install cd..
Download Flatbuffers:
cd $WORKING_DIR wget https://github.com/google/flatbuffers/archive/v2.0.6.tar.gz tar xf v2.0.6.tar.gz
Build Flatbuffers for x86:
cd $WORKING_DIR/flatbuffers-2.0.6 rm -f CMakeCache.txt rm -rf build-x86 mkdir build-x86 cd build-x86 rm -rf $WORKING_DIR/flatbuffers-x86 mkdir $WORKING_DIR/flatbuffers-x86 CXXFLAGS="-fPIC" $CMAKE .. \ -DFLATBUFFERS_BUILD_FLATC=1 \ -DCMAKE_INSTALL_PREFIX:PATH=$WORKING_DIR/flatbuffers-x86 make all install -j16
Note: -fPIC is added to allow users to use the libraries in shared objects.
Build Flatbuffers for Android:
cd $WORKING_DIR/flatbuffers-2.0.6 rm -f CMakeCache.txt rm -rf build-android mkdir build-android cd build-android rm -rf $WORKING_DIR/flatbuffers-android mkdir $WORKING_DIR/flatbuffers-android CC=/usr/bin/aarch64-linux-gnu-gcc CXX=/usr/bin/aarch64-linux-gnu-g++ \ CXXFLAGS="-fPIC" \ cmake .. \ -DCMAKE_ANDROID_NDK=$NDK_DIR \ -DCMAKE_SYSTEM_NAME=Android \ -DCMAKE_SYSTEM_VERSION=$ANDROID_API \ -DCMAKE_ANDROID_ARCH_ABI=arm64-v8a \ -DCMAKE_CXX_FLAGS=--std=c++14 \ -DFLATBUFFERS_BUILD_FLATC=OFF \ -DCMAKE_BUILD_TYPE=Release \ -DFLATBUFFERS_BUILD_TESTS=OFF \ -DCMAKE_INSTALL_PREFIX=$WORKING_DIR/flatbuffers-android make all install -j16
Clone Arm NN:
cd $WORKING_DIR git clone https://github.com/ARM-software/armnn.git
Checkout the Arm NN branch:
cd armnn git checkout <branch_name> git pull
For example, if you want to check out the 23.02 release branch:
cd armnn git checkout branches/armnn_23_02 git pull
This optional step is only required if you intend to build the TFLite delegate or parser for Arm NN.
First clone Tensorflow manually and check out the version Arm NN was tested with:
cd $WORKING_DIR git clone https://github.com/tensorflow/tensorflow.git cd tensorflow git fetch && git checkout "6f692f73cb2043b4a0b0446539cd8c15b3dd9220"
Or use the script that Arm NN provides:
git fetch && git checkout $(../armnn/scripts/get_tensorflow.sh -p)
Next, set variable TFLITE_ROOT_DIR and build Tensorflow Lite:
export TFLITE_ROOT_DIR=$WORKING_DIR/tensorflow/tensorflow/lite cd $WORKING_DIR mkdir -p tflite-out/android cd tflite-out/android CMARGS="-DTFLITE_ENABLE_XNNPACK=OFF \ -DFLATBUFFERS_BUILD_FLATC=OFF \ -DBUILD_SHARED_LIBS=OFF \ -DBUILD_TESTING=OFF" CMARGS="$CMARGS -DCMAKE_TOOLCHAIN_FILE=$NDK_DIR/build/cmake/android.toolchain.cmake \ -DANDROID_ABI=arm64-v8a \ -DANDROID_PLATFORM=$ANDROID_API" cmake $CMARGS $TFLITE_ROOT_DIR cd $WORKING_DIR cmake --build tflite-out/android -j 16
Now generate the Tensorflow Lite Schema for the TFLite parser:
cd $WORKING_DIR mkdir -p $WORKING_DIR/tflite-out/tensorflow/tensorflow/lite/schema SCHEMA_LOCATION=$WORKING_DIR/tensorflow/tensorflow/lite/schema/schema.fbs cp $SCHEMA_LOCATION $WORKING_DIR/tflite-out/tensorflow/tensorflow/lite/schema cd $WORKING_DIR/tflite-out/tensorflow/tensorflow/lite/schema $WORKING_DIR/flatbuffers-x86/bin/flatc -c --gen-object-api --reflect-types --reflect-names schema.fbs
Clone Arm Compute Library:
cd $WORKING_DIR git clone https://github.com/ARM-software/ComputeLibrary.git
Checkout Arm Compute Library release tag:
cd ComputeLibrary git checkout <tag_name>
For example, if you want to check out the 23.02 release tag:
cd ComputeLibrary git checkout v23.02
Arm NN and Arm Compute Library are developed closely together. To use a particular version of Arm NN you will need a compatible version of ACL. Arm NN provides a script that downloads the version of Arm Compute Library that Arm NN was tested with:
git checkout $(../armnn/scripts/get_compute_library.sh -p)
Build the Arm Compute Library:
scons arch=arm64-v8a os=android toolchain_prefix=llvm- compiler_prefix=aarch64-linux-android$ANDROID_API- \ neon=1 opencl=1 embed_kernels=1 extra_cxx_flags="-fPIC" \ benchmark_tests=0 validation_tests=0 -j16
Build Arm NN:
mkdir $WORKING_DIR/armnn/build cd $WORKING_DIR/armnn/build CXX=aarch64-linux-android$ANDROID_API-clang++ \ CC=aarch64-linux-android$ANDROID_API-clang \ CXX_FLAGS="-fPIE -fPIC" \ cmake .. \ -DCMAKE_BUILD_TYPE=Release \ -DCMAKE_ANDROID_NDK=$NDK_DIR \ -DNDK_VERSION=r25 \ -DCMAKE_SYSTEM_NAME=Android \ -DCMAKE_SYSTEM_VERSION=$ANDROID_API \ -DCMAKE_ANDROID_ARCH_ABI=arm64-v8a \ -DCMAKE_SYSROOT=$WORKING_DIR/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/sysroot \ -DARMCOMPUTE_ROOT=$WORKING_DIR/ComputeLibrary \ -DARMCOMPUTE_BUILD_DIR=$WORKING_DIR/ComputeLibrary/build \ -DARMCOMPUTENEON=1 -DARMCOMPUTECL=1 -DARMNNREF=1 \ -DFLATBUFFERS_INCLUDE_PATH=$WORKING_DIR/flatbuffers-x86/include \ -DFLATBUFFERS_ROOT=$WORKING_DIR/flatbuffers-android \ -DFLATC_DIR=$WORKING_DIR/flatbuffers-x86 \ -DBUILD_UNIT_TESTS=1 \ -DBUILD_TESTS=1 \ -fexception \
To include the Arm NN TFLite delegate add these arguments to the above list:
-DBUILD_ARMNN_TFLITE_DELEGATE=1 \ -DTENSORFLOW_ROOT=$WORKING_DIR/tensorflow \ -DTFLITE_LIB_ROOT=$WORKING_DIR/tflite-out/android \ -DTFLITE_ROOT_DIR=$WORKING_DIR/tensorflow/tensorflow/lite \
To include the Arm NN TFLite Parser add these arguments to the above list:
-DBUILD_TF_LITE_PARSER=1 \ -DTF_LITE_GENERATED_PATH=$WORKING_DIR/tflite-out/tensorflow/tensorflow/lite/schema \ -DTENSORFLOW_ROOT=$WORKING_DIR/tensorflow \ -DTFLITE_LIB_ROOT=$WORKING_DIR/tflite-out/android \
To include standalone sample dynamic backend tests, add these arguments to enable the tests and the dynamic backend path to the CMake command:
-DSAMPLE_DYNAMIC_BACKEND=1 \ -DDYNAMIC_BACKEND_PATHS=$SAMPLE_DYNAMIC_BACKEND_PATH # Where $SAMPLE_DYNAMIC_BACKEND_PATH is the path where libArm_SampleDynamic_backend.so library file is pushed
make -j16
This step is optional. The sample dynamic backend is located in armnn/src/dynamic/sample
mkdir build
cd build
#!/bin/bash CXX=aarch64-linux-android$ANDROID_API-clang++ \ CC=aarch64-linux-android$ANDROID_API-clang \ CXX_FLAGS="-fPIE -fPIC" \ cmake \ -DCMAKE_C_COMPILER_WORKS=TRUE \ -DCMAKE_CXX_COMPILER_WORKS=TRUE \ -DCMAKE_ANDROID_NDK=$NDK_DIR \ -DCMAKE_SYSTEM_NAME=Android \ -DCMAKE_SYSTEM_VERSION=$ANDROID_API \ -DCMAKE_ANDROID_ARCH_ABI=arm64-v8a \ -DCMAKE_SYSROOT=$WORKING_DIR/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/sysroot \ -DCMAKE_CXX_FLAGS=--std=c++14 \ -DCMAKE_EXE_LINKER_FLAGS="-pie -llog" \ -DCMAKE_MODULE_LINKER_FLAGS="-llog" \ -DARMNN_PATH=$WORKING_DIR/armnn/build/libarmnn.so ..
make
adb push libarmnn.so /data/local/tmp/ adb push libtimelineDecoder.so /data/local/tmp/ adb push libtimelineDecoderJson.so /data/local/tmp/ adb push GatordMock /data/local/tmp/ adb push libarmnnBasePipeServer.so /data/local/tmp/ adb push libarmnnTestUtils.so /data/local/tmp/ adb push UnitTests /data/local/tmp/ adb push $NDK_DIR/sources/cxx-stl/llvm-libc++/libs/arm64-v8a/libc++_shared.so /data/local/tmp/
adb shell mkdir -p /data/local/tmp/src/backends/backendsCommon/test/testSharedObject adb push -p $WORKING_DIR/armnn/build/src/backends/backendsCommon/test/testSharedObject/* /data/local/tmp/src/backends/backendsCommon/test/testSharedObject/ adb shell mkdir -p /data/local/tmp/src/backends/backendsCommon/test/testDynamicBackend adb push -p $WORKING_DIR/armnn/build/src/backends/backendsCommon/test/testDynamicBackend/* /data/local/tmp/src/backends/backendsCommon/test/testDynamicBackend/ adb shell mkdir -p /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath1 adb push -p $WORKING_DIR/armnn/build/src/backends/backendsCommon/test/backendsTestPath1/* /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath1/ adb shell mkdir -p /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath2 adb push -p $WORKING_DIR/armnn/build/src/backends/backendsCommon/test/backendsTestPath2/Arm_CpuAcc_backend.so /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath2/ adb shell ln -s Arm_CpuAcc_backend.so /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath2/Arm_CpuAcc_backend.so.1 adb shell ln -s Arm_CpuAcc_backend.so.1 /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath2/Arm_CpuAcc_backend.so.1.2 adb shell ln -s Arm_CpuAcc_backend.so.1.2 /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath2/Arm_CpuAcc_backend.so.1.2.3 adb push -p $WORKING_DIR/armnn/build/src/backends/backendsCommon/test/backendsTestPath2/Arm_GpuAcc_backend.so /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath2/ adb shell ln -s nothing /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath2/Arm_no_backend.so adb shell mkdir -p /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath3 adb shell mkdir -p /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath5 adb push -p $WORKING_DIR/armnn/build/src/backends/backendsCommon/test/backendsTestPath5/* /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath5/ adb shell mkdir -p /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath6 adb push -p $WORKING_DIR/armnn/build/src/backends/backendsCommon/test/backendsTestPath6/* /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath6/ adb shell mkdir -p /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath7 adb shell mkdir -p /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath9 adb push -p $WORKING_DIR/armnn/build/src/backends/backendsCommon/test/backendsTestPath9/* /data/local/tmp/src/backends/backendsCommon/test/backendsTestPath9/ adb shell mkdir -p /data/local/tmp/src/backends/dynamic/reference adb push -p $WORKING_DIR/armnn/build/src/backends/dynamic/reference/Arm_CpuRef_backend.so /data/local/tmp/src/backends/dynamic/reference/
If the standalone sample dynamic tests are enabled, also push libArm_SampleDynamic_backend.so library file to the folder specified as $SAMPLE_DYNAMIC_BACKEND_PATH when Arm NN is built. This is the example when $SAMPLE_DYNAMIC_BACKEND_PATH is specified as /data/local/tmp/dynamic/sample/:
adb shell mkdir -p /data/local/tmp/dynamic/sample/ adb push -p $WORKING_DIR/armnn/src/dynamic/sample/build/libArm_SampleDynamic_backend.so /data/local/tmp/dynamic/sample/
If the delegate was built, push the delegate unit tests too.
adb push $WORKING_DIR/armnn/build/delegate/DelegateUnitTests /data/local/tmp/ adb push $WORKING_DIR/armnn/build/delegate/libarmnnDelegate.so /data/local/tmp/
Run Arm NN unit tests:
adb shell 'LD_LIBRARY_PATH=/data/local/tmp:/vendor/lib64:/vendor/lib64/egl /data/local/tmp/UnitTests'
If the delegate was built run Arm Delegate NN unit tests:
adb shell 'LD_LIBRARY_PATH=/data/local/tmp:/vendor/lib64:/vendor/lib64/egl /data/local/tmp/DelegateUnitTests'
If libarmnnUtils.a is present in $WORKING_DIR/armnn/build/
and the unit tests run without failure then the build was successful.