BuildGuideAndroidNDK.md - platform/external/armnn - Git at Google

 # How to use the Android NDK to build Arm NN

 - [Introduction](#introduction)
 - [Initial Setup](#initial-setup)
 - [Download the Android NDK and make a standalone toolchain](#download-the-android-ndk-and-make-a-standalone-toolchain)
 - [Install Cmake](#install-cmake)
 - [Build Flatbuffers](#build-flatbuffers)
 - [Download Arm NN](#download-arm-nn)
 - [Get And Build TFLite](#get-and-build-tflite)
 - [Build Arm Compute Library](#build-arm-compute-library)
 - [Build Arm NN](#build-arm-nn)
 - [Build Standalone Sample Dynamic Backend](#build-standalone-sample-dynamic-backend)
 - [Run the Arm NN unit tests on an Android device](#run-the-arm-nn-unit-tests-on-an-android-device)


 ## Introduction
 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](scripts/build_android_ndk_guide.sh).
 Run the script with a -h flag to see the command line parameters.

 ## Initial Setup

 First, we need to specify the Android version and the directories you want to build armnn in and to install some applications required to build Arm NN and its dependencies.

 ```bash
 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.

 ### Required Applications
 Git is required to obtain Arm NN. If this has not been already installed then install it using:
 ```bash
 sudo apt install git
 ```

 Arm Compute Library requires SCons. If this has not been already installed then install it using:
 ```bash
 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:
 ```bash
 sudo apt install cmake
 ```

 ## Download the Android NDK and make a standalone toolchain

 Download the Android NDK from [the official website](https://developer.android.com/ndk/downloads/index.html):
 ```bash
 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.

 ## Install Cmake
 Cmake 3.19rc3 or later is required to build Arm NN. If you are using Ubuntu 20.04 the command given in [Initial Setup](#initial-setup) should install a usable version. If you're using Ubuntu 18.04 you may need to compile cmake yourself.

 ```bash
 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..
 ```

 ## Build Flatbuffers

 Download Flatbuffers:
 ```bash
 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:
 ```bash
 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:
 ```bash
 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=$NDK_DIR \
     -DCMAKE_SYSTEM_NAME=Android \
     -DCMAKE_SYSTEM_VERSION=27 \
     -DCMAKE_ANDROID_ARCH_ABI=arm64-v8a \
     -DCMAKE_CXX_FLAGS=--std=c++14 \
     -DFLATBUFFERS_BUILD_FLATC=OFF \
     -DCMAKE_BUILD_TYPE=Release \
     -DFLATBUFFERS_BUILD_TESTS=OFF \
     -DCMAKE_INSTALL_PREFIX=$WORKING_DIR/flatbuffers-android

 make all install -j16
 ```

 ## Download Arm NN
 Clone Arm NN:

 ```bash
 cd $WORKING_DIR
 git clone https://github.com/ARM-software/armnn.git
 ```

 Checkout the Arm NN branch:
 ```bash
 cd armnn
 git checkout <branch_name>
 git pull
 ```

 For example, if you want to check out the 23.02 release branch:
 ```bash
 cd armnn
 git checkout branches/armnn_23_02
 git pull
 ```

 ## Get And Build TFLite
 This optional step is only required if you intend to build the TFLite delegate or parser for Arm NN.

 First clone tensorflow:
 ```bash
 cd $WORKING_DIR
 git clone https://github.com/tensorflow/tensorflow.git
 cd tensorflow
 git fetch && git checkout "tags/v2.10.0"
 ```
 Arm NN provides a script that downloads the version of Tensorflow that Arm NN was tested with:
 ```bash
 git fetch && git checkout $(../armnn/scripts/get_tensorflow.sh -p)
 ```
 Next build Tensorflow Lite:
 ```bash
 cd $WORKING_DIR
 mkdir -p tflite-out/android
 cd tflite-out/android

 CMARGS="-DCMAKE_TOOLCHAIN_FILE=$NDK_DIR/build/cmake/android.toolchain.cmake \
     -DANDROID_ABI=arm64-v8a \
     -DANDROID_PLATFORM=$ANDROID_API"

 cmake $CMARGS $WORKING_DIR/tensorflow/tensorflow/lite

 cd $WORKING_DIR
 cmake --build tflite-out/android -j 16
 ```
 Now generate the Tensorflow Lite Schema for the TFLite parser:
 ```bash
 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
 ```

 ## Build Arm Compute Library
 Clone Arm Compute Library:

 ```bash
 cd $WORKING_DIR
 git clone https://github.com/ARM-software/ComputeLibrary.git
 ```
 Checkout Arm Compute Library release tag:
 ```bash
 cd ComputeLibrary
 git checkout <tag_name>
 ```
 For example, if you want to check out the 23.02 release tag:
 ```bash
 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:
 ```bash
 git checkout $(../armnn/scripts/get_compute_library.sh -p)
 ```
 Build the Arm Compute Library:
 ```bash
 scons arch=arm64-v8a os=android toolchain_prefix=llvm- compiler_prefix=aarch64-linux-android$ANDROID_API- \
     neon=1 opencl=1 embed_kernels=1 extra_cxx_flags="-fPIC" \
     benchmark_tests=0 validation_tests=0 -j16
 ```

 ## Build Arm NN

 Build Arm NN:

 ```bash
 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:

 ```bash
     -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:

 ```bash
     -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:

 ```bash
     -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
 ```

  * Run the build
 ```bash
 make -j16
 ```

 ## Build Standalone Sample Dynamic Backend
 This step is optional. The sample dynamic backend is located in armnn/src/dynamic/sample
 ```bash
 mkdir build
 cd build
 ```

 * Use CMake to configure the build environment, update the following script and run it from the armnn/src/dynamic/sample/build directory to set up the Arm NN build:
 ```bash
 #!/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 ..
 ```

 * Run the build
 ```bash
 make
 ```

 ## Run the Arm NN unit tests on an Android device


 * Push the build results to an Android device and make symbolic links for shared libraries:
   Currently adb version we have used for testing is 1.0.41.
 ```bash
 adb push libarmnn.so /data/local/tmp/
     adb push libtimelineDecoder.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/
 ```

 * Push the files needed for the unit tests (they are a mix of files, directories and symbolic links):
 ```bash
 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/:

 ```bash
 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.
 ```bash
 adb push $WORKING_DIR/armnn/build/delegate/DelegateUnitTests /data/local/tmp/
 adb push $WORKING_DIR/armnn/build/delegate/libarmnnDelegate.so /data/local/tmp/
 ```
 Run Arm NN unit tests:
 ```bash
 adb shell 'LD_LIBRARY_PATH=/data/local/tmp:/vendor/lib64:/vendor/lib64/egl /data/local/tmp/UnitTests'
 ```
 If the delegate was built run Arm Delegate NN unit tests:
 ```bash
 adb shell 'LD_LIBRARY_PATH=/data/local/tmp:/vendor/lib64:/vendor/lib64/egl /data/local/tmp/DelegateUnitTests'
 ```
 If libarmnnUtils.a is present in `$WORKING_DIR/armnn/build/` and the unit tests run without failure then the build was successful.
	# How to use the Android NDK to build Arm NN

	- [Introduction](#introduction)
	- [Initial Setup](#initial-setup)
	- [Download the Android NDK and make a standalone toolchain](#download-the-android-ndk-and-make-a-standalone-toolchain)
	- [Install Cmake](#install-cmake)
	- [Build Flatbuffers](#build-flatbuffers)
	- [Download Arm NN](#download-arm-nn)
	- [Get And Build TFLite](#get-and-build-tflite)
	- [Build Arm Compute Library](#build-arm-compute-library)
	- [Build Arm NN](#build-arm-nn)
	- [Build Standalone Sample Dynamic Backend](#build-standalone-sample-dynamic-backend)
	- [Run the Arm NN unit tests on an Android device](#run-the-arm-nn-unit-tests-on-an-android-device)


	## Introduction
	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](scripts/build_android_ndk_guide.sh).
	Run the script with a -h flag to see the command line parameters.

	## Initial Setup

	First, we need to specify the Android version and the directories you want to build armnn in and to install some applications required to build Arm NN and its dependencies.

	```bash
	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.

	### Required Applications
	Git is required to obtain Arm NN. If this has not been already installed then install it using:
	```bash
	sudo apt install git
	```

	Arm Compute Library requires SCons. If this has not been already installed then install it using:
	```bash
	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:
	```bash
	sudo apt install cmake
	```

	## Download the Android NDK and make a standalone toolchain

	Download the Android NDK from [the official website](https://developer.android.com/ndk/downloads/index.html):
	```bash
	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.

	## Install Cmake
	Cmake 3.19rc3 or later is required to build Arm NN. If you are using Ubuntu 20.04 the command given in [Initial Setup](#initial-setup) should install a usable version. If you're using Ubuntu 18.04 you may need to compile cmake yourself.

	```bash
	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..
	```

	## Build Flatbuffers

	Download Flatbuffers:
	```bash
	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:
	```bash
	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:
	```bash
	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=$NDK_DIR \
	-DCMAKE_SYSTEM_NAME=Android \
	-DCMAKE_SYSTEM_VERSION=27 \
	-DCMAKE_ANDROID_ARCH_ABI=arm64-v8a \
	-DCMAKE_CXX_FLAGS=--std=c++14 \
	-DFLATBUFFERS_BUILD_FLATC=OFF \
	-DCMAKE_BUILD_TYPE=Release \
	-DFLATBUFFERS_BUILD_TESTS=OFF \
	-DCMAKE_INSTALL_PREFIX=$WORKING_DIR/flatbuffers-android

	make all install -j16
	```

	## Download Arm NN
	Clone Arm NN:

	```bash
	cd $WORKING_DIR
	git clone https://github.com/ARM-software/armnn.git
	```

	Checkout the Arm NN branch:
	```bash
	cd armnn
	git checkout <branch_name>
	git pull
	```

	For example, if you want to check out the 23.02 release branch:
	```bash
	cd armnn
	git checkout branches/armnn_23_02
	git pull
	```

	## Get And Build TFLite
	This optional step is only required if you intend to build the TFLite delegate or parser for Arm NN.

	First clone tensorflow:
	```bash
	cd $WORKING_DIR
	git clone https://github.com/tensorflow/tensorflow.git
	cd tensorflow
	git fetch && git checkout "tags/v2.10.0"
	```
	Arm NN provides a script that downloads the version of Tensorflow that Arm NN was tested with:
	```bash
	git fetch && git checkout $(../armnn/scripts/get_tensorflow.sh -p)
	```
	Next build Tensorflow Lite:
	```bash
	cd $WORKING_DIR
	mkdir -p tflite-out/android
	cd tflite-out/android

	CMARGS="-DCMAKE_TOOLCHAIN_FILE=$NDK_DIR/build/cmake/android.toolchain.cmake \
	-DANDROID_ABI=arm64-v8a \
	-DANDROID_PLATFORM=$ANDROID_API"

	cmake $CMARGS $WORKING_DIR/tensorflow/tensorflow/lite

	cd $WORKING_DIR
	cmake --build tflite-out/android -j 16
	```
	Now generate the Tensorflow Lite Schema for the TFLite parser:
	```bash
	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
	```

	## Build Arm Compute Library
	Clone Arm Compute Library:

	```bash
	cd $WORKING_DIR
	git clone https://github.com/ARM-software/ComputeLibrary.git
	```
	Checkout Arm Compute Library release tag:
	```bash
	cd ComputeLibrary
	git checkout <tag_name>
	```
	For example, if you want to check out the 23.02 release tag:
	```bash
	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:
	```bash
	git checkout $(../armnn/scripts/get_compute_library.sh -p)
	```
	Build the Arm Compute Library:
	```bash
	scons arch=arm64-v8a os=android toolchain_prefix=llvm- compiler_prefix=aarch64-linux-android$ANDROID_API- \
	neon=1 opencl=1 embed_kernels=1 extra_cxx_flags="-fPIC" \
	benchmark_tests=0 validation_tests=0 -j16
	```

	## Build Arm NN

	Build Arm NN:

	```bash
	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:

	```bash
	-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:

	```bash
	-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:

	```bash
	-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
	```

	* Run the build
	```bash
	make -j16
	```

	## Build Standalone Sample Dynamic Backend
	This step is optional. The sample dynamic backend is located in armnn/src/dynamic/sample
	```bash
	mkdir build
	cd build
	```

	* Use CMake to configure the build environment, update the following script and run it from the armnn/src/dynamic/sample/build directory to set up the Arm NN build:
	```bash
	#!/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 ..
	```

	* Run the build
	```bash
	make
	```

	## Run the Arm NN unit tests on an Android device


	* Push the build results to an Android device and make symbolic links for shared libraries:
	Currently adb version we have used for testing is 1.0.41.
	```bash
	adb push libarmnn.so /data/local/tmp/
	adb push libtimelineDecoder.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/
	```

	* Push the files needed for the unit tests (they are a mix of files, directories and symbolic links):
	```bash
	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/:

	```bash
	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.
	```bash
	adb push $WORKING_DIR/armnn/build/delegate/DelegateUnitTests /data/local/tmp/
	adb push $WORKING_DIR/armnn/build/delegate/libarmnnDelegate.so /data/local/tmp/
	```
	Run Arm NN unit tests:
	```bash
	adb shell 'LD_LIBRARY_PATH=/data/local/tmp:/vendor/lib64:/vendor/lib64/egl /data/local/tmp/UnitTests'
	```
	If the delegate was built run Arm Delegate NN unit tests:
	```bash
	adb shell 'LD_LIBRARY_PATH=/data/local/tmp:/vendor/lib64:/vendor/lib64/egl /data/local/tmp/DelegateUnitTests'
	```
	If libarmnnUtils.a is present in `$WORKING_DIR/armnn/build/` and the unit tests run without failure then the build was successful.