prerequisite

install Android Studio

install Android Studio from https://developer.android.com/studio

Android NDK

the NDK is necessary to provide an LLVM toolchain for compiling native binaries for Android devices. the NDK can be downloaded from the SDK manager within Android Studio.

Note the installed version and install location.

Android jniLibs

https://developer.android.com/studio/projects/gradle-external-native-builds#jniLibs

static library objects need to be copied to the Android project at:

 <app_root>/src/main/jniLibs

known Android ABIs

- x86
- x86_64
- armeabi
- armeabi-v7a
- arm64-v8a

install rustup

this project requires the rustup and cargo tools to be installed. they can be installed from https://www.rust-lang.org/tools/install i.e.:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Rust Android ABI compilers

rustup target add aarch64-linux-android armv7-linux-androideabi

configure cargo

create a cargo config file at ~/.cargo/config:

• android_sdk is the install location of the Android SDK
• host-os is the architecture of the compiler on the host system. it should be the only one installed by default
• ndk_version is the version of the installed NDK from the SDK manager
• other ABIs will need to be added if you want to support those architectures

[target.aarch64-linux-android]
linker = "<android_sdk>/ndk/<ndk_version>/toolchains/llvm/prebuilt/<host-os>/bin/aarch64-linux-android30-clang++"

[target.armv7-linux-androideabi]
linker = "<android_sdk>/ndk/<ndk_version>/toolchains/llvm/prebuilt/<host-os>/bin/armv7a-linux-androideabi30-clang++"

run the app

building and copying of the Rust binaries is automated by gradle. tasks were added that build, copy, and cleanup libraries for supported ABIs. these tasks are executed automatically for build and clean tasks.

building the app including the static object binaries is as easy as clicking run in Android Studio or simply running ./gradlew build.