Doc building for android

Rust has been ported to Android OS running on ARM architecture. Android on other architectures is not yet supported.

In the issue tracker, Android-related issues are labelled A-android, and ARM-related issues are labelled A-ARM.

Instructions to build a cross compiler to Android on ARM, to cross compile Rust sources, and to run resulting binaries follow.

1. Setup android ndk standalone tool chain with platform=14 option

   Download android NDK version r9b or later (you might not be able to build jemalloc with previous version) from http://developer.android.com/tools/sdk/ndk/index.html

   example command to setup standalone tool chain:

    ~/android-ndk-r9b/build/tools/make-standalone-toolchain.sh --platform=android-14 --install-dir=/opt/ndk_standalone --ndk-dir=~/android-ndk-r9b
   

   In case of 64bit linux system, android ndk needs 32bit linux libraries.

    e.g) /lib32/libc.so.6, /usr/lib32/libz.so.1, /usr/lib32/libstdc++.so.6.0.17
   

   You can simple install at Ubuntu System by

    apt-get install libc6-i386 lib32z1 lib32stdc++6
   

2. Download rustc from git repository

    git clone  http://github.com/mozilla/rust.git
   

3. Configure with ndk toolchain path

    mkdir build; cd build
   
    ../configure --target=arm-linux-androideabi --android-cross-path=[path of standalone toolchain dir]
   

4. Build

    make
   
    make install (Optional) 
   

   It will copy rustc binaries and libraries into /usr/local (or as defined with --prefix)

5. How to cross compile

    rustc --target=arm-linux-androideabi --android-cross-path=[path of standalone toolchain dir] hello.rs
   

6. How to run on Android

   Remount your device for get the read/write permission on /system partition

    adb remount
   

   Push arm libs and Android GNU STL shared lib

    adb push NDK_TOOLCHAIN_PATH/arm-linux-androideabi/lib/libgnustl_shared.so
    adb push /usr/local/lib/rustc/arm-unknown-android/libextra-a7c050cfd46b2c9a-0.7.so /system/lib
    adb push /usr/local/lib/rustc/arm-unknown-android/librustrt.so /system/lib
    adb push /usr/local/lib/rustc/arm-unknown-android/libstd-6c65cf4b443341b1-0.7.so /system/lib
    e.g) adb push YOUR_NDK_TOOLCHAIN_PATH/build/x86_64-unknown-linux-gnu/stage2/lib/rustc/arm-linux-androideabi/liblibrustrt.so /system/lib
   

   Push your binary

    adb push hello /system/bin
    chmod 777 hello
   

   Run using adb shell

    adb shell /system/bin/hello