Doc building for android

These are preliminary build instructions for Android. Note that ARM and Android integration are still very early and incomplete. Some features do not work yet, and as such this information is primarily for hackers that want to work on the ARM port.

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

   Android NDK can be downloaded from http://developer.android.com/tools/sdk/ndk/index.html

   example command to setup standalone tool chain:

    ~/android-ndk-r8d/build/tools/make-standalone-toolchain.sh --platform=android-14 --install-dir=/opt/ndk_standalone --ndk-dir=~/android-ndk-r8d
   

   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-triples=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