Doc building for android

These are preliminary build instructions for Android. Note that ARM and Android integration are still very early and incomplete. This information is 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 libc-i386 lib32z1 libstdc++6
   

2. Download rustc from git repository

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

3. Configure with ndk toolchain path

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

4. Build

    make
   
    make install  
   

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

5. How to cross compile

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

6. How to run on Android

    use adb -e push command to push all arm libs as specified in 6 b
   

   push your binary

   set LD_LIBRARY_PATH

   run using adb shell