What is the standalone toolchain?

This blog posting may answer your question:

http://clseto.mysinablog.com/index.php?op=ViewArticle&articleId=3480794

There is a recommended way to build native C/C++ program on Android: List your source files in a script (Android.mk) and run 'ndk-build'. It may not be a problem if you are writing new programs but if you already have a working build script (like those open source softwares) which can build you program nicely on Linux, it would be a headache to migrate your script to Android.mk. All you need in this situation is a C/C++ cross compiler and then replace the variables in your script (such as CC, CXX, AR, AS, RANLIB, ...) to something like 'arm-linux-androideabi-gcc', 'arm-linux-androideabi-g++', ...

Fortunatley, inside the 'Android NDK Dev Guide', there is a section 'Standalone Toolchain' which just describes what we need....

First of all, the best guide for stand alone toolchains in Android is here: https://developer.android.com/ndk/guides/standalone_toolchain.I have used it several times for different devices and platform.

You need to download NDK and then run the script 'make-standalone-toolchain.sh' with a few parameters (as said in the link above) that will determine the API levels of your apps, the architecture of the device etc.

The output of the script will be a directory that you can use as a toolchain in order to cross compile native C/C++ code to run on Android devices. You need to put in your Makefile the path to the toolchain directory and add the architecture suffix for the binaries inside (for example 'arm-eabi-'). Something like:

CROSS_COMPILE = /path-to-toolchain-dir/bin/arm-eabi-

There should be files like '/path-to-toolchain-dir/bin/arm-eabi-gcc' in your toolchain directory.

Anyway, this will tell the Makefile to use your toolchain's binaries in order to compile the C/C++ native code and create the compatible executables for your target machine.

For example, this is the commands I used to create a stand alone tool chain for a certaion Android device:

./make-standalone-toolchain.shj --arch=arm --platform=android-21 --install-dir=<dest-dir> --toolchain=arm-linux-androideabi-4.9