Building native executables for Android
If you want to support devices running Android versions lower than 5.0 (API 21), you need to compile your binary with
APP_PLATFORM set to an older API, e.g.
android-8. This is a consequence of Android 5.0 enforcing Position Independent Binaries (PIE), whereas older devices do not necessarily support PIEs. Therefore, you need to use either the PIE or the non-PIE, depending on the device version. If you want to use the binary from within your Android application, you need to check the API level and extract the correct binary.
APP_ABI can be changed to specific platforms such as
armeabi to build the binary for those architectures only.
In the worst case, you will have both a PIE and a non-PIE binary for each architecture (about 14 different binaries using ndk-r10e).
To build the executable:
You will find the binaries at
project/libs/<architecture>/hello_world. You can use them via
chmod it with executable permission) or from your application (extract and
chmod it with executable permission).
To determine the architecture of the CPU, retrieve the build property
ro.product.cpu.abi for the primary architecture or
ro.product.cpu.abilist (on newer devices) for a complete list of supported architectures. You can do this using the
android.os.Build class from within your application or using
getprop <name> via ADB.
How to clean the build
If you need to clean the build:
How to log in ndk
First make sure you link against the logging library in your
Then use one of the following
Or use those in a more convenient way by defining corresponding macros:
How to use a makefile other than Android.mk
ndk-build NDK_PROJECT_PATH=PROJECT_PATH APP_BUILD_SCRIPT=MyAndroid.mk