Introduction

Creating Android binaries from C programs requires cross-compilation, as Android devices typically use different architectures (ARM, x86) compared to development machines. This guide will walk you through the process of creating and deploying Android binaries using the Android NDK.

Prerequisites

  • Android NDK (Native Development Kit) installed
  • Android SDK with ADB (Android Debug Bridge)
  • A C program to compile
  • An Android device or emulator for testing

Cross-Compilation Process

A simple C program sample:

#include <stdio.h>

int main() {
    printf("Hello World");
    return 0;
}

The basic workflow involves using the NDK’s Clang compiler to target specific Android architectures. Here’s the command structure:

~/Library/Android/sdk/ndk/<version>/toolchains/llvm/prebuilt/darwin-x86_64/bin/clang \
    -target armv7a-linux-androideabi21 \
    -o hello-android \
    hello.c

Deploying to Device

After compilation, use these commands to deploy and run your binary:

# Push binary to device
adb push hello-android /data/bin/hello

# Set executable permissions
adb shell chmod 777 /data/bin/hello

# Run the binary
adb shell /data/bin/hello

Notes

  • The target -target armv7a-linux-androideabi21 specifies ARMv7 architecture with Android API level 21
  • Adjust the target based on your device’s architecture (ARM, ARM64, x86, etc.)
  • Ensure your device has proper permissions to execute binaries in the /data/bin directory