Building for Android

Build the FreeRDP Android app from source using the NDK build script and Android Studio.

The FreeRDP Android port consists of three parts:

• Android Java GUI — located in client/Android/Studio
• Native FreeRDP libraries — built with the Android NDK and CMake
• JNI bindings — client/Android/android_freerdp.c and the corresponding Java class LibFreeRDP.java

More documentation may be found at the FreeRDP Compilation wiki.

Build requirements

For the native JNI libraries

• CMake >= 3.13 — install via Android SDK Manager (SDK Tools section)
• Android NDK >= r15c

For the Java GUI

• Android SDK
• Android Studio (recommended) or Gradle

Optional dependencies

• cJSON — required for logging in to Azure accounts
• MIT or Heimdal Kerberos — for Kerberos authentication
• libjpeg — for JPEG support (akallabeth/jpeg8d has been tested)

FreeRDP requires OpenSSL libraries, which are not part of the Android NDK. They must be pre-built manually. The android-build-freerdp.sh script handles this automatically.

Building the native libraries

From the repository root, run the build script passing the paths to your NDK and SDK installations:

./scripts/android-build-freerdp.sh \
  --ndk <ANDROID_NDK> \
  --sdk <ANDROID_SDK>

Replace <ANDROID_NDK> and <ANDROID_SDK> with the absolute paths on your machine.

The script will fetch and build:

• OpenSSL
• OpenH264
• libjpeg
• The FreeRDP native libraries

Supported ABIs

The default configuration builds for all four common ABIs:

ABI	Description
armeabi-v7a	32-bit ARM
arm64-v8a	64-bit ARM
x86	32-bit x86 (emulator)
x86_64	64-bit x86 (emulator)

The default build configuration is at scripts/android-build.conf and produces debug builds targeting API level 21 and above.

Release builds

For release binaries (with older Android API support), build the 32-bit and 64-bit architectures separately using the dedicated conf files:

32-bit architectures

./scripts/android-build-freerdp.sh \
  --ndk <ANDROID_NDK> \
  --sdk <ANDROID_SDK> \
  --conf ./scripts/android-build-32.conf

When the script completes, the built libraries are placed at:

client/Android/Studio/freeRDPCore/src/main/jniLibs/

Android Studio will pick them up automatically from that location.

Building the APK

Android Studio

1. Import the project

   Open Android Studio and choose Open (or Import Project). Navigate to client/Android/Studio inside the repository and select it.

2. Build

   Use the standard Build > Make Project menu or run the app directly on a device or emulator.

Gradle (command line)

1. Change to the Studio directory

   cd client/Android/Studio
   
2. Build the APK

   ./gradlew build
   
3. List available tasks

   ./gradlew tasks
   

CMake preload configuration

The repository ships ci/cmake-preloads/config-android.txt with the settings used in CI. Key options:

set(CMAKE_TOOLCHAIN_FILE "$ANDROID_NDK/build/cmake/android.toolchain.cmake" CACHE PATH "ToolChain file")
set(FREERDP_EXTERNAL_SSL_PATH $ENV{ANDROID_SSL_PATH} CACHE PATH "android ssl")
set(WITH_KRB5 OFF CACHE BOOL "Kerberos support")
set(WITH_CLIENT_SDL OFF CACHE BOOL "SDL client")
set(WITH_SERVER OFF CACHE BOOL "ci default")
set(WITH_X11 OFF CACHE BOOL "ci default")
set(WITH_MANPAGES OFF CACHE BOOL "ci default")

Updating the JNI bindings

Whenever the FreeRDP C API changes or you need additional functionality exposed to Java:

1. Edit client/Android/android_freerdp.c and add the new function to the methods struct.
2. Edit client/Android/Studio/freeRDPCore/src/main/java/com/freerdp/freerdpcore/services/LibFreeRDP.java to mirror the change.