Building

Prerequisites

Due to the use of symlinks, a unix-based operating system is required. Make sure you configured a full-working build setup and have Android SDK and Java installed properly.

Please note that building with other operating systems is not officially supported.

Build stand-alone App with Gradle

Get the source code and clone it into your directory of choice:

git clone https://github.com/microg/android_packages_apps_GmsCore.git
cd android_packages_apps_GmsCore/
git submodule update --recursive --init

The cloned repository contains all required build scripts for gradle and the wrapper, which is needed to start the build process. Make sure you have your ANDROID_SDK_HOME and JAVA_HOME properly defined in your ~/.profile or ~/.bashrc. It currently works with Java 8, newer versions might cause exceptions.

To build GmsCore, execute in your cloned directory

./gradlew build

The generated apks can be found in the subdirectory play-services-core/build/outputs/apk/.

You may want to sign your apk using the following commands in the apk directory with your specific configuration:

jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore ~/path_to_your/keystore.jks play-services-core-release-unsigned.apk your_keystore_username --signedjar play-services-core-release-signed.apk
$ANDROID_SDK_HOME/build-tools/23.0.2/zipalign -p -v 4 play-services-core-release-signed.apk com.google.android.gms.apk

Alternatively, you can use this small bash script, which automates all required steps from above:

#!/bin/bash

mkdir microg
cd microg
mkdir outputs
mkdir keystores

ANDROID_SDK_PATH="/opt/android-sdk-update-manager"
KEYSTORES_PATH="keystores"

# Generate keystore
echo "We need to create a keystore for GmsCore:"
keytool -genkey -v -keystore $KEYSTORES_PATH/playservices.jks -alias playservices -keyalg RSA -keysize 4096 -validity 10000


# GMSCore
git clone https://github.com/microg/android_packages_apps_GmsCore.git
cd android_packages_apps_GmsCore
git submodule update --init --recursive
echo "sdk.dir=$ANDROID_SDK_PATH" > local.properties
echo "sdk-location=$ANDROID_SDK_PATH" >> local.properties
./gradlew build
cp play-services-core/build/outputs/apk/release/play-services-core-release-unsigned.apk ../outputs/play-services-core-release.apk


# Sign APK
cd ../outputs
jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore $KEYSTORES_PATH/playservices.jks play-services-core-release.apk playservices
$ANDROID_SDK_PATH/build-tools/22.0.1/zipalign -p -v 4 play-services-core-release.apk com.google.android.gms.apk

Congratulations, you got your com.google.android.gms.apk! Now head over to Installation.

Gradle integrated signing

You can also sign and zipalign directly as part of the ./gradlew build call. To do so, create a file play-services-core/user.gradle with the following content:

android {
    signingConfigs {
        release {
            storeFile file('~/path_to_your/keystore.jks')
            storePassword 'keystore password'
            keyAlias 'key alias'
            keyPassword 'key password'
        }
    }

    buildTypes {
        /* Optional: sign debug builds with release key
        debug {
            signingConfig signingConfigs.release
        }
        //*/
        release {
            signingConfig signingConfigs.release
        }
    }
}

When doing so, ./gradlew build will produce the final file at play-services-core/build/outputs/apk/play-services-core-release.apk

Integrate GmsCore in AOSP-based ROM

In case you want to integrate GmsCore into an AOSP-based ROM build, you can add its repository to your local_manifests.xml to keep it updated by repo:

<remote  name="github"
             fetch="https://github.com/" />

<project path="packages/apps/GmsCore" name="microg/android_packages_apps_GmsCore" remote="github" revision="master" />

You may want to add <project ... /> lines for GsfProxy and FakeStore/BlankStore, too.

Now edit your device.mk in ~/path_to_aosp/device/your_manufacturer/your_model and add the package names you want to include in your build:

# OTHER PACKAGES
PRODUCT_PACKAGES += \
   GmsCore \
   GsfProxy \
   FakeStore

The default android build process will respect GmsCore and automatically create an APK on the /system partition image.

Please note, that to make GmsCore work, your ROM has to support Signature Spoofing.