Real Java on AArch64
Hacking.
MainActivity is a java class running on the Dalvik/ART/Android platform. Hence, it needs to be compiled with the appropriate compiler (sic)
It calls into graallauncher.c which will launch the graal-compiled java app. This is the one that matters (not the Android activity)
The pre-compiled app is included in binariesfornow: hello.helloworld.o
Source of this class:
package hello;
public class HelloWorld {
public static void main(String[] args) {
String javaVersion = System.getProperty("java.version");
System.out.println("Hello World on Graal, javaVersion = "+javaVersion);
}
}
Compiled on an AArch64 Linux with the following command:
export GRAAL=/home/ubuntu/graal/vm/mxbuild/linux-aarch64/GRAALVM_SVM_BGU/graalvm-svm-19.3.0-dev
$GRAAL/bin/native-image \
--no-fallback -H:TempDirectory=tmphw \
-H:+SpawnIsolates \
-H:+ReportExceptionStackTraces \
-H:+AllowIncompleteClasspath \
-cp $CP \
hello.HelloWorld
As a result, tmphw contains a file hello.helloworld.o which is the one that is here placed in the binariesfornow directory
Create a keystore:
/opt/java/bin/keytool -genkey -alias server-alias -keyalg RSA -keypass foofoo -storepass barbar -keystore ~/android.keystore.jks
When asked for password, enter barbar
run adb logcat -v threadtime and start the app, you should see something like this:
09-16 13:34:11.792 3718 3718 W System.err: Hello WORLD ACTIVITY, onCreate called
09-16 13:34:11.818 3718 3733 D OpenGLRenderer: HWUI GL Pipeline
09-16 13:34:11.842 3718 3733 I Adreno : QUALCOMM build : 8e59954, I0be83d0d26
09-16 13:34:11.842 3718 3733 I Adreno : Build Date : 09/22/17
09-16 13:34:11.842 3718 3733 I Adreno : OpenGL ES Shader Compiler Version: EV031.21.02.00
09-16 13:34:11.842 3718 3733 I Adreno : Local Branch : O17A
09-16 13:34:11.842 3718 3733 I Adreno : Remote Branch :
09-16 13:34:11.842 3718 3733 I Adreno : Remote Branch :
09-16 13:34:11.842 3718 3733 I Adreno : Reconstruct Branch :
09-16 13:34:11.843 3718 3733 D vndksupport: Loading /vendor/lib64/hw/gralloc.msm8992.so from current namespace instead of sphal namespace.
09-16 13:34:11.852 3718 3718 V GraalActivity: [MainActivity] Surface created in activity.
09-16 13:34:11.852 3718 3718 W System.err: loading lib
09-16 13:34:11.852 3718 3733 I Adreno : PFP: 0x00000000, ME: 0x00000000
09-16 13:34:11.862 361 361 W /system/bin/hwservicemanager: getTransport: Cannot find entry android.hardware.configstore@1.0::ISurfaceFlingerConfigs/default in either framework or device manifest.
09-16 13:34:11.863 3718 3718 W System.err: loaded lib
09-16 13:34:11.863 3718 3718 W System.err: metrics = DisplayMetrics{density=2.625, width=1080, height=1794, scaledDensity=2.625, xdpi=422.03, ydpi=424.069}
09-16 13:34:11.863 3718 3718 W System.err: DENSITY??? 2.625
09-16 13:34:11.863 3718 3718 E GraalGluon: SurfaceReady, native window at 0x0
09-16 13:34:11.864 3718 3718 W System.err: Surface created, native code informed about it.
09-16 13:34:11.864 3718 3718 V GraalActivity: Surface created, native code informed about it.
09-16 13:34:11.864 3718 3718 V GraalActivity: [MainActivity] surfaceChange, format = 4, width = 1080, height = 1731
09-16 13:34:11.864 3718 3718 W System.err: [MainActivity] surfaceChange, format = 4, width = 1080, height = 1731
09-16 13:34:11.864 3718 3718 W System.err: metrics = DisplayMetrics{density=2.625, width=1080, height=1794, scaledDensity=2.625, xdpi=422.03, ydpi=424.069}
09-16 13:34:11.864 3718 3718 W System.err: DENSITY??? 2.625
09-16 13:34:11.864 3718 3718 W System.err: [MainActivity] surfaceRedrawNeeded, we will launch our app now
09-16 13:34:11.864 3718 3733 I zygote64: android::hardware::configstore::V1_0::ISurfaceFlingerConfigs::hasWideColorDisplay retrieved: 0
09-16 13:34:11.866 3718 3733 I OpenGLRenderer: Initialized EGL, version 1.4
09-16 13:34:11.866 3718 3733 D OpenGLRenderer: Swap behavior 2
09-16 13:34:11.869 3718 3734 E GraalGluon: Start GraalApp!
09-16 13:34:11.870 3718 3735 D GraalCompiled: ALLOCATE MEMORY asked for 1048576
09-16 13:34:11.871 3718 3735 D GraalCompiled: Hello World on Graal, javaVersion = 11.0.4