How to build caffe.so for Arm64 CPUs like Snapdragon 810

[sh1r0]

How to build caffe.so for Arm64 CPUs like Snapdragon 810

[sh1r0]

The exact error for using ANDROID_ABI="armeabi" is shown below:

caffe-android-lib/opencv/3rdparty/libwebp/cpu-features/cpu-features.c:61:0:
android-ndk-r10e/platforms/android-21/arch-arm/usr/include/machine/cpu-features.h:52:6: error: #error Unknown or unsupported ARM architecture

Perhaps, you can fix this error by using a lower api level (say android-19). But IMHO, I would not recommend you to run caffe on ARMv5 devices due to the concern for performance.

I just updated the master branch, and you could build caffe libs for aarch64 devices by setting ANDROID_ABI="arm64-v8a" (with USE_OPENBLAS=0).

[etjay]

When i use export ANDROID_ABI="armeabi" got this error :

[ 50%] Built target pch_Generate_opencv_imgproc
[ 50%] [ 52%] [ 52%] [ 52%] Building CXX object 3rdparty/openexr/CMakeFiles/IlmImf.dir/IlmImf/ImfRgbaFile.cpp.o
Building CXX object 3rdparty/openexr/CMakeFiles/IlmImf.dir/IlmImf/ImfLineOrderAttribute.cpp.o
Building CXX object 3rdparty/openexr/CMakeFiles/IlmImf.dir/IlmImf/ImfRational.cpp.o
Building CXX object 3rdparty/openexr/CMakeFiles/IlmImf.dir/IlmImf/ImfChannelListAttribute.cpp.o
[ 52%] [ 52%] Building CXX object 3rdparty/openexr/CMakeFiles/IlmImf.dir/IlmImf/ImfKeyCodeAttribute.cpp.o
Building CXX object 3rdparty/openexr/CMakeFiles/IlmImf.dir/IlmImf/ImfTiledOutputFile.cpp.o
Linking CXX static library ../lib/armeabi/libIlmImf.a
[ 52%] Built target IlmImf
make: *** [all] Error 2

[etjay]

@sh1r0 Thank you for help !

[keer2012]

I ran into the same issue.need help with it.
02-22 10:29:11.671 22055-22055/com.sh1r0.caffe_android_demo E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.sh1r0.caffe_android_demo, PID: 22055
java.lang.UnsatisfiedLinkError: dlopen failed: cannot locate symbol "sigfillset" referenced by "libcaffe.so"...
at java.lang.Runtime.loadLibrary(Runtime.java:364)
at java.lang.System.loadLibrary(System.java:526)
at com.sh1r0.caffe_android_demo.MainActivity.(MainActivity.java:53)
at java.lang.Class.newInstanceImpl(Native Method)
at java.lang.Class.newInstance(Class.java:1208)
at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2122)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2271)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1205)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5146)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:796)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:612)
at dalvik.system.NativeStart.main(Native Method)
02-22 10:34:12.061 22055-22055/? I/Process: Sending signal. PID: 22055 SIG: 9

Thxs,@sh1r0

[sh1r0]

@keer2012 Did you build the libs with ANDROID_ABI="arm64-v8a"?

[mgarbade]

Hi
I'm just facing the same error. I imported your project into Android-Studio and tried to run it from there on my Galaxy S10 Note (ARM Cortex-A9 MPCore 32-bit processor).
Where would you add this command ANDROID_ABI="arm64-v8a?
Do I need to compile the android project using a shell? (adb ? )
If yes, could you maybe give some example command?

[mgarbade]

Ok I guess I'm getting closer: Apparantly there are two important git-repositories:

1. caffe-android-lib
2. caffe-android-demo

To compile 1) I need to run ./build.sh . The file build.sh itself contains the line export ANDROID_ABI="${ANDROID_ABI:-"armeabi-v7a with NEON"}" which I will probably have to change to export ANDROID_ABI="arm64-v8a" ?
But it's still not working, when I try to run the code from 2) in Android Studio on my device the error remains.
By the way: How does the code from 2) know where the compiled code of 1) is lying? Or do I need to add some path to the build path in 2) (caffe-android-demo) ?

[sh1r0]

@keer2012 @mgarbade
To clarify, for supporting aarch64 devices:

1. Build caffe-android-lib with ANDROID_ABI="arm64-v8a". This can be set by export ANDROID_ABI="arm64-v8a" before calling ./build.sh without modifying anything.
2. If you hope to use caffe-android-demo on your aarch64 devices, you need to put the libs built from 1. in the right directory according to the abi. Please refer to https://github.com/sh1r0/caffe-android-demo/tree/master/app/src/main/jniLibs and http://developer.android.com/ndk/guides/abis.html for details.

[mgarbade]

Thank you for your advice but I think the problem lies somewhere else.

After some googeling I'm know quite conviced that my Galaxy Note 10.1 (2014 Edition) features a 32bit "Qualcomm Snapdragon 800 MSM8974" Chipset which expects a ARMv7 instruction set.

Anyway I tried both copying the libcaffe.so and libcaffe_jni.so from caffe-android-lib to the caffe-android-demo compiled
a) with export ANDROID_ABI="arm64-v8a"
b) without it

Trying a) failed with the following error:
dlopen("/data/app-lib/com.sh1r0.caffe_android_demo-7/libcaffe.so") failed: dlopen failed: "/data/app-lib/com.sh1r0.caffe_android_demo-7/libcaffe.so" not 32-bit: 2
Trying b) fails on the above mentioned cannot locate symbol "sigfillset" referenced by "libcaffe.so"

I even started creating numerous Android Virtual Devices with API 15 and API 19 including
i) armeabi-v7a
ii) x86
But still the Running of the app crashes on boot-up.

Error when launching on a armeabi-v7a - Emulator:
Launching application: com.sh1r0.caffe_android_demo/com.sh1r0.caffe_android_demo.MainActivity.
DEVICE SHELL COMMAND: am start -D -n "com.sh1r0.caffe_android_demo/com.sh1r0.caffe_android_demo.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Client not ready yet.
Client not ready yet.
Client not ready yet.
Client not ready yet.
Client not ready yet.
Client not ready yet.
Client not ready yet.
Client not ready yet.
Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.sh1r0.caffe_android_demo/.MainActivity }

Waiting for process: com.sh1r0.caffe_android_demo
Client not ready yet.
Client not ready yet.
Connected to the target VM, address: 'localhost:8618', transport: 'socket'

When I commenting these few lines
static {
System.loadLibrary("caffe");
System.loadLibrary("caffe_jni");
}

at least for a short second the main window pops up, but after 1 second the screen turns black and the program freezes.
(In that case it runs until the lines:
caffeMobile.setNumThreads(4);

Could you tell me what is the exact combination of API and ANDROID_ABI that you tested this app on?

[sh1r0]

@mgarbade
First, you should not to export ANDROID_ABI="arm64-v8a" if your device has a 32-bit ARMv7 processor.
Second, this project depends on android api 21 and I will not put extra efforts in supporting older versions than android 5 (#39).

[mgarbade]

It works :-))))))) thank you so much!
I updated my Galaxy to 5.1.1 Lollipop and now I can run the app on it!
When using the Android device emulator the program also didn't crash anymore but also it could not load fully. Seems like the App needs too much hardware resources for the emulator to run it.

Besides the files mentioned I had also to push the 240MB Imagenet model to my phone using
adb push path/to/caffe-android-demo/caffe/models/bvlc_reference_caffenet/ bvlc_reference_caffenet.caffemodel /sdcard/caffe_mobile/bvlc_reference_caffenet/