Run OpenCL sample in Android

Hi Aravind,

So I've given it a go at producing the Android NDK makefiles necessary to build the OpenCL samples... I've attached a zip which you should be able to unzip over the top of your OpenCL SDK. It will add a couple of jni folders, one in lib and one in samples\hello_world_opencl. To build the hello_world_opencl sample fire up a command prompt and do the following:

1. cd to Mali_OpenCL_SDK_v1.1.0\lib
2. run ndk-build
3. cd to Mali_OpenCL_SDK_v1.1.0\samples\hello_world_opencl
4. run ndk-build

The first ndk-build will build the OpenCL stub library, which exists purely to satisfy the link requirements for the samples. It is not a real implementation of OpenCL, and indeed at runtime you will be running against the real implementation present on the device. The second ndk-build will build the sample.

Note that this is only enough to make it build, I have made no modifications to the source code itself to make it run correctly, i.e. looking for files in the right place, etc, but this should be enough to get you building and running at least. I'd recommend building clinfo and checking that you get the correct diagnostic output.

Hth,

Chris

Thanks a lot Chris.

I tried ndk-build for OpenCL stub.

ara@Aravind:~/Downloads/Mali_OpenCL_SDK_v1.1.0/lib$ ndk-build

make: *** No rule to make target `jni\../..\lib\opencl_stubs.c', needed by `obj/local/armeabi-v7a/objs/OpenCL/..\lib\opencl_stubs.o'.  Stop.

It is not finding the opencl_stub file. I changed the Android.mk from LOCAL_SRC_FILES := opencl_stubs.c        to     LOCAL_SRC_FILES := ..\lib\opencl_stubs.c

But no use. can u plse help?

Thanks

Hi Aravind,

My bad, Linux doesn't like the backslashes (I wrote this on Windows ) change the backslashes to forward slashes in the Android.mk files and you're good to go

Cheers,

Chris

Hello Chris

Thanks a lot.It worked.

A libs folder and and obj folder is created inside <hello_world_sample> and inside <Mali_SDK--- / lib >

How should I run it?

Also the procedure is the same for all samples right , except we have to change the source file ?

Thanks a lot

Aravind

Hi Aravind,

Yeah the process is the same, just look at the makefiles to see what files are compiled and what the includes are for specific samples and recreate the Android.mk files I provided for those samples to run them, just copy the binary to the device, chmod it so it's executable and run it from the shell. It will fall over trying to load a file most likely, so you will need to modify the source so it looks in /sdcard/ or something. From memory at present it will look for an Assets folder in the current working dir.

Hth,

Chris

Thks Chris

So i will have to copy the hello_world_opencl executable present inside obj->local->armeabi-v7a to device.

i run $ adb shell pm setInstallLocation 2 to install it in sdcard.

To modify source, u mean i will hv to change the Android.mk file LOCAL_SRC_FILES := hello_world_opencl.cpp  to look inside sdcard? Sorry i dont understand

Thanks

Aravind

Hi Aravind,

setInstallLocation is a package manager command, and will only affect where the package manager installs packages. In this case you don't have a package to install, I assume you'll probably just push the thing with adb push somewhere like /sdcard/ and run it from there?

As for source, I am referring to the actual C++ source code, not the Android.mk file. Generally speaking there may be some minor issues running on Android which you may need to fix, e.g. broken file paths, but then again it might just work without issues. We don't routinely test on Android as we don't support it out of the box.

Hth,

Chris

adb push thing /sdcard/thing isn't working? Does the device have an /sdcard/ directory? If adb push isn't working on your device then that's a support request for HardKernel I think!

Hth,

Chris

Yes there is a sd card directory.But the "error" is not specific to ODROID but ubiquitous in many devices.

Can u plse suggest an alternative?

Thanks

I'm afraid I've never had any trouble with adb push. Can you copy the exact line you're typing? I guess without using the Android tools you're limited to moving files onto/off the device with USB keys etc.

Hth,

Chris

With production devices, even with root capabilities, you cannot push directly to the system partition - even if you remount it as rw.

For these devices with this security feature, you have to push it to the sdcard first, then adb shell and copy the files from the sdcard to your destination (note: mv will not work due to cross-filesystem limitations, a cp will work)

However you should have an eng build running on a devboard such as the XU3, so pushing directly to a rw system partition is possible, but only after you first run the following commands:

adb root

adb remount

It sounds like you are having a lot of basic problems. A lot of the issues you are now raising are not related to Mali, or indeed ARM.

Please google for the answer to generic problems before posting here.

We cannot and will not do the work for you.

Thank you for understanding, and we are more than happy to help with any Mali and/or ARM specific issues or questions you may have.

Kind Regards,

Michael McGeagh

Hi aravind,

The libOpenCL.so shipped in the SDK is just a shim library to satisfy the compile-time link requirements. If you're getting runtime issues then it might be that your device's libOpenCL.so is missing some functions. I'd sanity check the implementation on the device contains the entrypoints it thinks is missing.

Hth,

Chris