Forums - FastCV 1.7.1 Linux Embedded - linking errors during cross compilation

Hello,

I have a C++ application that performs Canny edge detection, among other things. The host platform is x86_64 (amd64) with Ubuntu 18.04 LTS 64-bit. The target platform is aarch64 (Kryo) CPU on Qualcomm SA6155. We were able to cross-compile the original C++ application for the target platform with the aarch64-linux-gnu-g++ compiler. We were also able to execute the binary thus created on the ARM CPU of SA6155 platform, which runs Linux.

Now, I am attempting to accelerate the Canny edge detection function. So I installed the FastCV library version 1.7.1 for Linux Embedded platform, substituted the original C++ function with the fcvFilterCannyu8() function from the FastCV library, and attempted to cross-compile the application. The build command lines are as follows:

$ aarch64-linux-gnu-g++-5 -c -std=c++11 -fPIC -march=armv8-a -pthread -O2 -I src <source-file> -o <object-file>
$ aarch64-linux-gnu-g++-5 -no-pie -L/usr/aarch64-linux-gnu/lib -L/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib <list-of-object-files> -lc -ldl -lfastcv -o my_executable

I placed the 64-bit version of libfastcv.a in the path /home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib. I expected that the other libs (pthread, dl, c) would be linked automatically from the path /usr/aarch64-linux-gnu/lib.

But when I attempted to build this way, I encountered the following errors:

/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcv.o): In function `uR(fcvOperationMode, FCV_FUNC_MANAGER*, FCV_IMPL)':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcv.cpp:4087: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcv.cpp:4113: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcv.cpp:4120: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcv.cpp:4127: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcv.cpp:4134: undefined reference to `dlsym'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcv.o):/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcv.cpp:4141: more undefined references to `dlsym' follow
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcv.o): In function `uR(fcvOperationMode, FCV_FUNC_MANAGER*, FCV_IMPL)':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcv.cpp:4098: undefined reference to `dlerror'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvHW.o): In function `fcvTableHWInitRemote(FCV_FUNC_MANAGER*, fcvOperationMode)':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcvHW.cpp:165: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcvHW.cpp:228: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcvHW.cpp:243: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcvHW.cpp:173: undefined reference to `dlerror'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcvHW.cpp:236: undefined reference to `dlerror'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/common/fastcvHW.cpp:250: undefined reference to `dlerror'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMserFxpC.o): In function `fcvThreadCreate(int (*)(void*), void*, void**)':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: undefined reference to `pthread_create'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: undefined reference to `pthread_create'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: undefined reference to `pthread_create'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: undefined reference to `pthread_create'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: undefined reference to `pthread_create'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMserFxpC.o):/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: more undefined references to `pthread_create' follow
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMserFxpC.o): In function `fcvThreadJoin(void*, int*)':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: undefined reference to `pthread_join'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: undefined reference to `pthread_join'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: undefined reference to `pthread_join'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: undefined reference to `pthread_join'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: undefined reference to `pthread_join'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMserFxpC.o):/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: more undefined references to `pthread_join' follow
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMserFxpC.o): In function `fcvThreadCreate(int (*)(void*), void*, void**)':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: undefined reference to `pthread_create'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMserFxpC.o): In function `fcvThreadJoin(void*, int*)':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: undefined reference to `pthread_join'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMserFxpC.o): In function `fcvThreadCreate(int (*)(void*), void*, void**)':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: undefined reference to `pthread_create'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: undefined reference to `pthread_create'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: undefined reference to `pthread_create'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: undefined reference to `pthread_create'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: undefined reference to `pthread_create'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMserFxpC.o):/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:55: more undefined references to `pthread_create' follow
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMserFxpC.o): In function `fcvThreadJoin(void*, int*)':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: undefined reference to `pthread_join'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: undefined reference to `pthread_join'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: undefined reference to `pthread_join'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: undefined reference to `pthread_join'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: undefined reference to `pthread_join'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMserFxpC.o):/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:72: more undefined references to `pthread_join' follow
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvHwAndroid.o): In function `fcv_check_only_cpu':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvCpuFeatures.c:288: undefined reference to `pthread_once'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvHwAndroid.o): In function `fcv_android_getCpuFamily()':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvCpuFeatures.c:265: undefined reference to `pthread_once'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvHwAndroid.o): In function `fcv_android_getCpuImplementer()':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvCpuFeatures.c:282: undefined reference to `pthread_once'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvHwAndroid.o): In function `fcv_android_getCpuFeatures()':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvCpuFeatures.c:274: undefined reference to `pthread_once'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvRemoteLibAndroid.o): In function `fcvCheckRemoteLibPresent()':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:186: undefined reference to `dlopen'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvRemoteLibAndroid.o): In function `fcvCheckRemoteLibSupport()':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:58: undefined reference to `dlerror'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:68: undefined reference to `dlsym'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvRemoteLibAndroid.o): In function `fcvCheckRemoteLibPresent()':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:186: undefined reference to `dlopen'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:186: undefined reference to `dlopen'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvRemoteLibAndroid.o): In function `fcvRemoteLibAvailableHWComponent(fcvOperationMode)':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:133: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:140: undefined reference to `dlerror'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:141: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:152: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:155: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:148: undefined reference to `dlerror'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvRemoteLibAndroid.o): In function `fcvCheckRemoteLibPresent()':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:186: undefined reference to `dlopen'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvRemoteLibAndroid.o): In function `fcvRemoteLibCleanUp()':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:173: undefined reference to `dlsym'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvRemoteLibAndroid.o): In function `fcvRemoteLibClean()':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:198: undefined reference to `dlclose'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvRemoteLibAndroid.o): In function `fcvCheckRemoteLibPresent()':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:186: undefined reference to `dlopen'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvRemoteLibAndroid.o): In function `fcvSelectQDSP6ModeRemoteLib':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:210: undefined reference to `dlsym'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvRemoteLibAndroid.o): In function `fcvCheckRemoteLibPresent()':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:186: undefined reference to `dlopen'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvRemoteLibAndroid.o): In function `fcvQ6GetClkRemoteLib':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvRemoteLibAndroid.cpp:225: undefined reference to `dlsym'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMem.o): In function `fcvMutexTryLock(void*)':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:138: undefined reference to `pthread_mutex_trylock'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:138: undefined reference to `pthread_mutex_trylock'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMem.o): In function `fcvOnceRun(void volatile*, void (*)())':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:165: undefined reference to `pthread_once'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:165: undefined reference to `pthread_once'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMem.o): In function `_fcvSlbChk()':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/processor/x86/fastcvMem.cpp:485: undefined reference to `dlopen'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/processor/x86/fastcvMem.cpp:491: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/processor/x86/fastcvMem.cpp:494: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/processor/x86/fastcvMem.cpp:497: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/processor/x86/fastcvMem.cpp:500: undefined reference to `dlsym'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/processor/x86/fastcvMem.cpp:503: undefined reference to `dlsym'
/home/sagar/qualcomm/vfs_all_cam_repo/vfs_all_cam_arm_linux/lib/libfastcv.a(libfastcv_la-fastcvMem.o): In function `fcvOnceRun(void volatile*, void (*)())':
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:165: undefined reference to `pthread_once'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:165: undefined reference to `pthread_once'
/usr/src/debug/fastcv-noship/git-r0/fastcv-noship/src/platform/android/fastcvThread.inl:165: undefined reference to `pthread_once'
collect2: error: ld returned 1 exit status
Makefile:77: recipe for target 'my_executable' failed
make: *** [my_executable] Error 1

It looks like the 'pthread' and 'dl' libraries are not getting linked together with the FastCV library.

How can I resolve this problem?

Thank you.