Qt World Summit: Register Today!

Qt5.4 + EGLFS on BeagBone Black

  • Hello.
    I successful build kernel + SGX drivers + Qt5.4.2.
    But I have one problem: my programs starts only from root user. In this case all work properly (HDMI ot cape output, usb mouse or touch input).
    But when I tried to start from not root, I have next messages:
    lims@arm:~$ ./eInst
    Could not initialize egl display

    user lims in video group, can write to /dev/fb0.

    when I'm trying to start using linuxfb - it works:
    lims@arm:~$ ./eInst -platform linuxfb
    "Settings: settings file/home/lims/eInst.confwas empty."

    What can I do to solve this problem?


  • Hi,
    Here, I have the same problem with another custom ARM board.
    Appreciate any advice,

  • Hi,

    After digging the issue, the cause was related with permission in folder /dev/galcore (in my case, galcore is the Vivante GPU driver).
    To test the solution, you could change the owner of the folder as below:

    sudo chown -R username:group /dev/galcore

    To obtain the root cause, you could perform the following test:

    strace yourapp -platform eglfs
    open("/dev/galcore", O_RDWR)            = -1 EACCES (Permission denied)
    open("/dev/graphics/galcore", O_RDWR)   = -1 ENOENT (No such file or directory)
    --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0xd4} ---
    +++ killed by SIGSEGV +++
    Segmentation fault


Log in to reply