I have cross-compiled Qt 5.1.1 for an i.MX6 powered Nitrogen6x board running Debian 7 (wheezy).
I have configured Qt with the -egl parameter and eglfs has been listed as QPA backend in the configure output.
However if I try to run a small example application with the -platform eglfs parameter I am running into this error:
stdin: is not a tty
[ 1] HAL user version 4.6.9 build 6622 Aug 15 2013 13:22:40
[ 2] HAL kernel version 4.6.9 build 1210
QML debugging is enabled. Only use this in a safe environment.
bash: line 1: 3673 Segmentation fault DISPLAY=:0.0 /opt/Test/bin/Test -platform eglfs
Remote application finished with exit code 139.
OpenGL ES2 and EGL are installed on the board and can be found in /usr/lib and /usr/include.
Sadly I couldn't find proper documentation for eglfs, so I am hoping that someone around here has made some experiences with it.
This is the backtrace output:
run Test-platform eglfs
Starting program: /opt/Test/bin/Test Test -platform eglfs
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/arm-linux-gnueabihf/libthread_db.so.1".
[ 1] HAL user version 4.6.9 build 6622 Aug 15 2013 13:31:17
[ 2] HAL kernel version 4.6.9 build 1210
QML debugging is enabled. Only use this in a safe environment.
[New Thread 0x2c6b7460 (LWP 4057)]
Program received signal SIGSEGV, Segmentation fault.
0x2bab6f48 in gcoHAL_QueryChipCount () from /usr/lib/libGAL.so
(gdb) backrace full
Undefined command: "backrace". Try "help".
(gdb) backrace full[1@t
#0 0x2bab6f48 in gcoHAL_QueryChipCount () from /usr/lib/libGAL.so
No symbol table info available.
#1 0x2ba7ccbc in veglGetThreadData () from /usr/lib/libEGL.so.1
No symbol table info available.
#2 0x2ba74cd0 in eglBindAPI () from /usr/lib/libEGL.so.1
No symbol table info available.
#3 0x2be41934 in ?? () from /usr/local/Qt-Debian/plugins/platforms/libqeglfs.so
No symbol table info available.
#4 0x2be41934 in ?? () from /usr/local/Qt-Debian/plugins/platforms/libqeglfs.so
No symbol table info available.
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb) info registers
r0 0x1 1
r1 0x23e54 147028
r2 0x738 1848
r3 0x0 0
r4 0x2bb67d84 733379972
r5 0x23e18 146968
r6 0x2e70c 190220
r7 0x2b430198 725811608
r8 0x7efff9e8 2130704872
r9 0x8 8
r10 0x2b0725c4 721888708
r11 0x7efffae0 2130705120
r12 0x2bab6f1c 732655388
sp 0x7efff8f0 0x7efff8f0
lr 0x2ba7ccbc 732417212
pc 0x2bab6f48 0x2bab6f48 <gcoHAL_QueryChipCount+44>
cpsr 0x80000010 -2147483632
(gdb) x/16i $pc
=> 0x2bab6f48 <gcoHAL_QueryChipCount+44>: ldr r3, [r3, #12]
0x2bab6f4c <gcoHAL_QueryChipCount+48>: sub r2, r3, #1
0x2bab6f50 <gcoHAL_QueryChipCount+52>: cmp r2, #2
0x2bab6f54 <gcoHAL_QueryChipCount+56>: bhi 0x2bab6f70 <gcoHAL_QueryChipCount+84>
0x2bab6f58 <gcoHAL_QueryChipCount+60>: ldr r2, [r4]
0x2bab6f5c <gcoHAL_QueryChipCount+64>: mov r0, #0
0x2bab6f60 <gcoHAL_QueryChipCount+68>: str r3, [r1]
0x2bab6f64 <gcoHAL_QueryChipCount+72>: add r3, r2, #1
0x2bab6f68 <gcoHAL_QueryChipCount+76>: str r3, [r4]
0x2bab6f6c <gcoHAL_QueryChipCount+80>: pop {r4, pc}
0x2bab6f70 <gcoHAL_QueryChipCount+84>: mvn r0, #8
0x2bab6f74 <gcoHAL_QueryChipCount+88>: bl 0x2baad5fc
0x2bab6f78 <gcoHAL_QueryChipCount+92>: ldr r3, [r4]
0x2bab6f7c <gcoHAL_QueryChipCount+96>: mvn r0, #8
0x2bab6f80 <gcoHAL_QueryChipCount+100>: add r3, r3, #1
0x2bab6f84 <gcoHAL_QueryChipCount+104>: str r3, [r4]
(gdb) thread apply all backtrace
Thread 2 (Thread 0x2c6b7460 (LWP 4057)):
#0 0x2b52ef96 in ?? () from /lib/arm-linux-gnueabihf/libc.so.6
#1 0x2b568634 in _IO_file_close () from /lib/arm-linux-gnueabihf/libc.so.6
#2 0x2b568ffe in _IO_file_close_it () from /lib/arm-linux-gnueabihf/libc.so.6
#3 0x2b56113a in fclose () from /lib/arm-linux-gnueabihf/libc.so.6
#4 0x2bea8d00 in udev_new () from /lib/arm-linux-gnueabihf/libudev.so.0
#5 0x2be7d2e4 in ?? () from /usr/local/Qt-Debian/plugins/platforms/libqeglfs.so
#6 0x2be7d2e4 in ?? () from /usr/local/Qt-Debian/plugins/platforms/libqeglfs.so
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
Thread 1 (Thread 0x2bcb9220 (LWP 4056)):
#0 0x2bab6f48 in gcoHAL_QueryChipCount () from /usr/lib/libGAL.so
#1 0x2ba7ccbc in veglGetThreadData () from /usr/lib/libEGL.so.1
#2 0x2ba74cd0 in eglBindAPI () from /usr/lib/libEGL.so.1
#3 0x2be41934 in ?? () from /usr/local/Qt-Debian/plugins/platforms/libqeglfs.so
#4 0x2be41934 in ?? () from /usr/local/Qt-Debian/plugins/platforms/libqeglfs.so
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb) quit
How could I possibly fix that error?
I fixed this issue by switching to Yocto and therefor gaining access to most recent releases of essential components. If you're developing for an i.MX cpu I strongly recommend to have a look at https://github.com/Freescale/fsl-community-bsp-platform
It is very important to remove "x11" from default-distrovars and "wayland" from poky.conf as these will cause you to run into errors.
Building Qt5 on such a setup works fine.