How to build linuxfb for QT5

[kuoyuyu]

Hi All,

I have question for imx6ulevk and QT5. When I run my QT5 app on imx6ulevk via backend (fb). I get some error message like below:

root@imx6ulevk:~# ./myapp -platform eglfs
MESA-LOADER: malformed or no PCI ID
gbm: failed to open any driver (search paths /usr/lib/dri)
gbm: Last dlopen error: /usr/lib/dri/vivante_dri.so: cannot open shared object file: No such file or directory
failed to load driver: vivante
gbm: failed to open any driver (search paths /usr/lib/dri)
gbm: Last dlopen error: /usr/lib/dri/kms_swrast_dri.so: cannot open shared object file: No such file or directory
failed to load driver: kms_swrast
gbm: failed to open any driver (search paths /usr/lib/dri)
gbm: Last dlopen error: /usr/lib/dri/swrast_dri.so: cannot open shared object file: No such file or directory
failed to load swrast driver
failed to load module: /usr/lib/gbm/gbm_gallium_drm.so: cannot open shared object file: No such file or directory
Could not initialize egl display
Aborted

root@imx6ulevk:~# ./myapp -platform linuxfb:fb=/dev/fb0
This application failed to start because it could not find or load the Qt platform plugin "linuxfb".

Available platform plugins are: eglfs, minimal, minimalegl, offscreen.

Reinstalling the application may fix this problem.
Aborted

I find some solution on this community(qt5 application is not work with frame-buffer backend. ), they say need to build the 'linuxfb' Qt back-end. But I have not get the process to build the 'linuxfb' Qt back-end.

My BSP is repo

imx-3.14.52-1.1.0_ga

My build command is

MACHINE=imx6ulevk source fsl-setup-release.sh -b build-fb -e fb

bitbake fsl-image-qt5

My question is how to build 'linuxfb' Qt back-end?

[kuoyuyu]

Hi Yuri,

I have other question for this issue, please help me to clean it.

The backend x11 can support QT5 apps is that x11 has provided software implemented graphics recipe, right?

If my backend select x11, I can run the QT5 apps on imx6 UL, right?

Have a great day,

Kuoyu

[Yuri]

Hello,

  Strictly speaking, NXP Linux BSP does not support QT5 without GPU :

there is no option for software graphic implementation 

Regards,

Yuri.

[kuoyuyu]

Hi Yuri,

Thank you for your forward.

I use same NXP BSP to build below two images for imx6 UL EVK, I get different result. Can help me to clean it?

1. When I use below command to build image, I can run my QT5 apps on the image.

BSP is repo

imx-3.14.52-1.1.0_ga

Build command is

MACHINE=imx6ulevk source fsl-setup-release.sh -b build-x11 -e x11

bitbake fsl-image-qt5

2. When I use below command to build image, I can not run my QT5 app on the image.

BSP is repo

imx-3.14.52-1.1.0_ga

Build command is

MACHINE=imx6ulevk source fsl-setup-release.sh -b build-fb -e fb

bitbake fsl-image-qt5

Why -e x11 can, -e fb not? (same BSP)

Regards,

Kuoyu

[kuoyuyu]

Hi Yuri,

Your mean is that I can't use QT at "backend fb" on the i.MX 6UltraLite. Because the i.MX 6UltraLite have not GPU, right?

Have a great day,

Kuoyu

[Yuri]

Hello,

Correct, i.MX6 UL does not support QT5 because of GPU absence.

Regards,

Yuri.

[kuoyuyu]

Hi Yuri,

Thank you for your support.

Have a great day,

Kuoyu

[Yuri · Accepted solution]

Hello,

  The NXP BSP does not provide software implemented graphics recipe and this does not

allow to use the NXP BSP for QT building for devices without GPU.

From "Freescale_Yocto_Project_User's_Guide.pdf" : "fsl-image-qt5 : Builds an opensource
Qt 5 image. These images are only supported for i.MX SoC with hardware graphics. They are

not supported on the i.MX 6UltraLite and i.MX 7Dual."

Have a great day,
Yuri

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