Running cross-compiled application on Rock Pi 4 (RK3399)

Brainite

Hello everyone,

I am currently trying to get cross-compiled applications running on a Rock Pi 4 (running the latest official Debian 10 buster downloaded from here).

Using the instructions and configuration switches seen here I managed to cross-compile Qt 5.12.10 as well as examples [i.e., calendarwidget, for the time being] and the application I am trying to port from a NanoPi to the Rock Pi and deploy them using QtCreator.

Using 'Run' in QtCreator I do no receive any errors but also no indication that the application is running or even started to begin with. However, when I try to run the applications (my custom application, as well as calendarwidget, makes no difference) locally on the target machine, I see these errors:

Failed to mmap framebuffer (Invalid argument)
linuxfb: Failed to initialize screen
Device discovery cannot open device "/dev/input/event0"
Device discovery cannot open device "/dev/input/event1"
Device discovery cannot open device "/dev/input/event2"
Device discovery cannot open device "/dev/input/event3"
Device discovery cannot open device "/dev/input/event4"
Device discovery cannot open device "/dev/input/event0"
Device discovery cannot open device "/dev/input/event1"
Device discovery cannot open device "/dev/input/event2"
Device discovery cannot open device "/dev/input/event3"
Device discovery cannot open device "/dev/input/event4"
Device discovery cannot open device "/dev/input/event0"
Device discovery cannot open device "/dev/input/event1"
Device discovery cannot open device "/dev/input/event2"
Device discovery cannot open device "/dev/input/event3"
Device discovery cannot open device "/dev/input/event4"
no screens available, assuming 24-bit color
Cannot create window: no screens available
Aborted

I've looked at /dev/fb0 (as mentioned here) which I suppose would be the default framebuffer, and the default user rock is part of the video group which owns /dev/fb0.

This question here describes a similar problem (but seems to be unresolved, as well as, dealing with (Permission denied) instead of (Invalid argument).

Could anyone please suggest how to debug and fix these errors and get the UI to start?
Thanks in advance.