the only way to connect the board to QT is using the board IP address and updating the device IP in QT creator KIT settings.
The general guide for yocto systems (not krogoth specific), is available here: http://variwiki.com/index.php?title=Fil ... reator.pdf
Our boards start a dhcp request on eth port at powerup.
What do you mean by "it doesn't works"?
No dhcp request?
No dhcp answer?
Not reachable by QT creator?