Rotate QML-Application to portrait mode via EGLFS ?

[themts]

Hi guys,
I have an qml-application that runs on a rasp4 via EGLFS.
Is there a way to rotate my application in portrait mode?

I'm using a Pi4 with bullseye (full KMS).

I could rotate my top-level QML-Item but then every frame will be rotated 90° in the GPU.
90° image flipping should be something very easy for the board as it only has to switch some display-signals.

THX
mts