EGLFS and Fbdev compatibility

[rzizanie]

Hi,

I've an usb display :
robopeak rpusbdisp using fbdev driver(?) to run

i've read :
http://doc.qt.io/qt-5/embedded-linux.html

and i'm trying this tutorial :
https://wiki.qt.io/RaspberryPi2EGLFS

Because i'd like to get native opengl/3d display without x server latency on my usb display.

Maybe the answer is obvious but does a buffer/display compatible with LinuxFB makes it also compatible with EGLFS ?
EGLFS is a layer above LinuxFB and will write buffer on /dev/fbX or it uses another system ?

Thank you