1.Get on 2.5 Hearts or lower so the pearl will kill you

2.Jump into end portal

3. use ender Pearl right before you go in

4.you should be generating world forever or until you quit the game via "X" button or alt f4

5.you might be able to still open chat after the first few 30 sec of generation world i was unable to open chat for the first min or 2 and my mouse was also not moving

video 

https://www.youtube.com/watch?v=nV_kG4mGweQ