Thanks a lot for the instructions.
I managed to get a waveshare 3.5 A clone work by doing it like this:
modprobe fbtft_device custom name=fb_ili9486 gpios=dc:18,reset:2 speed=16000000 busnum=1 rotate=90
But with the “Armbian_5.25_Orangepizero_Ubuntu_xenial_default_3.4.113” image the boot halts just after starting to load kernel when I point the vt to fb8
"extraargs="fbcon=map:8"
"con2fbmap 1 8"
works ! strange