Just to inform interested people. I tested mainline nightly release. Monitor switches on shortly without something visible and than goes off with "no signal".
Dmesg shows:
root@orangepipc:~# dmesg|grep frame
[ 3.251293] simple-framebuffer 7e05c000.framebuffer: framebuffer at 0x7e05c000, 0x1fa4000 bytes, mapped to 0xf1c80000
[ 3.251303] simple-framebuffer 7e05c000.framebuffer: format=x8r8g8b8, mode=3840x2160x32, linelength=15360
[ 3.401661] Console: switching to colour frame buffer device 480x135
[ 3.550976] simple-framebuffer 7e05c000.framebuffer: fb0: simplefb registered!
fbset shows:
root@orangepipc:~# fbset
mode "3840x2160"
geometry 3840 2160 3840 2160 32
timings 0 0 0 0 0 0 0
rgba 8/16,8/8,8/0,0/0
endmode
Legacy works so far, even with 3840x2160 but does not seem to be accelerated out of the box.