[OpenIndiana-discuss] Dual screen setup with intel DRM & VESA

[Araragi Hokuto]

Hello everyone.

I'm trying to setup an OI installation for my illumos dev tasks. My 
system has a i7-6700 CPU and RX480 graphics card, with a dual monitor 
setup. Since there is no AMDGPU driver avaliable for illumos (Correct me 
if I'm wrong, but https://www.illumos.org/issues/8069 does not seem to 
have a corresponding kernel module, and I couldn't get that working by 
simply installing the userland component, I'm assuming there is still no 
actual support at this moment?), I'm currently using VESA xorg driver, 
which works fine for me; but since it uses VESA BIOS for display, there 
is no dual screen support.

But I noticed that there is intel DRM support on illumos, and I do have 
a intel GPU (the integrated GPU in my i7), so I'm thinking: is it 
possible to utilize both GPU for dual screen support?

More specifically, these are what I'm trying to do:

a) Use VESA driver for RX480, and connect the primary screen to its HDMI 
output, which is already working by default, and:

b) Enable intel DRM on the integrated GPU, and connect the secondary 
monitor to the HDMI port provided by my motherboard.

a) is working by default now, and enabling intel GPU while keep the AMD 
GPU working is certainly doable in my BIOS (verified under Linux with 
xrandr). But I'm not sure how to configure X server on illumos to make 
it aware of this setup.

Therefore, is there anyone have ideas of what configure should I try, or 
some alternative way to setup dual screen with VESA/intel DRM? 
Unfortunately there is only one HDMI port on my motherboare, so I don't 
think connecting both monitor to intel GPU is an option (again, correct 
me if I'm wrong).

Thanks in advance.