AMD Vega 3 APU NVRAM pathway found

Middleman

Member
Joined
Jan 29, 2021
Messages
52
Just thought to share with you all an interesting find I made last night.

So I was busy testing and checking the EFI settings for my Atari VCS Vega 3 setup, changing the ACPI and device properties, to try to include the framebuffer-unifiedmem values to (because it was reporting very little VRAM ie. 31mb). I was wondering why it wasn't reporting the changes I'd made when I stumbled upon this driver path while looking in Windows under the AMD Radeon Win10 drivers.

amd-system-vega3b.png


The full path is: /REGISTRY/MACHINE/SYSTEM/CurrentControlSet/Control/Class/{4d36e968-e325-11ce-bfc1-08002be10318}/0000

It seems AMD has a NVRAM address for the VCS' Vega 3 driver responsible for 2D acceleration. I believe this could be why the Vega 3 and other AMD APUs haven't been able to report (or work) the full VRAM of the GPU which is 2GB. If we could somehow tweak it, it may hold the key to full 3D acceleration for AMD APUs.

Anyways I'd tried to activate it under Opencore by adding it to the NVRAM settings and adding npci=0x2000 agdpmod=pikera. It didn't quite work and managed to stall under VirtualSMC as well as Lilu.
 

Shaneee

Administrator
Staff member
The AMD Guy
Joined
Mar 13, 2020
Messages
911
Are you using framebuffer-patch-enable? It enables WhateverGreen's patching capabilities. Not sure if it's required for setting framebuffer-unifiedmem.
 

Middleman

Member
Joined
Jan 29, 2021
Messages
52
Are you using framebuffer-patch-enable? It enables WhateverGreen's patching capabilities. Not sure if it's required for setting framebuffer-unifiedmem.
Yes I had been. In previous instances I have seen it as a prerequisite for the framebuffer injection (according to output from Hackintool anyway).
 
Top Bottom