- Nov 4, 2016
- Core i7-6700k
- AMD FirePro W9000 + Radeon 7970
Interesting. Is it possible that Clover itself is causing the problem? Has anyone managed to boot macOS without Clover outputting to the graphics card?@LostVector: It's not necessarily the "first" card which will be dead, the bug only occurs when the AMD GPU has been init'ed by the UEFI driver, which isn't always the same.
Two examples from my system (other UEFI implementations can behave differently):
When booting with CSM disabled, the UEFI video driver will not be initialized when no display is connected to the AMD GPU during boot time, no matter if it's the primary or secondary video adapter. As a consequence the macOS drivers will work fine.
When booting with CSM enabled, firmware will always initialize the primary video adapter, regardless of any connected displays. To make a AMD GPU work in OS X, one has to configure it as secondary one.
The difference during boot phase is what we'd have to figure out to fix this issue.
A genuine Mac Pro 5,1 apparently does not use GOP to initialize the video card, only UGA. So if Clover always used GOP to draw its interface then perhaps that is giving the AMD driver fits.