Progress, but not there yet.
Mork has posted a comment over in the HDMI audio part (
https://www.tonymacx86.com/threads/...d-xfx-rx-480-8gb-reference-card.213498/page-6 post #56). I thought I would see how the approach would work on my RX 460 so I followed along with what he is asking the RX 480 folks to try. [I got the same as I alway have, so nothing great to report on that part.]
I had removed the AMD 4100 kext to run the test, so I had put it back to restore the system to original and restarted, but I had forgotten to reset the BIOS option to use the IGPU instead of the PCIe graphics card. The system completely booted without the usual kernel panic with the characteristic purple line of dots on the monitor. None of the ports worked (all showed no-signal to the monitor) but the system was not locked up, I was able to blindly log-in and get the usual disk activity LEDs flashing as if the system was acting normally. Just without any kind of graphics. I did this several times including a hard shutdown and startup as well as several warm reboots. I have not tried this in a while, but something has changed in either the Apple - AMD 9510 controller and 4100 kext or in Clover's newer version or in both.
Here is the background info that I have.
macOS Sierra 10.12.4 Public Beta v6
Clover v 4035
Gigabyte GA-Z97N Gaming 5, BIOS version F5, i-4690S, 16GB RAM
BIOS was set to use PCIe
I do not directly have the BIOS entry CSM -Disable/Enable, this option used to be there but was changed in the BIOS F5 to be separate entries (my board went from F3 to F5). I have in its place:
Windows 8 Feature
Other OS
Boot Mode Selection
UEFI Only
LAN PXE Boot Option ROM
Disabled
Storage Boot Option Control
UEFI Only
Other PCI Devices ROM Priority
UEFI opROM
It is progress, but not there yet.
Edit: This BIOS also has a setting found in the Peripherals section called Intel Processor Graphics -- Enables or disables the onboard graphics function. (Default: Enabled). Setting this to disabled along with using PCIe graphics has no effect. But the system is running and not locked up in a kernel panic. Presently, the startup logo screen, the Clover screen and the Apple progress loading screen are visible up to the point when (I assume it is) the 4100 kext is loaded. Then the monitor loses the signal (all the connectors turn off) but the system continues loading and I can log-in. But no graphics from here. Since the IGPU is turned off, this makes it truly a headless Mac, which is not really useful for a desktop system.
So how does one go about re-initializing the PCIe graphics card?