Just thought I'd share this in case others have an issue. I used to triple boot my MacPro with refind using the old Radeon 6870 with included efi drivers.
See this thread for my experience getting the Sapphire Pulse OC RX560 4GB card working there. Some good advice on this forum.
Thought I would add that I got Linux working, had tried reinstalling refind but it didn't work. Now when I upgraded debian stretch to buster, refind starting working, but I lost my display with the new card. No hope getting in to linux.
I checked the boot logs and realised it was not even booting... Forceably removed refind by deleting it from the EFI. BAM! Grub comes back (no display) and debian boots.
Rock and roll. Seems like Refind is halting boot on this device.
See this thread for my experience getting the Sapphire Pulse OC RX560 4GB card working there. Some good advice on this forum.
Thought I would add that I got Linux working, had tried reinstalling refind but it didn't work. Now when I upgraded debian stretch to buster, refind starting working, but I lost my display with the new card. No hope getting in to linux.
I checked the boot logs and realised it was not even booting... Forceably removed refind by deleting it from the EFI. BAM! Grub comes back (no display) and debian boots.
Rock and roll. Seems like Refind is halting boot on this device.