I've got a PC video card that I'd like to get boot screen support for on my Mac Pro. In particular, it is a Gigabyte R9 270X. The card is supported on the Mac once it boots, but I would like to get boot screen back since my old 8800GT has been baked in the oven a few too many times by now :-)
I've seen numerous guides on the internet about flashing the BIOS on the video cards and also ones that speak about adding the EFI BIOS, but in the haphazard forum approach, it isn't clear how this all works. To some degree, I've recently come away with the notion that you don't get rid of the existing BIOS, but rather add an EFI partition to it that the Mac would recognize. If that assumption is correct, then it would lead me to believe that adding an EFI BIOS that works on a similar card (R9 280X or 7950 which are both close but not quite) should work since I'm assuming that the existing BIOS would be similar enough to hook in. Failing that, I'm not clear how you would get a card-specific EFI BIOS for boot screen support.
Anyone an expert on this? I'm just really having a hard time trying to sift through all this and hoping to get a more direct answer!