Hello all!
I have a Mac Pro 1,1/2,1 from 2006/2007 (originally came with MP 1,1/2006 EFI firmware, but upgraded to the 2,1/2007 EFI firmware) and this is probably the messiest EFI implementations around.
Apple computers often need their graphics cards flashing with “Magic” (UGA support?) in order to get EFI boot screens. They don’t support GOP (so no boot screens in EFI mode unless the card is flashed with some funky Apple ROM, called UGA if memory serves correctly) and they only use the legacy option ROM when booting into BIOS compatibility mode (for booting Windows). So in a gist, you can only use a “normal” PC graphics card in this thing either if you’re legacy booting or if you’ve flashed the card (en example of this is making a ROM for AMD 7xxx GCN 1.0 cards, here: http://forum.netkas.org/index.php?PHPSES…10&topic=5619.0 ).
To add insult to injury, Apple decided to give a machine with 64bit processors a 32bit EFI, making it difficult to install any modern OS and to find EFI modules to load via rEFInd.
I was wondering if anyone has any ideas in regards to modifying the firmware or creating an ia32 EFI module that can load a legacy option ROM from a PC graphics card, or to load the GOP part of a standard PC graphics card. This has somewhat been achieved with newer Mac Pro machines that have a 64bit EFI implementation, such as here: https://forums.macrumors.com/threads/boo…otocol.2089181/ ( source code for this modified rEFInd can be found here: https://sourceforge.net/u/jief7/refind/ci/GOPScreen/tree/ ).
This system uses the Intel 5000 Series Chipset and has two CPU sockets. I have a dump of the EFI/BIOS firmware which I obtained using flashrom, but I’m unsure as to if it’s legally possible to post the file publicly (I can share it privately with anyone who is up for the task of modifying/taking apart the firmware). I’m able to open the file using UEFITool ( https://github.com/LongSoft/UEFITool ) without issues.
Other Mac computers have also been modified to add NVME support, like so: https://twitter.com/gillesaurejac/status…6135385089?s=20
Sorry if I’ve missed anything important out. Would be super happy for any valuable input.