Mac Pro 3.1 with non Apple GPU

[Apolloza]

hi all

Recently i got a Mac Pro 3.1. The unit was badly gutted, no GPU, no HDD, single 2GB memory stick.

I got a second hand RX560 as graphics card.

With a ton of effort I finally got a OpenCore patcher boot USB with Big Sur on it. USB starts the installer all as intended And I can install the OS. But when it reboots it keeps on going to the USB installer.

i have tried pressing the Alt key (windows keyboard) but I’m not presented with a boot menu at all.

my mind is a bit fussy with all the things ive tried so asking for some advice. Started from a dead box I’ve gotten so close!!

I either need to flash the RX560 or maybe get opencore to have a boot menu?

 

[Apolloza]

Another random thought, can’t i use the terminal on the installer to copy over the opencore software to the new OS drives EFI partition? Once the correct boot files are there then I should be able to boot without the USB stick in?

 

[Apolloza]

Another random thought, can’t i use the terminal on the installer to copy over the opencore software to the new OS drives EFI partition? Once the correct boot files are there then I should be able to boot without the USB stick in?

This idea worked like a charm!

Started the mac os installed, then opened Terminal, mounted both EFI partitions (SSD and USB), copied over the files from the USB to the SSD and here we are!