I'm still using mojave on my 5,1 and want to install opencore so I can upgarde to Big Sur. I tried following the instructions on the video and at first tried to create the EFI partition it on my nvme installation of Mojave. It created the EFI partition but it was empty. So, as the video said, I created the EFI directory and copied the BOOT and OC directories into it. Keep in mind there was no APPLE folder in the EFI directory as shown in the video because I had to create the EFI directory from scratch. When I tried to bless EFI, I got the following error:
3: Could not set boot device
property: 0xe00002e2
I assumed that I got this error because there was no APPLE directory. I couldn't find a way to undo what I had done, so I simply tried it again, but got the same error. I then read the readme and it says that if I have UEFI Windows already installed, it would be better to put EFI on that drive. I do have a Windows installed on a bootcamp SSD drive so I decided to try running EFI partition again, but this time on my Windows SSD. This time the EFI directory WAS created and there was an APPLE directory inside. So I copied the the BOOT and OC directories again and tried to bless the Windows SSD. But again I got the same error as above.
I'm afraid to reboot my mac now because I'm not sure if I just bricked it by putting a failed EFI partition on two of my hard drives. How do I undo the damage? Why was I getting that error?
Some info: I'm using a 2009 5,1 mac pro with a Radeon Sapphire Pulse RX 580 GPU (unflashed). Mojave is isntalled on an NVME drive plugged into a PCI-E slot and my Windows SSD is plugged into a SATA slot. SIP is disabled, I recently flashed my bootrom and did a 3x NVRAM Reset.
Edit: The problem was SIP wasn't disabled properly. I'm not sure why, but only some of the SIP options was disabled. After disabling SIP I tried resetting the NVRAM 3 times again but it didn't seem to work, I got the following error:
-bash/jamesmurray/Volumes >nvram -c
nvram: Error clearing firmware variables: (iokit/common) not permitted
I tried resetting the NVRAM by pressing cmd+options+p+r at startup but it didn't seem to work either. So I decided to skip this step and just try to mount and bless EFI again. This time it didn't give me the option to set up EFI on my bootcamp SSD because it didn't show up in the list of drives when I ran "Mount EFI Partition" so I mounted it on my Mojave NVME drive. It seemed to work, as when I restarted my mac I got a boot screen. Now I'm just trying to figure out how to install Big Sur.