MP 1,1-5,1 Another cMP OCLP boot question

[moondigger]

Hi. Brief background: I have successfully used OCLP to update a 2011 Mac Mini and a 2017 MacBook Air to recent versions of MacOS. So I'm not completely unfamiliar with the process. But now I've run into a problem:

I have a Mac Pro 5,1 running Mojave. I'd like to update it to Monterey, which is the version most often recommended for this model. I should mention here that I installed an AMD Radeon RX 560 a few years ago so that I could update to Mojave. If I recall correctly, the eBay listing said it had been flashed with Mac-compatible firmware. It works in Mojave, but presents a black screen (no Apple logo) until late in the boot process.

So for my current effort to upgrade it to Monterey with OCLP... Everything went smoothly until I got to the 'reboot while holding the option key' part. The screen remains blank, and the system doesn't appear to boot at all. If I press the power button, the system powers off immediately.

I have tried toggling the option in OCLP for AMD GOP insertion. There is no change in behavior whether that setting is on or off. I have tried resetting parameter RAM. I have tried installing OpenCore onto one of my internal boot disks rather than the USB installation drive. None of this has made any difference.

A lot of what I've found on Google seems specific to much older versions of OCLP, or refers to procedures that I get the impression are outdated. (e.g., referring to versions of OCLP prior to 1.0, or referencing stuff that must once have been a manual procedure which are now covered within the OCLP checkboxes.)

Any suggestions would be greatly appreciated.

 

[tsialex]

It works in Mojave, but presents a black screen (no Apple logo) until late in the boot process.

So, this is is the exact behavior of a not flashed/standard PC GPU from factory. With a flashed GPU, you would see the Apple logo right after power on and the Boot Picker would work when ALT is pressed at power on.

To make the native and OCLP BootPicker working, you gonna need EnableGop EFI module injected to the Mac Pro BootROM - after that any modern PC GPU will work almost exactly as any AppleOEM GPU works from factory:

EnableGop: Pre-OpenCore GOP support for EFI-era iMacs and Mac Pros

You wait ten years for a driver to enable pre-boot graphics on unsupported GPUs in EFI era Macs, and then two come along at once... This post is to announce a firmware driver to enable the native Apple boot picker and early macOS boot progress bar (plus other parts of the firmware UI: target...

forums.macrumors.com

If you can't do it by yourself, my BootROM Reconstruction service already include EnableGop injection and will be ready to work with any supported UEFI GOP GPU.

 

[moondigger]

So, this is is the exact behavior of a not flashed/standard PC GPU from factory. With a flashed GPU, you would see the Apple logo right after power on and the Boot Picker would work when ALT is pressed at power on.

To make the native and OCLP BootPicker working, you gonna need EnableGop EFI module injected to the Mac Pro BootROM - after that any modern PC GPU will work almost exactly as any AppleOEM GPU works from factory [...]

Thanks for the reply -- I'll look into that. But isn't that issue what this setting in OCLP is for?

OCLP defaulted to leaving this unchecked, which made me think my RX 560 didn't need it. (Everything else that's required for this system seems to have been selected.) But it didn't work, so I tried checking that box and then reinstalled open core. Again, nothing. I'm fine with investigating the EnableGOP EFI module you linked to, but it seems like that checkbox in OCLP 2.4.1 should cover the issue already. Or is there some subtle distinction I'm missing?

 

[tsialex]

No, this won't work with Mac Pros. This is a complicated topic and I'll greatly simply.

MacPro4,1/5,1 default graphics protocol is a flavor of GOP that was developed by Apple years before UEFI GOP was ratified as a standard by UEFI Consortium and Microsoft. Almost the same, but incompatible.

The GPU needs to be initialized by the Mac Pro firmware at POST or OC/OCLP won't have a working display - the option of OCLP to inject GOP is to make some stubborn compatible card to behave correctly (usually for MacPro3,1 and iMacs), but won't make an incompatible card at pre-boot to work.

The only way to have display working at pre-boot for OC/OCLP to work is one of the options below:

• having an AppleOEM GPU,
• having a PC GPU flashed to Mac Pro pre-boot display compatibility, like MacVidCards or older self-flashed GPUs,
• having the combo of EnableGop injected to the Mac Pro BootROM plus UEFI PC GPU with the factory firmware unmodified (there are reasons for that, like for example the Mac Pro BootROM rejecting to load any GPU firmware that was modified and have invalid cryptographic signing of the firmware).

For you, the last option is the one that is gonna work.

 

[moondigger]

[...]

• having the combo of EnableGop injected to the Mac Pro BootROM plus UEFI PC GPU with the factory firmware unmodified (there are reasons for that, like for example the Mac Pro BootROM rejecting to load any GPU firmware that was modified and have invalid cryptographic signing of the firmware).

For you, the last option is the one that is gonna work.

Thanks again for the quick reply. I'm concerned about the warning here -- I'm fairly sure when I bought this GPU on eBay that the listing said (or strongly implied) the firmware was updated -- "Modified to work with OS X 10.14 Mojave" or something like that. Which would mean that the factory firmware was modified. But I have no way of checking that listing years later.

I've been reading through the documentation, and also came across this:

The requirements for using this driver are:
- EFI-era (~2009-2012) MacPro4,1/5,1 or iMac with most recent main firmware.
- A GPU which does not produce native pre-boot graphics (such as native picker when pressing ALT key during boot)
before OpenCore starts (otherwise, you do not need it).
- A GPU which produces graphics when using OpenCore (this must include successfully showing the native Apple boot
picker when started via the latest version of OpenCore tool `BootKicker.efi`) (otherwise, the driver will not work).

The first two requirements make sense. It's that third one that has me a little confused. I can't tell if my GPU will produce graphics when using OpenCore, because I don't have OpenCore working yet. How will I know if this card meets that requirement before I've gotten it going?

 

[tsialex]

From what you wrote on the first post, your GPU have a display working ONLY AFTER macOS loads the GPU driver in the final part of the loading process and no OCLP BootPicker at all.

So, you'll need EnableGop injected to the BootROM and to make sure that you have a factory unmodified GPU firmware - since you could have a messed-up mining or gaming GPU. Read more about it here, there are a lot of info applicable to you in the posts near mine, read it all:

EnableGop: Pre-OpenCore GOP support for EFI-era iMacs and Mac Pros

If the GPU is flashed to a mining firmware, even if the mining firmware have GOP, the incorrect signing will make the Mac Pro firmware to discard the GOP module right after failing to validate it. In my own experience, second hand eBay/AliExpress GPUs most of the time come with incorrect...

forums.macrumors.com

Run Windows, dump your GPU firmware with GPU-Z and verify the checksum of the firmware with TechPowerUp dumps of your exact GPU.

This is the post that you gonna need if the GPU firmware is really modified and you need to go back to the factory GPU firmware:

EnableGop: Pre-OpenCore GOP support for EFI-era iMacs and Mac Pros

I very recently solved the same situation you seem to have: 5,1 bootROM with EnableGOP, OCLP, and a (used eBay) Sapphire Pulse RX 580 8GB with dual BIOS switch but no boot picker unless AMD Inject GOP was selected in the advanced OCLP config. There is a method for flashing GPU directly on a...

forums.macrumors.com