iM 4,1-14,4 EnableGop: Pre-OpenCore GOP support for EFI-era iMacs and Mac Pros

[trifero]

Forget OCLP installs for debugging a GPU. OCLP Ventura/Sonoma are unusable for testing multiple GPUs, you can't change hardware with OCLP since the GPU drivers for all other GPUs besides the GPU you installed are removed. Test with vanilla Mojave.

Btw, how do you are sure that the card have the factory firmware? Did you dumped and verified with the TechPowerUp dump?

Dear @tsialex , as usually, you hit the nail in the head. Booting form Mojave, no OCLP, the ASUS ROG STRIX RX 570 works like a charm, in all his ports. Boot screen also works.

Can you point me in the right direction to make it work in OCLP Sonoma?

Inmy other MAc Pro I have also a RX 570, but the "normal" model, and never had a problem. It worked at first.

Thanks a lot for your time.

 

[tsialex]

Dear @tsialex , as usually, you hit the nail in the head. Booting form Mojave, no OCLP, the ASUS ROG STRIX RX 570 works like a charm, in all his ports. Boot screen also works.

Can you point me in the right direction to make it work in OCLP Sonoma?

Thanks a lot for your time.

Just do a clean install. If you try to undo the root patches, will take days.

 

[trifero]

Just do a clean install. If you try to undo the root patches, will take days.

Thank you, dear sir. Good idea. Wil try now. But not in that way. I´m gonna put again the card it works, uninstall root patchs, and boot with the new card. Crossing fingers.

 

[keng2000]

Thank you, I will update again after trying according to your suggestions.

last weekend I've had the time to study up on flashing the GPU as tsialex and Macschrauber have advised. I finally succeeded in flashing the GPU back to factory GPU firmware and EnableGOP.

Now I can see the option in the boot screen when holding down the option key during boot.

As per the instructions, the RX580 I received had the firmware modified before it was delivered to me. So when I flashed the GPU back to factory GPU firmware everything worked fine.

Thank you both again for your help and advice this time.

 

[Macschrauber]

last weekend I've had the time to study up on flashing the GPU as tsialex and Macschrauber have advised. I finally succeeded in flashing the GPU back to factory GPU firmware and EnableGOP.

Now I can see the option in the boot screen when holding down the option key during boot.

As per the instructions, the RX580 I received had the firmware modified before it was delivered to me. So when I flashed the GPU back to factory GPU firmware everything worked fine.

Thank you both again for your help and advice this time.

don't forget credits to @Bmju, he is the one that could make it happen at all.

 

[Bmju]

don't forget credits to @Bmju, he is the one that could make it happen at all.

Thank you. Many thanks also to yourself and @tsialex, and others who contribute on this thread, with many details about the various GPUs of this era that I never needed to learn to get EnableGop to work! (And onward credits to vit9696, and everyone else who also contributed to the OpenCore UEFI GOP code which EnableGop is built on.)

 

[keng2000]

don't forget credits to @Bmju, he is the one that could make it happen at all.

I regret not mentioning important people. It's really true that I have to thank him. @Bmju thank you very much.

 

[keng2000]

Thank you. Many thanks also to yourself and @tsialex, and others who contribute on this thread, with many details about the various GPUs of this era that I never needed to learn to get EnableGop to work! (And onward credits to vit9696, and everyone else who also contributed to the OpenCore UEFI GOP code which EnableGop is built on.)

I want to thank you @Bmju for all the wonderful things you have created. It is useful for many things. People, myself included, thank you so much for taking the time for this.

 

[vworks]

Hi, guys!


Before flashing the rom of my mac pro, I woudl like to know if already flashed cards (to display boot screen) will work once GOP is enabled.
Or do I have to flash back the original ROM to these GPUs in order to use GOP.


Thanks!

 

[tsialex]

Hi, guys!


Before flashing the rom of my mac pro, I woudl like to know if already flashed cards (to display boot screen) will work once GOP is enabled.
Or do I have to flash back the original ROM to these GPUs in order to use GOP.


Thanks!

Depends.

EnableGop is in general not compatible with most GPUs flashed with MacVidCards firmware (no pre-boot configuration at all) or any GPU that is flashed with a mining firmware or have an invalid GOP firmware. You will have a black screen until macOS loads the GPU drivers.

EnableGop does not affect AppleOEM GPUs or GPUs flashed with a firmware derived from AppleOEM GPUs (or Mac Edition GPUs, like Sapphire HD 7950 MacEdition or eVGA GTX 680 MacEdition and any GPUs flashed with firmware from these cards), the pre-boot configuration provided by the AppleOEM GPUs or GPUs flashed with a firmware derived from AppleOEM GPUs still works.

Edited to make it clear that AppleOEM GPUs provided pre-boot configuration still works with a MacPro BootROM injected with EnableGop, not that EnableGop works with AppleOEM GPUs (AppleOEM GPUs have no UEFI GOP).

 

[Bmju]

EnableGop works with AppleOEM GPUs or GPUs flashed with a firmware derived from AppleOEM GPUs.

Is that right? It's not how I would have described it. It actually works (i.e. gives a native bootpicker) with most GPUs of the right era which have GOP (i.e. (U)EFI Graphics Output Protocol; as of course you already know, but for clarity) - even GPUs which might not actually work with macOS/OS X. So I must be misunderstanding what you're saying by mentioning AppleOEM GPUs!

EDIT: Ofc I agree with your basic point, it's not compatible with most GPUs flashed with MacVidCards firmware or any GPU that is flashed with a mining firmware or has invalid GOP firmware!

 

[tsialex]

Is that right? It's not how I would have described it. It actually works (i.e. gives a native bootpicker) with most GPUs of the right era which have GOP (i.e. (U)EFI Graphics Output Protocol; as of course you already know, but for clarity) - even GPUs which might not actually work with macOS/OS X. So I must be misunderstanding what you're saying by mentioning AppleOEM GPUs!

Let me rephrase.

EnableGop does not interfere with an AppleOEM GPU, the pre-boot configuration provided by the AppleOEM GPU still works as expected, while with a MacVidCards GPU you won't have EnableGop or MacVidCards provided pre-boot configuration GPU, just a black screen.

 

[vworks]

Hi and thanx for the quick answers!

I flashed myself (following Netka's instructions a while ago) 2 cards that I use in my mac pro's to have the boot sceens.
R9 280 and GTX770

So I get it that I should reflash these with the original VBIOS in order to use them with the GOP firmware.
Otherwise, what happens? They will work if not flashed to the original vbios or just black screen and all?

 

[tsialex]

Hi and thanx for the quick answers!

I flashed myself 2 cards that I use in my mac pro's to have the boot sceens.
R9 280 and GTX770

So I get it that I should reflash these with the original VBIOS in order to use them with the GOP firmware.
Otherwise, what happens? They will work if not flashed to the original vbios or just black screen and all?

The best answer to that without knowing what you flashed is:

EnableGop does not interfere with an AppleOEM GPU or a GPU flashed with a firmware derived from an AppleOEM GPU firmware, the pre-boot configuration provided by the AppleOEM GPU still works as expected, while with a MacVidCards GPU you won't have EnableGop or MacVidCards provided pre-boot configuration GPU, just a black screen.

 

[trifero]

Just do a clean install. If you try to undo the root patches, will take days.

Dear @tsialex , once again, for a change, you were right. Although I dont understand.
I had in that mac two graphics cards, a Vega 64 , and another RX 570. And I switched then often and no problem. Simply, Ioften appears a windows saying about reinstall root patches. If not, i uninstall them , switch card, an boot always.

Withbthis model , imposible. I tried simple switch. Then uninstalling root patches. Nothing.

The only way is yours. Belive me I was sceptic. But a clen install worked like charm. So weird. Then I uninstall root patches, used Migration asistant and all as before but with thw new card. Both DVI´s are 2x, so no adapters needed for my two HD Cinema 30"

Why a RX570 is fine to switch and not the other

Buy the way , for those who are wondering why change a RX 570 for another one....__::

Well, this model I had is not stabdard size, about 4mm thicker, So I lost a PCI port. No way.

This new one is standard size.

So, if you need all your PCIe slots, dont buy this one.


Thank you so much for your help, @tsialex

 

[vworks]

Let me rephrase.

EnableGop does not interfere with an AppleOEM GPU, the pre-boot configuration provided by the AppleOEM GPU still works as expected, while with a MacVidCards GPU you won't have EnableGop or MacVidCards provided pre-boot configuration GPU, just a black screen.

I'm sorry, just to clarify : black screen, OK but after that the OS will load and the card will work right?

 

[trifero]

The best answer to that without knowing what you flashed is:

EnableGop does not interfere with an AppleOEM GPU or a GPU flashed with a firmware derived from an AppleOEM, the pre-boot configuration provided by the AppleOEM GPU still works as expected, while with a MacVidCards GPU you won't have EnableGop or MacVidCards provided pre-boot configuration GPU, just a black screen.

That is correct, I found out the other day while i used my old supported GTX680

 

[trifero]

I'm sorry, just to clarify : black screen, OK but after that the OS will load and the card will work right?

But you have GoP??

 

[vworks]

But you have GoP??

Not yet, I am probably going to flash my mac in order to use it.
But before that I wanted to know how my flashed cards would behave.
I already got the bootscreen wil NOT show up.
All I want to know is if they will work even without bootscreen. My guess is yes but want to be 100% sure.

 

[tsialex]

I'm sorry, just to clarify : black screen, OK but after that the OS will load and the card will work right?

Usually a black screen until macOS loads the GPU drivers, but I've found some situations that a MacVidCards flashed GPU blocked a GPU to work when EnableGop was flashed to the MacPro BootROM, like when you have dual GPUs and one is MacVidCards, but there are reports from other users that some MacVidCards do not work at all, even when macOS loads the GPU drivers.

No simple and definitive answer for that.

 

[vworks]

Hmm ok, thanks a bunch, tsialex!

I will flash the mac pro when I change to RX 580

 

[tsialex]

Dear @tsialex , once again, for a change, you were right. Although I dont understand.
I had in that mac two graphics cards, a Vega 64 , and another RX 570. And I switched then often and no problem. Simply, Ioften appears a windows saying about reinstall root patches. If not, i uninstall them , switch card, an boot always.

Withbthis model , imposible. I tried simple switch. Then uninstalling root patches. Nothing.

The only way is yours. Belive me I was sceptic. But a clen install worked like charm. So weird. Then I uninstall root patches, used Migration asistant and all as before but with thw new card. Both DVI´s are 2x, so no adapters needed for my two HD Cinema 30"

Why a RX570 is fine to switch and not the other

Buy the way , for those who are wondering why change a RX 570 for another one....__::

Well, this model I had is not stabdard size, about 4mm thicker, So I lost a PCI port. No way.

This new one is standard size.

So, if you need all your PCIe slots, dont buy this one.


Thank you so much for your help, @tsialex

Other people probably have better experience reverting root patches, but in my tests and several other people that I helped, you can only change GPUs with OCLP if the GPU use the exact same drivers and do not require any special settings via config.plist.

If the GPU use different drivers or require any fine tuning via config.plist is better to just re-install from scratch than try to revert the root patches.

 

[trifero]

Other people probably have better experience reverting root patches, but in my tests and several other people that I helped, you can only change GPUs with OCLP if the GPU use the exact same drivers and do not require any special settings via config.plist.

If the GPU use different drivers or require any fine tuning via config.plist is better to just re-install from scratch than try to revert the root patches.

Lesson learnt. Thnk you sir.

 

[Macschrauber]

In my experience EnableGop firmware works with almost every low and mid end GPU what is flashed with an UGA (lent) Apple firmware.

My test box has EnableGop 1.4 in its firmware and I have not came across a GPU with built in bootscreen what is not working. Including GOPless, like old HD5770 and such. This box has seen dozens of GPUs.

Reminds me to test a GT640 with MacVidCards rom, but I am pretty sure I had that GPU in, as well. Will test again.

 

[tsialex]

In my experience EnableGop firmware works with almost every low and mid end GPU what is flashed with an UGA (lent) Apple firmware.

So you are testing GPUs from MacPro1,1/2,1/3,1?

MacPro4,1 and MacPro5,1 AppleOEM GPUs are not UGA, but GOP, albeit an Apple version of GOP (and not the same as UEFI 2.3.1c ratified GOP).

My test box has EnableGop 1.4 in its firmware and I have not came across a GPU with built in bootscreen what is not working. Including GOPless, like old HD5770 and such. This box has seen dozens of GPUs.

Reminds me to test a GT640 with MacVidCards rom, but I am pretty sure I had that GPU in, as well. Will test again.

Not all MacVidCards flashed GPUs are incompatible with EnableGOP, but most newer ones definitively are not compatible, like Polaris and VEGA ones.