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

[Bmju]

Seems not NVRAM, but vBIOS flash chip

That is an NVRAM chip, even though it's not the BIOS NVRAM chip.

 

[Bmju]

@Tratkazir_the_1st - Any success report from yourself yet from the flash to fix Radeon VII bug?

 

[Tratkazir_the_1st]

@Bmju Still thinking... Actually there are 2 Macs with such cards. But I don't want to brick any of them . M.b. at week-end.

 

[Bmju]

@Bmju Still thinking... Actually there are 2 Macs with such cards. But I don't want to brick any of them . M.b. at week-end.

Well, I believe it will just work for you ... but it's your risk so ...

If you want to be really certain you won't brick it, you need to buy a USB CH341A plus SOIC clip, and you need to practice clipping on to the VBIOS flash chip and reading from it, and really, to be sure, writing back to it what you read from it; i.e. practice removing the graphics card and then reading/writing to its flash using a clip and another computer.

Then you will have a backup and you can basically be sure that you have the technology to restore it to its previous state if needed.

But given the other success stories above, the updated VBIOS should just work...

 

[FilthyMuppetInnuendo]

I’d like to add (for the sake of SEO and others looking for the information since it’s not in the OP) and say that EnableGOP works perfectly to make a GTX 980 have a pre-boot screen… from its DVI port (if it has one). DisplayPort ports don’t show a pre-boot screen. I also have an HDMI port on this card, but I have nothing to connect to it so I can’t say if it works.

Further, with this modification, you can’t use the pre-boot screen “blind” anymore (that is, holding Option even when you can’t see it and using the arrow keys and Return to select your boot volume, which is what I did for countless years).

 

[DIY Monkey]

Radeon VII

• This flagship card appears to have a buggy GOP ROM - replacing the GOP with the one from the Radeon VII Pro makes it fully work. The DirectGopRendering setting in OpenCore and EnableGopDirect are no longer needed - with this replacement EnableGop can be used.

I tried this on my AMD Radeon Vii with the Vbios you supplied, and it did not give me an Option key boot screen,
card still worked fine just no Option key boot screen, so I re-flashed it back to its original Vbios,
yes i made a backup with GPUZ before i made any changes.

I had a look for the Vbios at TechPowerup and the only VBios close to "Radeon vii pro" I could find was "Radeon PRO vii", a much later model card, is this the card you meant???

I was using amdvbflash_win_3.15 as it gave me a GUI to work with,
when i tried to use amdvbflash_win_5.0.874 all i got was a command window with no interface.

 

[Tratkazir_the_1st]

@DIY Monkey
Do you have EnableGop module in main Mac firmware? This works only in conjunction with it AFAIK.

 

[DIY Monkey]

Um no i do not, so the Vbios for the Radeon Vii only works with the firmware tweak?

was hoping i would not have to mess with the machine's firmware.

I'm running cMP5,1 with latest firmware 144.0.0.0.0, 6 core 3.46 Xeon, Radeon Vii, 64 gig 1333 mhz memory,
Mojave under Martin Lo’s OCLP config, machine runs great was just hoping to get an options key boot screen with out having to prod the firmware, no joy there i guess lol,

its mainly my games machine, mojave is only there for updating/editing Martins OCLP config.plist when needed,
so i don't really need an options key boot screen, but it would have been nice to have it lol.
I have a 2018 Mac Mini for serious stuff like book keeping and so on.

 

[tsialex]

Um no i do not, so the Vbios for the Radeon Vii only works with the firmware tweak?

Correct.

 

[DIY Monkey]

OK think I'll just leave things as they are.

Machine is running fine as is, don't want to risk it,
i have no use for an expensive door stop.