MP 1,1-5,1 Recovering Mojave and upgrading firmware without EFI GPU on cMP 5,1

[Vega20]

Hello, I am in a bit of a pinch trying to recover MacOS Mojave after a surge which wiped out my MacintoshHD and Windows. It was originally using the Mojave DosDude patcher with the High Sierra BIOS revision but now I only have the original ATI Radeon that does not support Metal and a Radeon VII that was used in Mojave. Any DosDude or OpenCore USB appears with the prohibited sign as there is nothing installed and I cannot create a High Sierra USB due to my other Macs being too new. What steps do I need to take to get Mojave or newer back and update the firmware? Thank you!

 

[tsialex]

Please read the first post of the thread below:

MP5,1: What you have to do to upgrade to Mojave (BootROM upgrade instructions thread)

 

[Vega20]

Please read the first post of the thread below:

MP5,1: What you have to do to upgrade to Mojave (BootROM upgrade instructions thread)

Thank you for writing that, I had a feeling there was already a thread but it is often difficult to thumb through threads here. Looks like I need hunt down a Polaris GPU then. Thanks for pointing me in the right direction.

 

[tsialex]

Thank you for writing that, I had a feeling there was already a thread but it is often difficult to thumb through threads here. Looks like I need hunt down a Polaris GPU then. Thanks for pointing me in the right direction.

You don't need to buy a GPU.

You can download El Capitan or Sierra and create a createinstallmedia USB installer via installinstallmacos.py with any Intel Macs, you don't need the MacAppStore at all.

With your original Apple GPU you can check what is the current EFI firmware and then proceed accordingly.

 

[tsialex]

Let me explain the El Capitan or Sierra suggestion - High Sierra installs require at least MP51.0089.B00 and Mojave requires 144.0.0.0.0, so you won't install it without having the correct firmwares, while El Capitan or Sierra can be installed whatever your EFI release is at this moment.

 

[Vega20]

Let me explain the El Capitan or Sierra suggestion - High Sierra installs require at least MP51.0089.B00 and Mojave requires 144.0.0.0.0, so you won't install it without having the correct firmwares, while El Capitan or Sierra can be installed whatever your EFI release is at this moment.

Thank you. I do have MP51.0089.B00 and am attempting to get to 144.0.0.0.0. I was able to get Sierra back on through the gibmacos python utility but the Mojave installer does not detect the VII due to the lack of drivers on Sierra and the unpatched Mojave installer refuses to work with the ATI. Hence with accordance to your guide I'll need something else to get the firmware up to speed or just use the patcher again and forget about it. Sorry about not being clearer in the earlier comment, my bad!

 

[tsialex]

Thank you. I do have MP51.0089.B00 and am attempting to get to 144.0.0.0.0. I was able to get Sierra back on through the gibmacos python utility but the Mojave installer does not detect the VII due to the lack of drivers on Sierra and no acceleration without patches with the ATI. Hence with accordance to your guide I'll need something else to get the firmware up to speed or just use the patcher again. Sorry about not being clearer in the earlier comment, my bad!

Correct, you will need a METAL supported GPU that works with the macOS version that you are running.

You can also workaround the firmware upgrade requirement with a BootROM reconstruction service, you will get a bootROM image upgraded to the most recent components (EFI, NVRAM, hardware descriptor, BootBlock, etc) and with 144.0.0.0.0. I can send a PM with instructions/cost, if you want to go this route.

 

[Vega20]

Correct, you will need a METAL supported GPU that works with the macOS version that you are running.

You can also workaround the firmware upgrade requirement with a BootROM reconstruction service, you will get a bootROM image upgraded to the most recent components (EFI, NVRAM, hardware descriptor, BootBlock, etc) and with 144.0.0.0.0. I can send a PM with instructions/cost, if you want to go this route.

Sure, there is also a bunch of cheapo RX560's floating around on local classifieds which fulfills the requirement. I guess it all depends on whats cheaper. Send it on over and I'd be thrilled to take a look!

Also, I should clarify I made the USB though gibmacos and some utility on Windows as my other Macs are M1 based.

 

[tsialex]

Sure, there is also a bunch of cheapo RX560's floating around on local classifieds which fulfills the requirement. I guess it all depends on whats cheaper. Send it on over and I'd be thrilled to take a look!

Done!

Also, I should clarify I made the USB though gibmacos and some utility on Windows as my other Macs are M1 based.

No problem, you will clean install Mojave with your Radeon VII after you get 144.0.0.0.0.

 

[Vega20]

Done!


No problem, you will clean install Mojave with your Radeon VII after you get 144.0.0.0.0.

Thank you! I did end up finding a RX560 at work yesterday which worked like a charm. Thanks again