MP 7,1 Mojave on a 2019 Mac Pro 7,1. Time to hack.

[mattspace]

Would a virtual machine be an option for this?

Getting Mojave running on a 7,1 sounds very complicated from reading the posts.

The virtual machine approach might be simpler.

The real issue for virtualising is you don't get graphics / 3D acceleration prior to Monterey as a guest, and as far as I've been able to determine, none of the options support multiple displays for the guest on a multi-display host.

The platonic ideal would be to be able to have your VM guest have the same number of displays as your host, and set it to be full screens in a mission control space.

 

[sfalatko]

One thing to try which I used to get Catalina working on my cMP5,1 is to edit the PlatformSupport.plist file in the reboot and recovery partitions to include the info for the 7,1 (boardID and Model number) so Mojave will think the 7,1 is supported. This eliminates the need for boot args.

 

[Minghold]

One thing to try which I used to get Catalina working on my cMP5,1 is to edit the PlatformSupport.plist file in the reboot and recovery partitions to include the info for the 7,1 (boardID and Model number) so Mojave will think the 7,1 is supported. This eliminates the need for boot args.

What are the file-paths for each of those? TIA.

 

[ProDFX]

I installed Mojave on MacBook Pro 2019 using OpenCore. Loads without a graphics adapter driver. On Mac Pro 7.1 with RX 580 it should be no problem.

 

[sfalatko]

What are the file-paths for each of those? TIA.

Unfortunately I can't recall exactly and I no longer have my cMP. Look in System/Library/Coreservices - that's where it is in Monterey.

Again - I don't recall how I installed Catalina - where I edited the file in the install USB. But once installed I would boot into Mojave and then mount the Catalina PreBoot partition and find the PlatformSupport.plist and add the MacPro5,1 model identifier and boarded (there are two sections in the file). I would do the same in the Recovery partition. With that done I would be able to boot into Catalina without "no_compat_check" and also into recovery.

With every OTA update I would potentially have to reedit the two files. If that was the case I would boot into Mojave and do the edits.

Sorry I can't be more specific.

 

[Minghold]

Unfortunately I can't recall exactly and I no longer have my cMP. Look in System/Library/Coreservices - that's where it is in Monterey.

Again - I don't recall how I installed Catalina - where I edited the file in the install USB. But once installed I would boot into Mojave and then mount the Catalina PreBoot partition and find the PlatformSupport.plist and add the MacPro5,1 model identifier and boarded (there are two sections in the file). I would do the same in the Recovery partition. With that done I would be able to boot into Catalina without "no_compat_check" and also into recovery.

With every OTA update I would potentially have to reedit the two files. If that was the case I would boot into Mojave and do the edits.

Sorry I can't be more specific.

What I hoping to do is find a way to clone a working Mojave onto 2019 16" MBPs and 2020 iMacs (the very last intel machines, with that 10-core i9 being a screamer). (But the best hack of all would be a means of disabling PlatformSupport checking entirely, permitting Mojave to at least attempt to launch on anything, Apple or not.)

 

[sfalatko]

I don't know if you can bypass the platform check but on a real Mac you could edit the PlatformSupport.plist in the preboot and recovery partitions, clone it, and it should work. You could try with an external disk and see if you can get it to boot and if that works clone it onto the internal disk.

The main catch is if the target computer has hardware that Mojave doesn't support. Catalina has complete hardware support for everything the cMP5,1 has so getting past the compatibility check everything worked perfectly. Getting to later versions of macOS takes OpenCore to deal with hardware issues. Getting to something Ventura or beyond you need to root patch because of missing AVX/AVX2 so you need OCLP.

 

[benmuetsch]

Mojave should basically work on a MP7.1 maybe besides networking and stuff. Would be really interested in this for scientifical reasons

I would tinker around with my 7.1 a bit but it's my work and production machine so too risky atm

 

[Minghold]

I don't know if you can bypass the platform check but on a real Mac you could edit the PlatformSupport.plist in the preboot and recovery partitions, clone it, and it should work. You could try with an external disk and see if you can get it to boot and if that works clone it onto the internal disk.

The main catch is if the target computer has hardware that Mojave doesn't support. Catalina has complete hardware support for everything the cMP5,1 has so getting past the compatibility check everything worked perfectly. Getting to later versions of macOS takes OpenCore to deal with hardware issues. Getting to something Ventura or beyond you need to root patch because of missing AVX/AVX2 so you need OCLP.

OCLP is for people trying to put new OSes on old Macs; we're trying to put a (better) "old" OS on intel hardware that is should be capable of running on, but for which deemed Catalina to be the base OS.

 

[Minghold]

I'm curious why you want to run Mojave on the 7,1. Is it for the 32bit app compatibility? If so, What I was wondering is might it be easier to bring the mountain to Mohamed so to speak and copy those libraries over into Catalina and get 32bit apps running under Catalina. But you may have different reasons, curious as to what they are?

Mojave is the last OS that'll run in HFS+ (AKA MacOS Extended-journaled drive partition), which is demonstrably faster than APFS, twenty billion times easier to make a bootable backup of, and for which dozens of third-party recovery and management utilities exist.