MP 1,1-5,1 Editing PlatformSupport.plist for Catalina

[mangombia]

I'm looking for guidance or step-by-step to modifying the PlatformSupport.plist file in Catalina so I can clear my NVRAM of the boot args.

I realize it will probably be overwritten or replaced on updates, but I'm going to pull the Catalina drive and perform updates from a 2018 MBP and can reapply the fix or replace the file after updates are performed and before putting back into the cMP.

 

[tsialex]

I'm looking for guidance or step-by-step to modifying the PlatformSupport.plist file in Catalina so I can clear my NVRAM of the boot args.

I realize it will probably be overwritten or replaced on updates, but I'm going to pull the Catalina drive and perform updates from a 2018 MBP and can reapply the fix or replace the file after updates are performed and before putting back into the cMP.

It's not a god idea, Catalina is being updated weekly, 3 updates already (builds 19A583, 19A602, 19A603) with the new continuous integration being used by Apple.

Anyway, you have two PlatformSupport.plist that you need to edit, first one in the Catalina system partition that is now read-only, usually Macintosh\ HD, and the second one inside a hidden Preboot partition:

Preboot/xxx-xxx-xxx-xxx/System/Library/CoreServices/PlatformSupport.plist

You have to add the board-id and remove the MacPro5,1 from the list of blocked Macs. If you really want to do it, ask help here: macOS 10.15 Catalina on Unsupported Macs[/code]