Hi there,
First of all I’m surprised to hear you say that your system doesn’t support OC anything above 0.6.9. The whole idea of OC is that it extends its support to the oldest systems. So the way to do it therefore would be you upgrade to OC 0.7.1 first. The easiest way to do this is to use OCAuxiliaryTools (OCAT), download that and use that to edit and update your config.plist OC version and kext files automatically. Once you have that in place (and saved the config.plist file), using a Plist editor like Propertree or Plist Editor simply go to
https://github.com/AMD-OSX/AMD_Vanilla, click on the green Code button and download the patches.plist zipped file. Unzip and open in Plist editor both your config file and the patches.plist and simply copy and paste over to the current Kernel > Patches > Add, replacing what was there before not forgetting to fill in the three cpuid core count fields.
Thanks a lot for the info, but I have some confusing and some good news.
For some reason everything above OC 0.6.9 (I tried OC 0.7.1, 0.7.5, etc. up to 0.8.x) was not booting into Opencore menu. Most of the time I had some strange error responses and used to get stuck just after the first OC messages. Usually I was downloading the OC package, transfered all necessary files (kexts, SSDTs, etc.) to the proper directories from my old working OC package, opened the config.plist with ProperTree editor, did a new snapshot to pick all the files and proceeded to make the adjustments according to the instructions from Dortania for AMD 15h 16h CPUs. Well, it didn;t work. I was really frustrated and getting ready to give up.
But, by chance, looking around (googling with DuckDuckGo, LOL) I stumbled upon an entry on this site from a guy who had managed to install Big Sur on a FX 8xxx series system. I downloaded his EFI file, modified it only for the correct number of cores (06) and put it in my USB Big Sur installer. And, There Was Light! The installer booted fine and came to the utilities/intall screen. After that the path was clear. I installed it on a small SSD (120GB) for trial.
I now have a functional Big Sur system and as a matter of fact managed to make audio work (Big Sur breakes VoodooHDA as a kext injected by Opencore). I installed VoodooHDA to Library/Extensions after applying the Big Sur VoodooHDA OC (dmg) application (which did not solve the problem) and then followint the instruction of another guy that said to remove the VoodooHDA.kext injector form config.plist after the run of the allication and insert the VoodooHDA.kext file into Library/Extensions.
So, I have not tried yout method because I did not know abouut it, but I have a working Big Sur AMD system now.
