Actually, the brightness keys did not work (but the brightness sliders were ok). I have disabled SSDT-KEYS.aml and the appropriate patches (_Q10 and _Q11) and used BrightnessKeys.kext instead. Now, the brightness control keys (and also the sliders) work as they should do.
Thank you very much for...
Yes, my fault, I haven't noticed that I put config.plist in a wrong place. Now, the last EFI starts OK but still there is a bug. See the enclosed debug file. Maybe we are very close to a success. Thanks very much, I am learning a lot from you.
Ok, I copied all the files to OC debug version (also added -v) but I cannot find the place in config.plist where to enable debugging, Anyway, now we have soma logs before picker starts and indeed there errors in configuration (see the attached screen image). I am enclosing the debug version EFI...
Basically you need to update OpenCore and kernel Extensions to make it work with Big Sur. kernel extensions are easy, just have to replace files in Kexts folder with newer version. OpenCore is little complicated have to replace OpenCore files with newer and also modify/update...
Below I enclose the corrected EFI which works fine with Catalina but when booting Big Sur it stops at exactly the same error: Stuck on [EB|#LOG:EXITBS:START] despite the applied corrections.
I would be extremely grateful if you could try to update this EFI for macOS Big Sur.
Anyway, I will try...
Thank you once more for your help. I did check mentioned by you Dostania guide and after changing only two Quirks I have successfully booted Catalina (I can also boot this Catalina with Clover). Unfortunately those changes are not enough to boot Big Sur 11.5.2.
I tried to boot Catalina using your EFI (from downloaded OC RequiredFiles).
The attempt stops quickly, the screen is below. Could you please tell me what I have wrong.
Previous booting with your clover bootloader worked very well. Unfortunately, due to the disk failure