Update - Mojave
I had downloaded the Mojave installer as soon as it was available on the App Store but didn't install straight away and instead kept an eye on the relevant forums here to check how people were faring with it.
It seemed to me that there were a lot of problems. Initially I thought it was about 50-50 but then I realised maybe a lot of people had successful upgrades but weren't writing the process up. Maybe it was easier than than I thought...
I took the plunge last night and here goes:
First thing I did was update Clover to the latest. A "problem" straight away. I now had the Christmas theme on my boot selector! This had happened once before a long time ago, due to a BIOS clock reset. I checked this again but no, everything was as it should be. I rolled-back my Clover install and this seems to have worked. I had installed 4674, so used MultiBeast 10.4 to replace it with 4630. The Christmas theme was at least gone now.
The installation took probably 15-20 minutes with about three reboots along the way. Once done I now have four boot options: Preboot, install Preboot, Boot my SSD and Recovery. It looks messier than before but I just let it timeout to my SSD and it boots.
No audio. **Important point - once Mojave has installed go to your System/Library/Extensions folder and back-up the AppleHDA.kext so you have an untouched copy somewhere safe in case you need it in future.
This gets complicated. Sorry, but it's probably worth sticking with me for a surprising conclusion ...
My motherboard has ALC892 and checking the forums shows this is causing problems.
I removed all audio patches from my config.plist and uninstalled realtekALC.kext, before I got down to things.
First up I tried using the now preferred AppleALC/Lilu kexts solution. Sadly this did not work. I tried installing them in different locations - EFI/CLOVER/kexts/Other, L/E, S/L/E but none of them produced any sound devices. Obviously I rebuilt my kext caches between trials.
I read that Apple have deprecated a lot of Audio ID layouts but my usual one - 2 - was still supported. I did try a couple of others just in case but this made no difference.
Encouragingly I *was* getting sound from my RX560 GPU via HDMI though. That happened with no problem at all. Clearly the default macOS drivers for RX560 work well.
With the Lilu/AppleALC kexts in my EFI/CLOVER/kexts/Other folder, and feeling adventurous (or reckless), I
also installed the VooDooHDA.kext in L/E. Oddly this duplication of code effort actually worked but I detected a fair bit of "crackle" sneaking in to playback audio.
The final solution, the one that worked completely, went against the latest guidance not to use MultiBeast 10.4. More out of frustration than anything else, I decided to give it another try "just in case". I had already removed any previous patches from my config.plist and re-installed the vanilla AppleHDA.kext in S/L/E. I had also removed realtekALC.kext from L/E and rebuilt my kext-caches. Then I used MultiBeast to add all the necessary config patches and install for ALC892. And held my breath.
The result is that, using MultiBeast 10.4 on Mojave against advice, audio is back and working properly as it did previously.
So that's the Mojave upgrade completed ...
Well not quite ...
Preview and Quicklook were not working for JPG/JPEG files
There is a
thread about this here and I've posted the solution there too.
How it was Solved (thanks to
@vulgo for pointing me in the right direction). I now would recommend Method 3 of the following, but have left the others in out of interest.
Method 1:
1) Navigate to the System/Library/PrivateFrameworks/AppleVPA.framework/Versions/A/Resources folder and open the Info.plist with your favourite plain-text editor (Textedit is fine).
2) Locate your own Board ID from the SMBIOS section of your config.plist
3) Search through the Info.plist you've opened (above) for your Board ID. If you find it, back-up the Info.plist in case anything goes wrong, then delete the <key> that contains it and the <dict> ... </dict> below it.
For example:
<key>Mac-123456789ABCDE</key>
<dict>
<key>forceOfflineRenderer</key>
<true/>
<key>jpeg</key>
<true/>
</dict>
Save the Info.plist
4) Reboot.
Hopefully you will have Preview and Quicklook hardware rendering working again.
Method 2:
Simply change your System Definition to MacPro6,1 because it *isn't* in the Info.plist. However be aware that doing this changes your serial-number and might get iCloud asking you to log in and verify things...
1) Ensure iGPU is set to "Auto" or "Off" in your BIOS (I already do this).
2) Remove the Whatevergreen kext
3) Set System definition to MacPro6,1
Method 3:
@vulgo has produced a kext you can just install in your EFI/CLOVER/kexts/Other folder to cure the problem and means there is no need to edit frameworks or change your system-definition.
Thanks to both
@markmac and
@vulgo here.
Working again.
As a P.S - I used HFS+ previously on High Sierra and APFS *is* a lot slower. Sorry to all those who ask why some of us prefer the older version. It may be very clever but it means hardware is working a lot harder just to stand still.