Can't boot after changing System Definition to MacPro5,1

[skafo]

Hello TonyMac community! Need some help here please. I run a (circa 2012) desktop CustoMac on a Z77X-UD5H motherboard and a i3770k processor. Its got Mountain Lion cause that system was most new when I built the rig, but since its been a couple years I thought it was time to update my OS. I've also read about the new Clover loader (mine stills uses Chimera) and was planning on doing the whole loader and OS update. So I try to download Sierra as my first step, but AppStore says my system doesn't support it. Quick search and I read that I have to update my system definitions via Multibeast. So I download the latest Mountain Lion Multibeast 5.5.5 and proceed to change my System Definition to MacPro5,1. I read they suggest iMac14,2, but my Multibeast doesn't have that option, so I guess I will be fine with 5,1. After that I tried to reboot and couldn't.

I follow instructions from here (https://www.tonymacx86.com/threads/kernel-panic-after-changing-system-to-macpro5-1.52999/) and change the 5,1 to 3,1 in Single User mode, but still fails to reboot.

Please help. Want to get my system back so I can download Sierra so I can update to Clover+Sierra.
Thanks!

 

[P1LGRIM]

This is probably because you used a MacPro5,1 system definition but neglected to delete the AppleTyMCEDriver.kext.

Boot in Safe Mode and in Finder navigate to /System/Library/Extensions/ and move AppleTyMCEDriver.kext to the Trash.

Restart and boot without caches.

 

[skafo]

This is probably because you used a MacPro5,1 system definition but neglected to delete the AppleTyMCEDriver.kext.

Boot in Safe Mode and either change your system definition to one that doesn't use ECC RAM or,
In Finder navigate to /System/Library/Extensions/ and move AppleTyMCEDriver.kext to the Trash.

Restart and boot without caches.

I didn't delete AppleTyMCEDriver.kext, I dont know how to do it either. Can you help me with this?

I can't boot in Safe Mode, when I try to (by using the -x flag on Chimera) the system just fails to boot and then turns itself off.

As I said, I did change back the smbios.plist to MacPro3,1 with the instructions provided in thread (https://www.tonymacx86.com/threads/kernel-panic-after-changing-system-to-macpro5-1.52999/), but systems still fails to boot.

Im still kinda noobish with this, thanks for your help

 

[P1LGRIM]

I didn't delete AppleTyMCEDriver.kext, I dont know how to do it either. Can you help me with this?

I can't boot in Safe Mode, when I try to (by using the -x flag on Chimera) the system just fails to boot and then turns itself off.

As I said, I did change back the smbios.plist to MacPro3,1 with the instructions provided in thread (https://www.tonymacx86.com/threads/kernel-panic-after-changing-system-to-macpro5-1.52999/), but systems still fails to boot.

Im still kinda noobish with this, thanks for your help

Seems like you may have screwed up your Org.Chameleon.Boot.plist.
Maybe you can boot from a UniBeast USB flash drive ?

 

[skafo]

I can do that, it takes me to the installer.
What do I do next?

 

[P1LGRIM]

I can do that, it takes me to the installer.
What do I do next?

Open the Terminal app :

rm -r /System/Library/Extensions/AppleTyMCEDriver.kext

Press Return

Restart

 

[skafo]

When I entered the command, it asked this:

override rw-r--r-- root/wheel hidden for /System/Library/Extensions/AppleMyMCEDriver.kext/Contents/_CodeSignature/CodeDirectory?

If I press "y" and Return it then says:

rm: /System/Library/Extensions/AppleMyMCEDriver.kext/Contents/_CodeSignature/CodeDirectory: Read-only file system

And proceeds to ask again but with a different directory:

override rw-r--r-- root/wheel hidden for /System/Library/Extensions/AppleMyMCEDriver.kext/Contents/_CodeSignature/CodeRequirements?

Is this ok?

 

[Going Bald]

Removing the AppleTyMCEDriver.kext is not the solution as any update of the OS will just put it back. Easiest is to make a Clover boot stick and apply the patch for the kext in Clover config.plist to allow boot without ECC RAM: https://clover-wiki.zetam.org/Configuration/KernelAndKextPatches#kernelandkextpatches_kextstopatch

Then boot with the Clover USB and change the System/Sharing to MacPro5,1
Remove the org.chameleon.boot.plist from /Extra, reboot with the USB.
Confirm About this Mac now shows MacPro5,1 SysDef

 

[skafo]

I can't find a way to make a Clover boot stick if my system doesn't boot. However I do have a Chimera Mountain Lion boot stick, will this help?

Is there a way to just change things the way they were before I changed my SysDef?

 

[skafo]

UPDATE:
I managed to boot into the system using Single User mode. Not sure how I did it to be honest. I entered "sudo nano /Extra/smbios.plist", string showed MacPro3,1 in the file, I didn't even change anything, then just wrote "exit" and it just booted normally. So I took the oportunity to install back SysDef MacPro3,1 from Multibeast. Still no luck booting. Tried same method as before to boot (strangely enough, if I just wrote "exit" from Single User it wouldn't boot, I had to open the smbios.plist, not do anything to it, "exit" and then I could boot) and this time I ran the whole DSDT-Free installation. Still no luck booting, but apparently I updated my Chimera from 1.1 to 2.2 this time. Tried to boot again using same method as before to no avail. Then it worked (dont know what I did differently) and now Im booted in my system. I will just leave it on until I get further instructions from you guys. Please help me get my system back! Thanks for your precious time.