Catalina iMac 2011 pretend (OC) to be 2012, Panic during sleep

[Inspiring]

Hi All,

I am using an iMac 2011 with K1100M graphics card and in High Sierra, Mini Display Port to my 4k@60hz external display works fine.

After upgrading to Catalina using the Dosdude1's patch, all works fine however Mini Display Port only outputs HDMI signal(5v, 4k@30hz) but NO Display Port Signal(3.3v, 4k@60hz)

After reading https://www.tonymacx86.com/threads/mojave-to-catalina-displayport-not-working.284983/ , as if it was magic, DisplayPort resurrected! I have modified my iMac 2011 (SandyBridge) iMac into iMac2012 (Ivy Bridge) using OpenCore.

However, I found that going into sleep would cause Kernel Panics:

Catalina 10.15.4 would say:

Spoiler

panic(cpu 1 caller 0xffffff8022c4c32a): Kernel trap at 0xffffff7fa68fef61, type 14=page fault, registers:
..

      Kernel Extensions in backtrace:


         com.apple.iokit.IOGraphicsFamily(575.1)[D47CA481-C5E5-3F03-9B04-6634DF5F3121]@0xffffff7fa3be3000->0xffffff7fa3c33fff


            dependency: com.apple.iokit.IOPCIFamily(2.9)[1B1F3BBB-9212-3CF9-94F8-8FEF0D3ACEC4]@0xffffff7fa3531000


         com.apple.driver.AppleIntelSNBGraphicsFB(10.0.4)[628D2F1C-66EC-340F-AB0A-576401250CCC]@0xffffff7fa68dc000->0xffffff7fa6908fff


            dependency: com.apple.iokit.IOACPIFamily(1.4)[9D1FF279-C4A2-3344-902F-E0B22B508689]@0xffffff7fa380a000


            dependency: com.apple.iokit.IOPCIFamily(2.9)[1B1F3BBB-9212-3CF9-94F8-8FEF0D3ACEC4]@0xffffff7fa3531000


            dependency: com.apple.iokit.IOGraphicsFamily(575.1)[D47CA481-C5E5-3F03-9B04-6634DF5F3121]@0xffffff7fa3be3000





BSD process name corresponding to current thread: kernel_task


Boot args: -no_compat_check

Catalina 10.15.5 would say:

Spoiler

panic(cpu 0 caller 0xffffff7fa67ac306): NVRM[0/1:0:0]: Read Error 0x00070000: CFG 0x0ff610de 0x00100000 0x00000000, BAR0 0xb0000000 0xffffff8202cfd000 0x0e7360a2, D3, P0/3

..


      Kernel Extensions in backtrace:


         com.apple.nvidia.driver.NVDAResman(14.0)[ECB33CB3-2FE3-3E99-A4E6-ED7C5DA6D543]@0xffffff7fa673f000->0xffffff7fa6a16fff


            dependency: com.apple.iokit.IOPCIFamily(2.9)[BE052F4D-9B80-3FCD-B36D-BACB7DEE0DF2]@0xffffff7fa4101000


            dependency: com.apple.iokit.IONDRVSupport(576.1)[946300BB-3488-3655-B4A3-2263D72C525C]@0xffffff7fa5c39000


            dependency: com.apple.iokit.IOGraphicsFamily(576.1)[B1C0006F-E1F5-37D9-9548-5F918E92B422]@0xffffff7fa5be8000


            dependency: com.apple.AppleGraphicsDeviceControl(5.2.4)[CD6E2942-2A23-3CE8-9BCA-D5A772667EB8]@0xffffff7fa6735000


         com.apple.nvidia.driver.NVDAGK100Hal(14.0)[D9BD5415-852D-3F99-B5D9-9E4FD7CABEEC]@0xffffff7fa6a17000->0xffffff7fa6bc2fff


            dependency: com.apple.nvidia.driver.NVDAResman(14.0.0)[ECB33CB3-2FE3-3E99-A4E6-ED7C5DA6D543]@0xffffff7fa673f000


            dependency: com.apple.iokit.IOPCIFamily(2.9)[BE052F4D-9B80-3FCD-B36D-BACB7DEE0DF2]@0xffffff7fa4101000


         com.apple.iokit.IOAcceleratorFamily2(438.5.4)[D695D9DA-7C20-35D6-910F-E7A332A0F515]@0xffffff7fa6bc3000->0xffffff7fa6c86fff


            dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[E35D090D-DB9E-3DD0-9723-651FA730AA13]@0xffffff7fa3f87000


            dependency: com.apple.iokit.IOPCIFamily(2.9)[BE052F4D-9B80-3FCD-B36D-BACB7DEE0DF2]@0xffffff7fa4101000


            dependency: com.apple.iokit.IOSurface(269.11)[F1E7389D-2807-3C5D-8A7F-5422542E867F]@0xffffff7fa5282000


            dependency: com.apple.iokit.IOGraphicsFamily(576.1)[B1C0006F-E1F5-37D9-9548-5F918E92B422]@0xffffff7fa5be8000


            dependency: com.apple.iokit.IOReportFamily(47)[1FB49168-0280-3F04-A99A-F830C915E994]@0xffffff7fa402f000


         com.apple.GeForce(14.0)[BF59B26E-F3C1-3B72-B731-1E4E5F506524]@0xffffff7fa6c87000->0xffffff7fa6d22fff


            dependency: com.apple.iokit.IOPCIFamily(2.9)[BE052F4D-9B80-3FCD-B36D-BACB7DEE0DF2]@0xffffff7fa4101000


            dependency: com.apple.iokit.IOSurface(269.11)[F1E7389D-2807-3C5D-8A7F-5422542E867F]@0xffffff7fa5282000


            dependency: com.apple.iokit.IONDRVSupport(576.1)[946300BB-3488-3655-B4A3-2263D72C525C]@0xffffff7fa5c39000


            dependency: com.apple.nvidia.driver.NVDAResman(14.0.0)[ECB33CB3-2FE3-3E99-A4E6-ED7C5DA6D543]@0xffffff7fa673f000


            dependency: com.apple.iokit.IOGraphicsFamily(576.1)[B1C0006F-E1F5-37D9-9548-5F918E92B422]@0xffffff7fa5be8000


            dependency: com.apple.iokit.IOAcceleratorFamily2(438.5.4)[D695D9DA-7C20-35D6-910F-E7A332A0F515]@0xffffff7fa6bc3000





BSD process name corresponding to current thread: WindowServer


Boot args: -no_compat_check



[CODE]
[SPOILER]

It is quite funny in a way that 10.15.4 seem to complain about AppleIntelSNBGraphicsFB however 10.15.5 seem to complain about com.apple.nvidia.driver.NVDAResman. So do make up your mind Catalina!

So now I am stuck and I had to set the iMac to not to sleep at all, which is not really ideal.

I have only found this [URL]https://github.com/acidanthera/HibernationFixup[/URL] but I doubt that this is the fix. I wonder if anyone can help to suggest how I can try to fix this problem?

Also would there be any other downside for telling OSX that it is running on Ivy Bridge where actually it was on Sandy Bridge?

Many Thanks.