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Optiplex 9020: Big Sur / Opencore 0.6.6


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I have Big Sur running well on my Optiplex 9020, with Opencore. 

It should support 4K, but only with DP to DP cord. I can't test 4K because I don't have a monitor with DP input. 

I have tested Internal graphics, they do work with a DP to HDMI cable.

I am presently using a GeForce GT710 2GB graphics card. I have been using it since Catalina because I need reliable dual-screen and also because it works OOB.



First thing is to flash bios to A25.

Then disable CFG Lock, and set DVMT to 64MB for 4K video. The tool "modGRUBShell.efi" in the Opencore Tools folder makes this easy to do. Put Opencore folder on an EFI partition on a thumb drive. Boot off the thumb drive, (F12, then select the EFI of the drive), then at the Opencore menu select modGRUBShell.efi. Now at the grub> prompt you type these commands:

          Command                                               Function

setup_var    0xDA2 0x0                 this will Disable CFG     >>>>     Example, at prompt type setup_var  then space,  then 0xDA2 space, then 0x0 [enter] don't worry about error warning.

setup_var    0x263 0x2                 this will set DVMT to 64MB


Next ones are not needed, but are recommended. These disable EHCx ports which are only needed with Legacy boot. If you are dual-booting with Windows you should be using UEFI anyways.

setup_var    0x2  0x1                     Enable EHCI Handoff

setup_var    0x144 0x1                  XHCI Enabled Mode

setup_var    0x15A 0x2                 Route EHCx Ports to XHCI

setup_var    0x146 0x0                 Disable EHCx Ports

setup_var    0x147 0x0                 Disable EHCx Ports


Then just type "reboot" and press [ENTER].

In the Opencore folder, open the Config plist and make edits, fill in....

PlatformInfo -> Generic -> MLB

PlatformInfo -> Generic -> ROM

PlatformInfo -> Generic -> SystemSerialNumber

PlatformInfo -> Generic -> SystemUUID


Okay now make your Big Sur installer, and place your Opencore folder on the EFI Partition. Boot off drive and select install Big Sur.


Anyone with a 4K monitor that has a display port input, please let us know if 4K is working.


Lastly, this was composed from reading 3 or 4 guides that I found online.


Happy Testing! :)




Cleaned up the Config. 

Sound & Sleep now working.

Updated Opencore.





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@Jake, mine is a SFF. I was using your 9020 SFF USB ports kext for a while. After I also changed the ethernet kext, it hung on boot, probably cause I did something wrong to the config, but I went back to the first config and kexts folder to start over again.


Another thing, the OC picker actually works with my dual-boot, so I don't need to use F12 to boot Windows.

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Morpheousman, Thanks. Lets try it. Do I really need that firmware upgrade?

Do those setup_var commands stay active after a future upgrade of the firmware or reset bios to default? 


@Jake Lo, is there a chance https://osxlatitude.com/forums/topic/6006-optiplex-9020-mavericks-el-capitan-sierra-high-sierra-mojave-catalina/ will be updated with big sur / and open core configs etc?

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Directions I had said update to A25, so not a big deal to do  on my dual-boot. I have not tried it on any other firmware myself.


I also had recent experience where power was off for a bit, and the bios battery needed replacing, all bios edits needed to be done again, but just a 5 minute fix to do them again.


Probably the best desktop hack I have had in 15 years or so of doing these. Just about trouble free. 


Edit: Now Updated to 11.4, and Opencore 0.6.8.


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I finally had a chance to convert to OC and tested your files but updated to 0.7.0. 

For some reason sleep/shutdown and restart doesn't work. I switch back to your 068 version and still same issue, resetting NVRam...nothing works.

Getting frustrated, I switch the Lenovo display to the Dell display which was working previously with Clover.

To my amazement, with the Dell all was working perfectly even with the update 0.7.0 files.

Both displays are 1440p capable, but why Lenovo is causing such issue?


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Are your displays 2k and above?

I get the large stretched boot screen. Seems only way to fix is disable Legacy Option ROMs, but that break sleep / Wake.

With Clover, there's csmVideoDxe.efi, wonder if there's an OC equivalent.

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