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MSI X299 SLI Plus + BigSur Beta 6 + OC 0.6.1

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Hi everyone:


This is to report a success (!) in installing macOS Big Sur Beta 6 (version 20A5364e) on my system MSI X299 SLI Plus with Intel i9 9940X using OpenCore 0.6.1. I followed the main OpenCore guide here:


Make sure you look for the Skylake-X or HEDT sections.

The SMBIOS is for the iMacPro1,1.


There were two main issues that had to be taken care of:


* I needed the kernel argument 


otherwise USB would not work.


* I had to replace the precompiled SSDT-AWAC with my own RTC SSDT, as explained here:

The problem is that my SSDT does not have any AWAC to be patched. A sign that I needed this was that booting into the installer hanged around loading Lilu or some of the SMC extras.


The path to replace in the provided SSDT-RTC0 is:

** PCI0 -> PC00

** LPCB -> LPC0

This is probably specific to my motherboard. Instead of using the SSDT-AWAC, I use my own RTC0 like this:

DefinitionBlock ("", "SSDT", 2, "ACDT", "RTC0", 0x00000000)
    External (_SB_.PC00.LPC0, DeviceObj)    // (from opcode)

    Scope (_SB.PC00.LPC0)
        Device (RTC0)
            Name (_HID, EisaId ("PNP0B00"))  // _HID: Hardware ID
            Name (_CRS, ResourceTemplate ()  // _CRS: Current Resource Settings
                IO (Decode16,
                    0x0070,             // Range Minimum
                    0x0070,             // Range Maximum
                    0x01,               // Alignment
                    0x08,               // Length
                IRQNoFlags ()
            Method (_STA, 0, NotSerialized)  // _STA: Status
                If (_OSI ("Darwin"))
                    Return (0x0F)
                    Return (Zero)

Only the lines:

    External (_SB_.PC00.LPC0, DeviceObj)    // (from opcode)
    Scope (_SB.PC00.LPC0)

are different from the original SSDT-RTC0 here:


By following the guide above and implementing these two differences, I was able to install macOS Big Sur beta 6.


Big thanks to the amazing OpenCore team for allowing this. Not only the complete tools, files, binaries, are fantastic, but the manual is amazing!


Edited by slurpi
extra info on the need for RTC
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