The macOS Big Sur 11.2.1 is officially released for download and upgrade. This post will show how I installed on my Windows Laptops and Desktops. This OS did change quite a few things that will not work with the older Catalina setup. To use OpenCore to boot, we need 0.6.3+ version, I did use 0.6.4 to be able to boot into the flash drive. I also need to install CtlnaAHCIPort.kext to be able to see the SATA internal hard drive. The SMCBatteryManager.kext no longer works, need to use ACPIBatteryManager.kext from Rehabman for the battery to display. The DW1820a must have an argument on boot brcmfx-driver=2 for the WiFi to work. For error “waiting for root device” , make sure to have USBInjectAll.kext installed.
If the Catalina is working, all we need is to update those above and make sure to get the new Lilu.kext (14.9), WhateverGreen.kext (14.4), AppleALC.kext (15.4) and everything should work. The boot to installer is extremely long (1 hr total time).