Resolved Monterey install finishes, goes back to Big Sur

[stooovie]

I let the Monterey upgrade run (from the Software Update control panel). It runs the whole course, gives no errors or warnings... and then boots back into Big Sur

Here's the log. I had zero issues upgrading from Catalina to Big Sur on this system (10850k, RX 580, Asus Prime Z490-P, 64GB RAM). Any clues?

My kexts: LILU, VirtualSMC, AppleALC, EnergyDriver (Intel Power gadget), Realtek RTL8111, SMCProcessor, SMCSuperIO, CPUFriend, custom USBMap, CPUFriendDataProvider, Whatevergreen, DroboTBT (had issues with Drobo until I put the kext right into EFI), TrustedDataSCSIProvider (same), HibernationFixup, NVMeFix, all fully updated. Tried without the Drobo and SMCSuperIO kexts, no difference.

Tried to manually pick a boot drive on the installation's restarts (shouldn't be required, OC should take care of it), at no point is there any "install" volume, but the install DOES go through with the usual "around X minutes remaining" and the thing taking roughly 20 minutes. It just boots back to BS after it finishes.

 

[stooovie]

SOLVED:

It was my {censored}ed up EFI.

I probably failed to copy an updated EFI back from my "update usb stick" to the boot drive. I always do it by hand and check with current ocvalidate. I'm wondering that it even boots and works flawlessly (except the upgrade thing) with so many errors!

With everything updated and fixed, the upgrade went fine. Everything so far works in Monterey - BT/Wifi, Continuity, sleep, GPU, dual displays, GPU/CPU power management, Airplay Receiver...

 

[MBAir2010]

now if only monterrey can go back to MOJAVE!
;~)