EFI partition lost on unsupported BigSur Imac 12.1

[agala68]

Hi,
recently I had one of the disks (not the system one) broken, and trynig to restore it I did a SMC/PRAM reset, after t I was not able to boot anymore, I think the problem can be that I don't find the possibility to choose EFI partition, it is disappeared.
Is there any way to recover that partition, in general to recover ability to boot?
Thank in advance

 

[joevt]

Boot an external disk or connect your iMac to another Mac and boot into Target Disk Mode. Then you can examine the disk.

 

[agala68]

Hi,
tahnks for reply, I am able to boot in recovery mode and examine disk, but I am not able to resume the ability to boot onto the System disk

 

[agala68]

I am a real stupid man, it was enaugh to boot from EFI partition of the usb installer disk, FIXED.