Careful with playing around with nvram on an M1 Mac. I was trying to find the same thing you are and I managed to make my Mac only boot into recovery. I was able to issue an nvram reset command from the recovery terminal command line. I think it wasThe so called 'AutoBoot feature' is really annoying. I need to be able to disinfect the keyboard on a regular basis and this is not possible when the M1 machine keeps booting as soon as any key is touched. I have noticed at setting in the nvram called 'AutoBoot' being set as 'true'. From previous post both here and elsewhere I understand that this setting control the AutoBoot feature and on older machines (before M1) it was possible to switch off the autoboot feature by issuing the command 'nvram AutoBoot=%00'. But apparently this will not work on the M1 machines. I can still issue the command but it has no effect. I have taken this up with Apple Support, but Apple Support refuses to give any advise on how to manipulate the configuration through the use of commands in terminal🤬
I have a strong feeling that it should still be possible to change the AutoBoot setting in nvram but I need some advise as to exactly how. I even tried using the security settings (holding the start button for a few seconds at start) but no luck so far.
Any advise on this will be appreciated.
nvram -c
but it was nerve wracking.