Resolved No Boot Options Problem and Opencore

[Paramods]

I have just installed a K1000M in my 21" Imac 2011 and its all dandy running High Sierra which is the max

I would like to run Big Sur now using open core etc.
The big problem is that as ive upgraded the card I dont get a boot option page now just a long delay till the system boots.

Am I stuck now or is there another solution?

 

[Paramods]

Just to add that I flashed the Vbios from a few months back.
I have seen on a few posts that the older one did allow boot picker? is this true?

 

[Nguyen Duc Hieu]

Just to add that I flashed the Vbios from a few months back.
I have seen on a few posts that the older one did allow boot picker? is this true?

The boot picker, by default, lasts only 5s, too short to be visible.
If you want to see it, Use Opencore Configurator to change the bootpicker delay time to 25 seconds or something.
Hope you know how to use Opencore Configurator.