Can't access BIOS

It’s not as simple as the title says. I have nixos right now installed on my machine. I tried plugging in a usb live iso(wanted to install another os). From there, as usual, I first partitioned my disks by wiping them with “wipefs -a /dev/sdX”. Then, idk what happened but I couldn’t wipe my second disk where nixos is because it was busy. I then rebooted, and now I’m stuck in an endless loop of trying to press the arrow keys in GRUB at the right time. (It doesn’t work)

I forgot to mention that I enabled fast boot from the BIOS previously by mistake and that by consequence F2, F12, DEL keys do not work. Performing any systemctl command from my half broken nixos doesn’t work either.

Someone please help me

  1. You probably do not have a BIOS, but thats not the matter here
  2. Remove the battery powering your firmawares memory, unplug the computer from AC, remove battery if it is a laptop, wait 10 minutes or so, plug everything back in, power on your computer, get into its firmware, set the date/time correctly, and reconstruct all the other relevant settings.

if all else fails, you could try taking out the drives. With no drives to boot from you should get kicked into the BIOS, and then you can disable fast boot (does fast boot actually disable the enter BIOS keys though? cause i wasn’t aware of that).

Thanks for you guys response. After trying both of these methods, it finally worked with what @juipeltje said. I managed to later disable fast boot from the BIOS.

Thank you all!