Asrock h110m hdv r3.0 questions

[quce]

Hello today i builded new pc with g4600 and asrock h110m hdv r3.0 and so on.I have a questions about the bios of the motherboard. What will happen if i enable ultra fast boot and something happen to the os? How could i boot to the bios without restart to uefi. Also what is that csm thing? I putted everything on uefi mode.

 

[CountMike]

You don't need an OS to BOOT to UEFI/BIOS
"csm thing" is Compatibility Support Module is a component of the UEFI firmware that provides legacy BIOS compatibility by emulating a BIOS environment, allowing legacy operating systems and some option ROMs that do not support UEFI to still be used.