ASROCK PRO Series User Manual page 101

H670M Pro RS
execute both legacy and UEFI option ROM.
Launch Storage OpROM Policy
Select UEFI only to run those that support UEFI option ROM only. Select Legacy
only to run those that support legacy option ROM only. Select Do not launch to not
execute both legacy and UEFI option ROM.
Other PCI Device ROM Priority
For PCI devices other than Network. Mass storage or Video defines which OpROM
to launch.
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