User`s manual

CT-XBT0x Mini-ITX Motherboard

5.1.9 CSM Configuration

GateA20 Active:

[Upon Request] – GA20 can be disabled using BIOS services.

[Always] – do not allow disabling GA20; this option is useful when any RT

code is executed above 1MB.

Option ROM Message: Set display mode [Force BIOS] or [Keep Current] for

Option ROM.

INT19 Trap Response: BIOS reaction on INT19 trapping by Option ROM:

IMMEDIATE – execute the trap right away; POSTPONED – execute the traps

during legacy boot.

Boot option filter: This option controls what devices system can boot to [UEFI

and Legacy], [Legacy only] or [UEFI only].

Option ROM Execution Order: Controls the execution Option ROM, [Do not

launch], [UEFI only] or [Legacy only].