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MB991AF
User’s Manual
4.4.10 CSM Configuration
BIOS Setting
Description
CSM Support
Enables / Disables CSM support.
GateA20 Active
•
Upon Request
disables GA20 when using
BIOS services.
•
Always
cannot disable GA20, but is useful
when any RT code is executed above 1 MB.
Option ROM
Messages
Sets display mode for Option ROM.
Options: Force BIOS, Keep Current
INT19 Trap Response Sets how BIOS reacts on INT19 trap by Option
ROM.
•
Immediate
executes the trap right away.
•
Postponed
executes the trap during legacy
boot.
Boot option filter
Controls the priority of Legacy and UEFI ROMs.
Options: UEFI and Legacy / Legacy only / UEFI
only
Network
Controls the execution of UEFI and Legacy PXE
OpROM.
Options: Do not launch / Legacy