Advantech ASMB-925 Series User Manual page 55

3.2.2.10 CSM Configuration
CSM Support

This item enables/disables the UEFI CSM (compatibility support module) from
supporting a legacy PC boot process.
GateA20 Active

This item is useful when RT code is executed above 1MB. When set as Upon
Request, GA20 can be disabled in the BIOS. When set as Always, disabling of
GA20 is not allowed.
47 ASMB-925 User Manual