Advantech ASMB-927 Series User Manual page 58

3.2.2.10 CSM Configuration
CSM Support

Enable or disable UEFI CSM (Compatibility Support Module) to support a leg-
acy PC boot process.
GateA20 Active

This items is useful when RT code is executed above 1MB. When it's set as
"Upon Request" GA20 can be disabled using BIOS services. When it's set as
"Always" it does not allow disabling GA20.
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