Biostar X570GTA Manual page 19

CSM Configuration
CSM Support
This option enables or disables CSM support.
Options: Enabled (Default) / Disabled
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.
Options: Upon Request (Default) / Always
Option ROM Messages
This item set display mode for Option ROM.
Options: Force BIOS (Default) / Keep Current
INT19 Trap Response
This item BIOS reaction on INT19 trapping by Option ROM: IMMEDIATE - execute the trap right
away ; POSTPONED - execute the trap during legacy boot.
Options: Postponed (Default) / Immediate
HDD Connection Order
This some OS require HDD handles to be adjusted, i.e. OS is installed on drive 80h.
Options: Adjust (Default) / Keep
Boot option filter
This option controls Legacy/UEFI ROMs priority.
Options: UEFI and Legacy (Default) / Legacy only / UEFI only
Network
This option controls the execution of UEFI and Legacy Network OpROM
Options: Legacy (Default) / UEFI / Do not launch
Storage
This option controls the execution of UEFI and Legacy Storage OpROM
Options: Legacy (Default) / UEFI / Do not launch
X570GTA
2. Advanced Menu | 19