Supermicro X12 Secure Boot Configuration Instructions page 10

Super Secure Boot Configuration Instructions for the X12 Motherboards User's Guide
Step 4. Press <Del> during system boot to enter the BIOS Setup utility. Navigate to the
Security tab and enter the Secure Boot menu. Set Secure Boot to Enabled.
For the changes to take effect, press <F4> to save the settings and exit the BIOS Setup utility.
Press <Del> during system boot to enter the BIOS Setup utility. Navigate to the Security tab
and enter the Secure Boot menu. The following screen will appear.
Note: Once Secure Boot is enabled, CSM Support will become disabled and the legacy
platform will no longer supported; only the authorized UEFI applications such as UEFI
OS, AOC UEFI FW, and UEFI PXE server will be allowed in the platform.
10