Supermicro X11DSC+ User Manual page 161

Step 4. For the changes to take effect, press <F4> to save the settings and exit the BIOS
Setup utility. Then, Press <Del> key continuously 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. CSM Support has been set to Disabled, and both Secure Boot and Vendor Keys
are Active.
Note 1: Once Secure Boot is enabled, CSM Support will become disabled and the
legacy environment is no longer valid. The authorized UEFI support such as UEFI OS,
AOC UEFI FW, and UEFI PXE server are allowed.
Note 2: If CSM Support has not been set to Disabled after the completion of Step 4,
please be sure to set it to Disabled.
Appendix F: Secure Boot Settings
161