[coreboot] Secure Boot

Hi,

I need to enable secure boot to load esxi installer. But it is failing with message Uefi secure boot is not enabled. So i need to enable it in coreboot. I have a uefi payload binary from Intel. Payload binary one with normal and another with secure functions. With normal payload i am able to boot Ubuntu but not esxi installer. It fails with Uefi secure boot is not enabled. When trying with uefi secure payload binary, the payload itself fails to come up.

Do i need to enable anything in coreboot to enable secure boot?.
Is coreboot support secure boot using Verified Boot. If so I enabled VBoot also but still the esxi loader fails to load.
Is boot guard to be enabled for secure boot?

Regards,
gsenk