Supermicro H11SSL-I/C/NC User Manual page 85

Chapter 4: BIOS (for EPYC 7001 Series)
 OsRecovery Signature
This item uploads and installs an OSRecovery Signature. You may select options for Set New for
a factory default key, or select Append to get it from a file. The file formats accepted are:
1) Public Key Certificate
a. EFI Signature List
b. EFI CERT X509 (DER Encoded)
c. EFI CERT RSA2048 (bin)
d. EFI SERT SHA256 (bin)
2) EFI Time Based Authenticated Variable
When prompted, select "Yes" to load Factory Defaults or "No' to load from a file.
85