Vendor Authorized Boot Image Descriptors (Type 0x1D) Rules
Boot Image Descriptors (Type 0x1D) entry in the FIT is required only for platforms which support Vendor Authorized Boot. The Boot Image Descriptors Manifest is an optional header only required on SPI flash for the BIOS as a structure to define number of Image Descriptors that follow it. There can only be zero or one Type 0x1D record present in the FIT.
- The Version field should be set to 0x0100.
- The C_V bit in this entry should be clear
- The Checksum field is set to 0.
- The entry must be 64 byte aligned.
- Address + size must be under (4GB – 1) and above (4GB – 16MB).