[…]This provides specific guidance for firmware based upon the EFI Developer Kit II (EDKII) and coreboot. Because this document deals with host firmware internal requirements, it is not intended to provide side channel mitigation guidance for general application developers.
Scope: This addresses bare-metal firmware runtime risks and mitigation suggestions for the bounds check bypass, branch target injection, rogue data cache load, rogue system register read, and speculative store bypass side channel methods. Our examples and context are primarily focused on ring 0 firmware runtimes (for example: EFI Developer Kit II, PI SMM, and coreboot SMM). Other firmware execution environments are out of scope.[…]