Defending the BIOS requires a multi-layered "Chain of Trust" that begins at the hardware level.
: Modern systems use Intel Boot Guard or AMD Hardware-Validated Boot to verify the digital signature of the BIOS before execution. Secure Boot then extends this verification to the OS loader. Attacking and Defending BIOS
: SMM is a highly privileged execution mode used for low-level hardware control. Attackers target SMI (System Management Interrupt) handlers —specifically looking for "SMI input pointer" vulnerabilities—to extract protected data from SMRAM or overwrite firmware. Defending the BIOS requires a multi-layered "Chain of