Firmware Interface Table

BIOS Specification

ID Date Version Classification
599500 03/01/2025 Public
Document Table of Contents
Document Table of Contents
Legal Revision History Firmware Interface Table Introduction Summary Of Key Requirements FIT Pointer Firmware Interface Table
Legal
Revision History
Firmware Interface Table Introduction
Summary Of Key Requirements
FIT Pointer
FIT Pointer FIT Pointer Rules
FIT Pointer Rules
Firmware Interface Table
Firmware Interface Table FIT Ordering Rules FIT Header (Type 0) Rules Microcode Update (Type 1) Rules Startup ACM (Type 2) Rules Diagnostic ACM (Type 3) Rules Platform Boot Policy (Type 4) Rules Memory Microcontroller Firmware Image (Type 5) Rules FIT Reset State (Type 6) Rules BIOS Startup Module (Type 7) Rules TPM Policy Record (Type 8) Rules BIOS Policy Data Record (Type 9) Rules Intel® TXT Policy Data Record (Type 0xA) Rules Key Manifest Record (Type 0xB) Rules Boot Policy Manifest (Type 0xC) Rules FSP Boot Manifest (Type 0xD) Rules Intel® CSE Secure Boot (Type 0x10) Rules Vendor Authorized Boot Provisioning Table (Type 0x1A) Rules Vendor Authorized Boot Key Manifest (Type 0x1B) Rules Vendor Authorized Boot Image Manifest (Type 0x1C) Rules Vendor Authorized Boot Image Descriptors (Type 0x1D) Rules (Deprecated) VAB Authorization Code Patch Image Manifest (Type 0x1E) Rules SACM Debug Record (Type 0x2C) Rules Feature Policy Record (Type 0x2D) Rules Granular SCRTM Error Record (Type 0x2E) Rules
FIT Ordering Rules
FIT Header (Type 0) Rules
Microcode Update (Type 1) Rules
Startup ACM (Type 2) Rules
Startup ACM (Type 2) Rules Legacy Record Modern Record CPU Processing Rules
Legacy Record
Modern Record
CPU Processing Rules
Diagnostic ACM (Type 3) Rules
Platform Boot Policy (Type 4) Rules
Memory Microcontroller Firmware Image (Type 5) Rules
FIT Reset State (Type 6) Rules
BIOS Startup Module (Type 7) Rules
TPM Policy Record (Type 8) Rules
TPM Policy Record (Type 8) Rules TPM Enabling Policy
TPM Enabling Policy
BIOS Policy Data Record (Type 9) Rules
Intel® TXT Policy Data Record (Type 0xA) Rules
Intel® TXT Policy Data Record (Type 0xA) Rules TXT Configuration Policy
TXT Configuration Policy
Key Manifest Record (Type 0xB) Rules
Boot Policy Manifest (Type 0xC) Rules
FSP Boot Manifest (Type 0xD) Rules
Intel® CSE Secure Boot (Type 0x10) Rules
Vendor Authorized Boot Provisioning Table (Type 0x1A) Rules
Vendor Authorized Boot Key Manifest (Type 0x1B) Rules
Vendor Authorized Boot Image Manifest (Type 0x1C) Rules
Vendor Authorized Boot Image Descriptors (Type 0x1D) Rules (Deprecated)
VAB Authorization Code Patch Image Manifest (Type 0x1E) Rules
SACM Debug Record (Type 0x2C) Rules
Feature Policy Record (Type 0x2D) Rules
Granular SCRTM Error Record (Type 0x2E) Rules

FIT Pointer

The processor locates the FIT by following the FIT Pointer, which is located at the fixed address 4 GB - 40h (i.e., 0FFFFFFC0h). The FIT pointer points to the first byte of the Header (type 0) entry in the FIT.

FIT Pointer Rules