UEFITool/common/fit.h

/* fit.h

Copyright (c) 2015, Nikolaj Schlej. All rights reserved.
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution.  The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHWARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
*/

#ifndef FIT_H
#define FIT_H

#include "basetypes.h"
#include "ubytearray.h"

// Make sure we use right packing rules
#pragma pack(push, 1)

// Memory address of a pointer to FIT, 40h back from the end of flash chip
#define FIT_POINTER_OFFSET 0x40

// Entry types 
#define FIT_TYPE_HEADER            0x00
#define FIT_TYPE_MICROCODE         0x01
#define FIT_TYPE_BIOS_AC_MODULE    0x02
#define FIT_TYPE_BIOS_INIT_MODULE  0x07
#define FIT_TYPE_TPM_POLICY        0x08
#define FIT_TYPE_BIOS_POLICY_DATA  0x09
#define FIT_TYPE_TXT_CONF_POLICY   0x0A
#define FIT_TYPE_AC_KEY_MANIFEST   0x0B
#define FIT_TYPE_AC_BOOT_POLICY    0x0C
#define FIT_TYPE_EMPTY             0x7F

#define FIT_HEADER_VERSION         0x0100
#define FIT_MICROCODE_VERSION      0x0100

const UByteArray FIT_SIGNATURE
("\x5F\x46\x49\x54\x5F\x20\x20\x20", 8); 

typedef struct FIT_ENTRY_ {
    UINT64 Address;
    UINT32 Size : 24;
    UINT32 : 8;
    UINT16 Version;
    UINT8  Type : 7;
    UINT8  CsFlag : 1;
    UINT8  Checksum;
} FIT_ENTRY;

typedef struct {
    UINT16 IndexRegisterAddress;
    UINT16 DataRegisterAddress;
    UINT8  AccessWidth;
    UINT8  BitPosition;
    UINT16 Index;
} FIT_ENTRY_VERSION_0_CONFIG_POLICY;

// This scructure is described in Section 9.11.1 of the Intel Software Developer manual Volume 3A Part 1
typedef struct INTEL_MICROCODE_HEADER_ {
    UINT32 Version;             // 0x00000001
    UINT32 Revision;
    UINT16 DateYear;            // BCD
    UINT8  DateDay;             // BCD
    UINT8  DateMonth;           // BCD
    UINT32 CpuSignature;
    UINT32 Checksum;            // Checksum of Update Data and Header. Used to verify the integrity of the update header and data.
                                // Checksum is correct when the summation of all the DWORDs (including the extended Processor Signature Table)
                                // that comprise the microcode update result in 00000000H.
    UINT32 LoaderRevision;      // Sane values are less than 0x100
    UINT8  CpuFlags;
    UINT8  CpuFlagsReserved[3]; // Zeroes
    UINT32 DataSize;            // Specifies the size of the encrypted data in bytes, and must be a multiple of DWORDs.
                                // If this value is 00000000H, then the microcode update encrypted data is 2000 bytes (or 500 DWORDs).
                                // Sane values are less than 0x1000000
    UINT32 TotalSize;           // Specifies the total size of the microcode update in bytes.
                                // It is the summation of the header size, the encrypted data size and the size of the optional extended signature table.
                                // This value is always a multiple of 1024 according to the spec, but Intel already breached it several times.
                                // Sane values are less than 0x1000000
    UINT8  Reserved[12];        // Zeroes
} INTEL_MICROCODE_HEADER;

#define INTEL_MICROCODE_REAL_DATA_SIZE_ON_ZERO 2000

typedef struct INTEL_MICROCODE_EXTENDED_HEADER_ {
    UINT32 EntryCount;
    UINT32 Checksum; // Checksum of extended processor signature table.
                     // Used to verify the integrity of the extended processor signature table.
                     // Checksum is correct when the summation of the DWORDs that comprise the extended processor signature table results in 00000000H.

    UINT8  Reserved[12];
    // INTEL_MICROCODE_EXTENDED_HEADER_ENTRY Entries[EntryCount];
} INTEL_MICROCODE_EXTENDED_HEADER;

typedef struct INTEL_MICROCODE_EXTENDED_HEADER_ENTRY_ {
    UINT32 CpuSignature;
    UINT32 CpuFlags;
    UINT32 Checksum; // To calculate the Checksum, substitute the Primary Processor Signature entry and the Processor Flags entry with the corresponding Extended Patch entry.
                     // Delete the Extended Processor Signature Table entries.
                     // Checksum is correct when the summation of all DWORDs that comprise the created Extended Processor Patch results in 00000000H.
} INTEL_MICROCODE_EXTENDED_HEADER_ENTRY;

#define INTEL_MICROCODE_HEADER_VERSION_1    0x00000001

#pragma pack(pop)

#endif // FIT_H