firmware/include/gbb_header.h

/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 *
 * Data structure of Google Binary Block (GBB)
 */

#ifndef VBOOT_REFERENCE_GBB_HEADER_H_
#define VBOOT_REFERENCE_GBB_HEADER_H_

#include "sysincludes.h"

#define GBB_HEADER_SIZE    128

#define GBB_SIGNATURE      "$GBB"
#define GBB_SIGNATURE_SIZE 4

/* GBB version constants.
 *
 * If the major version is different than the reader can handle, it
 * shouldn't attempt to parse the GBB.
 *
 * If the minor version is different, the reader can still parse it.
 * If the minor version is greater than expected, new fields were
 * added in a way which does not interfere with the old fields.  If
 * it's less than expected, some of the fields expected by the reader
 * aren't initialized, and the reader should return default values for
 * those fields. */
#define GBB_MAJOR_VER      1
#define GBB_MINOR_VER      1

/* Maximum length of a HWID in bytes, counting terminating null. */
#define GBB_HWID_MAX_SIZE  256

/* Flags for .flags field */
/* Reduce the dev screen delay to 2 sec from 30 sec to speedup factory. */
#define GBB_FLAG_DEV_SCREEN_SHORT_DELAY   0x00000001
/* BIOS should load option ROMs from arbitrary PCI devices. We'll never enable
 * this ourselves because it executes non-verified code, but if a customer wants
 * to void their warranty and set this flag in the read-only flash, they should
 * be able to do so. */
#define GBB_FLAG_LOAD_OPTION_ROMS         0x00000002
/* The factory flow may need the BIOS to boot a non-ChromeOS kernel if the
 * dev-switch is on. This flag allows that. */
#define GBB_FLAG_ENABLE_ALTERNATE_OS      0x00000004

#ifdef __cplusplus
extern "C" {
#endif  /* __cplusplus */

typedef struct GoogleBinaryBlockHeader {
  /* Fields present in version 1.0 */
  uint8_t  signature[GBB_SIGNATURE_SIZE]; /* GBB_SIGNATURE "$GBB" */
  uint16_t major_version;   /* See GBB_MAJOR_VER */
  uint16_t minor_version;   /* See GBB_MINOR_VER */
  uint32_t header_size;     /* size of GBB header in bytes */
  uint32_t flags;           /* Flags (see GBB_FLAG_*), should be 0 for 1.0. */

  uint32_t hwid_offset;     /* HWID offset from start of header */
  uint32_t hwid_size;       /* HWID size in bytes */
  uint32_t rootkey_offset;  /* Root Key offset from start of header */
  uint32_t rootkey_size;    /* Root Key size in bytes */
  uint32_t bmpfv_offset;    /* BMP FV offset from start of header */
  uint32_t bmpfv_size;      /* BMP FV size in bytes */
  uint32_t recovery_key_offset;  /* Recovery Key offset from start of header */
  uint32_t recovery_key_size;    /* Recovery Key size in bytes */

  uint8_t  pad[80];         /* To match GBB_HEADER_SIZE.  Initialize to 0. */
} __attribute__((packed)) GoogleBinaryBlockHeader;

#ifdef __cplusplus
}
#endif  /* __cplusplus */

#endif  /* VBOOT_REFERENCE_GBB_HEADER_H_ */