1/* SPDX-License-Identifier: MIT */
2/*
3 * Copyright (C) 2016 The Android Open Source Project
4 */
5
6#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION)
7#error "Never include this file directly, include libavb.h instead."
8#endif
9
10#ifndef AVB_FOOTER_H_
11#define AVB_FOOTER_H_
12
13#include "avb_sysdeps.h"
14
15#ifdef __cplusplus
16extern "C" {
17#endif
18
19/* Magic for the footer. */
20#define AVB_FOOTER_MAGIC "AVBf"
21#define AVB_FOOTER_MAGIC_LEN 4
22
23/* Size of the footer. */
24#define AVB_FOOTER_SIZE 64
25
26/* The current footer version used - keep in sync with avbtool. */
27#define AVB_FOOTER_VERSION_MAJOR 1
28#define AVB_FOOTER_VERSION_MINOR 0
29
30/* The struct used as a footer used on partitions, used to find the
31 * AvbVBMetaImageHeader struct. This struct is always stored at the
32 * end of a partition.
33 */
34typedef struct AvbFooter {
35  /*   0: Four bytes equal to "AVBf" (AVB_FOOTER_MAGIC). */
36  uint8_t magic[AVB_FOOTER_MAGIC_LEN];
37  /*   4: The major version of the footer struct. */
38  uint32_t version_major;
39  /*   8: The minor version of the footer struct. */
40  uint32_t version_minor;
41
42  /*  12: The original size of the image on the partition. */
43  uint64_t original_image_size;
44
45  /*  20: The offset of the |AvbVBMetaImageHeader| struct. */
46  uint64_t vbmeta_offset;
47
48  /*  28: The size of the vbmeta block (header + auth + aux blocks). */
49  uint64_t vbmeta_size;
50
51  /*  36: Padding to ensure struct is size AVB_FOOTER_SIZE bytes. This
52   * must be set to zeroes.
53   */
54  uint8_t reserved[28];
55} AVB_ATTR_PACKED AvbFooter;
56
57/* Copies |src| to |dest| and validates, byte-swapping fields in the
58 * process if needed. Returns true if valid, false if invalid.
59 */
60bool avb_footer_validate_and_byteswap(const AvbFooter* src, AvbFooter* dest)
61    AVB_ATTR_WARN_UNUSED_RESULT;
62
63#ifdef __cplusplus
64}
65#endif
66
67#endif /* AVB_FOOTER_H_ */
68