xref: /openbmc/u-boot/lib/libavb/avb_footer.h (revision 8e51c0f2)
1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * SPDX-License-Identifier:	MIT
5  */
6 
7 #if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION)
8 #error "Never include this file directly, include libavb.h instead."
9 #endif
10 
11 #ifndef AVB_FOOTER_H_
12 #define AVB_FOOTER_H_
13 
14 #include "avb_sysdeps.h"
15 
16 #ifdef __cplusplus
17 extern "C" {
18 #endif
19 
20 /* Magic for the footer. */
21 #define AVB_FOOTER_MAGIC "AVBf"
22 #define AVB_FOOTER_MAGIC_LEN 4
23 
24 /* Size of the footer. */
25 #define AVB_FOOTER_SIZE 64
26 
27 /* The current footer version used - keep in sync with avbtool. */
28 #define AVB_FOOTER_VERSION_MAJOR 1
29 #define AVB_FOOTER_VERSION_MINOR 0
30 
31 /* The struct used as a footer used on partitions, used to find the
32  * AvbVBMetaImageHeader struct. This struct is always stored at the
33  * end of a partition.
34  */
35 typedef struct AvbFooter {
36   /*   0: Four bytes equal to "AVBf" (AVB_FOOTER_MAGIC). */
37   uint8_t magic[AVB_FOOTER_MAGIC_LEN];
38   /*   4: The major version of the footer struct. */
39   uint32_t version_major;
40   /*   8: The minor version of the footer struct. */
41   uint32_t version_minor;
42 
43   /*  12: The original size of the image on the partition. */
44   uint64_t original_image_size;
45 
46   /*  20: The offset of the |AvbVBMetaImageHeader| struct. */
47   uint64_t vbmeta_offset;
48 
49   /*  28: The size of the vbmeta block (header + auth + aux blocks). */
50   uint64_t vbmeta_size;
51 
52   /*  36: Padding to ensure struct is size AVB_FOOTER_SIZE bytes. This
53    * must be set to zeroes.
54    */
55   uint8_t reserved[28];
56 } AVB_ATTR_PACKED AvbFooter;
57 
58 /* Copies |src| to |dest| and validates, byte-swapping fields in the
59  * process if needed. Returns true if valid, false if invalid.
60  */
61 bool avb_footer_validate_and_byteswap(const AvbFooter* src, AvbFooter* dest)
62     AVB_ATTR_WARN_UNUSED_RESULT;
63 
64 #ifdef __cplusplus
65 }
66 #endif
67 
68 #endif /* AVB_FOOTER_H_ */
69