1 /* SPDX-License-Identifier: BSD-3-Clause */
2 /*
3  * This is from the Android Project,
4  * Repository: https://android.googlesource.com/platform/system/core
5  * File: libsparse/sparse_format.h
6  * Commit: 28fa5bc347390480fe190294c6c385b6a9f0d68b
7  * Copyright (C) 2010 The Android Open Source Project
8  */
9 
10 #ifndef _LIBSPARSE_SPARSE_FORMAT_H_
11 #define _LIBSPARSE_SPARSE_FORMAT_H_
12 #include "sparse_defs.h"
13 
14 typedef struct sparse_header {
15   __le32	magic;		/* 0xed26ff3a */
16   __le16	major_version;	/* (0x1) - reject images with higher major versions */
17   __le16	minor_version;	/* (0x0) - allow images with higer minor versions */
18   __le16	file_hdr_sz;	/* 28 bytes for first revision of the file format */
19   __le16	chunk_hdr_sz;	/* 12 bytes for first revision of the file format */
20   __le32	blk_sz;		/* block size in bytes, must be a multiple of 4 (4096) */
21   __le32	total_blks;	/* total blocks in the non-sparse output image */
22   __le32	total_chunks;	/* total chunks in the sparse input image */
23   __le32	image_checksum; /* CRC32 checksum of the original data, counting "don't care" */
24 				/* as 0. Standard 802.3 polynomial, use a Public Domain */
25 				/* table implementation */
26 } sparse_header_t;
27 
28 #define SPARSE_HEADER_MAGIC	0xed26ff3a
29 
30 #define CHUNK_TYPE_RAW		0xCAC1
31 #define CHUNK_TYPE_FILL		0xCAC2
32 #define CHUNK_TYPE_DONT_CARE	0xCAC3
33 #define CHUNK_TYPE_CRC32    0xCAC4
34 
35 typedef struct chunk_header {
36   __le16	chunk_type;	/* 0xCAC1 -> raw; 0xCAC2 -> fill; 0xCAC3 -> don't care */
37   __le16	reserved1;
38   __le32	chunk_sz;	/* in blocks in output image */
39   __le32	total_sz;	/* in bytes of chunk input file including chunk header and data */
40 } chunk_header_t;
41 
42 /* Following a Raw or Fill or CRC32 chunk is data.
43  *  For a Raw chunk, it's the data in chunk_sz * blk_sz.
44  *  For a Fill chunk, it's 4 bytes of the fill data.
45  *  For a CRC32 chunk, it's 4 bytes of CRC32
46  */
47 
48 #endif
49