1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef _LIBSPARSE_SPARSE_FORMAT_H_
18 #define _LIBSPARSE_SPARSE_FORMAT_H_
19 #include "sparse_defs.h"
20 
21 #ifdef __cplusplus
22 extern "C" {
23 #endif
24 
25 typedef struct sparse_header {
26   __le32 magic;          /* 0xed26ff3a */
27   __le16 major_version;  /* (0x1) - reject images with higher major versions */
28   __le16 minor_version;  /* (0x0) - allow images with higer minor versions */
29   __le16 file_hdr_sz;    /* 28 bytes for first revision of the file format */
30   __le16 chunk_hdr_sz;   /* 12 bytes for first revision of the file format */
31   __le32 blk_sz;         /* block size in bytes, must be a multiple of 4 (4096) */
32   __le32 total_blks;     /* total blocks in the non-sparse output image */
33   __le32 total_chunks;   /* total chunks in the sparse input image */
34   __le32 image_checksum; /* CRC32 checksum of the original data, counting "don't care" */
35                          /* as 0. Standard 802.3 polynomial, use a Public Domain */
36                          /* table implementation */
37 } sparse_header_t;
38 
39 #define SPARSE_HEADER_MAGIC 0xed26ff3a
40 
41 #define CHUNK_TYPE_RAW 0xCAC1
42 #define CHUNK_TYPE_FILL 0xCAC2
43 #define CHUNK_TYPE_DONT_CARE 0xCAC3
44 #define CHUNK_TYPE_CRC32 0xCAC4
45 
46 typedef struct chunk_header {
47   __le16 chunk_type; /* 0xCAC1 -> raw; 0xCAC2 -> fill; 0xCAC3 -> don't care */
48   __le16 reserved1;
49   __le32 chunk_sz; /* in blocks in output image */
50   __le32 total_sz; /* in bytes of chunk input file including chunk header and data */
51 } chunk_header_t;
52 
53 /* Following a Raw or Fill or CRC32 chunk is data.
54  *  For a Raw chunk, it's the data in chunk_sz * blk_sz.
55  *  For a Fill chunk, it's 4 bytes of the fill data.
56  *  For a CRC32 chunk, it's 4 bytes of CRC32
57  */
58 
59 #ifdef __cplusplus
60 }
61 #endif
62 
63 #endif
64