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      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