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 typedef struct sparse_header { 18 __le32 magic; /* 0xed26ff3a */ 19 __le16 major_version; /* (0x1) - reject images with higher major versions */ 20 __le16 minor_version; /* (0x0) - allow images with higer minor versions */ 21 __le16 file_hdr_sz; /* 28 bytes for first revision of the file format */ 22 __le16 chunk_hdr_sz; /* 12 bytes for first revision of the file format */ 23 __le32 blk_sz; /* block size in bytes, must be a multiple of 4 (4096) */ 24 __le32 total_blks; /* total blocks in the non-sparse output image */ 25 __le32 total_chunks; /* total chunks in the sparse input image */ 26 __le32 image_checksum; /* CRC32 checksum of the original data, counting "don't care" */ 27 /* as 0. Standard 802.3 polynomial, use a Public Domain */ 28 /* table implementation */ 29 } sparse_header_t; 30 31 #define SPARSE_HEADER_MAGIC 0xed26ff3a 32 33 #define CHUNK_TYPE_RAW 0xCAC1 34 #define CHUNK_TYPE_FILL 0xCAC2 35 #define CHUNK_TYPE_DONT_CARE 0xCAC3 36 37 typedef struct chunk_header { 38 __le16 chunk_type; /* 0xCAC1 -> raw; 0xCAC2 -> fill; 0xCAC3 -> don't care */ 39 __le16 reserved1; 40 __le32 chunk_sz; /* in blocks in output image */ 41 __le32 total_sz; /* in bytes of chunk input file including chunk header and data */ 42 } chunk_header_t; 43 44 /* Following a Raw or Fill chunk is data. For a Raw chunk, it's the data in chunk_sz * blk_sz. 45 * For a Fill chunk, it's 4 bytes of the fill data. 46 */ 47 48