diff options
Diffstat (limited to 'include/image-sparse.h')
-rw-r--r-- | include/image-sparse.h | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/include/image-sparse.h b/include/image-sparse.h new file mode 100644 index 0000000000..29242f4fd5 --- /dev/null +++ b/include/image-sparse.h @@ -0,0 +1,67 @@ +/* + * This is from the Android Project, + * Repository: https://android.googlesource.com/platform/system/core + * File: libsparse/sparse_format.h + * Commit: 28fa5bc347390480fe190294c6c385b6a9f0d68b + * Copyright (C) 2010 The Android Open Source Project + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#ifndef _IMAGE_SPARSE_H +#define _IMAGE_SPARSE_H + +struct sparse_header { + __le32 magic; /* 0xed26ff3a */ + __le16 major_version; /* (0x1) - reject images with higher major versions */ + __le16 minor_version; /* (0x0) - allow images with higer minor versions */ + __le16 file_hdr_sz; /* 28 bytes for first revision of the file format */ + __le16 chunk_hdr_sz; /* 12 bytes for first revision of the file format */ + __le32 blk_sz; /* block size in bytes, must be a multiple of 4 (4096) */ + __le32 total_blks; /* total blocks in the non-sparse output image */ + __le32 total_chunks; /* total chunks in the sparse input image */ + __le32 image_checksum; /* CRC32 checksum of the original data, counting "don't care" */ + /* as 0. Standard 802.3 polynomial, use a Public Domain */ + /* table implementation */ +}; + +#define SPARSE_HEADER_MAGIC 0xed26ff3a + +#define CHUNK_TYPE_RAW 0xCAC1 +#define CHUNK_TYPE_FILL 0xCAC2 +#define CHUNK_TYPE_DONT_CARE 0xCAC3 +#define CHUNK_TYPE_CRC32 0xCAC4 + +struct chunk_header { + __le16 chunk_type; /* 0xCAC1 -> raw; 0xCAC2 -> fill; 0xCAC3 -> don't care */ + __le16 reserved1; + __le32 chunk_sz; /* in blocks in output image */ + __le32 total_sz; /* in bytes of chunk input file including chunk header and data */ +}; + +/* Following a Raw or Fill or CRC32 chunk is data. + * For a Raw chunk, it's the data in chunk_sz * blk_sz. + * For a Fill chunk, it's 4 bytes of the fill data. + * For a CRC32 chunk, it's 4 bytes of CRC32 + */ + +static inline int is_sparse_image(const void *buf) +{ + const struct sparse_header *s = buf; + + if ((le32_to_cpu(s->magic) == SPARSE_HEADER_MAGIC) && + (le16_to_cpu(s->major_version) == 1)) + return 1; + + return 0; +} + +struct sparse_image_ctx; + +struct sparse_image_ctx *sparse_image_open(const char *path); +int sparse_image_read(struct sparse_image_ctx *si, void *buf, + loff_t *pos, size_t len, int *retlen); +void sparse_image_close(struct sparse_image_ctx *si); +loff_t sparse_image_size(struct sparse_image_ctx *si); + +#endif /* _IMAGE_SPARSE_H */ |