Features/QED

Specification

The file format looks like this:

+--------+--------------+---------+---------+-----+
| header | extent table | extent0 | extent1 | ... |
+--------+--------------+---------+---------+-----+

Header

Header {
    uint32_t magic;      /* COW2 */
    uint32_t features;   /* format feature bits */

    uint32_t chunk_size; /* in bytes */
    uint64_t max_chunks; /* total image size in bytes = max_chunks * chunks_size */

    uint32_t backing_offset; /* backing filename offset from start of file */
}