YaFFS2 disk image parser
Yet Another Flash FileSystem
YaFFS2 may use the 'YA\xffS' signature
YaFFS2 uses fixed size blocks
Depends on OOB data, so use a dump from nanddump -o
OOB data format may vary, use hexinspect mydump 2048 64 to manually inspect and adapt parse_oob()
OOB data used to store YaFFS block metadata
- object_id = file/inode identifier
- chunk_id = data offset where the data in this block fits inside the file
- block_seq = block version information
- higher value supersedes lower value for a given objid+chkid
- same value supersedes earlier instance in the same flash erase block
chunk_id 0 holds file metadata
- file name
- file size
- object_id of parent directory
- mtime
File deletion: rename file to 'deleted' or 'unlinked' and change parent directory id to 3 or 4
ruby yaffs2.rb mtd0
List all objects / filenames
ruby yaffs.rb mtd0 42
Dump object with id 42 in objid_42_<filename>
- Output all versions of file data from chunk history
logfile has debug info, incl metadata
ruby yaffs.rb mtd0 -a
Dump all objects
ruby yaffs.rb mtd0 -r
Rebuild a filesystem hierarchy from a previous -a full dump under root/