These disc images are only used on dev units and not retail units.
There are two important differences compared to normal Wii disc images:
- The data starts 0x8000 bytes into each partition instead of 0x20000
- The data of a partition is stored unencrypted and contains no hashes
Our old implementation was just guesswork and doesn't work at all.
According to testing by GerbilSoft, this commit's implementation
is able to read and extract files in the filesystem correctly,
but the tested game still isn't able to boot. (It's thanks to their
info about unencrypted disc images that I was able to make this commit.)
This is useful for blob types that store Wii data unencrypted
(such as WIA and discs extracted to directories) so that
we don't have to waste CPU time encrypting in the blob code
just to decrypt right afterwards in the volume code.
Instead of expecting callers to know how the size of directory file infos
relates to which files are in which directories, filesystems now offer a
GetRoot() method, and file infos offer a way to get their children. As
a bonus, m_FileInfoVector no longer has to be created and kept around
in RAM. Only the file info objects that actually are used are created.
Some callers already have the file info, making the relatively slow
FindFileInfo calls unnecessary. Callers that didn't have the file info
will now need to call FindFileInfo on their own.
JosJuice