- remove si_schedule function. Move it inside write_si_reg body.
- add word-alignment restriction on dram address, and do word-copy
- rename si_type to dma_dir, also SI_DMA_NONE is now SI_NO_DMA
- pif_addr validity test is more relaxed (test only 25 bits).
- add more comments
PI controller now accepts 4 different dma handler, one for each DMA'able
region (DD ROM, CART SAVE, CART ROM, 1FD00000). Each handler is
responsible for effective data transfer and some extra operation as
needed (cached_code invalidation for instance).
savestate loading code was trying to poweron rumble pak on a
non-initialized rumble pak.
Now we check that the game is rumble pak compatible (therefore it has
been initialized) before calling the poweron function.
A similar issue was also present for transferpak.
Also during this process, I felt necessary to slightly alter functions
prototypes (better name, easier usage/implementation).
I also specified the NULL terminated strings ownership, and thus
reworked some aspects of objects ownership.
NULL or empty strings usage also have been documented. For ROM, empty or
NULL strings allow to have an empty transferpak. For RAM, empty or NULL
strings will let the core generate a suitable save filename and
initialize it with empty content. This can be helpful when a GB save
file is not available and the game doesn't really care about the initial
saved content (for instance Perfect Dark).
The init_gb_cart function as also been slightly modified to better
handle loading failures (and not leak stuff in this case).
The GB pak switch function is now only activable when the game is
compatible with the Transferpak. Still you can change what is inside the
transferpak even when the transferpak is not plugged in.
Also
* Move backends implementations under backends directory.
* Rework file_storage to be a real implementation of storage_backend.
* Fixup PIF_PDT_EEPROM types
* Extract joybus stuff from pif module.
* Extract cart stuff from pif module.
* Extract controllers and paks from si module.
