cso support

[SWAT]

(25.11.2020 09:24)sundance2 писал(а):  Thanks for the new sdloader binary @swat ! Much appreciated !

Unfortunately, when trying to test it, I get into an immediate crash.
And I believe it's unrelated to the loader itself.

Rather, while within the ISO loader program, when merely _selecting_ the *.cso file,
it instantly crashes.
I think it doesn't reach the point where it tries to load the image.

Presumably, ISO loader does something when selecting the image, like analyzing the header,
and maybe it doesn't expect a ziso header.

I vaguely remember that it was the pb I used to identify when trying to debug this topic earlier this year.

Do you experience the same issue on your side ?

No, this problem did not exist before. Which DS version are you using?

(25.11.2020 13:05)sundance2 писал(а):  2 KB for an LZO decoder feels overkill.
This kind of trivial compression format should be decodable using a ~200 bytes routine.
Granted, hand assembly is likely out of scope,
but given the baseline, I would have hoped that a good compiler would make it < 1 KB.

Not only algo used this space, also csio format reading (and some other) code too.

(25.11.2020 13:05)sundance2 писал(а):  I presume the "implementation that does not use additional memory" would be employing in-place decompression ?
This is a feature for many of these low-complexity formats, allowing decompressed data to overwrite the compressed one previously stored in the same buffer.
In general, there is a need for some margin for it to work properly (aka, the end of the compressed block is not positioned at the end of the decompressed block, but rather a few bytes beyond that).
How much is the margin depend on each format. If it's not known or not documented, it can be generously evaluated. Typically one cache line (32-bytes on SH4) should be enough.

Yes it is, but some games had a problem with music (judging by my own comment) with this method and maybe not only with music.
This is ~10 years old code:
https://github.com/DC-SWAT/DreamShell/bl...?ts=4#L791

In general, I just did not deal with ciso support anymore, since the focus is more on the IDE mod, only it can allow all the games to run.
Although, in theory, all games can be run on SD too, but a hack is required.