ROM Hack Yoshi's Island DS ROM Hacking Question

[iZackefx]

Well, I've seen ALOT of music hacks for Yoshi's Island DS, and I haven't seen one actual rom hack for it. And by "Rom Hack", I mean stuff like custom levels and such. My question is, is it possible to actually hack Yoshi's Island DS besides music hacks and stuff? If so, I would like to request an editor if possible.

 

[FAST6191]

If you can run the ROM on the DS you can edit it and nothing I have seen thus far has much in the way of restrictions here beyond AP in the games themselves which is solved by getting a flashcart with a good loader.

To my knowledge nobody has tangled with the level format so you might be going from scratch but knowing Nintendo there is likely to be a fair bit of code reuse so looking at the likes of the princess peach games and maybe NSMB would be a good idea. Some of artoon's other stuff might be an idea but hold that for no as most of their other games do not appear that similar.

Tools for it. Even if it is slightly different (I know you probably meant if there are some already) and you could reasonably adapt one of the editors for NSMB or something asking for tools to be made is probably a bit much as there are other games that people have taken to hacking far more (NSMB, mario kart and to a slightly lesser extent Mario 64 DS) although I would certainly argue this is sufficiently different to warrant some attention.

This said I had a quick look at the game and most things seem to be compressed (standard type 10 LZ compression) but otherwise using non SDK formats I have not seen before (although they do not look terribly complex).
As for levels themselves nothing jumped out at me (5 worlds at 10 levels per world including secrets/bonus stuff) which immediately points at the CRSB files (50 of them in 5 "classes" with 8 normal names a piece and two extras) but they are probably too small to do anything as far as whole levels goes (none are more than a kilobyte and although the likes of N+ has similarly sized levels there is a lot less to them/going on in those and these have a bit more wasted space) but that is too big a coincidence to be dismissed so it probably plays a role. The other stuff appears to largely be graphics, animations or otherwise unrelated save for the mpdz files

The game also has a fair few overlays (44 for a game this early raises an eyebrow) but I did not check a single thing there beyond noting there are quite a few of them.I doubt I will but hopefully I will get some time to check further.

 

[iZackefx]

It seems quite funny because no-one, for probably 6 years, once again, no-one has actually made a custom level of Yoshi's Island DS. I thought it would be easy to hack because of the NITRO File System. And from what I heard, Yoshi's Island and Yoshi's island DS do somewhat follow the same data. And, ARTOON decided to implement their own LZ10 compression method instead of using the NDS BIOS, which is the only compression method used for the files. Well, now that's from what I heard. Some slight differences between Yoshi's Island and Yoshi's Island DS would be all level parts per translevel are loaded into RAM.

Yes, I realize asking for Editors can be harsh, for I am sorry.

But still... The game is one of my favorites. I would be delighted to hack the games without painful HEX edits.

 

[Rydian]

The people that made tools for other games didn't sit around wishing somebody else did it, because if everybody does that it never gets done.

 

[FAST6191]

Having the file system certainly helps matters when it comes to hacking- a bit of basic pattern matching on file names, file extensions and directory names to find sound, some graphics and more as well as having definite limits to the sizes of those sections is awesome compared to older "all in the binary" systems like the GBA and most things in the 16 bit era and earlier. That it is an early game means some of the now ultra common formats were not standardised but even then/on newer games you still find highly custom stuff to pull apart. Cross platform similarities has me curious though as with the exception of the likes of (NS)BMD and (N)ARC being fairly similar between the gamecube, wii and DS (and from what little is known probably the 3ds as well) I have not seen an awful lot done from that perspective; most of it is just if a muliplatform game is developer there might be some developer left extras from other platforms (the DS version of the Greg Hastings Paintball game has a nice xbox live logo in it and some sports games make reference to the other versions). Loading all into RAM is not that unthinkable/uncommon as unlike the older consoles the cart itself is not directly addressable in RAM (give or take bankswitching, mappers and such).

I must admit I just looked at the start of the files and Crystaltile2's but them using a custom compression method has me curious. Certainly I have seen developers implement their own decompression functions rather than use the comparatively slow/resource hungry BIOS methods (they are nice methods but it is a tradeoff between resources and speed) but true custom compression is few and far between even if it is just fewer restrictions vs the standard type.

This is not really getting much done though so although it would be a pain to do a simple search for things thanks to the compression it is probably time to take it to a memory viewer and then trying to puzzle out what is going on there or trying something a bit more brute force.

 

[iZackefx]

So I'm guessing why no-one looked into that was because of the custom compression method? Hmmm.

 

[FAST6191]

There are areas of hacking and games that you will be hard pressed to be the first and only especially if you do not take it to ASM level but frankly there are what 3800 odd games when not counting region dupes? I am a little surprised it happened here as usually Nintendo first party/major franchises are the things that get all the tools and attention; think all the stuff pokemon, mario platform, mario kart, advance wars, fire emblem, goldun sun, metroid zelda, smash brothers.... which leaves what Sonic, final fantasy and mega man being about the only non Nintendo things (even if the latter two were more traditionally associated with Nintendo consoles) to sit up there with those titles mentioned along with Castlevania and Chrono trigger if I push it a bit? Add in that most hacking effort seems to focus on asset ripping, audio hacking and translation hacking and it probably makes a clearer case.

As for custom compression in some ways that is like a challenge (I say long having had the El Tigre: Make my mule and Puzzle Quest compression to properly figure out) and moreover if you had not said something I would have carried on thinking it was standard type 10 compression (indeed it might still be)- on the DS using SWI logs as compression detection/tool targeting like you might on the GBA does not really happen and even if you did try it would gain you very little and frankly if it decompresses and compresses back with standard tools nobody really cares if it uses the BIOS or not.

 

[iZackefx]

Hmm. What do you think you can do, if simply requested?