Homebrew Is it possible to use a load another game using a romfs in conjunction with an unrelated game cart?

dushbadge

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Could I for example load SMT4 apocalypse using an SMT4 apocalypse romfs file with the Fire Emblem cartridge?

Or better example: Could I load A Link Between Worlds USA using a romfs for that with the Japanese cartridge for A Link Between Worlds?
 

Craftyawesome

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Could I for example load SMT4 apocalypse using an SMT4 apocalypse romfs file with the Fire Emblem cartridge?

Or better example: Could I load A Link Between Worlds USA using a romfs for that with the Japanese cartridge for A Link Between Worlds?
Maybe if you replace the romfs and exefs? (code will definitely need to be decompressed first)
 

PabloMK7

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Could I for example load SMT4 apocalypse using an SMT4 apocalypse romfs file with the Fire Emblem cartridge?

Or better example: Could I load A Link Between Worlds USA using a romfs for that with the Japanese cartridge for A Link Between Worlds?
No, you need the exefs (where the code is), the romfs (where the resources are) and the exHeader (where all the "settings" for the game are stored including the code size and other stuff).

Having those three it would be stupid to use a game card as you could just build a cia with them.

If you still want to use the game card as a base, it would still fail as the romfs/exefs/exHeader checksums and decryption keys stored in the NCCH header would cause the system to panic.

If you say what if you use the NCCH from the other game as well? Then you have a full cxi executable that can be built into a cia or 3ds file so again has no point. :P
 
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Replacing a title's complete RomFS for a different title's RomFS is a bad idea. When you launch that title, there's an executable file called .code that'll go looking for its dependencies in RomFS (ie, images, music, text, etc.). If it doesn't find what it's looking for, you'll crash. Even for twin games like Pokemon X/Y or Yokai Watch, this will happen.

You can replace and modify individual files within RomFS. Attributes you can change depends on the type of file like color, skin, music, and some game physics. You just gotta make sure the files are similar enough.
 

dushbadge

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Replacing a title's complete RomFS for a different title's RomFS is a bad idea. When you launch that title, there's an executable file called .code that'll go looking for its dependencies in RomFS (ie, images, music, text, etc.). If it doesn't find what it's looking for, you'll crash. Even for twin games like Pokemon X/Y or Yokai Watch, this will happen.

You can replace and modify individual files within RomFS. Attributes you can change depends on the type of file like color, skin, music, and some game physics. You just gotta make sure the files are similar enough.

Then I guess that goes back to my 2nd point. What if we used a Japanese cartridge as a base for loading a digital only US title?
 

Kingpinn02

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I'm very curious about this since I'm considering buying the Japanese version of Yokai Watch 3 (since the US version seems to have had a low print run and sells for ridiculous prices as a result) and using the romfs of an American CIA. I can tell this process is going to be a tricky one and I've read everyone's responses, but I'm gonna give it a try and see what happens. Of course, I'm gonna try and be careful while keeping the exact same naming convention of the files from the Japanese version. Also, I won't be surprised if this fails, but my curiosity wants to at the very least try it out. I'll let you guys know if it fails miserably!
 

Kingpinn02

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Oh PFFFT, I didn't know you were still paying attention! Well, I had to put the experiment on hold for the moment, but I'll let you know how it goes once I try it out.
Welp, I tried it out! I can confirm for sure that it did not work. Granted, there was only one large text file for Yokai Watch 3 instead of seperate text files like they would do in a game like EX troopers. I didn't extract the file, I simply placed the English file in the directory of the Japanese game via Luma's patching system and it caused the screen to go black. Idk if I would've had better luck extracting the text file and invesitigating what was inside, but this is pretty much as far as I'll go for this experiment.
 

dushbadge

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Welp, I tried it out! I can confirm for sure that it did not work. Granted, there was only one large text file for Yokai Watch 3 instead of seperate text files like they would do in a game like EX troopers. I didn't extract the file, I simply placed the English file in the directory of the Japanese game via Luma's patching system and it caused the screen to go black. Idk if I would've had better luck extracting the text file and invesitigating what was inside, but this is pretty much as far as I'll go for this experiment.
Okay, thanks. I figured it wouldn't work. Just like with repatch on vita.
 

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