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

Discussion in '3DS - Homebrew Development and Emulators' started by dushbadge, Apr 8, 2018.

  1. dushbadge
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    dushbadge Member

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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?
     
  2. Craftyawesome

    Craftyawesome GBAtemp Regular

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    Maybe if you replace the romfs and exefs? (code will definitely need to be decompressed first)
     
  3. PabloMK7

    PabloMK7 Red Yoshi! ^ω^

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    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
     
    Last edited by PabloMK7, Apr 9, 2018
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  4. TurdPooCharger

    TurdPooCharger Meh

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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.
     
  5. dushbadge
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    dushbadge Member

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    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?
     
  6. lone_wolf323

    lone_wolf323 GBAtemp Addict

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    Its taken you over a year to finally ask that? Are you sure you still even care about this at this point?
     
  7. dushbadge
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    dushbadge Member

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    Indeed. I am still interested.
     
  8. Amapola62

    Amapola62 GBAtemp Advanced Fan

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    What about launching Conquest with Birthright inserted and vice versa? For bonus irony. ​
     
  9. Kingpinn02

    Kingpinn02 Newbie

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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!
     
  10. dushbadge
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    dushbadge Member

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    I await your results.
     
  11. Kingpinn02

    Kingpinn02 Newbie

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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.
     
  12. Kingpinn02

    Kingpinn02 Newbie

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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.
     
  13. dushbadge
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    dushbadge Member

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    Okay, thanks. I figured it wouldn't work. Just like with repatch on vita.
     
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