3DBrew / ctrtool / 3DSExplorer discussion

Discussion in '3DS - Flashcards & Custom Firmwares' started by 3DSGuy, Aug 26, 2012.

Aug 26, 2012
  1. 3DSGuy
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    Member 3DSGuy No longer in scene

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    I thought it would be a good idea to make a thread for anyone to ask questions about, What a specific update to 3DBrew/ctrtool/3DSExplorer means/does? And what does it mean in the grand scheme of things? Or just explaining a file format. It's mainly for those without the knowledge/resources to figure it out themselves. Hopefully any false hopes leading to homebrew can be squashed before harm or can be done or more 50 page threads made. :)

    So if you have any questions, ask away. Hopefully myself or someone else will have the answer or at least an educated guess.
     
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  2. yuyuyup

    Member yuyuyup GBAtemp Psycho!

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    Thanks for your help and also that great dev unit post from a while ago, the latest github from neimod updated with the following: Added preliminary support for RomFS. Does this mean anything? https://github.com/3dshax/ctr
     
  3. 3DSGuy
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    Member 3DSGuy No longer in scene

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    This update allows ctrtool to list and extract the resources from a RomFS file(the 'preliminary' part of the update comment, probably means that it's not perfect, or neimod intends to expand on the extracting capabilities). This is good, as at the moment no other tool can read/extract data from RomFS files.

    Some background info on the RomFS file format:

    RomFS files are part of the NCCH file format which are found in game ROMs(officially known as CCI files), eShop downloads and System titles
    RomFS is a file format which contains resources which is used by the executable code like textures, graphics and sounds, even level layouts perhaps. It can also hold the download play app which is sent over between 3DS' and it can also hold the electronic manual used by the home menu.
     
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  4. FAST6191

    Reporter FAST6191 Techromancer

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    Perhaps unrelated and I meant to ask in the dev thread but with the dev stuff and these tools is there a way to get either some dev binaries and/or assets in plaintext (well plain as far as the basic inbuilt ROM encryption). I ask as I would not mind a crack at reverse engineering some of the file formats in 3ds games like we did for the wii once decryption tools were released there ( http://gbatemp.net/topic/72013-wii-decryption-tool-released/page__st__15 ).
     
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  5. Cyan

    Global Moderator Cyan GBATemp's lurking knight

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    Is there a visual schematics of a CCI, with each part nested?

    like:
    CCI (the rom dump)


    Something like that. Is that correct? It's not full, I put very few info inside, but it display visually the content of a CCI.

    I guess on the RomFS and ExeFS, there are different partitions (defined in the NCCH Header)
     
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  6. 3DSGuy
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    Member 3DSGuy No longer in scene

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    Hmm there are some mistakes, I'll re-do your spoiler tree.
     
  7. 3DSGuy
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    Member 3DSGuy No longer in scene

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    NCSD i.e. CCI (the rom dump)

    That's more accurate. But looking at a rom in 3DSExplorer will give you a file tree, if you want something accurate.
     
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  8. 3DSGuy
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    Member 3DSGuy No longer in scene

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    Yes you can, if you have a developer NCCH(CXI/CFA) encrypted with the 'zeros' key ctrtool can decrypt the RomFS and dump the assets from the RomFS. (it can be encrypted with another key, but you have know the encryption key, and you have to specify the key when attempting to decrypt the NCCH with ctrtool)
     
  9. yuyuyup

    Member yuyuyup GBAtemp Psycho!

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    Sorry for the bump, but I noticed the http://3dbrew.org/wiki/Title_list was updated on the 7th. Would you mind explaining any updates (if any are even worth caring about,) you know me just trying to keep abreast
     
  10. 3DSGuy
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    Member 3DSGuy No longer in scene

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    This list got reduced to a manageable size by deleting the demo list and cartridge list and shrinking the size of the regular eShop list. I've moved the full lists to my github wiki page and keep them updated there.
     
  11. elisherer

    Member elisherer I ♥ 3DS

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    There's a more robust list handled by mtheall on the irc channel..
     
  12. 3DSGuy
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    Member 3DSGuy No longer in scene

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    I didn't know mtheall upkept a list of eShop apps? is the irc channel you refer to "#3dsdev"?

    EDIT: isn't yellows8 mtheall?
     
  13. Pippin666

    Member Pippin666 SSF43DE Master

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    Can we extract icon from the rom with this tool ?? I wish I could extract SMB3DLand and HoR's icon.

    Pip'
     
  14. SifJar

    Member SifJar Not a pirate

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    Only if you happen to have the key for the NCCH. Or else a developer NCCH (for which the key is all zeros, if I am understanding 3DSGuy correctly).

    So no, basically.

    EDIT: Actually, the icon is in the ExeFS, not the RomFS. So this may be wrong. I have no idea if anything can actually view/extract ROM icons, but I don't think so. I haven't seen any extracted icons before, so I am assuming it can't be done.
     
  15. elisherer

    Member elisherer I ♥ 3DS

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  16. 3DSGuy
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    Member 3DSGuy No longer in scene

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    Thanks for clarifying :)
     
  17. RodrigoDavy

    Member RodrigoDavy GBAtemp Maniac

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    Just to confirm, the SD filesystem is encrypted with console unique keys under the Nintendo 3DS directory, does that means even the .sav files uses this kind of encryption? And if I want to backup a savefile, can I keep the encrypted copy in my computer and then transfer it to the sd card whenever I want?
     
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  18. heartgold

    Member heartgold GBAtemp Psycho!

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    Yeah sure, I've done that plenty of times. Heck I had a Metriod fusion backup save on my PC along with other 3DS data, my current SD became faulty so I used the backup data and everything worked. Although I was a few levels behind in Metriod cos you know that was the backup when it was taken.
     
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  19. 3DSGuy
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    Member 3DSGuy No longer in scene

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    Yep. Like heartgold said, you can keep backups of SD card game saves on your PC and restore them whenever you want.
     
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  20. sightlight

    Member sightlight GBAtemp Fan

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    Hey guys, are we close to hack the System?
     

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