Emunand and Sysnand clarification, please

Discussion in '3DS - Flashcards & Custom Firmwares' started by Gorkensnorkel, Dec 26, 2016.

  1. Gorkensnorkel
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    Gorkensnorkel GBAtemp Regular

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    I have spent the last week reading everything I can find on emunand and system and I don't mean to sound retarded here but... I am still not getting the full scope of what these two words imply (as far as hacking the 3ds goes at least).

    I understand the emunand is the emulator nand and the system nand is the main-3ds-game-playing nand, right?

    I followed the GUIDE and set up A9LH and Luma and made my backups at the requested times during the guide. But what backup do I have exactly? Emunand or Sysnand?

    Do I need to make more backups (or rather, do I need to backup other files like Sysnand) than the one that the GUIDE specified just to be safe?
     
  2. SirHaxALot

    SirHaxALot Yum Cookies! :3

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    EmuNAND is a hidden partition on your SD Card containing a copy of your sysNAND (the storage chip inside your 3DS). When setting up EmuNAND you usally format either Sys- or EmuNAND in order to unlink the SD folder, as both would use the same installed apps, which can be problematic. If you never played with CFW and probally Menuhax before, you mostly don't have setup an EmuNAND and all you have are SysNAND backups.

    (Dunno, I hope this is not too confusing)
     
  3. Gorkensnorkel
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    Gorkensnorkel GBAtemp Regular

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    It kinda helps, I followed the guide and installed A9LH and Luma. After doing so, from what you are saying, I do not have a emunand backup, correct? So the backup the guide makes is a sysnand backup?

    What are the benefits of separating (un-linking) your emunand and sysnand? And the benefits of backing up emunand?
     
  4. squall14716

    squall14716 GBAtemp Maniac

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    SysNAND refers to the contents of the 3DS's internal memory (it's stored on a NAND chip, hence the name).

    EmuNAND is a copy of the 3DS's internal memory, stored on the SD card (in a hidden partition). When booting a CFW into EmuNAND, the system software is patched to redirect calls to the 3DS's internal memory to that part of the SD card instead, leaving the contents of SysNAND untouched.

    EmuNAND was mainly popular before A9LH allowed people to update their SysNAND and retain the ability to launch a CFW. It allowed you to leave your SysNAND alone on 9.2 (or 4.x before that) since that was required to launch a CFW and run a fully updated (usually) version at the same time. Now it is no longer nearly as required as it once was, but there are still cases when it is useful.
     
    Last edited by squall14716, Dec 26, 2016
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  5. nl255

    nl255 GBAtemp Addict

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    Emunand is exactly that, an emulated NAND (firmware) image on your SD card that you boot into rather than the one on the actual NAND chips (which is sysnand). Back in the old days before a9lh/k9lh you had to keep your sysnand on 9.2 because the only way to use cfw was to use a normal homebrew exploit (menuhax, oothax) to run the cfw loader (as a 3dsx) because it relied on an arm9 kernel exploit that was patched in versions higher than 9.2.

    Nowadays with a9lh/k9lh that is no longer necessary as it is an arm9 kernel exploit that works much earlier in the boot process, so there is no need to boot into firmware 9.2. Thus, the cfw can be loaded before booting the firmware on your sysnand though it is still possible to use emunand (or even multiple emunands) if you really want to. The only reason for non-developers to use emunand(s) nowadays is to work around the 300 game/app limit (some developers may want to have different emunands on different firmware versions for testing purposes).
     
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  6. SirHaxALot

    SirHaxALot Yum Cookies! :3

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    EmuNAND is more a relict of the past, used in times before A9LH existed, because this way you could keep a SysNAND with a vulnerabel FW (e.g. 9.2) while have a second NAND (EmuNAND) with the most current FW to play online etc. It was also kind of a protection layer, if you destroyed EmuNAND, you could easily create a new one. With A9LH theres no need for EmuNAND, as you can restore your sysNAND with Decrypt0/Hourglass9 if you've fucked it up.
     
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  7. wormdood

    wormdood pirate booty inspector

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    1. correct
    2. unlinking sysnand and emunand are things that don't really apply to a9lh
     
  8. Gorkensnorkel
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    Gorkensnorkel GBAtemp Regular

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    Ah ok, thanks a lot for all the replies. i think I get it now. I was just worried there was something else I might need to do AFTER installing A9LH and Luma.
     
  9. wormdood

    wormdood pirate booty inspector

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    make a backup and enjoy:yay3ds:
     
  10. SirHaxALot

    SirHaxALot Yum Cookies! :3

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    just keep at least one backup of your 3DS in a safe place, so you can recover from a brick.
     
  11. Gorkensnorkel
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    Gorkensnorkel GBAtemp Regular

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    I have the backup made during the guide of the nand and OTR file. That should do right?
     
  12. SirHaxALot

    SirHaxALot Yum Cookies! :3

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    yeah, just keep the NAND*.bin, the corresponding .sha and your OTP.bin at a safe place and you should be fine in case of emergency

    *maybe sysNAND, sysNANDmin, etc.
     
  13. Gorkensnorkel
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    Gorkensnorkel GBAtemp Regular

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    Hey, I want to try this out but am I missing something... I don't see any specific instructions for installation. It just says to dump some file with Decrypt9 but it doesn't say where to place the file or whether to dump it before or after downloading the app from the Homebrew channel. I am kinda new to the 3ds scene so any advise would be greatly appreciated, thank you.

    I am using A9LH and Luma, btw.
     
  14. wormdood

    wormdood pirate booty inspector

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    . . . what app/ step are you attempting?
     
  15. Gorkensnorkel
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    Gorkensnorkel GBAtemp Regular

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    Opps, shit I posted this in the wrong thread... too many tabs open. I am trying to install CHMM2. Lol.