ROM Hack Injecting SysNAND of one 3DS into the EmuNAND of Another?

[FlappyFalco]

I currently have two 3DSes. One is an original 3DS that was gotten shortly after the price drop. Let's call this 3DS 1. The second is a 3DS XL that was gotten in the January of 2014 to prepare for Sm4sh. Let's call this 3DS 2.

Last year, I installed a CFW (RXTools) on the 3DS 1 as I had forgotten about it and was pleasantly surprised to find it on a firmware below 9.2. While I forget the exact process, I remember that it went fairly smoothly. There was almost nothing on the SysNAND to begin with as I had moved everything over to 3DS 2 long ago.

Later, around 3 months ago, when downgrading through the Userland Homebrew Launcher became a thing, I downgraded 3DS 2 to 9.2 and also installed RXTools. The process I used, however was very different. I used EmuNAND9 to set up the EmuNAND on the SD Card, however another step involved using an app on the 3DS called TinyFormat to format (completely wipe) and then "split" the SysNAND and EmuNAND or something.



So that's where we get my problem. I knew that I'd be able to sign back into Nintendo Network and get my games back (the account was "disconnected" from my 3DS and the games where gone, allowing another 3DS {or in this case, another NAND} to sign in to that account and download the games again, PSN style), and that saves on carts would be fine, but I also foolishly thought that the the data on my SD card would also be safe.

However, I was wrong obviously, as each 3DS has a unique way of saving saves and extradata to the SD card, and it can only be read/decrypted on that 3DS. I guess I was under the impression that the EmuNAND was just a clone of the SysNAND, but that's obviously not the case.

So now all of my saves for eShop games, as well as Fantasy Life (as that saves to the SD card) are gone, and no, neither Decrypt9 nor simply replacing the save files on the SD card, work. My current SysNAND also refuses to recognize the saves (corrupt data), so I'm guessing either TinyFormat or EmuNAND9 changed that up as well.

Now, thing is, I have a dump of the original NAND that was used to write those saves, as well as a back up of the SD card before I hacked 3DS 2, and I was thinking that I could replace that over the EmuNAND of 3DS 1 and then back up the saves with JK's Savemanager and just move them over. Would this be possible? And how could it be done?



TL;DR Is it possible to replace the EmuNAND of one 3DS with the SysNAND of another 3DS in order to recover saves on the SD card?

 

[Cinnamon]

You cannot use NANDs from a different 3DS.

Case 1:
If the Nintendo 3DS folder from your "3DS 2" with the saves etc are intact: Boot "3DS 2" Emunand and check if they are still there. That emunand should be a clone of your original sysNAND where you have you games etc. If you have a backup of your sysNAND, which you should, you may backup your existing emuNAND(remember backup) with it.

Case 2: (quite likely)
If you don't have a Nintendo 3DS folder on your sdcard: Making an emuNAND actually formats the whole card. EmuNAND9 may be the cause. If you have a backup of your sdcard, which you should have done before making the emuNAND, copy it back to the sdcard.

My tip:
0. Try just copying the SD card backup to your card first, it may work if you boot into emuNAND

1. Backup "3DS 2"'s current emuNAND just to be safe. Let's call this one "new"
2. Use EmuNAND9 to write your original NAND backup to EmuNAND.
3. Copy SD card backup to that same card.
4. Boot to emuNAND using your preferred CFW.
5. Use a savefile manager to backup all saves.
6. You can choose to continue using your 3DS 2 with the current setup or writing "new" to emuNAND after getting your saves. I would probably just roll with it to be honest.

 

[FlappyFalco]

You cannot use NANDs from a different 3DS.

Case 1:
If the Nintendo 3DS folder from your "3DS 2" with the saves etc are intact: Boot "3DS 2" Emunand and check if they are still there. That emunand should be a clone of your original sysNAND where you have you games etc. If you have a backup of your sysNAND, which you should, you may backup your existing emuNAND(remember backup) with it.

Case 2: (quite likely)
If you don't have a Nintendo 3DS folder on your sdcard: Making an emuNAND actually formats the whole card. EmuNAND9 may be the cause. If you have a backup of your sdcard, which you should have done before making the emuNAND, copy it back to the sdcard.

My tip:
0. Try just copying the SD card backup to your card first, it may work if you boot into emuNAND

1. Backup "3DS 2"'s current emuNAND just to be safe. Let's call this one "new"
2. Use EmuNAND9 to write your original NAND backup to EmuNAND.
3. Copy SD card backup to that same card.
4. Boot to emuNAND using your preferred CFW.
5. Use a savefile manager to backup all saves.
6. You can choose to continue using your 3DS 2 with the current setup or writing "new" to emuNAND after getting your saves. I would probably just roll with it to be honest.

Thanks, I never knew EmuNAND9 could inject NANDs, so I did just that, got my saves with JK's Save Manager and injected my old EmuNAND back in that I had just dumped minutes before, and imported the saves with JKSM again. Surprisingly painless, EmuNAND9 took less than 2 minutes to replace the entire NAND, and I even got back my Streetpass Plaza save (you need to export both "SaveData" and "ExtData" with JKSM).

So overall, this wasn't as big a deal as I made it out to be. Thanks again for pointing me in the right direction.

 

[naddel81]

I am having the same problem right now. I want to clone my EmuNAND from machine1 to my newly bought machine2 and use both. That is not possible by NAND transfer?

How about a system transfer and later restoring the SD card to its state before the transfer? Will that work on both machines?