How to make an emuNAND for region changing
This tutorial is for users who are looking to region change their 3DS from one region to another (using 3ds.guide), but at the same time have quick and easy access to their original region (by utilizing an emuNAND)
First, an explanation
NAND is a type of flash storage. Whenever someone says the word "NAND", they are really referring to the 3DS's storage, the hard drive of the 3DS essentially. The NAND stores everything important for your 3DS, things like the operating system, the preinstalled applications, user settings, etc. etc.
Region changing involves changing region-specific files in your NAND, so that on boot, the operating system that is loaded is not a e.g. a JPN one, but e.g. a EU one or a US one. However, if you want to quickly and easily switch between regions, you can't just change these region specific files on the spot. You have to go through the region-changing guide again.
emuNAND means having a separate copy of the NAND on your SD card, in a special 1GB-1.3GB (depending on your 3DS) partition at the start of the partition table, and then having this special copy of the NAND being the region-changed one, rather than your 3DS's NAND (named sysNAND). Therefore, upon boot, you can choose which NAND to boot into; Either the one on your SD card, or the one on your 3DS, and you can have your emuNAND be the region-changed one, and the sysNAND to be the untampered one.
How to make the emuNAND partition
In order to get this special partition on your SD card, you have to format the SD card with GodMode9. Formatting, as you already know, deletes everything from your SD card. So, make sure you have backed up all of your files from your SD card before proceeding.
Assuming you have backed up everything from your SD card, we can now proceed with making an emuNAND.
- Boot into GodMode9 by holding (Start) on boot
- Press the HOME button
- Select "More.." --> "SD format menu"
- Select "EmuNAND size (full)" from the "Choose EmuNAND size:" menu
- Select 32KB clusters
- Leave the SD card label as it is, and press (A)
- Enter the button combination to format the SD card
- Select "GW EmuNAND type"
- Let it finish the formatting
Once you are done formatting the SD card, press the power button, and then power off your 3DS. Don't forget to copy back your backup from your PC to your SD card!
Doing the region change on your emuNAND
You will be following the normal region changing guide over at 3ds.guide, however, with some modifications:
- At section II step 8, you will choose "transfer to emuNAND", not sysNAND
- At section II step 19, you will not press the (Start) key. You will instead power off the 3DS, and then boot it up by holding (L). Luma by default boots into sysNAND, but by holding L on boot you can instead tell it to boot into emuNAND. There is an option that you can set in the config that makes it autoboot into emuNAND without holding down (L), and you can set this if you want. Note that once you set this option, holding (L) on boot will do the exact opposite effect; Booting normally will boot into emuNAND, and holding (L) will boot into sysNAND
- At section V step 5, note that you are using an emuNAND instead of sysNAND
A note on linked and unlinked NANDs
Right now, your emuNAND and your sysNAND are linked. What this means, is that both NANDs are accessing the same "Nintendo 3DS" folder on your SD card.
What you need to understand is that the 3DS encrypts the "Nintendo 3DS" folder contents, and makes them console unique with a key named "movable.sed"1 (which is stored on your NAND). This is so that if for example you were to buy a game on one 3DS, you couldn't simply move the SD card to another 3DS and share games for free between the 2 3DSes. This is anti-piracy 101. The "Nintendo 3DS" folder however contains more than just games. Saves, Themes, Home menu configuration, images, etc. Are all in that folder.
When you made an emuNAND earlier, you also copied your sysNAND into this emuNAND, and in the process, you also copied the "movable.sed". This made it so that the two NANDs, were sharing the same "Nintendo 3DS" folder, making them linked.
This creates a problem, where changes on one NAND carry over to the other. Ideally you'd want the two NANDs to be seperate entities from one another, they shouldn't be sharing the same "Nintendo 3DS" folder.
You can format one of the two NANDs (ideally using TinyFormat), so that one of the two NAND's "movable.sed" changes, because "movable.sed" changes upon a format. Therefore making them not able to share the same "Nintendo 3DS" folder 2. The reason why TinyFormat is recommended over a normal format through system settings, is because it addresses an issue that occurs when your NANDs have the same NNID in them, because formatting one of them with a normal format would break the other NAND's ability to access NNID settings through the system settings.
Apart from that, you should be fine! And now you have a region changed emuNAND!
1: Technically it is not a key, it contains some other information as well. But in the context of this guide, we are only interested in the key part of this file.
2: I should mention that in practice, you don't have multiple "Nintendo 3DS" folders on your SD card, but rather you have multiple folders inside of the "Nintendo 3DS" folder (Having multiple "Nintendo 3DS" folders would be impossible to due overlapping file names).