If you have already hacked your device before and have a EmuNAND based CFW setup, this guide deals exclusively with SysNAND and you should follow all instructions from within or applying to SysNAND. Note that the terms EmuNAND and RedNAND refer to slightly different implementations of [the same concept](http://3dbrew.org/wiki/NAND_Redirection).
{: .notice--info}
If you downgrade to 2.1.0 on a 2DS or New 3DS and leave Wireless Communication off, you can re-enable the wireless by removing the battery and unplugging the charger for several seconds then booting back up.
{: .notice--info}
If you've been using the New 3DS's microSD Management to transfer files to your SD card, this will no longer work on 2.1.0. Ensure you have a microSD card reader available before proceeding.
{: .notice--info}
To use the [magnet](https://en.wikipedia.org/wiki/Magnet_URI_scheme) links on this page, you will need a torrent client like [Deluge](http://dev.deluge-torrent.org/wiki/Download)
Ensure your device's Wireless Communication is turned on as udsploit will need the wireless module to be active to function. Wireless Communication only has to be on; connecting it to an access point is not required.
**For now, connecting your device to the internet is REQUIRED to continue after the 2.1.0 CTRTransfer.**
{: .notice--warning}
**Disable the parental controls of your device before doing the 2.1.0 CTRTransfer. If you do not know the password, see [this](https://mkey.salthax.org/) site. If you cannot disable parental controls because the linked NNID is for a child under 13, you can instead set all parental control options to "do not restrict".**
{: .notice--warning}
**Performing a CTRTransfer will remove all user-installed tickets (which allow access to games) from your device until the created backup is restored.**
{: .notice--danger}
**Never format a 2DS while on a version <6.0.0 or you will be unable to complete initial setup and will BRICK!**
{: .notice--danger}
**Never update a New 3DS running 2.1.0 (an Old 3DS firmware) or you will BRICK! You MUST restore a NAND backup or CTRTransfer back to standard New 3DS firmware first!**
{: .notice--danger}
{% capture notice %}
**Putting a New 3DS on 2.1.0 in sleep mode is known to cause an UNRECOVERABLE brick!**
**This only happens when shutting the lid _while your device is on_; this does not apply to turning your device off.**
**Your device only enters sleep mode when the lid is closed. It is not on a timer or anything like that.**
**Once on 2.1.0, you should continue without delay to avoid any possibility of this happening!**
In this section, we will be flashing your device's [CTRNAND](https://www.3dbrew.org/wiki/Flash_Filesystem#CTR_partition) partition to 2.1.0 in order to take advantage of an oversight in 2.1.0 for the purpose of extracting the [OTP](https://www.3dbrew.org/wiki/OTP_Registers) unique to your device. This OTP file is required to install arm9loaderhax, and **cannot** be shared with other consoles.
This is accomplished by [installing a premade CTRTransfer image](https://www.reddit.com/r/3dshacks/comments/4zhe4a/) containing 2.1.0, copying your device specific files (such as `moveable.sed` and `SecureInfo_A`) to it, then fixing the title databases.
#### What you need
* The latest release of [SafeCTRTransfer](https://github.com/d0k3/SafeCTRTransfer/releases/latest)
* The latest release of [safehax](https://github.com/TiniVi/safehax/releases/latest)
* The 2.1.0 CTRTransfer image for your device and region
*(if your device is not from one of these regions, just pick one)*:
+ <i class="fa fa-magnet" aria-hidden="true" title="This is a magnet link. Use a torrent client to download the file."></i> - [New 3DS or Old 3DS or 2DS 2.1.0 - EUR - CTRTransfer](magnet:?xt=urn:btih:89acc9c1b488b8b38251de0ddf07975d6bd354a1&dn=2.1.0-4E%5FCTRTransfer%5Fo3ds.zip&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.opentrackr.org%3A1337%2Fannounce&tr=http%3A%2F%2Ftracker.opentrackr.org%3A1337%2Fannounce&tr=udp%3A%2F%2Fzer0day.ch%3A1337%2Fannounce&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969%2Fannounce&tr=http%3A%2F%2Fexplodie.org%3A6969%2Fannounce&tr=udp%3A%2F%2Fexplodie.org%3A6969%2Fannounce&tr=udp%3A%2F%2F9.rarbg.com%3A2710%2Fannounce&tr=udp%3A%2F%2Fp4p.arenabg.com%3A1337%2Fannounce&tr=http%3A%2F%2Fp4p.arenabg.com%3A1337%2Fannounce&tr=udp%3A%2F%2Ftracker.aletorrenty.pl%3A2710%2Fannounce&tr=http%3A%2F%2Ftracker.aletorrenty.pl%3A2710%2Fannounce&tr=http%3A%2F%2Ftracker1.wasabii.com.tw%3A6969%2Fannounce&tr=http%3A%2F%2Ftracker.baravik.org%3A6970%2Fannounce&tr=http%3A%2F%2Ftracker.tfile.me%2Fannounce&tr=udp%3A%2F%2Ftorrent.gresille.org%3A80%2Fannounce&tr=http%3A%2F%2Ftorrent.gresille.org%2Fannounce&tr=udp%3A%2F%2Ftracker.yoshi210.com%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.tiny-vps.com%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.filetracker.pl%3A8089%2Fannounce)
+ <i class="fa fa-magnet" aria-hidden="true" title="This is a magnet link. Use a torrent client to download the file."></i> - [New 3DS or Old 3DS or 2DS 2.1.0 - JPN - CTRTransfer](magnet:?xt=urn:btih:3dbb9c9c85a33c6242f424dcbaebcacdd8a5912b&dn=2.1.0-4J%5FCTRTransfer%5Fo3ds.zip&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.opentrackr.org%3A1337%2Fannounce&tr=http%3A%2F%2Ftracker.opentrackr.org%3A1337%2Fannounce&tr=udp%3A%2F%2Fzer0day.ch%3A1337%2Fannounce&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969%2Fannounce&tr=http%3A%2F%2Fexplodie.org%3A6969%2Fannounce&tr=udp%3A%2F%2Fexplodie.org%3A6969%2Fannounce&tr=udp%3A%2F%2F9.rarbg.com%3A2710%2Fannounce&tr=udp%3A%2F%2Fp4p.arenabg.com%3A1337%2Fannounce&tr=http%3A%2F%2Fp4p.arenabg.com%3A1337%2Fannounce&tr=udp%3A%2F%2Ftracker.aletorrenty.pl%3A2710%2Fannounce&tr=http%3A%2F%2Ftracker.aletorrenty.pl%3A2710%2Fannounce&tr=http%3A%2F%2Ftracker1.wasabii.com.tw%3A6969%2Fannounce&tr=http%3A%2F%2Ftracker.baravik.org%3A6970%2Fannounce&tr=http%3A%2F%2Ftracker.tfile.me%2Fannounce&tr=udp%3A%2F%2Ftorrent.gresille.org%3A80%2Fannounce&tr=http%3A%2F%2Ftorrent.gresille.org%2Fannounce&tr=udp%3A%2F%2Ftracker.yoshi210.com%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.tiny-vps.com%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.filetracker.pl%3A8089%2Fannounce)
+ <i class="fa fa-magnet" aria-hidden="true" title="This is a magnet link. Use a torrent client to download the file."></i> - [New 3DS or Old 3DS or 2DS 2.1.0 - USA - CTRTransfer](magnet:?xt=urn:btih:1609ce9ee7b0ed9b6dea0b3e7cca4fc52dad6ff4&dn=2.1.0-4U%5FCTRTransfer%5Fo3ds.zip&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.opentrackr.org%3A1337%2Fannounce&tr=http%3A%2F%2Ftracker.opentrackr.org%3A1337%2Fannounce&tr=udp%3A%2F%2Fzer0day.ch%3A1337%2Fannounce&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969%2Fannounce&tr=http%3A%2F%2Fexplodie.org%3A6969%2Fannounce&tr=udp%3A%2F%2Fexplodie.org%3A6969%2Fannounce&tr=udp%3A%2F%2F9.rarbg.com%3A2710%2Fannounce&tr=udp%3A%2F%2Fp4p.arenabg.com%3A1337%2Fannounce&tr=http%3A%2F%2Fp4p.arenabg.com%3A1337%2Fannounce&tr=udp%3A%2F%2Ftracker.aletorrenty.pl%3A2710%2Fannounce&tr=http%3A%2F%2Ftracker.aletorrenty.pl%3A2710%2Fannounce&tr=http%3A%2F%2Ftracker1.wasabii.com.tw%3A6969%2Fannounce&tr=http%3A%2F%2Ftracker.baravik.org%3A6970%2Fannounce&tr=http%3A%2F%2Ftracker.tfile.me%2Fannounce&tr=udp%3A%2F%2Ftorrent.gresille.org%3A80%2Fannounce&tr=http%3A%2F%2Ftorrent.gresille.org%2Fannounce&tr=udp%3A%2F%2Ftracker.yoshi210.com%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.tiny-vps.com%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.filetracker.pl%3A8089%2Fannounce)
#### Instructions
##### Section I - Prep Work
1. Remove your SD card from your device, leaving it on the Homebrew Launcher, then insert your SD card into your computer
1. Create a folder named `CTRTransfer` on the root of your SD card if it does not already exist
1. Copy the 2.1.0 `.bin` and `.bin.sha` from the CTRTransfer `.zip` to the `/CTRTransfer/` folder on your SD card
1. Copy `safehax.3dsx` to the `/3ds/` folder on your SD card
+ If it freezes, just force the console to power off by holding the power button, then try again
1. If the exploit was successful, you will have booted into SafeCTRTransfer
##### Section III - CTRTransfer
1. Allow the SafeCTRTransfer initialization and safety checks to proceed automatically
+ If you get an error, ensure you have all files in the correct locations and that you have enough free space on your SD card as detailed in [Get Started](get-started)
1. When prompted, input the key combo given to confirm CTRTransfer to 2.1.0
+ This process will take some time
+ This process will automatically create a backup of your device's NAND at `/ctrtransfer/<serialnumber>_nand.bin`
+ If you get a critical error, [follow this troubleshooting guide](troubleshooting#ts_transfer)
1. Once this process has completed, remove your SD card from your device to reboot
+ The reboot will take about 2 seconds to trigger
+ While on 2.1.0, your device will black screen on boot if your SD card is inserted before the home menu loads
+ Every time your device is rebooted on 2.1.0, you will need to take out your SD card before boot and put it back in after the home menu loads
+ For now, leave your SD card out as you will be copying files to it in the next page
+ This will be fixed once you restore your device in the next page
___
*(Screen distortions or discolorations are normal for some devices while on 2.1.0, they will go away once you restore your backup)*
{: .notice--info}
{% capture notice %}
**Putting a New 3DS on 2.1.0 in sleep mode is known to cause an UNRECOVERABLE brick!**
**This only happens when shutting the lid _while your device is on_; this does not apply to turning your device off.**
**Your device only enters sleep mode when the lid is closed. It is not on a timer or anything like that.**
**Once on 2.1.0, you should continue without delay to avoid any possibility of this happening!**
