[**Homebrew**](https://wikipedia.org/wiki/List_of_homebrew_video_games) usually refers to software that is not authorized by Nintendo. This includes homebrew tools, applications, games, and emulators.
In many cases, running homebrew on your device is 100% free using just the Nintendo 3DS Sound app. There are also various other exploits in commercial games and the browser to get homebrew running.
firmware to boot9strap powered Custom Firmware. 一部のバージョンではHomebrewを利用していますが、最終的にはカスタムファームウェアを導入します。
boot9strap is the newest and best method of launching Custom Firmware that gives us nearly full control of the system only milliseconds into boot, which is similar to the effect of BootMii for the Wii. It gives us even earlier control than arm9loaderhax did, and, unlike standard sighax, boot9strap uses an NDMA overwrite exploit in order to gain Boot9 code execution. This means that any console running boot9strap is capable of dumping the console unique OTP (`OTP.bin`), the ARM11 bootrom (`boot11.bin`), and the ARM9 bootrom (`boot9.bin`).
The benefits of boot9strap over other Custom Firmware launch methods are numerous, and as such it is recommended to use this guide over any other that relies on outdated software (such as menuhax + rxTools, arm9loaderhax, or even normal sighax).
+ If you have already hacked your 3DS before to get an EmuNAND setup, and would like to move the contents of your previous EmuNAND to your new SysNAND CFW, you should follow all instructions and restore your existing EmuNAND when prompted once you reach [Finalizing Setup](finalizing-setup).
+ If you need to format a brand new SD card, you can use [guiformat](http://www.ridgecrop.demon.co.uk/index.htm?guiformat.htm) and set to an Allocation Unit Size of 32K (32768).
+ The Old 2DS is essentially identical to the Old 3DS in terms of software, while the New 2DS is essentially identical to the New 3DS in terms of software. Any steps which say "Old 3DS" also apply to Old 2DS, and any steps which say "New 3DS" also apply to New 2DS.