[**Homebrew**](https://en.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, runnin' homebrew on ye device be 100% free usin' jus' th' Nintendo 3DS Sound app. There also be various other exploits in commercial games 'n th' browser fer gettin' homebrew runnin'.
**Custom Firmware** ("CFW") enables ye to use more advanced hacks that userland homebrew can't easily do. Fer instance, signature patches let ye be installin' unsigned titles that appear right on ye HOME Menu.
boot9strap be th' newest 'n best method 'o launchin' Custom Firmware that gives us nearly full control 'o th' system only milliseconds into boot, which be similar to th' effect 'o BootMii fer th' Wii. It be givin' us even earlier control than arm9loaderhax did, 'n unlike standard sighax, boot9strap uses an NDMA overwrite exploit in order to be gainin' Boot9 code execution. 'Tis be meanin' that any console runnin' boot9strap be capable 'o dumpin' th' console unique OTP (`OTP.bin`), th' ARM11 bootrom (`boot11.bin`), 'n th' ARM9 bootrom (`boot9.bin`).
Th' benefits 'o boot9strap over other Custom Firmware launch methods be bountiful, 'n as such it be recommended to use 'tis guide over any other that be relyin' on outdated software (such as menuhax + rxTools, arm9loaderhax, or even normal sighax).
+ **Before beginnin' th' guide, ye must be knowin' th' risks 'o 3DS hackin': EVERY time ye be modifyin' ye system, there be always th' potential fer an UNRECOVERABLE brick. They be rare, but still a possibility so make sure ye follow ALL directions EXACTLY.**
+ If ye have already hacked ye 3DS before to get an EmuNAND setup, 'n would like to move th' contents 'o ye previous EmuNAND to ye new SysNAND CFW, ye should follow all instructions 'n be restorin' ye existin' EmuNAND when prompted once ye reach [Finalizin' Setup](finalizing-setup).
+ If everythin' goes accordin' to plan, ye gunna lose no data 'n be endin' up wit' everythin' that ye started wit' (games, NNID, saves, etc gunna be preserved).
+ Ye SD card should be [MBR, not GPT](http://www.howtogeek.com/245610/) (th' SD card that comes wit' ye device gunna be MBR by default). The easiest way to test this is to check if the SD card works in your 3DS. If it works, the SD card is MBR.
+ If you need to format a brand new SD card, you can use [guiformat](http://ridgecrop.co.uk/index.htm?guiformat.htm) and set to an Allocation Unit Size of 32K (32768). If your SD card is 64GB or larger, use an Allocation Unit Size of 64K (65536) instead.
+ 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.