OpenFirmInstaller 3DS

From GameBrew

Last Updated2019/04/06
TypeSystem Tools

OpenFirmInstaller is a safe, simple and user-friendly installer for sighax bootloaders.

It is based on SafeB9SInstaller and works the same way as that. All input files go into sdmc:/ofi. At the present time, only boot9strap and fastboot3DS are supported as input files.


Building this requires firmtool, Python 3.5+ and devkitARM. To compile the CakesROP entrypoint you also need xxd from the vim package installed (install it via pacman -S vim).

User guide

For this, we are assuming you already have boot9strap and CFW installed, your 3DS is in working order and you want to switch to fastboot3DS.

  • Create a folder called ofi on your 3DS SD card.
  • Download fastboot3DS and copy fastboot3ds.firm from the ZIP file to ofi/fastboot3ds.firm on your SD card.
  • [optional] Get GodMode9 and copy GodMode9.firm to gm9/payloads/GodMode9.firm on your SD card. For Luma3DS user, move GodMode9.firm from luma/payloads/GodMode9.firm to gm9/payloads/GodMode9.firm.
  • Copy OpenFirmInstaller.firm to your SD card. For Luma3DS user, the file goes to luma/payloads/OpenFirmInstaller.firm.
  • Run OpenFirmInstaller.firm from your SD card. For Luma3DS user, thats as simple as holding Start when booting the console and selecting OpenFirmInstaller.firm when (if) prompted. You may also run OpenFirmInstaller.firm from GodMode9 (press A > FIRM options... > Boot FIRM).
  • Follow the on screen instructions. When you're asked to input a key sequence to confirm, input the key sequence.
  • Done, now fastboot3DS is your bootloader. Further configuration is not required. Your CFW is autobooted as you are used to, and - if you installed it - GodMode9 is booted when you hold Start after turning on your console.

OpenFirmInstaller can also work from A9LH systems (you also need to provide secret_sector.bin then), from unhacked systems on earlier OS versions and via ntrboot cards. Refer to the usual instructions for these special cases. fastboot3DS is highly customizable, you can set boot from CTRNAND, add more payloads via key combos, change splashes (but you absolutely don't have to!). You may enter the fastboot3DS menu by holding Home when booting.



  • This new release greatly simplifies fastboot3DS setup even for novice users. If you had problems with GodMode9 v1.8.0 and Luma 9.1, or if you're just curious, it is suggested you use this release to switch to fastboot3DS now.


  • First public release of OpenFirmInstaller - thanks everyone who helped make this possible.


  • Normmatt, for sdmmc.c/sdmmc.h.
  • Cha(N), Kane49, and all other FatFS contributors for FatFS.
  • Myria for the sighax bruteforcer and for finding the sighax (retail&dev) signature.
  • SciresM for dumping boot9, creating boot9strap.firm and for being the first fearless person to test this.
  • hedgeberg for her tireless efforts in dumping the bootrom.
  • TuxSH for FIRM research and useful hints.
  • Plailect for providing the guide and making SafeB9SInstaller accessible to the common user.
  • stuckpixel for his tireless behind-the-scenes work.
  • Gelex for being of great help on countless occasions.
  • profi200 and derrek for enabling compatibility with fastboot3DS.
  • The fine folks on freenode #Cakey.
  • All editors.
  • Everyone who helped test this, especially Al3x_10m, Wolfvak, Shadowhand, Lilith Valentine and Crimson.

External links