Installing boot9strap (kartdlphax)


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Required Reading

kartdlphax is an exploit for the Download Play mode of Mario Kart 7. It can be used with universal-otherapp to install custom firmware on target devices.

In order to follow these instructions, you will need the following:

  • A second 3DS with custom firmware (the source 3DS) that is the same region as the 3DS you are trying to modify (the target 3DS)
  • A physical or digital copy of Mario Kart 7 that is the same region as both consoles
  • An SD card for both devices

What You Need

On the source 3DS (the 3DS with custom firmware):

On the target 3DS (the 3DS that you are trying to modify):

Section I - Prep Work (source 3DS)

  1. Insert the SD card of your source 3DS in your computer
  2. Copy Luma 3GX Loader Edition’s boot.firm to the root of the source 3DS’s SD card
  3. Copy kartdlphax’s plugin.3gx to the following directory on the source 3DS’s SD card, depending on the region of your copy of Mario Kart 7:
    • USA: luma/plugins/0004000000030800
    • EUR: luma/plugins/0004000000030700
    • JPN: luma/plugins/0004000000030600
    • Create the plugins and 00040000... folders if they do not already exist
  4. Eject the SD card and put it in the source 3DS

Section II - Prep Work (target 3DS)

  1. Insert the SD card of your target 3DS in your computer
  2. Copy boot.firm and boot.3dsx from the standard Luma3DS .zip to the root of your SD card
  3. Create a folder named boot9strap on the root of your SD card
  4. Copy boot9strap.firm and boot9strap.firm.sha from the boot9strap .zip to the /boot9strap/ folder on your SD card
  5. Copy SafeB9SInstaller.bin from the SafeB9SInstaller .zip to the root of your SD card
  6. Eject the SD card and put it in the target 3DS

Section III - kartdlphax

  1. Power on the source 3DS
    • If you are prompted to set up Luma3DS, just press START to save the configuration
  2. Once in the home menu, press (Left Shoulder) + (Down D-Pad) + (Select) to bring up the Rosalina menu
  3. Select “Enable plugin loader”
  4. Press (B) to exit the Rosalina menu
  5. Launch Mario Kart 7
    • Ensure that wireless connectivity is enabled
    • kartdlphax should tell you that it is running
  6. Navigate to Local Multiplayer -> Create Group
  7. Power on the target 3DS
    • Ensure that wireless connectivity is enabled
  8. On the target 3DS, open the Download Play application (), then select “Nintendo 3DS”
  9. Join the group created by the source 3DS
  10. Select “Start” on the source 3DS once it has detected the target 3DS
  11. Once multiplayer has loaded, navigate to Grand Prix -> 50cc -> (any driver) -> Mushroom Cup
  12. Wait a while (a percentage should be displayed on the source 3DS)
  13. If the exploit was successful, the target 3DS will have booted into SafeB9SInstaller

Section IV - SafeB9SInstaller

  1. Wait for all checks to complete
  2. When prompted, input the key combo given on the top screen to install boot9strap
  3. Once it has completed, press (A) to reboot your device

Section V - Configuring Luma3DS

  1. Your target 3DS should have rebooted into the Luma3DS configuration menu
  2. Use the (A) button and the D-Pad to turn on the following:
    • “Show NAND or user string in System Settings”

At this point, your console will boot to Luma3DS by default as long as the SD card is inserted.

  • Luma3DS does not look any different from the normal HOME menu. If your console has booted into the HOME menu, it is running custom firmware.
  • On the next page, you will copy Luma3DS to internal memory so that you can boot without an SD card.
  • You will not need to use your source 3DS to complete any further steps on this guide.

Continue to Finalizing Setup