Installing boot9strap (MSET9)

---

For support in English, ask for help at Nintendo Homebrew on Discord.

If you appreciate this guide, we accept Donations.

---

Technical Details (optional)

MSET9 is an exploit for the System Settings application developed by zoogie. It exploits a flaw where the ID1 (the second 32-character folder name inside of the Nintendo 3DS folder, inside of the ID0) can be any name as long as it is 32 characters. Performing a specific sequence of actions results in the console executing the instructions that are encoded into the ID1 folder name, which can be used to grant full control over the 3DS.

Compatibility Notes

This method requires a computer running Windows, Linux, or macOS. Phones or tablets are NOT currently supported. If you do not have access to a computer, you will need to use an alternate exploit.

What You Need

• The latest release of MSET9 (the Release .zip file)
• Any 3.x version of Python installed on your computer
  • If you are on Linux or macOS, you may already have Python 3. Check by opening a Terminal window and entering python3 -V. If this returns a version number, it will work for this guide.

Instructions

On this page, you will use the MSET9 script, which is used to trigger MSET9. If you get a numbered error (e.g. Error 01) when running the script, the solution to that error can most likely be found on the troubleshooting page.

Section I - Prep Work

In this section, you will prepare the SD card data necessary for the MSET9 exploit to trigger.

1. Power on your console with your SD card inserted
2. Open Mii Maker
3. Wait for your console to reach the “Welcome to Mii Maker” screen, then exit Mii Maker
   • You may see this screen, which indicates the necessary data has been created
   • If you just reach the normal Mii Maker screen, exit Mii Maker and continue to the next step
4. Power off your console
5. Insert your SD card into your computer

6. Copy everything from the Release .zip to the root of your SD card, overwriting any existing files

   

7. Run the MSET9 script:
   • Windows: Double-click mset9.bat
   • macOS: Double-click mset9.command and enter your password if prompted
   • Linux: open a Terminal window, cd to the root of your SD card, then type python3 mset9.py and press Enter

   

8. Type the number corresponding to your console model and version, then press Enter
   • The window should change to this:

   

   • Ensure that the correct console model and version is displayed
9. Type 1, then press Enter to ensure your console is prepared for MSET9
   • If you get an error, check the troubleshooting, then try again
10. If you see the message “Everything appears to be functional!”, MSET9 is ready to be injected. Press Enter to close the MSET9 script
11. Reinsert your SD card into your console
12. Power on your console

Section II - MSET9

In this section, you will trigger MSET9 to launch SafeB9SInstaller (the custom firmware installer).

These instructions must be followed EXACTLY, so double-check EVERYTHING you are doing to avoid errors!

1. Hover over the System Settings icon using the D-Pad (do not select it yet)
2. Power off, then power on your console
3. Press (A) to launch System Settings
4. Navigate to Data Management -> Nintendo 3DS -> Extra Data (image)
5. Do not press any buttons or touch the screen - ensure that you see the Mii Maker icon
6. With the console STILL ON, and without pressing any buttons or touching the screen, remove your SD card from your console
   • The menu will refresh and say that no SD card is inserted, which is expected
7. Insert your SD card into your computer
8. Run the MSET9 script:
   • Windows: Double-click mset9.bat
   • macOS: Double-click mset9.command and enter your password if prompted
   • Linux: open a Terminal window, cd to the root of your SD card, then type python3 mset9.py and press Enter
9. Type the number corresponding to your console model and version, then press Enter
10. In the MSET9 window, type 2, then press Enter to inject MSET9
    • You should see “MSET9 successfully injected!”
11. Press Enter to close the MSET9 script
12. Reinsert your SD card into your console without pressing any buttons or touching the screen
13. If the exploit was successful, you will have booted into SafeB9SInstaller
    • If you get a red screen or the console gets stuck on a loading screen, follow the troubleshooting guide

Section III - Installing boot9strap

In this section, you will install custom firmware onto your console.

1. When prompted, input the key combo given on the top screen to install boot9strap
   • If a step on the lower screen has red-colored text, and you are not prompted to input a key combo, follow this troubleshooting guide
2. Once it is complete, press (A) to reboot your console
3. Your console should have booted into the Luma3DS configuration menu
   • Luma3DS configuration menu are settings for the Luma3DS custom firmware. Many of these settings may be useful for customization or debugging
   • For the purpose of this guide, leave these options on the default settings (do not check or uncheck anything)
   • If your console shuts down when you try to power it on, ensure that you have copied boot.firm from the Luma3DS .zip to the root of your SD card
4. Press (Start) to save and reboot

Section IV - Removing MSET9

In this section, you will remove MSET9 to prevent further issues. (This will not remove the custom firmware that you just installed.)

Do NOT skip this section! If you skip it, applications may crash unexpectedly and you will encounter errors on the next page!

1. Power off your console
2. Insert your SD card into your computer
3. Run the MSET9 script:
   • Windows: Double-click mset9.bat
   • macOS: Double-click mset9.command and enter your password if prompted
   • Linux: open a Terminal window, cd to the root of your SD card, then type python3 mset9.py and press Enter
4. Type the number corresponding to your console model and version, then press Enter
5. In the MSET9 window, type 3, then press Enter to remove MSET9
   • You should see “Successfully removed MSET9!”
6. Press Enter to close the MSET9 script

At this point, your console will boot to Luma3DS by default.

• 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 install useful homebrew applications to complete your setup.

---

Did you follow Section IV (Removing MSET9)? That section is MANDATORY!

Continue to Finalizing Setup