Guide_3DS/_pages/vi_VN/installing-boot9strap-(safecerthax).txt

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title: "Installing boot9strap (safecerthax)"
---

{% include toc title="Table of Contents" %}

{% capture technical_info %}
<summary><em>Technical Details (optional)</em></summary>
For technical details on the exploit that you will be using on this page, see [here](https://github.com/MrNbaYoh/safecerthax).

{% endcapture %}
<details>{{ technical_info | markdownify }}</details>
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### Compatibility Notes

safecerthax is compatible with all Old 3DS and Old 2DS devices in all regions on system versions 1.0.0 through 11.14.0.

This exploit will not work on the New 3DS, New 3DS XL, or New 2DS XL. Please ensure that the device you are modding is an Old 3DS, Old 3DS XL, or Old 2DS before continuing.
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### What You Need

* The latest release of [SafeB9SInstaller](https://github.com/d0k3/SafeB9SInstaller/releases/download/v0.0.7/SafeB9SInstaller-20170605-122940.zip) (direct download)
* The latest release of [boot9strap](https://github.com/SciresM/boot9strap/releases/download/1.4/boot9strap-1.4.zip) (direct download)
* The latest release of [Luma3DS](https://github.com/LumaTeam/Luma3DS/releases/latest) (the Luma3DS .zip file)

### Instructions

#### Section I - Hardware Button Check

{% include_relative include/safemodecheck.txt %}

If the camera did NOT appear, you cannot follow this method. If this is the case, stay on your current firmware and ask [Nintendo Homebrew on Discord](https://discord.gg/MWxPgEp) for help.
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#### Section II - Prep Work

In this section, you will copy the files needed to trigger the safecerthax exploit.

1. Insert your SD card into your computer
1. Copy `boot.firm` and `boot.3dsx` from the Luma3DS `.zip` to the root of your SD card
  + The root of the SD card refers to the initial directory on your SD card where you can see the Nintendo 3DS folder, but are not inside of it
1. Create a folder named `boot9strap` on the root of your SD card
1. Copy `boot9strap.firm` and `boot9strap.firm.sha` from the boot9strap `.zip` to the `/boot9strap/` folder on your SD card
1. Copy `SafeB9SInstaller.bin` from the SafeB9SInstaller `.zip` to the root of your SD card
1. Reinsert your SD card into your device
1. Power on your device

#### Section III - safecerthax proxy

In this section, you will change your Internet connection settings to use a proxy network designed to exploit the System Update feature of your device.

{% include_relative include/addproxy.txt %}
1. Power off your device

#### Section IV - safecerthax

In this section, you will enter Safe Mode (a feature available on all 3DS family devices) where safecerthax will be triggered, which will launch you into the boot9strap (custom firmware) installer.

1. With your device still powered off, hold the following buttons: (Left Shoulder) + (Right Shoulder) + (D-Pad Up) + (A), and while holding these buttons together, power on your device
  + Keep holding the buttons until the device boots into Safe Mode (a "system update" menu)
1. Press "OK" to accept the update
  + There is no update. This is part of the exploit
1. Press "I accept" to accept the terms and conditions
1. The update will eventually fail, with the error code `003-1099`. This is intended behaviour
1. Press "OK" to close the error message
1. If the exploit was successful, you will have booted into SafeB9SInstaller
  + If the device freezes or crashes, force power off the device, then retry this section

#### Section V - Installing boot9strap

{% include_relative include/install-boot9strap-safeb9sinstaller.txt %}
{%- include_relative include/configure-luma3ds.txt %}

{% include_relative include/luma3ds-installed-note.txt %}

#### Section VI - Restoring default proxy

{% include_relative include/rmproxy.txt %}

___

### Continue to [Finalizing Setup](finalizing-setup)
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