NTON

NTON is a Nintendo Switch NRO to NSP Forwarder for firmware 12.0.0 and newer.

A forwarder lets you open Homebrew files from your SD card through the Nintendo Switch Home Screen instead of the Homebrew Launcher.

Features

⚙ Firmware 12.0.0+ Support
🛡️ Title ID Conflict Checks
🤖 Automatically Extracts Title Information and Icon from NRO
🕹️ Direct Game Forwarding
🎥 Enable or Disable Video Capture and Screenshots
💾 1MB NSP Install Size
🖼️ Custom Icons
🧩 Plug-and-play
✨ GUI and CLI Interfaces
❤️ Forever FOSS!

Installation

Windows Installers for the GUI version is available on the Releases page.

Alternatively you can download and install NTON from PIP/PyPI:

$ pip install nton[gui]

(Exclude [gui] if you do not plan on using the GUI)

Note If pip gives you a warning about a path not being in your PATH environment variable then promptly add that path then close all open command prompt Windows, or running nton won't work as it will not be recognized as a program.

You now have the nton package installed - Voilà 🎉!
Launch the GUI by running nton without another subcommand in your Terminal or Windows Run.
Otherwise, use the CLI by checking out nton --help.

Keys

Proprietary Keys known as prod.keys are required. You can obtain them from your own personal Switch using Lockpick_RCM.

It must be placed at C:\Users\<User>\.switch\prod.keys, in your current working directory, or in NTON's installation directory for NTON to be able to find and use the keys.

Usage

NTON is quite simple, just give it the path to the NRO on your microSD card!

For example, to create a forwarder for the Daybreak Homebrew included with Atmosphere, it's as simple as:

nton build "D:/switch/daybreak.nro"

This will build a forwarder with the Title Name, Publisher, Version, and Icon automatically extracted from the NRO. The Title ID will be a randomly assigned value within generally conformed bounds. You may manually set a value with --name, --publisher, --version, --icon, and --id respectively.

The Title ID is automatically checked against a periodically updated list of pre-existing System and Software Title IDs to ensure a collision does not occur. However, you should still be cautious and verify the Title ID is not already used by other Software before using.

Note
While NTON can be used on NRO files stored on your PC, it was designed to be used directly from your Switch's microSD card. If you prefer to create forwarders with NRO files on your PC, or for batch purposes, you can specify the path that the NRO file will reside on your microSD card during generation with --sdmc.

For example, to make a forwarder for an NRO that is on your PC:

nton build "C:/Users/rlaphoenix/Downloads/haze.nro" --sdmc "/switch/haze.nro"

Direct RetroArch Game forwarding

Use a RetroArch Game Core as the NRO path and provide the path to the ROM on your Switch's microSD card with --rom.
This will then load the Core directly under RetroArch and provide the path to the ROM as a startup argument to the RetroArch Core.

Note

You must use a path to a RetroArch Game Core NRO, not the path to the RetroArch NRO itself.

Do not move, delete, or rename the ROM or the Core NRO files that are on your microSD card, or it will break.

Storage Sizes

On Installation an NSP can allocate storage for specific purposes. There's three primary types of Storage:

User Account Save Data: Storage allocated to each User profile. Most titles use this to save game progress.
Device Save Data: Storage allocated to the Device itself. Typically used for data or information that should be set to and used by all User profiles. For example, Animal Crossing: New Horizons uses this to store the Island data for all profiles to use.
Cache Storage: Storage allocated for temporary data. Data stored here will be wiped without warning.

The NSP can specify how much data to allocate initially, as well as the maximum amount of storage that data can occupy over time. Furthermore, the initial and maximimum size allocated for Journaling (a form of recovery and data integrity) can also be specified.

A Forwarder like the ROM NTON uses does not need any form of storage or save data. Therefore, NTON automatically sets all storage sizes to 0 to reduce storage usage.

Troubleshooting

Before continuing try running the homebrew from the Homebrew Launcher and see if it works through there. If it does not work through the Homebrew launcher either, then it was never the forwarder's fault, and you should check on your NRO or application installation.

Please note that using Forwarders others have created has a good chance of not working on your system. The location of the NRO on their system may differ from the location on your system, hence the NSP won't be able to load the homebrew. I will not provide support if you are having an issue with a Forwarder you did not build yourself.

The forwarder does not launch, "The software was closed because an error occurred."

Your "sigpatches" (signature patches) that allow unsigned titles to launch is likely outdated or not set up correctly. Sigpatches can go outdated from Horizon OS firmware updates, Atmosphere updates (as well as silent updates). It is recommended to use the sys-patch sys-module to automatically patch your system from signature checks as well as other useful patches. The default configuration is fine for the majority of systems and is a simple copy & paste to your microSD card to install.

It's also possible the prod.keys you used with NTON is outdated for your firmware. Get new ones with Lockpick_RCM and make sure you choose to get keys from the SysMMC or EmuMMC that you will be installing the forwarder on (or whichever has a newer firmware version).

The forwarder starts loading but then crashes

The NRO path set when building the forwarder is incorrect or the NRO file is currently missing (or your microSD card is not inserted). Make sure the path you choose starts with / and is an absolute path to an existing NRO file on your Switch's microSD card (not your PC).

The forwarder's icon is a '?'

This happens when the icon_AmericanEnglish.dat within the built forwarder is not to the spec that Nintendo likes, in some way. This is usually caused by the format of the image not being JPEG, or it has EXIF data or other unnecessary extra metadata.

Note
This is considered a bug if it happens to you after using NTON as it should automatically sanitize the images when building the forwarder. If this happens to you, please report what image you chose to use, or give information on what exact NRO you were making a forwarder from.

The forwarder's icon is a loading circle, opening fails

The installation of the Forwarder NSP failed in some way and the result is a corrupt title under that Title ID. This may have happened when trying to install data to the Title ID you chose or had randomly assigned to your forwarder NSP on an unsupported firmware version. This also happens when trying to install DLC to a Title without having the minimum required Game Update for that DLC (i.e. Installing the DLC Courses while on Mario Kart 8 Deluxe v1.0). However, since this happened on your Forwarder NSP you can likely rule that out.

When this happens deleting and reinstalling the same NSP likely won't fix it or do anything. You may need to reinstall the NSP via Goldleaf and hit "Proceed" when it warns yo uthat the title is already installed. Goldleaf will deal with the pre-existing files properly unlike Tinfoil (where you likely had the corruption in the first place). DBI may also help you resolve this issue as it has tools to remove partial installs and leftover files.

The forwarder randomly stopped working, I've read everything so far

You most likely updated Atmosphere or Horizon OS's Firmware and need to update your Sigpatches. If that hasn't fixed it, make sure you haven't deleted or moved the NRO on your Switch's microSD card. It cannot be moved as the built forwarder has a hardcoded file path that it loads the NRO from when launched.

If it still does not work, it's possible a firmware update has broken the forwarder ROM that is used and needs to be updated. Both Firmware 9.0.0 and 12.0.0 have previously broken different forwarder ROMs requiring updates. If you believe this to be the case then please make an Issue.

Development

The following steps are basic instructions on downloading and working on the code under a Poetry environment.

Follow Poetry's Docs to Install Poetry.
Download NTON's latest code, git clone https://github.com/rlaphoenix/nton
Navigate to the downloaded code repository, cd nton
Optionally have Poetry install the virtual-env in the project, poetry config virtualenvs.in-project true
Install NTON's dependencies and development tools, poetry install -E gui
Run NTON from within the Poetry venv, poetry run nton --help

Note If you plan to work on or use the GUI during development, then add -E gui during Step 5.

As shown, running the nton executable is somewhat different to a normal installation. This is because Poetry installs all dependencies and the nton shim itself within a virtual-environment, which is like a clone of your Python install stripped clean, with only NTON's dependencies installed. That way you don't mess around with any dependencies from any other installed Python applications, nor the other way around. A secluded environment.

I recommend taking a look at Poetry's Docs for further information, why not get started by reading Poetry's guide on Using Your Virtual Environment.

Credit

meliodas2255 for their Open-Source forwarder ROM supporting v12.0.0+ with both direct RetroArch Forwarding and general forwarding both supported.
vgmoose for the sdl-hello-world NRO that is used in CI/CD testing.

Licensing

This software is licensed under the terms of GNU General Public License, Version 3.0. You can find a copy of the license in the LICENSE file in the root folder

This project uses the following software:

hacBrewPack licensed under GPL-v2 for packing the NSP: https://github.com/The-4n/hacBrewPack
nstool licensed under MIT for NRO extraction and verification: https://github.com/jakcron/nstool
hptnacp from hacPack licensed under GPL-v2 for creating new NACP partitions if the NRO did not have one: https://github.com/The-4n/hacPack/tree/master/hacPack-Tools/hacPackTools-NACP

No changes were made to any of the aforementioned software and copies of their licenses can be found next to their binaries within the bin folder.

Verdgil/nton-posix