What is PortMaster

 Why did I research PortMaster?

It's an app on a lot of retro game consoles. I want my games to be on the retro games console market.

PortMaster on the Anbernic RG35XX: A Comprehensive Guide

What Is PortMaster and How Does It Work on the RG35XX?

PortMaster is a management tool for Linux-based retro handhelds that makes it easy to install and play dozens of classic and homebrew games (“ports”) on devices like the Anbernic RG35XX. In essence, PortMaster provides a menu on your device where you can browse a library of game ports, download and install them with a button press, and then launch them directlyretrogamecorps.com. These are native ports of games (often open-source reimplementations or fan-made versions), meaning they run on the RG35XX’s hardware without emulation retrogamecorps.com. This allows the RG35XX to play PC games (and engine reimplementations) that have been optimized for its ARM-based system.

On the RG35XX, PortMaster runs as a standalone application (usually found in the “Ports” section of your device’s menu once installed). It integrates with the device’s firmware to add the new games to your game list. For example, after you install a game via PortMaster, it will appear under the Ports category of EmulationStation or the device’s frontend, so you can launch it like any other game. PortMaster requires an active internet connection (e.g. via Wi-Fi or Ethernet dongle, since the original RG35XX doesn’t have built-in Wi-Fi) to fetch the list of games and download them. Once a game is installed, you typically don’t need internet to play it, except to update or install more ports. (If your RG35XX firmware supports Wi-Fi dongles or you have the RG35XX variants with Wi-Fi, you can connect online; otherwise, you can still use PortMaster by manually transferring files—more on that later.)

Supported Firmware/OS: PortMaster started as part of the ArkOS custom firmware, but today it is platform-independent and works on many RG35XX firmware options. Custom firmware like GarlicOS, KUMI/Unofficial OS, Knulli, muOS, and others have added support for PortMaster. In some cases (e.g. Knulli or muOS), an installer for PortMaster is included by default in the “Ports” menu knulli.org. On other OSes you may need to install it yourself (see the installation section below). As of mid-2024, PortMaster support was extended to newer RG35XX models (Plus, “2024” H version, SP) and it’s continually being improved. The key point is that as long as you’re running a Linux-based firmware on the RG35XX, you can likely use PortMaster to expand your game library.

How PortMaster works on RG35XX: After launching PortMaster on the RG35XX, the app will update its game list and present you with categories (Featured, All Ports, Ready to Run, etc.) on the device’s screen. You navigate these with the d-pad and buttons. When you select a game to install, PortMaster will download all the necessary files (the game’s executable, assets, and any special runtime libraries required) onto your SD card. If the game is a “Ready to Run” free game, everything needed is downloaded and it will be installed ready to play. If the game is a “Files Needed” port (meaning the engine is free but requires original game data files), PortMaster will download the open-source engine and then prompt you to add the extra files (e.g. copy your .wad, .pak, or other data from a game you own) into the newly created game folder. In either case, PortMaster sets up the game’s folder and launch script on the device automatically. Once installed, you can launch the game either through PortMaster’s Manage Ports menu or directly from the RG35XX’s main menu under Ports.

Under the hood, PortMaster uses a backend script system (codename HarbourMaster) that handles downloading, unzipping, and organizing the game files on the SD card . It ensures each port is placed in its own directory (usually under the /roms/ports/ folder on your SD card) along with a launch script and metadata so that EmulationStation can list it. PortMaster is smart enough to filter the game list to show only titles that are compatible with your device’s hardware. For example, the RG35XX (which has an ARM32 or ARM64 processor and no 3D GPU drivers) will only see the ports that have been confirmed to run on it. This way, you won’t be cluttered with options that only work on more powerful handhelds. In short, on an RG35XX the PortMaster app acts as a one-stop “app store” for retro game ports, tailored to what the device can handle.

Packaging Ports for PortMaster

Ports are now contained within the port top level directory, each port has its own sub-directory named after the port itself. Each port must adhere to the portname rules stated above. Each port must have a port.json , screenshot.{jpg,png} , README.md , gameinfo.xml , a port script and a port directory. It may optionally include a cover.{jpg,png} .

The script should have capital letters (like Port Name.sh ) and must end in .sh , the port directory should be the same as the containing directory. Some legacy ports have different names, new ports won't be accepted unless they follow the new convention.

Scripts and port directories must be unique across the whole project, checks will be run to ensure this is right.

Learn more here: https://portmaster.games/packaging.html

Game Library: How PortMaster Finds and Organizes Games

PortMaster’s library is community-curated and ever-growing. As of 2024, there are roughly 500 games available in the PortMaster catalog, contributed by community developers and porting enthusiasts. The PortMaster team doesn’t automatically scrape random websites for games; instead, each game (or “port”) is added intentionally through open-source projects or with permission from the original developers. The library includes classic PC games (using open-source engine recreations for titles like Doom, Quake, etc.), freeware and open-source indie games, fan-made games, and even some modern indie titles that have source code available or special ARM builds. New ports are added frequently, often in response to community suggestions or developer contributions. (There is an official PortMaster suggestion portal and an active Discord server where users can request or help test new game ports.) The PortMaster maintainers also reach out to indie developers for permission to include their games when necessary – a lot of coordination happens behind the scenes to expand the library. For example, many itch.io indie games built in engines like Godot or GameMaker have been added after obtaining the developer’s green light. This means the collection is both legally and technically vetted.

Game organization in PortMaster: When you open PortMaster on the RG35XX, you’ll see the games organized into a few main categories for easy browsing:

• Featured Ports: A selection of highlighted or recommended games chosen by the PortMaster team (e.g. popular titles or new additions)knulli.org.

• All Ports: The full list of available ports that are compatible with your device. PortMaster auto-filters out games that wouldn’t run on an RG35XX, so “All Ports” really means “all supported games for your RG35XX” knulli.orgknulli.org. You can scroll through this master list or search within it.

• Ready to Run: This subsection lists only the games that are completely free and open-source – those that can be installed and played immediately with no additional files required. These include countless freeware games and open-source classics. If you’re just starting, this is a great place to find games that work out-of-the-box.

• Ports with Files Needed: (Often just shown as part of “All Ports” with a tag or in a separate filter). These are ports of commercial games where the engine is provided but you must supply your own game data to play. PortMaster will still install the port itself for you, but you’ll need to copy the original game files (such as game resource files from your Steam/GOG installation) into the port’s folder before you can launch it. PortMaster usually provides a README or on-screen prompt telling you exactly which files are required and where to put them.

• Manage Ports: This section allows you to view ports you’ve already installed on your RG35XX and manage them – you can update a port (if a new version of the engine or fixes come out), reinstall or uninstall it, etc.. For example, if a game isn’t working, you can try reinstalling it here or check for updates. Uninstalling via PortMaster will remove the game’s files from your SD card to free space.

Behind the scenes, each port in the library is defined by a metadata file (a port.json) maintained by the PortMaster team portmaster.games. This file includes information like the game’s name, description, genre, the download links for its files, compatibility flags, etc. The PortMaster app periodically updates its list by downloading an index of these JSON entries from the official repository (so you get new game listings without having to reinstall the app). The HarbourMaster backend also supports multiple repositories, meaning the community could add additional sources, but by default you’re using the official PortMaster repository. The compatibility filtering uses tags in those metadata files to ensure, for example, that a game requiring a 64-bit OS or more RAM won’t show up on a 32-bit RG35XX. When you choose a game to install, PortMaster downloads a pre-packaged zip for that port (which contains the game’s executable, libraries, and any free data files) and unzips it to your SD card. If the game needs external files, it will create the folder and then prompt you to add the files yourself thereafter.

It’s worth noting that PortMaster’s library is maintained by volunteers and developers who test these ports on various devices. The official PortMaster website and Discord are the hubs for this effort If a particular game isn’t in the list yet, it might be in testing or awaiting permission, or you can suggest it. The community aspect is strong – enthusiasts contribute by packaging games, and the PortMaster app is updated to include them after vetting. There’s even a Featured Ports rotation which highlights some community favorites. In summary, PortMaster finds its games via community submissions and porting projects (not by scraping random ROM sites or anything sketchy) and organizes them in an intuitive menu by category, with clear indicators for which games require extra files versus those you can play immediately.

Downloading and Installing PortMaster on the RG35XX

Installing PortMaster on your RG35XX is straightforward, and there are a couple of scenarios:

• If your firmware already includes a PortMaster installer: Some custom firmwares (like Knulli or newer versions of muOS) include a script called “Install PortMaster” in the Ports section by default. In that case, you can simply select that on your device. The script will automatically download and set up the latest PortMaster release for you. After it finishes, your device’s frontend will restart and you’ll see PortMaster available in the Ports menu, replacing the installer script. From there, you can launch PortMaster and start installing games.

• Manual installation via script: If your RG35XX’s OS doesn’t already have PortMaster, you can add it yourself easily. The official PortMaster site provides an installer script. Here’s how to do it:

  1. Download the installer: Go to the official PortMaster GitHub and download the file Install.PortMaster.sh (or the “Full” version with all runtimes, Install.Full.PortMaster.sh). These scripts are tiny and just contain instructions to grab the necessary files. (Tip: The official PortMaster websiteretrogamecorps.com has a download link that points to the GitHub releases for the latest version.)

  2. Copy the script to your SD card: Place this Install.PortMaster.sh file into the “ports” folder used by your firmware. For GarlicOS, ArkOS, and many others, this path is typically /roms/ports/ on the SD card. (If you use muOS, the path is mnt/mmc/ROMS/Ports/; on Knulli, it’s /userdata/roms/ports; see the official docs table for different firmwares.) Essentially, put the script where your device looks for standalone game ports.

  3. Run the installer on the device: Safely eject the SD card and put it back in your RG35XX. Boot up and find the “Install PortMaster” entry under Ports. Launch it like you would launch a game or app. You’ll see some text on screen as it installs. After it completes, it may reboot or restart the interface. Once done, you should now see PortMaster in your Ports menu.

If for some reason the installer script doesn’t show up on your device’s menu, ensure it’s named correctly (Install.PortMaster.sh) and placed in the correct folder. On some systems you might need to refresh the game list (for example, press Start > Game Settings > Update Gamelists in EmulationStation) to see new ports. If it still doesn’t appear, you can manually invoke it via SSH, but that’s rarely needed. According to the Knulli firmware wiki, if the PortMaster installer is missing, you can just re-download the script and add it again – it should then appear as a new port entry.

Once PortMaster itself is installed, using it is just like launching a new app on the RG35XX. Important: Ensure you have a Wi-Fi connection for your RG35XX when you launch PortMaster, because the first thing it will do is try to update the game list online. If your device has no network, PortMaster won’t be able to fetch the library (it will just show an empty list or an error). Some RG35XX units (like the original model) require a USB Wi-Fi dongle and appropriate drivers in the firmware to get internet, whereas the newer RG35XX “H” model has built-in Wi-Fi. Check your firmware’s documentation on how to connect to Wi-Fi. Once connected, open PortMaster and you’ll get the full menu of games. From there, you can select a game and follow the prompts to install it. The first time you install a port, PortMaster will also download any needed runtimes (like frameworks for Unity, Godot, or Box86) automatically, or it may prompt you to install a runtime if required. If you prefer to have all runtimes installed upfront (so you can use PortMaster offline to browse already-downloaded content), use the Install.Full.PortMaster.sh script initially – it bundles all runtimes in the installation.

After installing some games, you can disconnect Wi-Fi and enjoy them. Your installed ports will remain accessible under the device’s Ports menu, and you can always reconnect later to grab more games or updates. To update PortMaster itself, the app typically auto-updates its database on launch, and the core app can be updated by re-running the installer script or via package update if your OS integrates it. For troubleshooting or help, the PortMaster Discord is very active, and the Retro Handhelds/Reddit communities for RG35XX often have guides (for example, Retro Game Corps provides an excellent PortMaster starter guide).

Where to download: In summary, you can download PortMaster from the official site or directly from the PortMaster GitHub releases. Always get the latest release to ensure compatibility. Here are quick links:

• Official PortMaster Website: portmaster.games – has documentation and a download section.

• PortMaster GitHub Releases: The PortMaster project is open source on GitHub under the organization “PortsMaster”. The installer scripts and packages are available there for download.

• Community Forums: The r/RG35XX subreddit and the Retro Handhelds Discord have user-contributed installation tips if you get stuck, but the process above covers most of it.

Contributing a Homebrew Godot Game to PortMaster (Developer Guide)

If you’re a developer who has built an open-source homebrew game (for example, a game made with the Godot engine) and you want to add it to PortMaster’s public library, the good news is that PortMaster is designed to accept community contributions. Many of the ports in PortMaster started as hobby projects by developers like you. Below is a step-by-step overview of how to prepare and submit your game to PortMaster, along with technical requirements and community guidelines you should follow:

1. Ensure Your Game Is Eligible and Build-Compatible

To be accepted into PortMaster, your game should be either open-source or free with the developer’s permission to distribute. Since it’s your own game and you’re making it open-source, that’s perfect. You will need to include an appropriate license file in your submission so that the PortMaster team and users know the game’s licensing (e.g. MIT, GPL, etc.). Technically, the game must be able to run on the kind of hardware these handhelds use – typically ARM-based Linux with no X11 window system. In the case of Godot games, PortMaster uses a special build of the Godot engine (an FRT runtime which uses SDL2 and direct framebuffer) to run games without a desktop environment. This means you need to export or compile your Godot project for Linux ARM (32-bit or 64-bit depending on target) and possibly use the custom FRT template. The PortMaster documentation provides guidance on exporting Godot games: essentially, you’ll package your game’s .pck file and use the provided Godot runtime binary on the device (PortMaster includes pre-built Godot runtimes for various versions). In simpler terms: make sure your Godot game runs on a Raspberry Pi-like environment (OpenGL ES 2.0 if using Godot 3.x, no reliance on Windows/Mac-specific features). If your game uses Godot 3.x, you can use the FRT build provided by PortMaster; if it’s Godot 4, there may be additional steps (Godot 4 might require the WestonPack runtime which adds Wayland support). It’s recommended to reach out on the PortMaster Discord’s development channel for specific help with Godot exports, because members of the community (and PortMaster devs) can assist in creating a working binary for these devices.

Before submission, test the game on your RG35XX (or a similar device) if possible. You can do this by copying your game and the Godot FRT runtime to the RG35XX over SSH and running it manually to ensure performance and controls are good. Common limitations to keep in mind: the RG35XX has no GPU acceleration for OpenGL (most use software rendering or OpenGL ES via Lima driver), and a relatively modest CPU, so optimize your game accordingly (e.g., moderate resolution, avoid heavy shaders). Also, the RG35XX input can be read as a standard gamepad – PortMaster uses a utility called gptokeyb to map gamepad to keyboard if needed, or you can handle input in-engine. Once you have a working build of your game (typically a standalone executable or script plus a .pck for Godot), you’re ready to package it.

2. Package Your Game as a PortMaster “Port”

PortMaster has a specific structure and set of files required for each game port. You will need to create these files for your game. The main components are:

• A port directory named after your game (all lowercase, no spaces). For example, if your game is “Super Cool Game”, you might name the folder supercoolgame. Inside this folder will live all the files below.

• A port.json file – this is the key metadata file that describes your game to PortMaster. In this JSON, you specify the game’s name, version, description, author, what runtime it needs (for a Godot 3 game you’d specify the Godot runtime, e.g., "runtime": "godot3"), the download URLs for the game files, and any special instructions (like if external data is required or not). PortMaster has an online Port JSON Generator tool to help you create this file easily. This file is absolutely required – without it, PortMaster cannot recognize or list your game properly.

• A launch script (.sh) – a shell script used to launch the game on the deviceportmaster.games. This script sets up any environment variables and then executes your game’s binary. For Godot games, there is a template launch script available (you can borrow from an existing Godot port). Typically, the script will mount the Godot runtime SquashFS, set the PATH, and then call the Godot binary with your .pck fileportmaster.gamesportmaster.games. Name the script with Capitalized Words and .sh (e.g., Super Cool Game.sh) and place it in the port folderportmaster.games.

• A README.md – documentation for the user. Here you might include a brief description and any notes (especially if the game requires the user to add files or perform some setup)portmaster.games. This README will be bundled so users or the PortMaster site can show info about the game.

• A gameinfo.xml – this is used by EmulationStation to display metadata (like game name, genre, description in the menu) and possibly a reference to the image. It’s similar to other ports’ gameinfo files. You can model this off an existing port’s gameinfo.xml.

• Images: You should provide at least one screenshot image (named screenshot.png/jpg) that shows gameplay, and optionally a cover image (cover.png/jpg) for the gameportmaster.games. These are used in the PortMaster menu and the device’s interface to show artwork for your game.

• License file: Since your game is open source, include a file (or files) that contains the text of your open-source license, typically in a licenses/ subfolderportmaster.gamesportmaster.games. If you use any third-party libraries that require attribution (for example, if your game included code under MIT, etc.), include those license texts as well. PortMaster is very careful about licensing – they include all necessary license files with each portportmaster.games.

All of the above should be organized in a folder structure like this (for example, assuming your port is named supercoolgame):

pgsql
supercoolgame/  
├── port.json  
├── README.md  
├── gameinfo.xml  
├── screenshot.png  
├── cover.png (optional)  
├── Super Cool Game.sh  
├── licenses/ (directory)  
│   └── LICENSE (and any other license files)  
└── supercoolgame/ (directory containing the game’s files)  
    ├── game.pck (your Godot PCK file)  
    ├── any other game asset files or subfolders  
    └── (your game’s executable, if any – though for Godot, the runtime is provided by PortMaster’s environment)  

This is the “port package” that eventually will be distributed. A practical way to assemble this is to look at an existing Godot-based port in the PortMaster repository as an example (for instance, ports like Harvest Doom or others built with Godot). The PortMaster documentation even provides an example launch script for Godot portsportmaster.gamesportmaster.games.

After assembling your port folder, test it locally if you can: you might copy it into your RG35XX’s /roms/ports directory and see if it launches (appearing under Ports in EmulationStation). This can help you verify that your script and files are correct before submitting.

3. Follow Community Guidelines and Testing Standards

PortMaster is a community project, so there are some quality standards to meet before your contribution is accepted. The developers recommend that you announce or discuss your new port in the Discord’s #testing-n-dev channel and, if possible, share a test build with community members who have various devices. You should try to get feedback that the game runs on multiple common firmwares (ArkOS, AmberELEC, JELOS/Rocknix, etc.) and different device resolutions if applicableportmaster.gamesportmaster.games. For instance, the RG35XX has a 320×240 or 640×480 resolution depending on model – if your game UI can scale or if you need to include separate config for different resolution, note that. Community testing is not strictly mandatory, but PortMaster maintainers have a rule that Pull Requests without documented testing in the community will not be acceptedportmaster.games. This policy ensures that adding a new game won’t inadvertently break things on some devices. So, it’s highly encouraged to engage with the community testers. They might find bugs or provide suggestions (e.g., if your game doesn’t handle the gamepad input correctly, someone might help create a gptokeyb config for it).

Also, ensure your port name (the folder and script name) is unique and not already usedportmaster.games. Use a lowercase identifier for the folder. Check the PortMaster “Games” list to ensure no naming conflict. Keep the name short if possible.

In terms of community standards: of course, no piracy or unauthorized content is allowed. Since your game is homebrew and open-source, you’re fine on that front. Make sure all assets you include can be distributed (if you used third-party art or music, have the rights or license to include them). The PortMaster team is very respectful of developer rights – as you can see on their site, some games were only added after getting permission, and a few developers have declined, which PortMaster honorsportmaster.games. Since you are the developer, by submitting, you are implicitly giving permission to distribute your game via PortMaster.

4. Submit Your Game to PortMaster

Once you have a well-tested port package, the next step is to contribute it to the official PortMaster repository so that it becomes available to all users. The PortMaster project is hosted on GitHub, and they accept contributions via Pull Request. Here is the process:

• Fork the PortMaster repository: Go to PortsMaster/PortMaster-New on GitHubportmaster.games and create a fork under your account. This will allow you to add your game files in your own copy of the project.

• It’s recommended to disable GitHub Actions on your fork (the repository is large and has automation you don’t need for the fork)portmaster.games.

• Add your port files: In your fork, navigate to the ports/ directory. Create a new folder for your game (e.g., supercoolgame) and add all the files from your prepared package (port.json, script, etc.) into that folderportmaster.games. Double-check the structure matches the guidelines (especially the naming conventions).

• If your game requires large files (>50MB), the repo has a mechanism to handle that by splitting into chunks using a scriptportmaster.games. Check the docs about running build_data.py if applicable, but for most homebrew games it’s unlikely you have such large single files.

• Once your files are in place, it’s wise to run the project’s provided checks. If you have a Linux environment or WSL, you can run the tools/build_release.py --do-check script from the repo which will validate your port for missing files or errorsportmaster.games. This catches common mistakes (like forgetting the license file or a typo in port.json).

• Open a Pull Request: Commit your changes on a new branch in your fork and open a PR back to the PortMaster-New repository. In the PR description, introduce your game, and importantly, mention the testing you’ve done (e.g., “Tested on RG35XX (GarlicOS) and RG353V (ArkOS) – runs at full speed, no issues” and note if community members tested on other devices). If you have an open discussion on Discord about it, you might reference that. The maintainers will review your submission.

• Respond to feedback: It’s common for the PortMaster team to request minor changes – for example, adjustments to the port.json metadata, or improvements to the launch script. They might also ask if you can test on another device if something is in question. Work with them by updating your PR accordingly (committing new changes to your branch will update the PR).

• Once everything looks good, your PR will be merged and your game will be added to the official PortMaster library! 🎉 The maintainers will package it into the next release so that all users see it in their PortMaster app.

Keep in mind the review process ensures that your game runs well for everyone. Pull requests that haven’t been tested or that don’t meet the packaging guidelines will be politely asked to fix those issues before mergingportmaster.gamesportmaster.games.

If you need more detailed information, refer to the official PortMaster docs on Porting and Packaging (on portmaster.games) which cover things like setting up build environments and using helper tools. Also, the community Discord’s developer channels are incredibly helpful – many folks there have gone through the process and can offer advice on Godot-specific quirks. By contributing your game, you’re not only getting it in the hands of more players, but you’re also joining a group of hobbyists who share knowledge about optimizing games for these fun little devices.

5. Community Guidelines Recap

• Technical requirements: Provide all required files (metadata, script, images, license) and ensure the game runs on the intended hardware. Test thoroughly.

• Naming/structure: Follow the naming conventions (unique lowercase folder, script name with .sh)portmaster.games. Keep filenames sane (no spaces or special chars).

• License and legality: Only include content you have rights to. Include license files for your code and any third-party componentsportmaster.games.

• Testing and quality: Engage the community for testing on multiple devices. Fix issues that arise. Aim for a smooth user experience (for example, ensure the game exits cleanly back to menu on quit).

• Submission: Use the official repo via GitHub PR and be responsive to maintainer feedback. They may require evidence of testing (for broad compatibility) before acceptingportmaster.games.

Following these guidelines will greatly increase the chances of your game being added for all PortMaster users to enjoy. The PortMaster team is enthusiastic about new homebrew games, especially open-source ones, so they will be happy to help you through the process.

Manually Adding a Custom Game to Your PortMaster Installation

What if you have a custom or personal game (or an unofficial port) that isn’t (yet) in the official PortMaster database, and you want to add it to your RG35XX for your own use? This is possible – you can manually install a port on your device. There are two primary approaches: (a) adding the port’s files directly to your SD card, or (b) using PortMaster/HarbourMaster’s ability to install from a ZIP file. We’ll focus on the simpler method (direct file copy), but mention the alternative as well.

Manual file installation (direct copy): Because PortMaster stores each installed game as a set of files on the SD card, you can mimic that process manually. Essentially, you’ll take the port folder (the same structure discussed above: containing the game’s script, port.json, assets, etc.) and copy it onto your device. Here’s how:

1. Prepare the port folder for your game as described in the packaging section above. At minimum, you need a working launch script and the game files, but to integrate nicely with PortMaster, also include a proper port.json. Let’s say your custom game’s port folder is named mygame/ (containing My Game.sh, port.json, etc.).

2. Copy the folder to the device’s ports directory. On your RG35XX’s SD card, open the .../roms/ports/ directory (the exact path depends on firmware; for GarlicOS/ArkOS it’s roms/ports). Copy the entire mygame folder into there, alongside the other port folders. After doing this, the path might look like .../roms/ports/mygame/My Game.sh (plus the other files). Make sure the permissions of the files match the others (if you’re using Windows to copy to a Linux SD, you might need to adjust permissions via Linux, but usually it’s fine).

3. Refresh PortMaster or EmulationStation: Now, if you reboot your device or restart EmulationStation, it should detect the new game. If the game does not show up in your Ports menu, you can manually refresh the gamelist (on EmulationStation press Start > Update Gamelists)knulli.org. Because you included a port.json, the PortMaster app (HarbourMaster backend) will also recognize this as an installed port, even though you added it manually. In fact, HarbourMaster is designed to detect “newly installed ports” that were unzipped or placed manually, and will treat them as part of your installed libraryportmaster.gamesportmaster.games. You should see the game listed under PortMaster’s Manage Ports section as well (likely labeled as an “Unknown” source port, but it will be there).

Once these steps are done, you can launch your custom game either from the standard Ports menu (it will use the .sh script) or from within PortMaster’s interface under Manage Ports. If it doesn’t launch, double-check that your launch script is executable and that any runtime it needs is installed (for example, if it’s a Godot game, you might need to have installed a different PortMaster Godot game first to get the runtime, or use the Runtimes menu in PortMaster to install the Godot runtime environment).

Alternate method – using PortMaster CLI: PortMaster’s backend (HarbourMaster) also has a command-line interface that can install a port from a zip URLportmaster.games. If you’re comfortable with SSH or terminal on the device, you could zip up your mygame folder into mygame.zip, host it on a simple web server or even put it on a GitHub repo, and then run on the RG35XX:

nginx
harbourmaster install https://yourdomain.com/mygame.zip  

This will make PortMaster download the zip and install it as if it were from its repositoryportmaster.games. The URL method requires your device to be online and the file to be accessible via HTTP. Alternatively, if you already copied the zip onto the SD card, you might try a local file path (though harbourmaster expects a URL or a known source). For most users, the direct copy method is simpler.

Note: When adding a custom game manually, you won’t get automatic updates or an entry in the “All Ports” list, obviously. It’s a purely local addition. PortMaster might label it as an “unknown port” because it’s not in its official source list, but that’s fine. If you want to remove it later, you can just delete the folder from roms/ports and then update gamelists (and optionally remove any listing from PortMaster’s manage list if it still shows). HarbourMaster keeps a list of “known ports” and may identify some unofficial ones if they coincide with known projectsportmaster.games, but a truly custom homebrew will just be treated as installed content.

One more tip: ensure your manual port folder’s name doesn’t conflict with an official port. Using a unique name will avoid any confusion or overwrite if the PortMaster team later adds a port with the same name. If you do see a conflict (for example, PortMaster lists an update for it), avoid updating to prevent it from downloading over your version.

In summary, adding a custom game is as easy as dropping the right files in the right place. The PortMaster system is quite flexible – it will recognize manually added ports as long as the structure is correctportmaster.games. This allows you to enjoy your own creations or mods on the RG35XX without waiting for official integration. And if your game is something you want to share with the world, consider going through the contribution process to get it officially into PortMaster, so everyone can install it easily (the steps in the previous section will help you with that).

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References: The information above is gathered from official PortMaster documentation and community guides, including the PortMaster websiteportmaster.gamesportmaster.games, the Retro Game Corps guidesretrogamecorps.comknulli.org, and the Knulli Wiki for RG35XX devicesknulli.orgknulli.org. These sources cover what PortMaster is, how to install it on devices like the RG35XX, and guidelines for port developers. For further reading, check out the PortMaster Starter Guide by Retro Game Corpsretrogamecorps.com and the official PortMaster “Contribute” documentation for detailed packaging and submission instructionsportmaster.gamesportmaster.games. Enjoy your expanded library of games on the RG35XX with PortMaster!

https://portmaster.games/build-environments.html