How to Install Onion OS on Miyoo Mini Plus

The Miyoo Mini Plus, a beloved retro gaming handheld, has seen a surge in custom firmware development, with Onion OS emerging as a leading contender. This open-source operating system breathes new life into the device, offering enhanced features, improved performance, and a more streamlined user experience. Installing Onion OS is a rewarding process that unlocks the full potential of your Miyoo Mini Plus, transforming it into a more versatile and powerful handheld. This guide will walk you through the essential steps, from preparing your hardware to enjoying the polished interface of Onion OS.

Table of Contents

Understanding Onion OS and Its Benefits

Onion OS is not merely a cosmetic upgrade; it’s a fundamental shift in how your Miyoo Mini Plus operates. Developed by a dedicated community, it addresses many of the limitations of the stock firmware, offering a more robust and customizable platform.

Key Advantages of Onion OS

Enhanced Performance and Responsiveness: Onion OS is optimized to run more efficiently on the Miyoo Mini Plus hardware. This translates to faster boot times, smoother menu navigation, and improved emulation performance for a wider range of classic consoles. The system resources are managed more effectively, ensuring a snappier experience across the board.
Expanded Emulation Capabilities: While the Miyoo Mini Plus is capable of emulation out of the box, Onion OS significantly broadens its horizons. It often includes updated emulators and configurations that can tackle more demanding games and systems with greater accuracy and fewer issues. This means you can enjoy a broader spectrum of retro gaming titles with higher fidelity.
Streamlined User Interface: The stock firmware, while functional, can feel basic. Onion OS introduces a more modern and intuitive user interface. It’s designed for ease of use, with better organization of games, settings, and system options. Navigating through your library and adjusting settings becomes a much more pleasant experience.
Extensive Customization Options: One of the most compelling aspects of Onion OS is its flexibility. Users can extensively customize various aspects of the OS, from themes and icons to control mappings and performance tweaks. This allows you to tailor the Miyoo Mini Plus to your personal preferences, creating a truly unique gaming device.
Active Community Support and Development: The development of Onion OS is driven by an active and passionate community. This means ongoing updates, bug fixes, and new features are regularly released. The community also provides invaluable support through forums and online resources, making troubleshooting and learning new tricks much easier.
Improved Battery Management: Onion OS often incorporates optimizations for power consumption, potentially leading to better battery life compared to the stock firmware. Efficient resource management means your Miyoo Mini Plus can keep you gaming for longer on a single charge.
Advanced Features: Beyond basic emulation, Onion OS can unlock advanced features such as wireless networking (for certain models and setups), improved save state management, and integration with external devices. These additions enhance the overall functionality and user experience.

Preparing for the Installation

Before you can install Onion OS, proper preparation is crucial. This involves gathering the necessary materials and ensuring your Miyoo Mini Plus and its storage are ready for the process. Skipping any of these steps can lead to installation errors or data loss.

Essential Hardware and Software

Miyoo Mini Plus: The handheld device itself. Ensure it is in good working condition.
MicroSD Card: A high-quality MicroSD card (Class 10 or faster, at least 32GB recommended) is essential. This card will house the Onion OS and your game ROMs. It’s highly recommended to use a brand-new card or one that has been thoroughly formatted to avoid potential corruption.
MicroSD Card Reader: A reliable card reader to connect your MicroSD card to your computer.
Computer: A Windows, macOS, or Linux computer for downloading files and flashing the operating system.
USB-C Cable: The charging cable for your Miyoo Mini Plus, which will also be used for transferring files.

Formatting the MicroSD Card

A clean slate is vital for a successful Onion OS installation. Formatting your MicroSD card ensures that any old data or file system errors are cleared, preventing conflicts with the new operating system.

Backup Existing Data: If your MicroSD card currently contains games or other important files, back them up to your computer before formatting. Once formatted, this data will be lost.
Insert MicroSD Card: Connect the MicroSD card to your computer using the card reader.
Open Disk Management (Windows) or Disk Utility (macOS):
- Windows: Search for “Disk Management” in the Start menu.
- macOS: Open “Disk Utility” from the Applications > Utilities folder.
Locate and Format:
- Windows: Find your MicroSD card in the Disk Management window. Right-click on the card’s partition and select “Format.” Choose “FAT32” as the file system and ensure “Quick Format” is checked. Click “OK.”
- macOS: Select your MicroSD card from the sidebar in Disk Utility. Click the “Erase” button. For the “Format” option, choose “MS-DOS (FAT32)” and for “Scheme,” select “Master Boot Record (MBR).” Click “Erase.”
Confirm Formatting: The process will take a few moments. Once complete, your MicroSD card will be formatted and ready for Onion OS.

Step-by-Step Onion OS Installation

This section details the process of obtaining the Onion OS files and correctly installing them onto your prepared MicroSD card. Accuracy and adherence to these steps are paramount for a successful installation.

Downloading the Latest Onion OS Files

The Onion OS installation files are regularly updated to include new features, bug fixes, and performance enhancements. It’s crucial to download the latest stable release to ensure the best experience.

Visit the Official Source: Navigate to the official Onion OS GitHub repository or its designated download page. You can usually find links through dedicated retro gaming forums or community wikis. Be cautious of unofficial sources, which may distribute outdated or modified versions.
Locate the Latest Release: On the GitHub page, look for the “Releases” section. Identify the most recent stable release (often labeled with a version number like vX.X.X).
Download the ZIP File: Download the primary installation ZIP file. This file typically contains all the necessary system files and scripts for Onion OS. It might be named something like OnionOS-YYYYMMDD.zip or similar.
Download Additional Components (if applicable): Sometimes, specific emulators or custom themes might be provided as separate downloads or within the main ZIP. Ensure you download all required components as specified by the Onion OS documentation.

Flashing Onion OS to the MicroSD Card

Once you have the Onion OS files, the next step is to transfer them correctly to your formatted MicroSD card. This process uses a specialized tool to ensure the operating system files are written accurately.

Extract the Downloaded Files: Unzip the downloaded Onion OS ZIP file into a new folder on your computer. This will reveal the various files and folders that constitute the Onion OS.
Use a Flashing Tool: While simply copying files might seem intuitive, it’s essential to use a dedicated flashing tool for accuracy. The recommended tool for flashing Onion OS is often balenaEtcher (or balena-cli for command-line users). Download and install balenaEtcher if you haven’t already.
Prepare the Flashing Process:
- Open balenaEtcher.
- Click “Flash from file.” Select the Onion OS image file you extracted. This is often a .img file, or sometimes the ZIP file itself can be directly flashed by Etcher depending on how it’s packaged. Consult the specific instructions provided with your downloaded Onion OS version, as the exact file type for flashing might vary.
- Click “Select target.” Carefully choose your MicroSD card from the list. Double-check that you have selected the correct drive. Flashing to the wrong drive can erase your computer’s hard drive.
Initiate the Flash: Click the “Flash!” button. balenaEtcher will now write the Onion OS image to your MicroSD card. This process can take several minutes, depending on the size of the image and the speed of your MicroSD card.
Verification: After flashing, balenaEtcher will typically verify the written data to ensure integrity. This is a crucial step to confirm the OS has been installed correctly.

Transferring ROMs and BIOS Files

With Onion OS successfully flashed to the MicroSD card, you now need to populate it with your game ROMs and any necessary BIOS files for emulators to function.

Safely Eject MicroSD Card: Once balenaEtcher completes the flash and verification, safely eject your MicroSD card from your computer.
Insert into Miyoo Mini Plus (Initial Boot): Insert the flashed MicroSD card into your Miyoo Mini Plus. Power on the device. Onion OS should now boot up.
Access the SD Card on your Computer: With Onion OS booted, connect your Miyoo Mini Plus to your computer using the USB-C cable. Your Miyoo Mini Plus should appear as a USB drive on your computer, exposing the contents of the MicroSD card.
Locate ROMs and BIOS Folders: Navigate through the file structure of the MicroSD card. You will find specific folders designated for different emulators and their ROMs (e.g., GBA, SFC, NES, PS1). There will also typically be a BIOS folder.
Transfer ROMs: Copy your legally owned game ROM files into their corresponding emulator folders on the MicroSD card. For example, Game Boy Advance ROMs go into the GBA folder, Super Nintendo ROMs into the SFC folder, and so on.
Transfer BIOS Files: If certain emulators require BIOS files (e.g., for PlayStation or Neo Geo), copy these files into the designated BIOS folder. Ensure you have legally obtained these BIOS files. Without the correct BIOS files, many emulators will not function.
Organize and Configure: Some versions of Onion OS may have additional configuration files or themes that you can copy over at this stage. Refer to the Onion OS documentation for specific recommendations.
Safely Eject and Reboot: Once all files are transferred, safely eject the Miyoo Mini Plus from your computer and power it off.

Navigating and Customizing Onion OS

After successfully installing Onion OS and transferring your games, the next exciting phase is to explore its features and tailor it to your liking. Onion OS offers a significantly enhanced user experience over the stock firmware.

The Onion OS Interface

Upon booting, you’ll notice a cleaner, more modern interface. The primary menu usually displays available emulators and system options.

Main Menu: Typically organized by system or function. You’ll find icons for emulators (e.g., GBA, SNES, Genesis), settings, and utilities.
Game List: When you select an emulator, Onion OS will scan the designated ROM folder and display your games. Games are usually presented with their box art or a preview image, making browsing a visual delight.
Quick Menu: Accessed by pressing a designated button combination (often Select + X or a similar shortcut). This menu allows you to quickly save or load game states, change emulator settings, adjust video filters, and quit the current game without returning to the main menu.
System Settings: Found in the main menu, this section allows you to adjust core system preferences such as language, time, Wi-Fi settings (if applicable), display brightness, and sound volume.

Essential Customization and Settings

Onion OS is renowned for its extensive customization options. Here are some key areas you’ll want to explore:

Themes and Visuals: Onion OS often supports custom themes. You can download and apply new visual themes to change the look and feel of the operating system, from menu icons to font styles. These are usually found in a Themes folder on the SD card.
Emulator Settings: Each emulator can often be configured individually. Within the Quick Menu or dedicated emulator settings, you can:
- Video Filters: Apply shaders or filters to emulate the look of old CRT monitors or to upscale the image.
- Control Mapping: Remap buttons for individual games or emulators to suit your preferred control scheme.
- Aspect Ratio: Adjust the aspect ratio to match the original display of the console or to fit your screen.
- Audio Settings: Tweak audio output and quality.
Game Save States: Onion OS provides robust save state functionality. You can save your progress at any point in a game and load it later, allowing you to pick up exactly where you left off. This is accessed via the Quick Menu.
Performance Tweaks: For more advanced users, Onion OS may offer options to overclock the CPU or GPU for better performance in demanding emulators. Exercise caution when overclocking, as it can lead to increased heat and potentially reduce the lifespan of your device if not done correctly. Consult the Onion OS documentation for safe overclocking parameters.
Wi-Fi Configuration: If your Miyoo Mini Plus variant supports Wi-Fi, Onion OS allows you to connect to networks. This can be useful for transferring files wirelessly, accessing online features (if supported by specific emulators or applications), or for firmware updates.

Maintaining and Updating Onion OS

Like any operating system, Onion OS benefits from regular maintenance and updates to ensure optimal performance, security, and access to the latest features. Keeping your installation up-to-date is a straightforward process.

Checking for Updates

The Onion OS development community is active, meaning new versions are released periodically. It’s a good practice to check for updates every few months.

Official Sources: The primary method to check for updates is to revisit the official Onion OS GitHub repository or its dedicated download page. Look for new release tags or announcements in the community forums.
Community Announcements: Many retro gaming communities and forums will have dedicated threads for Onion OS where developers or users will announce new releases and significant changes.

Performing an Update

Updating Onion OS typically involves a similar process to the initial installation, but it’s crucial to follow the specific instructions provided with the update package, as some updates may require different steps.

Download the Latest Version: Download the new ZIP file for the latest stable release of Onion OS.
Backup Your Current Setup: This is a critical step. Before proceeding with an update, it is highly recommended to back up your entire MicroSD card. You can do this by using a disk imaging tool (like balenaEtcher to create a backup image of your card) or by simply copying all the files from the SD card to a separate folder on your computer. This backup serves as a safety net in case the update process encounters issues.
Format the MicroSD Card (Often Recommended): For major updates, it’s often recommended to perform a clean install. This means formatting your MicroSD card as you did during the initial setup (FAT32). However, some updates might be designed to be applied over an existing installation. Always refer to the update instructions. If a clean install is recommended, format your SD card.
Flash the New OS Image:
- If performing a clean install, use balenaEtcher to flash the new Onion OS image file to your MicroSD card, as described in the installation section.
- If the update is an overwrite, you might simply extract the new files into the root of your existing Onion OS partition. Again, follow the official update guide meticulously.
Transfer Your Data:
- If you performed a clean install, you will need to re-transfer your ROMs, BIOS files, and any custom themes or configurations you had.
- If it was an overwrite update, your ROMs and BIOS files should remain intact, but it’s good to verify.
Test Thoroughly: After the update, power on your Miyoo Mini Plus and test various emulators, games, and system functions to ensure everything is working as expected.
Restore from Backup (if necessary): If you encounter any critical issues that cannot be resolved, you can restore your MicroSD card from the backup you created.

Troubleshooting Common Issues

While Onion OS is generally stable, users might encounter occasional problems.

OS Not Booting: This is often due to an incorrectly flashed MicroSD card or a corrupted download. Re-flash the OS using balenaEtcher and ensure you’re using a good quality SD card.
Games Not Appearing: Verify that your ROM files are in the correct folders for their respective systems and that they are not corrupted. Ensure you have the necessary BIOS files for emulators that require them.
Emulators Crashing: This can sometimes be resolved by updating to the latest version of Onion OS or by ensuring you have the correct BIOS files. Some games might also be incompatible with specific emulators or versions.
Controls Not Working: Check your control mapping settings in the Quick Menu or system settings. Ensure that the buttons are correctly assigned for the emulator you are using.

By following these steps and staying informed through the official channels, you can ensure your Miyoo Mini Plus with Onion OS remains a powerful and enjoyable retro gaming experience for years to come.