Onion OS is the must-have custom firmware for the Miyoo Mini and Miyoo Mini Plus. It replaces the stock OS with a polished, feature-rich interface and dramatically expands the device's emulation capabilities.
What You Need
Before you begin, make sure you have:
- A Miyoo Mini or Miyoo Mini Plus
- A MicroSD card (16GB–256GB; quality matters — use Samsung or SanDisk)
- A Windows, Mac, or Linux computer
Step 1: Download Onion OS
Head to the official Onion OS GitHub releases page and download the latest stable release. You want the .zip file.
Step 2: Format Your MicroSD Card
Format your MicroSD card as FAT32. On Windows, use the official SD Card Formatter tool. On macOS, use Disk Utility and choose "MS-DOS (FAT)".
Step 3: Flash Onion OS
Extract the downloaded .zip file and copy its contents to the root of your MicroSD card. Do not copy the folder itself — copy the contents inside the folder.
Step 4: First Boot & Installation
Insert the MicroSD card into your Miyoo Mini and power it on. Onion OS will launch an installation wizard automatically. Follow the on-screen prompts — it takes about 2 minutes.
Step 5: Add Your ROMs
Onion OS creates the following folders on your SD card:
/Roms/GBA— Game Boy Advance/Roms/SFC— SNES/Roms/PS— PlayStation 1/Roms/FC— NES
Copy your legally-owned ROM files into the appropriate folders and restart the device.
Recommended Settings
Enable the following in the Onion OS settings menu for the best experience:
- Performance Mode: ON (extends to 1.4GHz CPU)
- Sleep Mode: 3 minutes (saves battery)
- Screen Brightness: 7/10 (sweet spot for indoors)