GammaOS Next Installation - TheGammaSqueeze/GammaOSNext GitHub Wiki

• GammaOS Next - Installation Guide for Anbernic T820 Devices

Note: Unlocking the bootloader will factory-reset (wipe) your device.
Note: Installing GammaOS will wipe your device if your bootloader is already unlocked.

1. Patreon Password

   • If you’re a Patreon supporter, obtain the GammaOS Next password from the Patreon post itself (https://www.patreon.com/GammaOS). The release is locked behind that password until it goes public in 60 days.

2. 7-Zip

   • Install 7-Zip (or another archive tool capable of extracting split archives). You’ll need it to combine and extract the .7z.001/.002/.003 files.

3. UnisocTools

   • Download the UnisocTools.7z flashing toolkit from the release page (https://github.com/TheGammaSqueeze/GammaOSNext/releases/tag/v.1.0.0-T820).
   • Extract the UnisocTools folder from the archive; you’ll find subfolders for drivers, bootloader unlock, and the flashing utility (ResearchDownload.exe).

1. Open the UnisocTools folder and navigate to the UnisocDrivers subfolder.
2. Run the driver installer (e.g., DPInst64.exe or whichever installer is provided) to install UniSoc/Spreadtrum USB drivers.
   • On Windows 11, the Windows 10 driver package works fine.
   • After installation, you should see UniSoc-related drivers listed in Device Manager once a device is connected in bootloader mode.

1. Power off your Anbernic device completely, ensure there is no USB cable connected.
2. In the extracted UnisocTools/UnlockBootloader folder, open the UnlockBootloader.bat script.
3. Hold down the Back button on the device (for RG556/RG-CUBE/RG406V/RG406H, the Back button is in the same location regardless of model).
4. While still holding Back, connect the USB cable to your PC.
5. The Unlock Bootloader tool will send the necessary commands; the device screen will show text indicating the bootloader is being unlocked. You can now let go of the Back button.
6. Wait until you see a confirmation message on the device (e.g., “INFO: LOCK FLAG IS: UNLOCK!!!”). Now disconnect the USB cable and ensure the device is powered off.

1. Download the GammaOS Next split archive files (e.g.:
   • RG_406H_GammaOS_Next_Full_v1.7z.001
   • RG_406H_GammaOS_Next_Full_v1.7z.002
   • RG_406H_GammaOS_Next_Full_v1.7z.003
     ) from the GitHub release.
2. Right-click on the .7z.001 file and choose “7-Zip → Extract Here”. Enter the Patreon password when prompted.
3. 7-Zip will automatically combine and extract all parts, producing a .pac file.

1. In the UnisocTools/SPRD_Download_Tool folder, locate and run ResearchDownload.exe (or the equivalent “SPD Flash Tool”).
2. In the Flash Tool window, click Load Packet (or the folder icon).
3. Browse to the folder you just extracted and select the .pac file for your device model (e.g., RG_406H_GammaOS_Next_Full_v1.pac).
4. The tool will parse the file and display information like device name (e.g., “RG406H”) and firmware version. Confirm it matches.
5. Ensure your device is still powered off (after bootloader unlock, it should remain off).
6. Click the Play/Start button in ResearchDownload.exe.
7. Hold down the Back button on the device, and while holding it, connect the USB cable to your PC. The flash tool will detect the device in “Download” mode.
8. The flashing process will begin—this takes around 5 minutes. You’ll see a progress bar; do not disconnect or power on during this step.
9. Once flashing completes, the tool will show a “Passed” or “OK” or “Reset” status. The device will automatically reboot and perform an internal format (factory reset). Disconnect your USB cable after this point.
10. Let the device finish formatting and then reboot. It will boot into GammaOS Next on its first launch, which can take up to 2–3 minutes as it initializes.

1. First Boot takes a bit longer—be patient while Android sets up file systems and initial configurations.
2. If you installed the Full (with Google Services) build, follow the on-screen prompts to sign into your Google account or skip it.
3. After Google setup (or skipping), GammaOS Next will run a brief configuration phase, installing key apps (RetroArch, Flycast, Daijisho, etc.).
4. Once that completes, you’ll land on the GammaOS Next home screen. Congratulations—your device is now running the new firmware!

• If the flash tool fails to detect your device, verify:
  • USB drivers were installed correctly.
  • The Back button is held down firmly during connection.
  • USB cable and port are functional.
• If the device doesn’t boot into GammaOS Next after flashing:
  • Double-check that you used the correct .pac for your model (e.g., RG406H vs. RG406V).
  • Ensure the device filesystem was formatted (it may reboot and re-format automatically).
  • Try unlocking the bootloader again and re-flash.
• For any errors or unexpected behavior, post details (error messages, device model) on the GammaOS Next GitHub Issues page.

You’re all set—enjoy exploring GammaOS Next on your Anbernic T820 device! If you encounter any issues or have feedback, let me know on Discord or GitHub.

Flashed using the same instructions as GammaOS Next:

• RG556: https://drive.google.com/file/d/1hYuUPBTHAghZXXVt5urnAhJP-_vofg3K/view?usp=sharing
• RG Cube: https://drive.google.com/file/d/1DBl9ZwvyqUdjMmetA2ekYWKS1uUcmI0b/view?usp=sharing
• RG 406V: https://drive.google.com/file/d/10ivdlP5CsVInWOa66RpjjCxLI38Lo1-2/view?usp=sharing
• RG 406H: https://drive.google.com/file/d/1UVdcEFBBagm4Dmj28w8tyiQuGFyVhXAk/view?usp=sharing

To fix OTAs after flashing stock again:

• https://github.com/TheGammaSqueeze/Bootloader_Unlock_Anbernic_T820/commit/e5f7dfc160c819460d095a83baec8bf81689af1b