Anbernic RG353P / RG353V / RG353M / RG ARC-D

GammaOS + GammaOS Lite Android Custom Firmware - v1.5.1

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Download and instructions

• GammaOS v1.5.1 download (for both SD card and Fastboot methods): https://github.com/TheGammaSqueeze/GammaOS-RK3566/releases
• (Changelog)

Instructions:

• Brand new install (Flash using SD Card)
• Upgrade from existing GammaOS install (Flash using fastbootd)
• Help! My device is no longer booting! Or I want to go back to Stock OS!

Information

GammaOS is based on LineageOS 19.1 (Android 12). It provides a debloated and performance optimized experience for users who are looking to get the best Android experience out of their Anbernic RG353 and ARC devices.

For the RK3566 series, it is recommended to use GammaOS Lite edition for further performance headroom. This replaces your built-in Android system for your device. Linux based CFW that boots from microSD are unaffected.

Features:

• Based on debloated and clean LineageOS 19.1 build, Android 12 for a smoother experience. Only comes with RetroArch for emulation, install standalone emulators as required.
  • GammaOS includes Google Services and Play Store.
  • GammaOS Lite excludes Google apps and services for extra performance headroom. (Recommended)
• Daijisho launcher as front-end, pre-configured with RetroArch for some systems. (Optimized settings for GB,GBC,GBA,NES,SNES,Genesis,PSX) (BIOS files need to be supplied by you).
• Aurora store included.
• Adguard ad blocking included as default (can be disabled via Private DNS settings).
• Magisk/root included.
• 60hz refresh rate fix for display (includes RG 353 V1 and V2 displays).
• Oversharpening display fixed.
• Analog stick calibration for more tighter controls.
• CPU, GPU, Memory now using performance governors for extra performance boost.
• L2/R2 fixed for apps and games with issues with those buttons.
• Change between XBOX and NS button layout by holding L1+R1+L3/Z
• Swap DPAD and Left analog stick input by holding L1+R1+Y (useful for RG ARC)
• Toggle between performance modes by holding down L1+R1+R3/C
  • Max Performance (everything set to max frequency, uses the most battery life)
  • Normal Performance (scales frequency according to load)
  • Power Save (lowers all frequencies to minimum for max battery life, useful for GBA and below).
  • Recommend enabling threaded video in RetroArch for Power Save mode, or change emulators to less demanding ones (SNES9X EX+, Duckstation standalone run better)
• SafetyNet fix, present as Pixel phone: for fixing TMNT etc
  • (Activated by toggling Magisk > Settings > Enable Zygote and reboot your device).

Other Information:

• RetroArch menu toggle: Short press HOME/Back/FN button
• RetroArch quit game (and save progress): Long press HOME/Back/FN button
• RetroArch shortcuts HOME/Back/FN +
  • L1 = Slow Motion
  • L2 = Load State
  • R2 = Save State
  • R1 = Fast Forward
  • X = Show FPS
  • Y = Screenshot
  • Vol Up/Down = Adjust brightness

What's missing:

• Built-in button to on-screen mapping software, alternative solutions can be found in app store.

Instructions - Brand new install (Flash using SD Card)

This is a straightforward process for a new install. You will need a Windows machine, a spare microSD card (minimum of 4GB recommended), and a microSD card reader for your Windows machine.

This will erase all your data currently on the device.

Just download the non FASTBOOT version of the release. If you are unable to install GammaOS using the SDDiskTool then use the fastboot method instead: - Upgrade from existing GammaOS install (Flash using fastbootd)

Remove your microSD card in slot TF2 on your Anbernic device until the install is complete and you have fully set up Android.

NOTE: Do not try and use a tool like Win32DiskImager or balenaEtcher, this will not work.

1) Download the relevant release for your device, and extract the zipped file. You will end up with this folder

2) Insert your spare microSD card into your microSD card reader, insert this into your PC.

3) Open the SDDiskTool_v1.69 folder, then open the SD_Firmware_Tool.exe application.

5) Ensure that you select "Upgrade Firmware", then click the Firmware button.

6) Locate your relevant GammaOS_RGXXX_XXXX_vXXX.img file that was in the folder that was extracted earlier, and open this

7) Click Create and let the process begin

8) Once this is completed, remove your microSD card from the card reader, insert the microSD card into your Anbernic device (TF Slot 1) and restart/turn on. It will start updating the software.

9) Once the install is complete, you will be asked to remove the microSD card. Once this is done, you will boot into GammaOS. The microSD card is no longer required.

Your first boot into GammaOS will take some time, so please be patient. Your screen may turn off and on during this process (sometimes it might stay off, just turn it back on), and the GammaOS logo may appear several times, this is normal. If signing into a Google account, initial updates may take some time and will install in the background. This may slow down the device until complete. Enjoy!

Instructions - Upgrade from existing GammaOS install (Flash using fastbootd)

Video guide here for upgrading your firmware from an existing GammaOS install: https://youtu.be/HQuK0o4PrDo

Prerequisites:

• Download the FASTBOOT versions of the release (begins with FASTBOOT_ at the beginning of the file name)
• Extract the GammaOS/GammaOSLite folder and its files before proceeding.
• Get ADB and Fastboot tools + drivers.

On Windows

• Ensure you install the Universal ADB Driver: https://github.com/K3V1991/ADB-and-FastbootPlusPlus

  • When installing, make sure both of these boxes are ticked:
  • 

• Install Unisoc Drivers (yes, this is right), run the DPInst64.exe program in your relevant OS folder. (Available here: https://github.com/TheGammaSqueeze/GammaOS/releases/download/GammaOS_v1_RG405M/UnisocDrivers.zip, Win10 drivers will also work on Win11.)

• Remove/rename any existing fastboot.exe application that exists on your PC to prevent issues with flashing such as the flashing stalling at vbmeta_a. Open a command prompt, type in the following command: where.exe fastboot.exe. This will show you where your fastboot.exe is being called from. Anything that is not in the C:\Program Files (x86)\ADB and Fastboot++\fastboot.exe location should be renamed to something else. Rename to something like oldfastboot.exe

On MacOS: Install homebrew: https://brew.sh/

Via homebrew on MacOS:

• brew update
• brew install android-platform-tools

The process on Linux differs from distro to distro.

On Arch, you can use the android-sdk-platform-tools from AUR.

On Garuda, simply run sudo pacman -Syu android-sdk-platform-tools since it has Chaotic-AUR preinstalled.

For those already on GammaOS:

• Hold down the power button, choose Restart, choose Recovery.
• Once in Recovery, use the volume buttons to navigate to Enter Fastboot.
• Connect your USB cable to the charging port on your device (not the OTG port)

For stock OS only:

• Enable USB Debugging: https://developer.android.com/studio/debug/dev-options
• Connect your USB cable to the charging port on your device (not the OTG port), issue the command via command line: adb reboot fastboot

Flashing the custom firmware:

• Close all command line windows from before
• Navigate to your extracted GammaOS/GammaOSLite folder
• Open the FlashPartitions script
  • Windows: double click the .bat file.
  • Mac/Linux, open a terminal in the GammaOS directory, issue the command sh FlashPartitions.sh
• It will begin flashing the firmware. This step can take up to 10 minutes so be patient.
• (MANDATORY FOR STOCK OS USERS OR IF YOU ARE SWITCHING BETWEEN GAMMAOS AND GAMMAOS LITE, IGNORE IF UPGRADING) Open the EraseUserData script
  • Windows: double click the .bat file.
  • Mac/Linux, open a terminal in the GammaOS directory, issue the command sh EraseUserData.sh
• It will begin factory resetting your device in preperation for GammaOS. When the script is complete, the command prompt window will close itself after 60 seconds.
• You can now reboot your device by pressing the power button once.
• Congratulations, you are now on the latest GammaOS!

Help! My device is no longer booting! Or I want to go back to Stock OS!

Anbernic provide factory images for the RK3566 devices. You can find downloads and instructions here:

RG353 Series: https://win.anbernic.com/download/233.html RG ARC: https://win.anbernic.com/download/289.html

Alternatively, you can download these here: https://github.com/TheGammaSqueeze/GammaOS-RK3566/releases/tag/StockFirmware_RG

The instructions are the same as flashing GammaOS, only except we are using Anbernics own update.img

Changelog

• (v1.5.1) Fixed audio issues with headphones and HDMI.
• (v1.5.1) Updated Mali GPU drivers to latest version for smoother performance.
• (v1.5.1) Fixed holding F to boot into Android breaking Linux SD card (this functionality is only supported on stock Linux OS, not any Linux CFW)
• (v1.5) Moved everything to Quick settings tiles for Performance modes, ABXY layout changes, Adjusting analog stick sensitivity, invert axis for analog left/right, swap dpad and left analog input (useful for RG ARC). No more need to hold down button combos.
• (v1.5) Add aptX BT audio support.
• (v1.5) Improve battery standby time and reduced memory consumption.
• (v1.5) Enable home/back key to act as menu button in RA, as well as the hotkey for other shortcuts.
• (v1.5) Holding down home/back key will save your progress now in RA, and lets you quick resume games, similar to the MM OnionOS game switcher.
• (v1.5) Update all RA cores, but stick with RA 1.15 due to touch screen regression.
• (v1.5) Add Firefox alternative browser.
• (v1.5) Fixed scope storage issues, can now launch Yaba2 and Redream directly from Daijisho (need to enable Allow All Files access for the relevant emulator first).
• (v1.3.3) - Initial release

Credits

TheGammaSqueeze - Author - https://github.com/TheGammaSqueeze/

TacoPizza#4158 - Boot Logo

Andy Yan - Providing GSI builds: https://sourceforge.net/projects/andyyan-gsi/files/lineage-19.x/