AYN

Details on Aya Odin Base/Pro

1. On your AYN device on Android or another device / OS.
2. Download SM8550-ABL.zip and extract it to an sdcard.
3. Boot Android ensure the you insert the sdcard with the extracted files.
4. Using the file manager (Files) copy the files off your sdcard onto the Android file system into a directory called odin2_custom_abl (this directory name is important).
5. To ensure you're using the correct location to create the odin2_custom_abl directory. In the File app, hit the hamburger symbol on the top right (three lines) and then choose your device (i.e. AYN Thor)
6. Go to Android settings, at the bottom in the Odin2 or Thor settings → Run script as Root and select the backup_and_flash.sh script from the directory called odin2_custom_abl.
7. The script will run quickly and back up the original boot loader to /sdcard/backup/ directory.
8. Keep this as a backup in case you want to rollback.
9. Download the Batocera SM8550 image and burn it on an micro SDCard. Warning: make sure you have a high quality SDcard. In my testings, I failed booting a 256GB no-name card, while a 128GB PNY went flawlessly.
10. Then, if you have your Batocera micro SDCard inserted in your SM8550 device, boot it up and it starts on Batocera.
11. Enter the bootloader fastboot menu by pressing [vol -] and [power] and switch the boot mode to Linux (use volume buttons and power to navigate and select).
12. Then navigate to 'Set device model'. There you must choose your device from the list (if you don't do it, your machine might not boot). Then navigate to 'START' and press power to boot.
13. If you want to go back to Android, remove the SDCard, enter the boot loader menu by pressing [vol +] and [power] and switch the boot selection from Linux to Android. and you'll be back to Android.

You can access some boot options by keeping pressed the [Vol +] and Power buttons. The boot loader menu is in portrait mode and looks like this: You can switch from Android to Linux booting from this menu.

Emulators with only a single screen (most systems actually) will leverage the bottom screen to run the Batocera Control Center (hotkey+east), keeping the upper screen for emulation.

But some systems have dual screen capacity, and here is how to enable them in Batocera 43:

In the ADVANCED SYSTEM OPTIONS you must select

1. MELONDS as the emulator (the standalone one, not libretro-melonds)
2. set DUAL SCREEN to ON

Only Azahar is supported for the moment. In the ADVANCED SYSTEM OPTIONS you must select

1. set SCREEN LAYOUT to SEPARATE WINDOWS