- Recovery:
adb reboot recovery- With the phone off, press and hold
Volume Up+Power. This is quite tricky since sometimes it doesn't work and the phone ends up booting Android normally.
- Download Mode (with bootloader lock & unlock options): With the phone off, hold both volume keys & plug the phone to a computer.
- Download Mode (only download):
adb reboot-bootloader
Additionally, the phone can always be forced to reboot by holding Volume Down + Power for some seconds.
The process is pretty much the same as in any other Samsung phone. Remember that this will perform a factory reset.
- Make sure your phone has internet connection
- Enable developer options and turn on OEM unlocking.
- Shut down the phone & boot into download mode
- Unlock the bootloader by holding
Volume Upto access the unlock menu & then confirm the action withVolume Up.
You can use Odin (Windows) or Heimdall (Windows/Linux).
Before flashing any partition, it's suggested to first flash an empty vbmeta image. If you don't, the bootloader may refuse to boot the device.
Due to a bug in the bootloader, recovery and boot images need to be "fixed" before being flashed, otherwise the phone will refuse to boot them with a "SECURE CHECK FAIL" error. More info in this repository.
TWRP is available for this device but there are some things you must know:
- If you are on the stock firmware (OneUI), the recovery is replaced by the stock one on each boot, making it hard to actually boot into TWRP.
- It's not able to access the internal storage nor anything in
/dataunless you disable encryption.
More information can be found on TrebleDroid's Wiki.
- XDA Developers Forum -Most threads are for the Exynos Galaxy A20, there's not much stuff for the A20s
- A20s Telegram Group -Here you can find more step-by-step instructions and get help from other users
