...
Make sure the device is turned off.
Make sure no debug cable is attached.
Long press the power button and volume button “-”
Release when you hear the drop sound
The recovery mode is enabled.
...
L2Ks
设备关机，长按电源键+音量减键，进入关机工模，选择清除emmc
Make sure the device is turned off.
Make sure no debug cable is attached.
Long press the power button and volume button “-”
Release when you hear the drop sound
The recovery mode is enabled.
Select clear emmc.