diagnosis mode in terminal - HappyZ/dpt-tools GitHub Wiki
After obtaining adb access:
rawdata --set_dump=boot_mode < /dev/urandom
reboot
This will permanently boot into diagnosis mode
Then in diagnosis mode:
rawdata --set_dump=boot_mode < /dev/zero
reboot
It shall boot into normal mode.
This is learnt from /system/xbin/change_boot_mode.sh