I have with me a Sharp RoBoHoN (SR-01M-W), it is an android device only sold in Asia, and there are very limited information about it on the internet and it is very hard to find outside of Japan, so I have been trying to learn as much as I can about how it works.
I have already decompiled a few of the system apps and learned some interesting things about it, but some of the things I want to do next will require root (swapping out systems apps, installing Google play store, doing a NANDroid backup, etc).
So how can I gain a root shell?
- I don't want to change anything on the device permanently / make sure anything I do is reversible, if root is gone after a restart/factory reset, that would be even better.
- I don't have the factory image.
- I am able to do a factory reset, but I don't know how to get into fastboot/recovery (It doesn't even have volume buttons).
- I have tried the DirtyCow exploit, which is able to write to run-as but it couldn't set my uid
- I know there are a few "one click root" apps out there, but they don't seems trust worthy and I want to do everything manually if possible to make sure I am not bricking it.
- It runs Android 5.0.2