Un-rooting and re-rooting my Android device

[jimleong]

Hello,

I'm currently using an Android media player, adapted into a kind of 'tablet PC'. Just recently I sent a support request to WhatsApp Support, which responded telling me to first remove root access to my device. Otherwise, they will not be able to help troubleshoot the WhatsApp issues on my device. I was not the one who first set up this media player so I don't know if the person who first set it up enabled root access from the onset.

i) May anyone please explain 'rooting' to me? I am not familiar with the concept and have never done rooting before.

ii) How do I unroot my device?

iii) After unrooting my device, will I be able to restore root access?

Any insight will be appreciated. Please do not hesitate to ask for more information if needed, e.g. if you need more information on the kind of device that I am using.

Thank you very much in advance.

Regards,
Jim

 

[Hadron]

Rooting generally means modifying the system software so that you can grant administrator rights to apps ("root" is the Linux administrator account, and Android is based on a variant of Linux). I say "generally" because occasionally you get devices which are sold rooted (usually off-brand Chinese devices), but in most cases, and all mainstream devices I can think of, they are sold without giving the user root access.

How you do it depends on the device and the software version. There is no "one size fits all" solution, though there are general principles, and there are apps that are capable of rooting many different devices.

There are a number of "root checker" apps in the Play Store. If you are unsure whether you are rooted or not, install one and see what it says.

The usual way of unrooting is to reflash the device with a complete set of official software, overwriting all modifications. This will commonly erase all user content in the process. The software tools to do this depend on the manufacturer. If it's the same software version you should be able to re-root in the same way it was originally done (which, if it was done to your device, you don't know in this case!). If it's a newer version there is the possibility that the same method might not work, since unless the manufacturer provides an official way of e.g. unlocking the bootloader the rooting method probably relies on an exploit, and sometimes updates close these vulnerabilities.

Hope that makes sense.

 

[jimleong]

Hi Hadron,

thank you for your help and apologies for my late response as I had been unable to access the Internet these past days.

If you don't mind, may you let me know
i) What does it mean to 'reflash the device'?
ii) When you mentioned that 'the software tools to do this depend on the manufacturer', may I ask if you are referring to unrooting or rooting? Also, does this mean that the tools are created by the manufacturer or are they downloadable from the Play Store?

iii)

If it's a newer version there is the possibility that the same method might not work, since unless the manufacturer provides an official way of e.g. unlocking the bootloader the rooting method probably relies on an exploit, and sometimes updates close these vulnerabilities.

Sorry but I do not quite understand what this paragraph means - may you please help clarify?

Thanks in advance for your help.

Regards,
Jim

 

[Hadron]

Sorry, very busy week here, so not been back much.

i) I mean completely reinstall the device software. Since this is stored in flash memory, it's common to refer to the process as "flashing".

ii) I meant both, and in general they are not downloadable from the Play Store. Most require a computer rather than just a phone in fact.

iii) Some manufacturers allow you to unlock the bootloader of the device (though when sold through a carrier the same device may have the bootloader locked down). If this is the case then you don't need to worry about the ability to root being lost after an update. Once the bootloader is unlocked you can flash (that word again) a custom version of the recovery program (provided someone built one for that phone model) and use that to install the patches that will root the phone.

Other methods of rooting (for devices which don't have unlockable bootloaders or where people don't want to leave signs that they had unlocked the device) rely on exploiting some vulnerability in the software in order to modify the ROM to give you root access. The manufacturers will generally try to close such vulnerabilities when they find them (as they could also be used maliciously). So if you used one of these rooting tools or apps, then restored the phone to official, unmodified software and accepted an update, there is the possibility that the rooting tool will not work again after the update as the vulnerability it relied on might have been fixed.

 

[jimleong]

Hi Hadron, sorry again for the delayed response. Very, very busy week here as well.

i) Just curious but when you mentioned that these tools are generally not obtainable from the Play Store, where else can they be obtained? Do you have any recommended ways in which I can obtain these unrooting / rooting tools or apps that are compatible for my device and software?

As alternatives, any recommended popular and stable rooting / unrooting apps?

I've also been recommended by someone to use SuperSU - do you have any particular opinions about this?

ii) More importantly, do I require a lot of technical expertise to carry out unrooting / rooting independently?

Thank you very much again for your help.

Regards,
Jim