Rooting an old Samsung Galaxy SII

esuhl

I've just performed a factory reset of my old Samsung Galaxy SII (running Android 4.1.2).

I'm now wondering whether it would be worth rooting it. The main reason is so that I can run xPrivacy, so I can control app permissions.

https://play.google.com/store/apps/details?id=biz.bokhorst.xprivacy.installer&hl=en_GB

But, also feel like I should root the thing, just because I've never done it before, and... why not?

But I'm a bit confused about the rooting process. I understand Linux on a PC, and the concept of the "root" user, but I'm not quite sure I understand how to root a phone. Do you have to replace the built-in OS by flashing it with a rooted version, or can you gain root access to the installed OS?

Are there any tips or tricks I should know about?

Thanks in advance!

cookie365

All you need to know is here:
http://forum.xda-developers.com/galaxy-s2

JJ_Egan

Basically its just flashing a very small file .
That in effect unlocks the locked system .
On a rooted phone banking apps may not work .

esuhl

Thanks both. So... the file that is flashed just unlocks the existing OS, without changing the firmware...?

I don't do internet banking (or anything privacy-sensitive) on my phone, so that's fine. I guess I could unroot the phone if I ever want to in future.

cookie365 wrote: »

All you need to know is here:
http://forum.xda-developers.com/galaxy-s2

I had a look at that link and there's a guide to rooting by flashing the phone with the "Siyah Root Kernel" ROM. So... flashing requires a change to the Linux kernel, but the rest of the OS is untouched...?

It seems like there are lots of different kernels available to give root access. What sort of differences might there be between them? Are there any particular benefits or drawbacks to using the Siyah ROM?

I'm just trying to work out all the options! If there are lots of different kernels available, what do I need to know to choose the best one for me?

JJ_Egan

You want to root or install a rom a rom is a full firmware/ os .
That kernel is just an unlocked kernel .
You need to ask about kernels in the forum .

Not sure on that model phone but my normal method is flashing Philz Recovery the SuperSu zip through recovery to root .

AndyPix

Rooting your S2 allows you to rid yourself of all the bloat that comes pre-installed by smasung too.
Which is handy on these aging (but still great) handsets.


Cygenomod is one of the more popular Roms you might want to look at.


But as stated above, banking apps and some other stuff will refuse to work on a rooted phone

DoaM

When I used to root my Nexus 4, I used to use Nexus Root Toolkit. This made the whole process very simple.

Don't be fooled by the name ... it works for any Android phone.

indesisiv

AndyPix wrote: »

But as stated above, banking apps and some other stuff will refuse to work on a rooted phone

Some banking apps are just rubbish at properly detecting root. Before I rooted my phone halifax wouldn't work as it said it was rooted. Even though it wasn't.
So i rooted the phone and then left halifax as my bank as it was bugging me :rotfl:
HSBC works on a rooted phone


I'd have thought for a handset with software of that age there are simple things to unlock and root it. XDA is really helpful for this as suggested. Its been a while since I messed about with Samsung as I don't like their phones.

forgotmyname

Yep Halifax app stopped working on mine but the Santander one worked OK.

esuhl

Right... I think I'm beginning to get my head round things. Is this right:

1) In order to root, you first need to unlock the bootloader. (How do you do that...?)

2) Once the bootloader's unlocked, you can modify something (what? how?) to gain root access to the OS.

3) Instead of rooting the existing OS, you can replace it by flashing with a custom ROM that will probably have root access by default.

Am I getting close?

So the big thing I need to decide is whether to root the existing OS or replace it with a custom ROM...

And what do I need to do to make sure I can return the phone to its original factory state? Presumably if I root it myself, I can just unroot it, lock the bootloader and do a "factory restore" via the menu.

But what if I install a custom ROM...? Do I need to backup my own firmware first, or can I download the official Samsung image for my phone and flash it with that...?

JJ_Egan

1) In order to root, you first need to unlock the bootloader. (How do you do that...?)

yes but only if the bootloader is locked and i would be 99% certain that S2 is not locked .


2) Once the bootloader's unlocked, you can modify something (what? how?) to gain root access to the OS.

Normally by flashing a file .Like CF Autoroot etc but must be for your model and firmware .


3) Instead of rooting the existing OS, you can replace it by flashing with a custom ROM that will probably have root access by default.

Yes rooted via an inbuilt app SuperSu .
To install a custom rom you need a custom recovery like CWm TWRP or Philz Recovery . Flashed via Odin . Custom rom zip copied to your sd card and flashed through recovery .

Unroot and restore is by flashing a stock rom via Odin .Factory reset will not repeat not restore anything but the last firmware you flashed .

I download the official Samsung image for my phone Yes sammobile.com and other sources .