Can we backup original ROM?

[midnite_]

This question has been wandering me for almost a year.

I saw from somewhere and some people say, after Rooted, the ROM is not ORIGINAL anymore. So, is there a way to take a copy of the original ROM before Rooting?

(Of course I have done more than enough searching and readings. But seems there is no answer of backup before Rooting.)

In fact what I want is simple. (I am not sure if the way to achieve it is difficult or not.)

1. I got a phone with its stock ROM now.
2. I will upgrade it to a new version of Android.
3. Then get it back to that old version of Android.

So the concept is:
1. Original ROM running in phone: [phone [original ROM] ]
2. Take a copy of the ROM: [phone [original ROM] ] ... [original ROM]
3. Phone being altered/updated: [phone [altered ROM] ] ... [original ROM]
4. Put back the original ROM: [phone [original ROM] ]

So all the changes have been rewind and the phone is like its ORIGINAL.

Can we?

If Rooting does not affect the original ROM, and we can "un-root" a phone, I have an idea of the procedure:
1. First, we have: [phone [original ROM] ]
2. Root it: [rooted phone [original ROM] ]
3. Some say we can use ClockworkMod Recovery without installing/flashing it: [rooted phone [original ROM] ] ... [CWM]
4. Backup the Original ROM: [rooted phone [original ROM] ] ... [CWM] ... [original ROM]
5. Phone being altered/updated: [rooted phone [altered ROM] ] ... [original ROM]
6. Put back the original ROM: [rooted phone [original ROM] ]
7. Un-Root the phone: [phone [original ROM] ]

Is it possible??


Thanks a lot for any input!!

Thanks wholeheartedly!!

midnite_

 

[Digital Controller]

Basically before putting the new ROM on your just make a backup with whatever ROM software you are using, like ClockWorkMod. We always tell members to make a backup, and yes this backup is of the original system(ROM).

So in other words this process that you described is how we wish all our members would approach rooting/ROMing.

Hope this answers your question.

 

[Hadron]

These things do depend on the phone. For example, with my handset there are 2 main rooting methods. With one everything is done in one step, so by the time you can make a backup the ROM is rooted. The other gives you the ability to install a custom recovery, and you then use that to root the ROM. In the second method then you could back up the ROM once you have installed a custom recovery but before rooting.

Rooting methods depend on the phone, so I can't give a general answer.

For many phones it's possible to get hold of the original software, which you can then flash if you need to return to stock