05-28-2016, 06:39 PM
What I wanna ask is, (I guess it's of most newbies concern as well), can we have a 100% backup of our system (stock ROM)? Obviously, it is important because:
If we perform an official (OTA) update to a new Android version. And we don't like it. It is possible to get back to the old original one which we are used to. (not everybody likes new things, and/or not every new thing is good)
If our phones are having some problems. And we have to give it back to the company for a fix. In most cases they will flash a new ROM for us. If we wanna keep using the old one (explained in #1), we have to keep a copy of it by ourselves.
If we want to try new custom ROMs, we may want to switch it back after trying.
Whenever we do any modifications, it's always better to keep a backup/roll-back point. In case anything goes wrong, we have a safeguard.
For the official warranty issue.
Yup I do see there are some official stock ROMs downloads for some particular phones. But those are not really a backup of our original ROMs. And it's always hard to verify if those downloads are the original official releases. And, if those downloads are 100% stock ROMs, this means some guys out there could make it, so what is the way to do so?
Or, how those mobile phone companies do it in their labs?
I have been doing researches on this topic for a few days. Some posts claim that their methods are "backup stock ROM" or "backup before rooting". But after digging into it, they requires rooting and/or flashing CWM. Here comes a few questions:
Rooting will in fact changes some files/data of the system. So backup after root is NOT getting the original stock ROM. Is it?
Is there a method to "un-root", so ALL the changes are TOTALLY reverted?
Installing/flashing things like CWM in phone requires rooting, which would make the ROM not original. Is there a way to extract the system backup from a computer externally?