[General Questions and Answers] midnite_:
Hi there,

I am new to xda and new to Android hacking.

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:

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?

In addition, I have found some related pieces. which could be useful to anyone viewing this post, and might be useful for you to solve this (my) question. :fingers-crossed:

* as I'm a new user, I can't post links directly. Please delete the blank spaces in between.

ht tp://www .modaco .com/topic/351269-backup-original-rom/

In reply #5, user C3C0 raised a method of backing up the original stock ROM without root. But it seems he is flashing CWM and that method is only for ZTE Skate.

adb backup tool of Android SDK

At the first sight i came across this approach, I thought it is the official method to do whole system (ROM) backup (WOW - how nice!). But after studying for a few more posts, I think adb backup can only backup app+app_data, and possibly some system settings only. Am I correct? And also, adb backup is only for ICS (Android 4.0), isn't it?

adb backup usage: ht tp://forum.xda-developers .com/showthread.php?t=1420351

(But mentioned in the bottom of #1 the poster is having some issues on using adb backup. Perhaps there are some bugs and not reliable(?)

One more question on adb backup: Can it backup just one app+app_data, and restore just one app+app_data, without affecting other things? If yes, we don't need to root and don't need Titanium Backup (which requires root) for backup app+app_data. Isn't it?

** In case I have said anything or any terms wrongly in this thread, please

DO

correct me, for helping me and helping others. :)

P.S. i am using LG Optimus 3D.

Thanks a lot, wholeheartedly,

midnite_