Database Develop

Confusions about rooting and rom flashing

I've been doing a lot of reading and searching but still can't find a definite answer...
My understanding is that I need to root the device to flash a custom rom
But from the instructions for noobs, they don't usually specify that I have to root
I assume that rooting is a pre-requisite for everything...but then some roms advertise that they are rooted (for example, LeoFroYo)
So it the rooting process tied to the rom itself and I have to root everytime I flash a new rom (if the rom is not rooted)? Or is it universal like HSPL on WinMo?

Rooting is per rom. What is required to flash a custom rom is having an unlocked bootloader and a custom recovery image. From there you can flash a pre-rooted rom.
The root instructions assume that you're gonna keep using the stock version with root abilities added on top. Whereas if you're using flashing something like CM, that already has root and OS tweaks.

FaJu said:
Rooting is per rom. What is required to flash a custom rom is having an unlocked bootloader and a custom recovery image. From there you can flash a pre-rooted rom.
The root instructions assume that you're gonna keep using the stock version with root abilities added on top. Whereas if you're using flashing something like CM, that already has root and OS tweaks.
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Click to collapse
Thanks! So does that mean when I get my phone out of the box, I have to root it once over the stock rom before I can flash any custom rom?

You need to root the phone originally and flash a custom rom. The "pre-rooted" means the rom is rooted. So if you flash that rom then you wont lose root. If you flash an un-rooted rom then you will lose it. So go through the steps and unlock your bootloader then flash a custom recovery image. Then decide which rom you wanted and flash it. All the custom roms are rooted.

futango said:
You need to root the phone originally and flash a custom rom. The "pre-rooted" means the rom is rooted. So if you flash that rom then you wont lose root. If you flash an un-rooted rom then you will lose it. So go through the steps and unlock your bootloader then flash a custom recovery image. Then decide which rom you wanted and flash it. All the custom roms are rooted.
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Click to collapse
That explains it. Thanks for your answer

one more question:
I take it as when bootloader is unlocked, there's no way to lock it again? Not even flashing the stock boot image?

No, once you unlock the bootloader, it stays unlocked.

Just to be clear here you don't _have_ to "root your phone once"
On _most_ phones you need an exploit to be able to get to the bootloader, this exploit is often referred to as rooting. After the exploit you generally have superuser access until you reboot, on some phone this may allow you to get at the bootloader and write anything you want there (E.G. an OS that give you superuser access at boot time)
However the N1 lets you issue the command "fastboot oem unlock" that unlocks the bootloader, from there you can flash a recovery image that will allow you to flash the main OS without having access to Google's release signing keys. Hence you _could_:
1. Bootloader unlock
2. Flash Custom recovery
3. Flash Custom OS
Without ever actually having "root" access, it just happens that most Devs prefer having root access available in both recovery and any custom rom they cook up.

ROM Manager Won't Doesn't Work

I have an N1 that I unlocked and rooted and was running CM7 RC1 when I decided to try the stock Gingerbread. This switch went perfectly, but now I don't think I want to stay on the stock GB but I can't seem to get ROM Manager to boot into recovery to allow me to flash another ROM. Do I have to do something differently now? BTW, I do not have root on the 'new' GB.
Thanks.

Unless you flashed a pre-rooted version of Gingerbread, you will have lost root and your custom recovery...
If this is the case, you have two options:
1 - Flash a custom recovery through an unlocked bootloader.
2 - passimg back to an older version of Android and root again...
Sent from my Nexus One using XDA App

tsprks said:
BTW, I do not have root on the 'new' GB.
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Click to collapse
This is your problem. ROM Manager installs a custom recovery, but only when your phone is rooted. You need to re-root GB.

Can I ask them how people flash custom recoveries without having root? I see threads all over the place that say that you don't have to root your phone to run these custom ROM's.

tsprks said:
Can I ask them how people flash custom recoveries without having root? I see threads all over the place that say that you don't have to root your phone to run these custom ROM's.
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You have to root, but you don't have to unlock your bootloader.

You have to do one of the things:
1) Root.
2) Unlock the bootloader.
Rooting allows you to bypass security mechanisms from within the OS, and flash the custom recovery from there.
Unlocking the bootloader turns off the security mechanisms, and you can flash whatever you want directly from bootloader.
Both achieve the same thing, but in different ways.
Root privileges in OS are lost upon official upgrades.
Unlocked bootloader is never lost.
Unlocked bootloader allows for an easy way to gain root in the first place, regardless of the ROM.

How does an unlocked bootloader allow me to flash whatever ROM I want? ROM Manager won't run without root? Am I missing something? I've read the wiki's and threads about rooting an N1 and they all just seem to stop at unlocking the bootloader, well, my bootloader is unlocked but I can't get it to boot into CWM so that I can select another ROM. Is there another way to do this?

ROM Manager is only one, and not the most successful nor most powerful, way to flash ROMs or recovery. ROM Manager was made for non-understanding people to make the process look and feel easier. The most powerful way is directly from bootloader - which needs to be unlocked to allow it.
If you read all the threads, you'll see that unlocking the bootloader is just a first step - you can look carefully at "installing custom ROM" guide in Wiki. Or, for example, here:
http://forum.xda-developers.com/showthread.php?t=636795
Read the Wiki, look for recovery installation instructions using unlocked bootloader, execute. I suggest Amon_Ra's.

Rooted with towelroot.What next?

Dear all,
I have rooted my device which is running 4.3 (c5502) (build number: . 101) with towelroot. Now i need to install any custom ROM. I came to know that it requires to install recovery first before flash any ROM. I stuck there..Can you please guide me. I didn't unlock my bootloader yet but I had my TA backup with me.Thanks in advance guys.

whatever u need to know is already there. just search for it. if u expect to be spoonfed then you really shouldn't mess with your phone

The thing is, do we really need to unlock boot loader to flash custom roms, or can it be closed just with root and recovery?
No one tryed it till now I think.
Greetings.

Lemmi1 said:
The thing is, do we really need to unlock boot loader to flash custom roms, or can it be closed just with root and recovery?
No one tryed it till now I think.
Greetings.
Click to expand...
Click to collapse
Yes for flashing custom Roms the bootloader must be unlocked and a recovery must be installed however if you want to flash a stock based Rom unlocked boot loader is not needed. Just Root and Recovery needed for flashing the stock based Roms. Correct me if i am wrong.

Cannot Install Custom Rom Xperia Z for T-Mobile (C606)

Hello,
I have been trying all day to install a custom rom on my Xperia Z for T-Mobile. I have succeeded in rooting it and installing the recovery, but it looks like the bootloader needs to be unlocked. I have followed this guide and have rooted and installed the recovery but when I install a custom rom, such as paranoid android lollipop, it gives me an error and I cannot reboot into a rom so I have to run the Sony PC Companion tool and repair the device. I now have a completely stock Xperia Z and wanted to know the best way to install a custom recovery and flash a rom. I have tried unlocking the bootloader but it says bootloader unlockable no when I dial service, even after installing root and recovery. I have tried anyways and it says operation not permitted when I try to cmd the unlock code into fastboot. I was hoping someone could help me and guide me on how to fix these issues and finally install a custom rom.
Thanks

T-mobile Z bootloader cannot be unlocked, therefore you cannot flash custom kernel, therefore you cannot flash a ROM that uses anything other than stock kernel. Look for the "LB" tag in the ROM title, these are for phones with (L)ocked(B)ootloaders, and should be STOCK based ROM's.
Just make sure you follow proper procedures when upgrading to different versions of Android.

[Help] Rooting LG L90 D410

Hi, I've been trying to Root, Unlock Bootloader and Flash a Custom Recovery in my LG L90 D410 Running Lollipop 5.0.2 Software v20a but there are too many methods and I'm confused. Some of them is just about rooting but also want to unlock bootloader and install recovery.
Please Help ASAP.

Hi. First step is rooting. As you are on 20a you should be able to use one-step rooting (search forum), which needs a computer. If it doesn't work or you want a simpler solution, you can use Kingroot, but be aware that there are some concerns about using it due to its constant communication to Chinese servers that aren't well explained so far AFAIK. You may want to replace it with SuperSU later using a script (not easy). It will be removed later if you flash a ROM anyway...
Once rooted: backup original bootstack and modemst partitions, flash unlocked bootstack (make sure you flash one for your exact phone model), flash recovery and then you should be able to flash any ROM.
PS: most custom ROMs only work with Kitkat bootstack, then either downgrade or flash KK bootstsck before flashing custom ROM.
PS2: it seems that at least latest versions of CM 12.1 work with either Kitkat or Lollipop bootstacks, so you may want to check the most recent info about the custom ROM you want to install first.
Sent from my LG-D410 using XDA Free mobile app