[Q] Root vs Bootloader Unlock - Xperia Arc Q&A, Help & Troubleshooting

I am new and fresh to this field, so what exactly is rooting and bootloader unlock?
Is it necessary for us to unlock bootloader before rooting the phone like most of the thread that i have read so far?
if we installing custom rom like Xperia Ultimate HD, paranoid,etc. is it necessary just to root/unlock bootloader or both is required?
Can we install custom rom without unlock the bootloader or rooting?
What is is the downfall of rooting and bootloader unlock?
Thanks for the reply in advance.

Rooting gives "admin" rights - allowing you to make changes to the system files on the phone.
Unlocking bootloader enables you to write to the /boot partition on the phone ( ie flash custom kernel) which is normally not writable even with root access.
it is phone dependent. Some phones need unlocked bootloader to be rooted, some do not. We have several rooting tools for locked bootloader, it's in the general section use the search button.
There are different types of rom - stock based and CM based.
But before that - kernels are only compatible with android version. You cannot use, say, JB kernel on ICS rom.
Stock based roms ( UHD, Zelly Cream etc) do not need unlocked BL bc they can run on the stock kernel.
CM based roms ( CM7.2, CM9, MIUI V5) need unlocked BL because they cannot run on stock.
So if you have locked BL, you root, copy Rom into sdcard, install recovery then install rom.
if you have unlocked BL, you simply flash kernel then flash rom. No need to root because custom roms are pre rooted.
Rooting does no harm to phone. Unlocking BL via official method makes u lose DRM keys and warranty but u can always relock and get warranty back. ( providing service centre does not check for DRM)
This is a simple overview for a more in-depth understanding check the general section there are many great guides in there.
Sent from my MiUI-ed Xperia arc S
\ press thanks if I've helped /

tangosierra_ said:
Rooting gives "admin" rights - allowing you to make changes to the system files on the phone.
Unlocking bootloader enables you to write to the /boot partition on the phone ( ie flash custom kernel) which is normally not writable even with root access.
it is phone dependent. Some phones need unlocked bootloader to be rooted, some do not. We have several rooting tools for locked bootloader, it's in the general section use the search button.
There are different types of rom - stock based and CM based.
But before that - kernels are only compatible with android version. You cannot use, say, JB kernel on ICS rom.
Stock based roms ( UHD, Zelly Cream etc) do not need unlocked BL bc they can run on the stock kernel.
CM based roms ( CM7.2, CM9, MIUI V5) need unlocked BL because they cannot run on stock.
So if you have locked BL, you root, copy Rom into sdcard, install recovery then install rom.
if you have unlocked BL, you simply flash kernel then flash rom. No need to root because custom roms are pre rooted.
Rooting does no harm to phone. Unlocking BL via official method makes u lose DRM keys and warranty but u can always relock and get warranty back. ( providing service centre does not check for DRM)
This is a simple overview for a more in-depth understanding check the general section there are many great guides in there.
Sent from my MiUI-ed Xperia arc S
\ press thanks if I've helped /
Click to expand...
Click to collapse
So, how about Xperia Arc and Xperia Arc S? does it require to unlock bootloader to root?
What is the main difference of Stock based roms and CM based roms? How to differentiate it?
Correct me if i mistake. Unlock the bootloader normally only required for flashing the custom kernel like lupus kernel which it is required for CM based rom. And if it is stock based it will only need root for the installation.

shuffle1990 said:
So, how about Xperia Arc and Xperia Arc S? does it require to unlock bootloader to root?
What is the main difference of Stock based roms and CM based roms? How to differentiate it?
Correct me if i mistake. Unlock the bootloader normally only required for flashing the custom kernel like lupus kernel which it is required for CM based rom. And if it is stock based it will only need root for the installation.
Click to expand...
Click to collapse
Firstly, Xperia Arc and Xperia Arc S use the same kernels, and the same ROMs, they're most likely the same phone. The stock-based ROMs, as far on my stay on xda I've learned that they are the ones based on the ROMs already released by sony, i.e Ice Cream Sandwich or Gingerbread. How to differentiate? Easy, on a first place the Rom Thread should clearly say if it's stock based or no, and you can see the tags [ICS] or [.587], or tags like that. CM based ROMs should be clearly stated too, plus it must say [CM10] or [CM10.1].
And yes, you're right, without unlocking bootloader you can still have a custom ROM, ICS based or GB based. You actually don't need root for the installation, and generally the ROMs that you install come pre-rooted. Hope it helped.

tangosierra_ said:
Unlocking bootloader enables you to write to the /boot partition on the phone ( ie flash custom kernel) which is normally not writable even with root access.
Click to expand...
Click to collapse
Just to correct this, unlocking bootloader allows custom, unsigned, kernels to be installed. /boot partition can still be edited by using stock kernels, which have been signed by Sony, these are the kernels within Flashtool FTF files. This can still be done with locked bootloader.

The thread titles will tell if it is stock or CM based
Ah yes forgot about the stock kernel, damn

Related

[Q] Confused about the order in which to do things

Ok, so I'm a bit confused about how to go around things. I wish to upgrade my phone to ICS 4.04; that I can handle. But I also wish to root it and install a custom ROM and kernel. My bootloader is currently locked and I understand that I need it to be unlocked for the custom ROM and kernel and the ICS root. I've already checked and my phone can be bootloader unlocked.
So here's the main question: What order should I do this in? Am I right in the method below?
Unlock bootloader
Install ICS via FT
Flash custom kernel with recovery
Flash custom ROM
Thanks.
yep...
Sent from my LT18i using xda premium
Pretty much so. I'd put the rom zip on your SD card first, then use fastboot for the kernel, then flash the rom.
sinkster©
So
1. Place custom ROM on SD
2. Use fastboot to install kernel
3. Boot Recovery
4. Install ROM
Right?
unlock bootloader
copy ROM to sd card
flash custom kernel
flash custom ROM
no need to flash ICS fw..
If you are going to unlock the official Sony way, before you unlock bootloader on your Arc beware of a few things.
1. Using the official Sony unlock will remove the DRM keys from your phone. This is not really a big deal, but some Sony apps, like for example TrackID, won't work without these keys.
2. Using the official Sony unlock means that if at some time down the line you return to using official Sony roms, using an OTA (over the air) update from Sony can brick your phone. I know it sounds ridiculous but search this site, or look it up on Google, either of which will confirm this. This, to my mind anyway, is certainly a bigger deal.
I'd recommend that you avoid the official Sony method for these reasons. Although it's not usually free, I'd recommend going with the testpoint method for unlocking.
I got my Arc unlocked and SIM-freed by an XDA member called jinx13 and have really enjoyed using my phone since. I've been jumping back and forth through custom roms and official roms without any problems.
PS. arpith.fbi is right, no need to flash ICS before custom rom, just go straight to the custom rom.

[Q] Installing custom roms on Arc S with locked boot loader

I'd just like to say hi to everyone, my name is Mick.
I have an Arc S, originally running GB, but currently running ICS, build 4.1.A.0.562 which I updated to via SEUS a while ago.
I've used DoomLord's one click method to root the phone, have CWM installed, and I've been happy with it since, but I've now decided to see about installing a custom rom.
I've done a lot of reading on here about locked and unlocked boot loaders, and mine's locked so a bit restrictive in what I can do I gather.
What I'd like to know is, a lot of the roms for locked bl's, say based on, or must have, the .587 build, but mine is the earlier .562.
What is the best way to proceed?
Can I flash the .587 kernel with flashtool as I've read that the stock, signed kernels can be flashed on locked bls. Is this right, and does flashing a stock .587 kernel affect rooting?
Any help, or links to whatever I haven't found yet, would be much appreciated.
Cheers,
Mick.
MickieH said:
I'd just like to say hi to everyone, my name is Mick.
I have an Arc S, originally running GB, but currently running ICS, build 4.1.A.0.562 which I updated to via SEUS a while ago.
I've used DoomLord's one click method to root the phone, have CWM installed, and I've been happy with it since, but I've now decided to see about installing a custom rom.
I've done a lot of reading on here about locked and unlocked boot loaders, and mine's locked so a bit restrictive in what I can do I gather.
What I'd like to know is, a lot of the roms for locked bl's, say based on, or must have, the .587 build, but mine is the earlier .562.
What is the best way to proceed?
Can I flash the .587 kernel with flashtool as I've read that the stock, signed kernels can be flashed on locked bls. Is this right, and does flashing a stock .587 kernel affect rooting?
Any help, or links to whatever I haven't found yet, would be much appreciated.
Cheers,
Mick.
Click to expand...
Click to collapse
First, .562 update is crap. Sony released a crappy 4.0.3 update, better update if you can.
Then installing stock firmware before installing a custom ROM is not necessary.
Yes, there is difference in .562 and .587 kernels. Apparently, .562 kernels have a security hole in it, which can be used for rooting, however .587 kernels don't have it anymore and you will have to install older kernel to root and then install newer kernel back.
Yes u can flash .587 kernel using flashtool & this will not effect on root... But I will suggest u to update ur phones firmware to .587 (.562 is full of bugs), root it & install cwm then flash stock based custom roms which supports locked bootloader..
Sent from my MT11i using Tapatalk 2
Samak46 said:
Yes u can flash .587 kernel using flashtool & this will not effect on root... But I will suggest u to update ur phones firmware to .587 (.562 is full of bugs), root it & install cwm then flash stock based custom roms which supports locked bootloader..
Sent from my MT11i using Tapatalk 2
Click to expand...
Click to collapse
It does. 4.1.A.0.562 kernel has a security hole in it, which is used to root via DooMLoRD's method. .587 kernel has that hole patched and that root method does not work.
Thanks for the replies.
Ok, so this means that I can use flashtool to flash the .587 kernel, and then whichever rom afterwards.
I have tried flashing roms with the .562 kernel, and they do work, but I get odd glitches.
The Walkman app in Zelly Cream 2.0 for instance says it has unexpectedly stopped whenever I click on My Music, and the Ultimte HD rom is really good, but the native Movie player won't work and does the same whenever I click on a video.
Each app works ok on one rom, but not on the other.
At the moment I've got the Zelly Cream rom installed and just disabled the Walkman, so had to download another player.
So far I've not had any issues with boot loops or anything, but I have been wiping properly before installing.
I have got a stock .587 kernel I found on here, so I'll try flashing that and see if it's any better.
It's a shame the boot loader is locked, but I've also read that removing the sim lock can fix this.
Thanks again for the info. :good:
587 kernel
Sorry, has anyone got a link for a generic .587 kernel as when I search, the ones that come up have been modified in some way, and my boot loader is locked.
Thanks.
Got it
Ah, it's ok, I think I've found it.
The first one I downloaded was reproting LT15 in Flashtool, so after a bit more searching found it here
http://forum.xda-developers.com/showthread.php?t=1838830
Should be ok.
Just download the whole ROM, but choose only kernel to install.
Sent from LT18i with custom firmware by myself.
Your phone's not covered under warranty anymore, so why don't you try unlocking the bootloader? Would barely take a few minutes.
Hi, Flash new .587 firmwar..... flash .562 kernel only.....root phone.....flash original .587 kernel only.....this video helped me a lot.
http://www.youtube.com/watch?v=Rjv71b9QcZE
Feel free to get in touch...good luck !!

Which ROMs can be installed with a locked bootloader?

Which ROMs can be installed with a locked bootloader? Mine can't be unlocked. As far as I know there's no way to get a different kernel with a locked bootloader.
You can only install custom ROMs based on stock ROM and use stock kernel. You can also head to the development section and find a ROM that runs on a phone with a locked bootloader. The developer will usually tell you if his ROM can run on a phone with locked bootloader.
僕のLT18iから送られてきた

[Q] stock and rooted 4.1.1

hello,
i want to flash an aokp rom,do i need to update the bootloader and modem first?
Before updating the bootloader beyond 4.1.1, unlock your phone using the free method, flash a custom recovery, then the custom ROM.
If you want to know if a particular ROM needs a specific bootloader, look at the updater script in the ROM itself for supported bootloaders.
Before updating your you should be aware that you cannot down grade your bootloader once you are on the 4.3 bootloader, this does affect which roms you can run. Do a search on 4.3 bootloader there are many threads with very good info on this topic.

Locked vs Unlocked Bootloader

Hi i would just like to ask something that has been confusing me for quite a while now. I've had my hydrogen for a week and ive unlocked bl, rooted now with a custom rom(rr rom 5.7.4 working great!!) I did not actually wanted to unlock the bootloader but to be safe, i followed the instructions.
so here it is, before mi max, I had a mi4i, an xperia, and a zenfone 4, done the same, root,install custom recovery, and flashed custom roms.. the only unit i unlocked bl was the xperia since i wanted to flash Official CM, (CM's comes with their own kernel right? so flashing them needs bl unlocked) but when BL was locked i could still flash roms, manual update, (ROMs that are meant for locked bl only). then with mi4i (locked bl) i was able to root, install twrp, manual flash updates, official roms, and custom rom (CM13).
The part where I am confused is, why do i need my bootloader unlocked if i was going to root,install twrp, and flash custom roms only on my max without touching the kernel? When in my previous experiences as long as i dont need touch/tweak the kernel, i dont need my bootloader to be unlocked.
Sorry for long post..
I hope my question makes sense

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