Root vs. Unlocked bootloader

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Logseman

Senior Member
Nov 22, 2010
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Tenerife
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In this thread I intend to give some basic insight about these two concepts, which are closely entwined with our phone's experience. I'm not a tech guy, but I think this little summary might clear some doubts for people who are new to this kind of issues (people who come from other non-Android phones especially). All feedback is welcome, in particular the one of people who can expand the topic with their knowledge.

"Root" is the common way to refer to the fact to the user account which has superuser rights on the device. Superuser rights imply full control over your phone's capacities, which are determined by the software and the hardware of the device. Non-superuser accounts have limitations, usually established for the sake of software security (for example, not allowing a user to disable critical functions such as phone or GPS), hardware safety (not allowing to change the processor's frequency speed, aka overclocking the CPU) or, in some cases, for someone's profit (disabling wi-fi tethering is a typical one as users are forced to buy data plans in order to use their devices to tether). In Android's case, Superuser is composed of an app* and a set of instructions to give this app root rights.

The bootloader is a program which accesses the internal storage and, basically, controls the loading of the programs and data necessary to initiate the sequence of launching the OS (aka booting, thus the name bootloader). We say that a bootloader is locked when it is programmed in such a way that it won't allow to load the device if it detects data from third-party sources. Unlocked bootloaders do allow these data and will load what these data contain, which will be usually a modified version of the phone's firmware, known as "Custom ROM".

As we can see, there was the fear that one would need to have unlocked bootloaders (i.e the ability to load third-party data in the booting sequence) in order to gain root rights. This would have been terribly inconvenient because only a minority of users will have unlocked bootloaders, since the phones with unlocked bootloaders by default are the ones sold carrier-unlocked. Said carrier-free phones will be a minority as the phone is pretty expensive: most Xperia Plays will be sold using carrier subsidies.

However, our fellow member Chainfire found an exploit (a programming loophole) in Gingerbread which allows said app and instructions to be loaded without the need of touching the bootloaders. Basically, his Gingerbreak program allows the user to have root rights without loading any bootloader-sensitive data. This widens the possibilities for the majority of users who will buy this phone with a subsidy.

*edit 3* Later on, it has become possible to unlock the bootloader even for SIM-locked devices, thanks to different unlockers like Alejandrissimo and Jinx13. This means that, provided that you pay what they charge, you can have your device set up without the bothers of having to buy a SIM-free phone. What's better: their method of unlocking the bootloader SIM-unlocks the phone as well.

I think this is more or less a succint framework of ideas which allows us to define "root" and "unlocked bootloaders" properly. As they say, knowing is half the battle, so I hope this nugget of information allows users to deal with their phones with more confidence.

*edit* as of version 2.3.3, this information has changed. Gingerbreak doesn't work with 2.3.3 anymore, and it seems now that the only way to root with locked bootloaders is to flash a 2.3.2 rom with FlashTool and update through OTA.

*edit2* note that this explanations pertains mostly to the Xperia Play. Other devices are NAND-locked, which means for us that they need unlocked bootloaders to even get root access.

*Note that Android is built in such a way that every app is a user account with limited rights (the ones specified before you download it). Thus, Superuser is a user account as any other app and the set of instructions is meant to give this user account root rights.
 
Last edited:

xperiaplay

Member
Jun 6, 2011
26
1
"As we can see, there was the fear that one would need to have unlocked bootloaders (i.e the ability to load third-party data in the booting sequence) in order to gain root rights. This would have been terribly inconvenient because only a minority of users will have unlocked bootloaders, since the phones with unlocked bootloaders by default are the ones sold carrier-unlocked. Said carrier-free phones will be a minority as the phone is pretty expensive: most Xperia Plays will be sold using carrier subsidies"

by carrier unlocked do you mean sim unlocked? sorry 4 noob question
 

TheBassman369

Senior Member
Dec 2, 2010
650
35
Indeed, that is what I mean.

Alright, I asked this question and it was answered, but I want to make sure before I try anything.

I just found out from SE that my phone is the Rogers version. It's obviously been unlocked because I'm using it on AT&T.

What I don't know, though, is whether the bootloader is unlocked. Another member recommended that I check TrackID to see if it worked because it depends on the manufacturer DRM's that are wiped in unlocking the bootloader. It did work, so I assume it's still locked, but I wanted to confirm because of being carrier unlocked.

Sent from my R800a using XDA App
 

Stief21774

New member
Apr 28, 2011
2
2
Austin
I have a Sim-Unlocked Xperia Play from Rogers that I am using on ATT's network. My phone is boot-locked. When powered off, if I hold the search key while plugging in the USB cable, I do not get a blue light.

I was able to flash the firmware by holding the back key while plugging in the usb cable (with the phone off). I get a green light when I do this. Using flashtool, I was able get 2.3.3 rooted by loading the 2.3.2 firmware, rooting, and then updating OTA.

I bricked my phone several times while loading the firmware and each time I was able to fix it with flashtool or Sony Ericsson's Upgrade Utility. I found that you need a good USB cable, and even then it failed sometimes. I just kept trying and eventually it worked.
 

tommyinhi27

Member
Jul 26, 2009
23
2
We wanted to provide an update on HTC’s progress with bringing bootloader unlocking to our newest phones. We know how excited some of you are for this capability, and we’ve put significant resources behind making this change as soon as possible. While we wish we could flip a simple switch and unlock all bootloaders across our device portfolio, this is actually a complex challenge that requires a new software build and extensive testing to deliver the best possible customer experience.

We’re thrilled to announce today that software updates to support bootloader unlocking will begin rolling out in August for the global HTC Sensation, followed by the HTC Sensation 4G on T-Mobile USA and the HTC EVO 3D on Sprint. We’re in the testing phase for the unlocking capability now, and we expect it to be fully operational by early September for devices that have received the software updates. We'll continue rolling out the unlocking capability over time to other devices as part of maintenance releases and new shipments.

HTC continues its commitment to unlocking bootloaders and supporting the developer community. Because of the importance of this community to us, please expect an update on this about every few weeks as we make progress toward launch. Thank you for your patience and continued support!

(they claim it will come to only two devices for starters the EVO 3D and the Sensation 4G and then it will slowly rollout to other devices that already have 2.3 or enough internal memory on them, this will all start in last August an early September for the first two droids listed... and others will soon follow suit, the only question is do you want you bootloader to come unlocked stock? Or will you buy it locked and be able to sit around and wait for your device to get an update to do so?? LOL
 
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LemonPlusTea

Senior Member
Jun 18, 2011
161
10
thats why my phone couldnt flash back to 2.3.2..(?)

I live in singapore.. phones are not carrier specific.. so does that mean my BL was unlocked even before I used gingerbreak? :eek:
 
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AndroHero

Senior Member
May 28, 2010
6,476
906
Manchester
I know this doesnt pertain to the play per se, but maybe you should add that, with nand locked devices, an unlocked bootloader is required to acheive full root, just incase someone with another device googles this question and ends up here :)
 
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tommyinhi27

Member
Jul 26, 2009
23
2
pros and cons of unlocked bootloader

Pros/Cons of rooting WITHOUT unlocking bootloader?
Since being interested in rooting my N1 I've been googling a lot but it's still somewhat confusing. One of the things that's making me hesitent is the idea of permanently (as of the date of this post) unlocking the phone and thus clearly/visibly voiding the warranty.

I've recently stumbled upon instructions for rooting without unlocking the bootloader? Am I correct in assuming this would make the phone appear (no unlock icon) to be unmodified? Also, does this mean one could fully reverse the rooting process and go back to fully stock google signed roms with OTA updates etc (essentially reverting it back as if it were never modified)?

It would seem this would be preferable to any method involving the unlocking of the bootloader. Are there any disadvantages of this? Any increased risks by NOT unlocking the bootloader? Is there a reason why most people have gone the rout of unlocking the bootloader?

My plan is simply to have root access to run setcpu on the stock FRF91 rom. As of now, I'm not interested in other ROMs (baby steps).
 

AndroHero

Senior Member
May 28, 2010
6,476
906
Manchester
Pros/Cons of rooting WITHOUT unlocking bootloader?
Since being interested in rooting my N1 I've been googling a lot but it's still somewhat confusing. One of the things that's making me hesitent is the idea of permanently (as of the date of this post) unlocking the phone and thus clearly/visibly voiding the warranty.

I've recently stumbled upon instructions for rooting without unlocking the bootloader? Am I correct in assuming this would make the phone appear (no unlock icon) to be unmodified? Also, does this mean one could fully reverse the rooting process and go back to fully stock google signed roms with OTA updates etc (essentially reverting it back as if it were never modified)?

It would seem this would be preferable to any method involving the unlocking of the bootloader. Are there any disadvantages of this? Any increased risks by NOT unlocking the bootloader? Is there a reason why most people have gone the rout of unlocking the bootloader?

My plan is simply to have root access to run setcpu on the stock FRF91 rom. As of now, I'm not interested in other ROMs (baby steps).

The N1 is made by HTC, generaly with htc devices, flashing a stock rom, will re-lock the bootloader, If you decide just to root, you will need a custom kernel before you can O/C :) All that unlocking the bootloader does is 2 things, It will security unlock the nand (on nand locked devices) allowing r/w access to read only partitions, and it allows you to issue fastboot commands to your device, the main reason alot of play owners went down the unlocking the bootloader path, is that atm it is the only way to flash custom roms :) other devices, have found sneaky ways to push a custom recovery without unlocking bootloaders, and thus do not need one to flash a custom rom :)
 
Last edited:

Logseman

Senior Member
Nov 22, 2010
2,513
651
35
Tenerife
logseman.svbtle.com
I know this doesnt pertain to the play per se, but maybe you should add that, with nand locked devices, an unlocked bootloader is required to acheive full root, just incase someone with another device googles this question and ends up here :)

I'm not too knowledgeable about the whole Nand thing, so I think you could give a much better explanation about it. I'll include it then ;)
 

isavegas

Senior Member
Mar 8, 2012
68
13
Spring
whoa whoa whoa!!!! i achieved root on 2.3.3 with no prob using superoneclick v2.3.3. it works beautifully! :D
 

netizenmt

Senior Member
Jan 20, 2011
1,211
363
Yes, but you're replying to a thread that's 8 months out of date too!

Sent from my R800x using XDA
 

isavegas

Senior Member
Mar 8, 2012
68
13
Spring
Lol. I know, but I've been trolling the site, and I think it may need a bit of new info so someone doesn't follow the steps here now that a better method has been found. :)

Sent from my R800at using XDA
 

FrEcP

Senior Member
Jul 29, 2006
369
72
Lol. I know, but I've been trolling the site, and I think it may need a bit of new info so someone doesn't follow the steps here now that a better method has been found. :)

Sent from my R800at using XDA
why not just stop bumping heavily old threads? then they can rest in piece
and nobody would care

the information thatit's outdated is alreada given in 1st post.

u also could ask a mod to close this as its outdated...
 

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  • 9
    In this thread I intend to give some basic insight about these two concepts, which are closely entwined with our phone's experience. I'm not a tech guy, but I think this little summary might clear some doubts for people who are new to this kind of issues (people who come from other non-Android phones especially). All feedback is welcome, in particular the one of people who can expand the topic with their knowledge.

    "Root" is the common way to refer to the fact to the user account which has superuser rights on the device. Superuser rights imply full control over your phone's capacities, which are determined by the software and the hardware of the device. Non-superuser accounts have limitations, usually established for the sake of software security (for example, not allowing a user to disable critical functions such as phone or GPS), hardware safety (not allowing to change the processor's frequency speed, aka overclocking the CPU) or, in some cases, for someone's profit (disabling wi-fi tethering is a typical one as users are forced to buy data plans in order to use their devices to tether). In Android's case, Superuser is composed of an app* and a set of instructions to give this app root rights.

    The bootloader is a program which accesses the internal storage and, basically, controls the loading of the programs and data necessary to initiate the sequence of launching the OS (aka booting, thus the name bootloader). We say that a bootloader is locked when it is programmed in such a way that it won't allow to load the device if it detects data from third-party sources. Unlocked bootloaders do allow these data and will load what these data contain, which will be usually a modified version of the phone's firmware, known as "Custom ROM".

    As we can see, there was the fear that one would need to have unlocked bootloaders (i.e the ability to load third-party data in the booting sequence) in order to gain root rights. This would have been terribly inconvenient because only a minority of users will have unlocked bootloaders, since the phones with unlocked bootloaders by default are the ones sold carrier-unlocked. Said carrier-free phones will be a minority as the phone is pretty expensive: most Xperia Plays will be sold using carrier subsidies.

    However, our fellow member Chainfire found an exploit (a programming loophole) in Gingerbread which allows said app and instructions to be loaded without the need of touching the bootloaders. Basically, his Gingerbreak program allows the user to have root rights without loading any bootloader-sensitive data. This widens the possibilities for the majority of users who will buy this phone with a subsidy.

    *edit 3* Later on, it has become possible to unlock the bootloader even for SIM-locked devices, thanks to different unlockers like Alejandrissimo and Jinx13. This means that, provided that you pay what they charge, you can have your device set up without the bothers of having to buy a SIM-free phone. What's better: their method of unlocking the bootloader SIM-unlocks the phone as well.

    I think this is more or less a succint framework of ideas which allows us to define "root" and "unlocked bootloaders" properly. As they say, knowing is half the battle, so I hope this nugget of information allows users to deal with their phones with more confidence.

    *edit* as of version 2.3.3, this information has changed. Gingerbreak doesn't work with 2.3.3 anymore, and it seems now that the only way to root with locked bootloaders is to flash a 2.3.2 rom with FlashTool and update through OTA.

    *edit2* note that this explanations pertains mostly to the Xperia Play. Other devices are NAND-locked, which means for us that they need unlocked bootloaders to even get root access.

    *Note that Android is built in such a way that every app is a user account with limited rights (the ones specified before you download it). Thus, Superuser is a user account as any other app and the set of instructions is meant to give this user account root rights.
    2
    I have a Sim-Unlocked Xperia Play from Rogers that I am using on ATT's network. My phone is boot-locked. When powered off, if I hold the search key while plugging in the USB cable, I do not get a blue light.

    I was able to flash the firmware by holding the back key while plugging in the usb cable (with the phone off). I get a green light when I do this. Using flashtool, I was able get 2.3.3 rooted by loading the 2.3.2 firmware, rooting, and then updating OTA.

    I bricked my phone several times while loading the firmware and each time I was able to fix it with flashtool or Sony Ericsson's Upgrade Utility. I found that you need a good USB cable, and even then it failed sometimes. I just kept trying and eventually it worked.
    1
    If TrackID works, your bootloader is locked, regardless of simlock.
    1
    We wanted to provide an update on HTC’s progress with bringing bootloader unlocking to our newest phones. We know how excited some of you are for this capability, and we’ve put significant resources behind making this change as soon as possible. While we wish we could flip a simple switch and unlock all bootloaders across our device portfolio, this is actually a complex challenge that requires a new software build and extensive testing to deliver the best possible customer experience.

    We’re thrilled to announce today that software updates to support bootloader unlocking will begin rolling out in August for the global HTC Sensation, followed by the HTC Sensation 4G on T-Mobile USA and the HTC EVO 3D on Sprint. We’re in the testing phase for the unlocking capability now, and we expect it to be fully operational by early September for devices that have received the software updates. We'll continue rolling out the unlocking capability over time to other devices as part of maintenance releases and new shipments.

    HTC continues its commitment to unlocking bootloaders and supporting the developer community. Because of the importance of this community to us, please expect an update on this about every few weeks as we make progress toward launch. Thank you for your patience and continued support!

    (they claim it will come to only two devices for starters the EVO 3D and the Sensation 4G and then it will slowly rollout to other devices that already have 2.3 or enough internal memory on them, this will all start in last August an early September for the first two droids listed... and others will soon follow suit, the only question is do you want you bootloader to come unlocked stock? Or will you buy it locked and be able to sit around and wait for your device to get an update to do so?? LOL
    1
    I know this doesnt pertain to the play per se, but maybe you should add that, with nand locked devices, an unlocked bootloader is required to acheive full root, just incase someone with another device googles this question and ends up here :)