Database Develop

[Q] What is a Bootloader?

What is a Bootloader? and what does unlocking a bootloader do?

This thread says "READ ME 1ST!" for a reason.

gagan_sj said:
What is a Bootloader? and what does unlocking a bootloader do?
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if you want to upgrade your ROM you must unlock your BL. So you can flash the kernel or alfs then flash the ROM!
I think bootloader is same thing like BIOS in computer..
so we can change everything inside the phone system
read this

BlackRabbit1703 said:
if you want to upgrade your ROM you must unlock your BL. So you can flash the kernel or alfs then flash the ROM!
I think bootloader is same thing like BIOS in computer..
so we can change everything inside the phone system
read this
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Actually that's not completely right
Sent from my XPERIA using XDA Premium.

Q: What is bootloader?
A: In simple terms, a bootloader is the code that runs on a device before the operating system starts up. This low-level code contains the instructions that tell a device how to start up and find the system kernel. Every time your phone starts up, that bootloader code is telling your device what to do in order to get you to the home screen. As you can imagine, this process is vitally important. As such, manufacturers often use security measures to keep you from tampering with the bootloader.
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Quoted from the thread I linked!

gagan_sj said:
What is a Bootloader? and what does unlocking a bootloader do?
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Here is what You need to read
https://en.wikipedia.org/wiki/Booting
If you have some IT skills you'll understand.

Bootloader locked

hi all recently have given me a Xperia sp but can not unlock the bootloader as it comes from the factory locked my question is if there is any way to unlock it, or can not be by any method.
Sorry my bad english.

http://developer.sonymobile.com/unlockbootloader/unlock-yourboot-loader/

forddark said:
hi all recently have given me a Xperia sp but can not unlock the bootloader as it comes from the factory locked my question is if there is any way to unlock it, or can not be by any method.
Sorry my bad english.
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If it says bootloader unlock allowed: no, then fastboot is missing from your phone which is necessary to unlock the bootloader. So yes, you cannot do that if that's the case.

shahrukhqasim said:
If it says bootloader unlock allowed: no, then fastboot is missing from your phone which is necessary to unlock the bootloader. So yes, you cannot do that if that's the case.
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Yes it says bootloader unlock allowed: no, then there is not way to change the status of bootloader for yes.[emoji22]

forddark said:
Yes it says bootloader unlock allowed: no, then there is not way to change the status of bootloader forma yes.[emoji22]
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No one has discovered it yet. If you find a solution, PM me too.

shahrukhqasim said:
No one has discovered it yet. If you find a solution, PM me too.
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This is a bad news, [emoji25]

forddark said:
This is a bad news, [emoji25]
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Very much!

shahrukhqasim said:
If it says bootloader unlock allowed: no, then fastboot is missing from your phone which is necessary to unlock the bootloader. So yes, you cannot do that if that's the case.
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Fastboot is always there... Even on carrier locked devices you can even flash a custom kernel if you want but it just won't boot you can also install a ROM for locked bootloader
Sent from my C5303 using XDA Free mobile app

noahvt said:
Fastboot is always there... Even on carrier locked devices you can even flash a custom kernel if you want but it just won't boot you can also install a ROM for locked bootloader
Sent from my C5303 using XDA Free mobile app
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Seriously?? Then might be we can find a solution somehow using custom kernels? But I have tried for hours I could never get into FASTBOOT mode. It went into FLASHTOOL(green light) mode but never into FASTBOOT mode. I inferred, FASTBOOT is missing from the device. I think it is missing.

Frp locked

I cant unlock frp as It is grayed out the option of oem unlocking in the dev options
pls I need help
Model : LLD-L21
OS : KangVIP Rom (EMUI 8.0.0)
Bootloader Status : Unlocked
In fastboot it says
Phone Unlocked
FRP Locked

did u try dload method?

yes I tried dload
It did not work

I can't upload zipI will send u the file to unlock frp or you can find that file in telegram group of our device

That wont work...
Go to terminal in root mode and do
Code:
Setprop sys.oem_unlock_allowed 1
Than you can change the value and its not longer greyed out.

Darkest-Dark said:
That wont work...
Go to terminal in root mode and do
Code:
Setprop sys.oem_unlock_allowed 1
Than you can change the value and its not longer greyed out.
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If that dosent work you can also follow the below procedure.
Relock your bootloader. Your phone will factory reset and boot. Then head to developer options and you will see oem unlock is not greyed out. Then just enable oem unlocking and unlock the bootloader. When you boot up again you will see that oem is greyed out but it'll be enabled. So you'll have unlocked fastboot and unlocked frp now.

Fredin_ said:
That wont work...
Go to terminal in root mode and do
If that dosent work you can also follow the below procedure.
Relock your bootloader. Your phone will factory reset and boot. Then head to developer options and you will see oem unlock is not greyed out. Then just enable oem unlocking and unlock the bootloader. When you boot up again you will see that oem is greyed out but it'll be enabled. So you'll have unlocked fastboot and unlocked frp now.
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This will just brick the device.

Fredin_ said:
If that dosent work you can also follow the below procedure.
Relock your bootloader. Your phone will factory reset and boot. .....<snip>.
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Never Ever a good idea to try and relock the bootloader.

viratbansal001 said:
This will just brick the device.
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Sparkrite said:
Never Ever a good idea to try and relock the bootloader.
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Umm why? Its working pretty fine for me. ?

Fredin_ said:
Umm why? Its working pretty fine for me.
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Have you Unlocked, Relocked and then Unlocked again ?

[/COLOR]
Sparkrite said:
Have you Unlocked, Relocked and then Unlocked again ?
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I haven't gone that far. I've unlocked and then relocked.
Everything fine. I believe it's completely safe if you have complete stock firmware installed ie, stock rom, stock recovery, stock Kernal and all that stuff. Otherwise you'll end up in a loop. Guess I forgot that part sorry.
So I know this is someone else's thread but can you tell me if I relocked bootloader will the service center be able to know I'd unlocked before? I don't have the phone unlocked warning at boot. Just curious.

Fredin_ said:
[/COLOR]
I haven't gone that far. I've unlocked and then relocked.
Everything fine. I believe it's completely safe if you have complete stock firmware installed ie, stock rom, stock recovery, stock Kernal and all that stuff. Otherwise you'll end up in a loop. Guess I forgot that part sorry.
So I know this is someone else's thread but can you tell me if I relocked bootloader will the service center be able to know I'd unlocked before? I don't have the phone unlocked warning at boot. Just curious.
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Hey will it work if I have complete stock firmware like you said? I want to take my device to service centre but my bootloader is unlocked and I have L OS installed. Will relockeing bootloader get me back my waranty?
PS. I have already asked in question and answers section but no reply yet. ?I

Fredin_ said:
[/COLOR]
I haven't gone that far. I've unlocked and then relocked.
Everything fine. I believe it's completely safe if you have complete stock firmware installed ie, stock rom, stock recovery, stock Kernal and all that stuff. Otherwise you'll end up in a loop. Guess I forgot that part sorry.
So I know this is someone else's thread but can you tell me if I relocked bootloader will the service center be able to know I'd unlocked before? I don't have the phone unlocked warning at boot. Just curious.
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Click to collapse
Some if not all bootloaders nowadays are not "locked" by the manufacturer using a code but are usually "locked" by employing a digital signature and/or a CID (carrier Id) hard coded into the OS. When we "unlock" a bootloader with a code we are simply using a routine written into the loader by the manufacturer to now ignore signatures and/or CIDs of the OS and this allows us to flash whatever we wish.
Sometimes upon unlocking using a code the DS/CID is erased/altered and cannot be retrieved, so not a good idea to relock an altered bootloader.
At least, that is my understanding of it.

Krazydon said:
Hey will it work if I have complete stock firmware like you said? I want to take my device to service centre but my bootloader is unlocked and I have L OS installed. Will relockeing bootloader get me back my waranty?
PS. I have already asked in question and answers section but no reply yet. I
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Click to collapse
Sparkrite said:
Some if not all bootloaders nowadays are not "locked" by the manufacturer using a code but are usually "locked" by employing a digital signature and/or a CID (carrier Id) hard coded into the OS. When we "unlock" a bootloader with a code we are simply using a routine written into the loader by the manufacturer to now ignore signatures and/or CIDs of the OS and this allows us to flash whatever we wish.
Sometimes upon unlocking using a code the DS/CID is erased/altered and cannot be retrieved, so not a good idea to relock an altered bootloader.
At least, that is my understanding of it.
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That's too bad. Means we won't get back our waranty if we relock it ?. So thanks for the heads up . I'll be careful while unlocking it again (if ever).?

Fredin_ said:
That's too bad. Means we won't get back our waranty if we relock it . So thanks for the heads up . I'll be careful while unlocking it again (if ever).
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Not necessarily, I doubt if most service centres would bother delving that deep, but maybe some would.
I don't know...........

Sparkrite said:
Not necessarily, I doubt if most service centres would bother delving that deep, but maybe some would.
I don't know...........
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Thanks for your quick reply but do you know any way to get back CID/DS

No, but I haven't delved that deeply into Huaweis bootloaders, but I NEVER attempt to re-lock them.

Sparkrite said:
No, but I haven't delved that deeply into Huaweis bootloaders, but I NEVER attempt to re-lock them.
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Anyways thanks for your replies. Means a lot ?

2021 Unlock BootLoader for Free

I did a lot of research, and the only way to unlock the BootLoader for free is to use PotatoNV software. Just wanted to let you guys know, so that you dont waste your time.
Tested and it worked on P9 Lite and P20 Lite.
If you need a guide, i can make one.

LycanRS said:
If you need a guide, i can make one
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Bro, Guide
Software

I finally unlocked the bootloader today, but most of the toolkits i tried seems to not work!
I'm still trying to install TWRP so that i can use it to root and install custom roms :/

Hello, can you make that guide you said? It would be great because I have no idea where to start from!

kohai_kuna said:
Hello, can you make that guide you said? It would be great because I have no idea where to start from!
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here

-Alf- said:
here
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Yeah I already checked that but Im not sure of how shoud I proceed with some of the steps.

Salam
Yes ! Its work on P9 Lite VNS-L21.
after use potatonv & unlock bootloader I get error " FAILED (remote: image verification error)" during installation TWRP in fastboot mode.
for fix this error , I unlock bootloader again with new bootloader code in fastboot.
type below command in fastboot :
fastboot oem unlock **************** (instead of * , type new bootloader code)
​​

I WASTED MY time for that.Potatonv s****s because why need disassembly for that

AlinTecsan said:
I WASTED MY time for that.Potatonv s****s because why need disassembly for that
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Well, yea? It's free, be glad.

RealDexxo said:
Well, yea? It's free, be glad.
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i have an problem why i said that, IT Said invalid when i copy correctly the imei from huawei not a chance to unlock it free

AlinTecsan said:
i have an problem why i said that, IT Said invalid when i copy correctly the imei from huawei not a chance to unlock it free
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Are you actually stupid? You don't put your imei there...

RealDexxo said:
Are you actually stupid? You don't put your imei there...
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me stupid
WHAT TO DO?

Question Relock bootloader

Hello. I wanted to root my redmi note 10s, and I unlocked the bootloader. But after reflexion, i want to cancel it, cause root will not be useful as I thought. Is it possible to relock the bootloader? And if yes, will the process erase all data ? And will everything be back like before? For example, will I be allowed to use Google One, witch doesn't work on bootloader unlocked devices ? Thanks by advance

XibalbaM said:
Hello. I wanted to root my redmi note 10s, and I unlocked the bootloader. But after reflexion, i want to cancel it, cause root will not be useful as I thought. Is it possible to relock the bootloader? And if yes, will the process erase all data ? And will everything be back like before? For example, will I be allowed to use Google One, witch doesn't work on bootloader unlocked devices ? Thanks by advance
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yes, relocking the bootloader will erase all your data, to do so just use miflash and select the option clean flash and lock

tutibreaker said:
yes, relocking the bootloader will erase all your data, to do so just use miflash and select the option clean flash and lock
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Thanks, and for Google one ?

XibalbaM said:
Thanks, and for Google one ?
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i m using it with unlocked bootloader

tutibreaker said:
i m using it with unlocked bootloader
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When I tried it was always Google pay, thanks. Miflash is an official tool?

And will it be possible to re unlock after ?

XibalbaM said:
When I tried it was always Google pay, thanks. Miflash is an official tool?
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XibalbaM said:
And will it be possible to re unlock after ?
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yes and yes