[Q] What is a Bootloader? - XPERIA X8 Q&A, Help & Troubleshooting

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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Click to collapse
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
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
Quoted from the thread I linked!

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

Related

i can't unlock bootloader

there's so many ROM that i can't falsh it on my phone due to kernel and i think to flash kernel u have to unlock bootloader. and manufacture of my phone doesn't support unlock coz will make a hard brick . for instance i want to flash prime hd8 i tried but it coz a soft brick>>>>>???? what to do
If You have followed instructions everything should be fine, without any bricks. So maybe try again. You can unlock bootloader, but not for free unfortunately.
First, of course you can unclock bootloader for free. WTF??
Second, PrimeHD is also available for stock kernel.
Third, no need to open two same threads.
Chris95X8 said:
First, of course you can unclock bootloader for free. WTF??
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Click to collapse
How he can unlock bootloader for free when he says:
love_story99000 said:
and manufacture of my phone doesn't support unlock coz will make a hard brick
Click to expand...
Click to collapse
my manufac above 29 it's w32 and it leads to a hard brick ?? i read it before in this site???
love_story99000 said:
my manufac above 29 it's w32 and it leads to a hard brick ?? i read it before in this site???
Click to expand...
Click to collapse
Yes, You're right (if it's 11W32). There's a risk that when You will try to unlock bootloader it will end with hardbrick.
so , isn't there anyway to do this stupid unlock to this stupid phone .
looks interesting http://forum.xda-developers.com/showthread.php?t=1506502

I'm about to sell my XZ

Cause my bootloader is locked... Here's the only solution i found http://forum.xda-developers.com/showthread.php?t=1896553
But unfortunately doesn't work on the XZ :silly: You guys think there will be a way soon?
Did you do this?
http://forum.xda-developers.com/showthread.php?t=2153261
Ofc and it says that my device can't be unlocked...
Poustic said:
Wtf ! I know that if bootloader unlock allowed says no my device can't be unlocked...
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Click to collapse
Well, you didn't write it in the first post... sorry
No problem i probably wasn't clear enough
Poustic said:
Ofc and it says that my device can't be unlocked...
Click to expand...
Click to collapse
have you rooted your phone or was bl unlock: no before rooting ?
Was bl unlock: no before and after rooting
Poustic said:
Cause my bootloader is locked... Here's the only solution i found http://forum.xda-developers.com/showthread.php?t=1896553
But unfortunately doesn't work on the XZ :silly: You guys think there will be a way soon?
Click to expand...
Click to collapse
Well..i am not sure what kind of locked device is this. We don't have career locked phones in my country. They sell it without any lock...
can anyone explain it what kind of lock is this ? and it's not even allowing to root...
Foas said:
Well..i am not sure what kind of locked device is this. We don't have career locked phones in my country. They sell it without any lock...
can anyone explain it what kind of lock is this ? and it's not even allowing to root...
Click to expand...
Click to collapse
Bootloader locked means u cannot load anything at boot that would tinker with the basic core of the device, like u cannot use custom kernels when ur bootloader is locked that is y ppl unlock their boot loaders Google for further info.
As for the OP's problem :
This is a known issue when u root ur device without unlocking bootloader, the solution to this is to do a full repair using Sony Suite which will result in loss of all data phone ,SD card etc .
check this link out its clearly stated over there
http://forum.xda-developers.com/showthread.php?t=2186368
Troubleshooting:
if your device has unlockable bootloader then after applying this hack the bootloader status will turn "Bootloader unlock allowed: No"
in that case dont worry the users have reported that doing a repair via SEUS will flash back stock firmware and turn this status to "Bootloader unlock allowed: Yes" (the same might also be achieved by flashing a stock FTF using FlashTool <yet to be confirmed>)
ROOT WILL BE LOST BY DOING THE ABOVE AND YOUR INTERNAL STORAGE MAY GET WIPED!
SO DO A BACKUP OF APPS & INTERNAL STORAGE ON AN EXTERNAL SDCARD/PC
How so some people can unlock the bootloader and some can't??
Sent from my LG-P990 using xda premium

[Q] Flash boot.img on locked bootloader

Hey!
My SP has a locked bootloader and I can't unlock it because it isn't allowed.
But I want to install FXP CM11. As I can't acces fastboot mode can I flash the boot.img file through CWM if a make a flashable zip file from it(android.stackexchange.com/questions/36265/flash-boot-img-without-using-fastboot-usb)? If yes, how to make it? I don't really get that description. Thanks in advance.:fingers-crossed:
koostamas said:
Hey!
My SP has a locked bootloader and I can't unlock it because it isn't allowed.
But I want to install FXP CM11. As I can't acces fastboot mode can I flash the boot.img file through CWM if a make a flashable zip file from it(android.stackexchange.com/questions/36265/flash-boot-img-without-using-fastboot-usb)? If yes, how to make it? I don't really get that description. Thanks in advance.:fingers-crossed:
Click to expand...
Click to collapse
AFAIK changing kernel in locked bootloader could result in brick, not bootloop. CMIIW, but you should be careful with carrier locked bootloader
You can't install custom kernel on a locked bootloader you will get error not installed..... Even if installed it won't boot up, you will end up with a very stylish paper weight.
DON'T EVEN TRY TO MAKE IT WORK.
just accept it can't be done and install a custom stock rom instead
Sent from my C5303 using Tapatalk
You can flash the boot.img
But then your phone will be a brick
So I wouldn't recommend it
i didnt had ay problem in flashing boot.img on locked bootloader
panagiotisgr said:
i didnt had ay problem in flashing boot.img on locked bootloader
Click to expand...
Click to collapse
Do you think these people are lying or something?
The whole point of a locked bootloader is that you cant modify kernel - the reason you can only used stock based ROMs.
If you can successfully flash a boot.img then yours is not locked.
Someone please correct me if i'm wrong.
yo-meister said:
Do you think these people are lying or something?
The whole point of a locked bootloader is that you cant modify kernel - the reason you can only used stock based ROMs.
If you can successfully flash a boot.img then yours is not locked.
Someone please correct me if i'm wrong.
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Click to collapse
omg im so sorry i thought i write unlocked. mine is unlocked. not locked. replying while in move not a good idea
panagiotisgr said:
omg im so sorry i thought i write unlocked. mine is unlocked. not locked. replying while in move not a good idea
Click to expand...
Click to collapse
Wow, you almost killed me
As highlighted in posts above and around the forum, it is not possible. This discussion can't go any further so..
Thread closed

[Q] Android M flash

hello guys ) i just wanna ask if its possible to flash android m with nexus root toolkit or no ??
Apparently, yes. https://plus.google.com/113329792100896065459/posts/ZFUJD6Yn4hm
jj14 said:
Apparently, yes. https://plus.google.com/113329792100896065459/posts/ZFUJD6Yn4hm
Click to expand...
Click to collapse
thank you for the fast reply
Yes I followed those steps and flashed it perfectly.
BossJ said:
Yes I followed those steps and flashed it perfectly.
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Click to collapse
yeah same here, everything went more then well.
Should I relock the bootloader after flashing M ?
M5Rahul said:
Should I relock the bootloader after flashing M ?
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Click to collapse
NOOO!!!!
To many folks have encountered an issue that soft-bricked their device afterwards.
You will still receive OTA with an unlocked bootloader.
M5Rahul said:
Should I relock the bootloader after flashing M ?
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Click to collapse
you can relock it (safer) but if you want to flash any new rom later you will loose all your data. cause everytime you flash you need to unlock the bootloader. its up to you
stricker said:
you can relock it (safer) but if you want to flash any new rom later you will loose all your data. cause everytime you flash you need to unlock the bootloader. its up to you
Click to expand...
Click to collapse
Hang on now, lets be clear about the advice that we're giving here.
Yes, a locked bootloader is safer if a thief were to get his hands on your device. However, locking the bootloader has a whole host of other problems linked to it. For example, if you end up in a boot loop with a locked bootloader because something breaks in the rom or kernel, if you have stock recovery, you can never unlock the bootloader again, without sending it for repair.
I would suggest people using experimental ROMs should keep their bootloader unlcoked to avoid this
danarama said:
Hang on now, lets be clear about the advice that we're giving here.
Yes, a locked bootloader is safer if a thief were to get his hands on your device. However, locking the bootloader has a whole host of other problems linked to it. For example, if you end up in a boot loop with a locked bootloader because something breaks in the rom or kernel, if you have stock recovery, you can never unlock the bootloader again, without sending it for repair.
I would suggest people using experimental ROMs should keep their bootloader unlcoked to avoid this
Click to expand...
Click to collapse
If I did lock the boot loader, can it not be unlocked again using NRT ? I'm wondering since this (Android M) is an official release from Google, there should be a way to unlock the Boot loader if someone wants to roll back to lollipop ... Am I wrong in this assumption ?
Sent from my Nexus 6 using Tapatalk
M5Rahul said:
If I did lock the boot loader, can it not be unlocked again using NRT ? I'm wondering since this (Android M) is an official release from Google, there should be a way to unlock the Boot loader if someone wants to roll back to lollipop ... Am I wrong in this assumption ?
Sent from my Nexus 6 using Tapatalk
Click to expand...
Click to collapse
It's a security feature whereby if you do not have "enable OEM unlocking" set in the rom, you cannot unlock the bootloader. If you don't have it set, have stock recovery then have a rom that will not boot, you cannot set that, ergo cannot unlock the bootloader. If you're going to mess with exxperiemental previews, I would suggest not re-locking the bootloader.
danarama said:
It's a security feature whereby if you do not have "enable OEM unlocking" set in the rom, you cannot unlock the bootloader. If you don't have it set, have stock recovery then have a rom that will not boot, you cannot set that, ergo cannot unlock the bootloader. If you're going to mess with exxperiemental previews, I would suggest not re-locking the bootloader.
Click to expand...
Click to collapse
I just checked and the 'OEM unlocking' option is turned on under Dev Options.
So, can I unlock the bootloader and flash back to 5.1.1 ?
Sent from my Nexus 6 using Tapatalk
M5Rahul said:
I just checked and the 'OEM unlocking' option is turned on under Dev Options.
So, can I unlock the bootloader and flash back to 5.1.1 ?
Sent from my Nexus 6 using Tapatalk
Click to expand...
Click to collapse
If you like.

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.
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
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>.
Click to expand...
Click to collapse
Never Ever a good idea to try and relock the bootloader.
viratbansal001 said:
This will just brick the device.
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Click to collapse
Sparkrite said:
Never Ever a good idea to try and relock the bootloader.
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Click to collapse
Umm why? Its working pretty fine for me. ?
Fredin_ said:
Umm why? Its working pretty fine for me.
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Click to collapse
Have you Unlocked, Relocked and then Unlocked again ?
[/COLOR]
Sparkrite said:
Have you Unlocked, Relocked and then Unlocked again ?
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
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.
Click to expand...
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
Click to expand...
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.
Click to expand...
Click to collapse
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).
Click to expand...
Click to collapse
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...........
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
Anyways thanks for your replies. Means a lot ?

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