Hello everybody,
I have a question about bootloader. I have searched before I asked. But most of the thing I got is something for someone who've already know what bootloader is.
So my first question is "What is bootloader?"
And everybody here seem to be happy with any manufacturers that they unlock the bootloader.
So my second question is "What will we get/earn when the bootloader is unlocked" or "What a unlocked bootloader can do?"
Or if my question is common and boring, please send me a link, or a page or something that I can get my answer.
I've searched before I asked but any information I got is for people who already know what it is, like bootloader update news or something new to do with bootloader.
Thank you.
"What is bootloader?"
in my understanding the phone company doesn't want the customers to install other roms beside the official rom provide by themself so they make "bootloader " as the "key code" to protect from installing other rom the official roms sbf
"What will we get/earn when the bootloader is unlocked" or "What a unlocked bootloader can do?"
the developers can totally modify and control and test and make us more roms ..you can install and exprience more roms (OS)with more features such as Miui ,cynagonmod nad many others
now that our XT720's bootloader is locked so the devs can only modify with limitation and can only make our rom base on old kernel..is bootloader is unlocked..they can get us more rom with newer or better kernel
The locked bootloader prevents using a custom kernel. So we can only use the original one. The kernel itself cannot be optimized or customized. So we can get features like swap support only using fastboot with usb connection to PC.
Additionally, the bootloader is the phone's version of BIOS if that helps. Unfortunately, there is a lot of misinformation out there. I used to be very confused about this, too. This is what finally cleared things up for me:
http://blog.opticaldelusion.org/2010/08/clearly-you-have-no-idea-what-efuse-is.html
There is more detail about the boot process at droid-developers.org
Now I understand what it is.
Thank you all you guys for your enthusiasms.
Wow very interesting paper!
Thanks for sharing it!
Mioze7Ae said:
Additionally, the bootloader is the phone's version of BIOS if that helps. Unfortunately, there is a lot of misinformation out there. I used to be very confused about this, too. This is what finally cleared things up for me:
http://blog.opticaldelusion.org/2010/08/clearly-you-have-no-idea-what-efuse-is.html
There is more detail about the boot process at droid-developers.org
Click to expand...
Click to collapse
thanks ,i learn alot from your link
Related
Noob question I know but I've tried reading up on the subject as much as I can - I still don't fully understand what exactly the locked loader does to this phone (aside from making it more difficult to root) and would really appreciate a brief explanation.
As I understand now the phone can be rooted, ROMs can be loaded (but they have to be specific to the VZW S3 right?), and full recovery options as well. Basically wondering what the disadvantages are and if they're more significant than just a little more work to root/mod the phone? Much thanks!
It prevents root access, you know jail breaking. You can't control your rom. You use the one provided to you by Verizon with all their bloatware. You can't change what software was delivered to you.
Sent from my SAMSUNG-SGH-I727 using xda app-developers app
It prevents changing boot.img
Sent from my SCH-I535 using xda app-developers app
saucyzest said:
Noob question I know but I've tried reading up on the subject as much as I can - I still don't fully understand what exactly the locked loader does to this phone (aside from making it more difficult to root) and would really appreciate a brief explanation.
As I understand now the phone can be rooted, ROMs can be loaded (but they have to be specific to the VZW S3 right?), and full recovery options as well. Basically wondering what the disadvantages are and if they're more significant than just a little more work to root/mod the phone? Much thanks!
Click to expand...
Click to collapse
A locked bootloader is ultimately intended to prevent you from potentially costing the carrier $money$ by:
Bricking your phone and then playing dumb when you return it for an exchange. (people on xda opening admit to this kind of fraud. kinda sad. you brick it you keep it!, or buy another)
Modifying your phone and then blaming bugs on the carrier. A support vampire.
Assuring content providers they've made exclusive deals with that their content is "secure".
Great Question!
If your phone was a Windows 7 computer....
If you rooted it, you'd have an account with Administrator access.
As for the bootloader... Suppose you wanted to upgrade to Windows 8, even though it hasn't been authorized by your ISP, on this Windows 7 computer with a locked bootloader.
You cant, c:\windows is locked. If you change anything in that directory, your Windows 7 computer will start, but only to display "Invalid System Software Installed! Please shutdown and return this computer to your ISP's store for assistance."
What we have on Verizon, is a phone with admin rights (rooted), where we can't re-install the software needed to boot a different operating system.
If you're interested in more detail on how the hardware prevents the bootloader from being cracked, and what the attack vectors are, you might be interested in the presentation linked from this post http://forum.xda-developers.com/showthread.php?t=1766638
(And yes I know that c:\windows isn't actually the boot partition on windows. Just trying to make it easier for the OP to understand.)
jmacko said:
Great Question!
If your phone was a Windows 7 computer....
If you rooted it, you'd have an account with Administrator access.
As for the bootloader... Suppose you wanted to upgrade to Windows 8, even though it hasn't been authorized by your ISP, on this Windows 7 computer with a locked bootloader.
You cant, c:\windows is locked. If you change anything in that directory, your Windows 7 computer will start, but only to display "Invalid System Software Installed! Please shutdown and return this computer to your ISP's store for assistance."
What we have on Verizon, is a phone with admin rights (rooted), where we can't re-install the software needed to boot a different operating system.
If you're interested in more detail on how the hardware prevents the bootloader from being cracked, and what the attack vectors are, you might be interested in the presentation linked from this post http://forum.xda-developers.com/showthread.php?t=1766638
(And yes I know that c:\windows isn't actually the boot partition on windows. Just trying to make it easier for the OP to understand.)
Click to expand...
Click to collapse
Thank you for this explanation, I found it helpful to hear such an analogy.
jmacko said:
Great Question!
If your phone was a Windows 7 computer....
If you rooted it, you'd have an account with Administrator access.
As for the bootloader... Suppose you wanted to upgrade to Windows 8, even though it hasn't been authorized by your ISP, on this Windows 7 computer with a locked bootloader.
You cant, c:\windows is locked. If you change anything in that directory, your Windows 7 computer will start, but only to display "Invalid System Software Installed! Please shutdown and return this computer to your ISP's store for assistance."
What we have on Verizon, is a phone with admin rights (rooted), where we can't re-install the software needed to boot a different operating system.
If you're interested in more detail on how the hardware prevents the bootloader from being cracked, and what the attack vectors are, you might be interested in the presentation linked from this post http://forum.xda-developers.com/showthread.php?t=1766638
(And yes I know that c:\windows isn't actually the boot partition on windows. Just trying to make it easier for the OP to understand.)
Click to expand...
Click to collapse
Thanks that really helped. So in the example of Jelly Bean -sounds like we need to wait for Verizon to release a version of it? Do all custom ROMs as well have to be based off of the VZW file that checks ok with the bootloader?
I'm really only concerned with Jelly Bean (knowing how long VZW takes to release stuff) and that wifi nag screen, I want to punch someone in the nose every time i see it...I will check out that presentation over lunch, would love to learn all about the details.
interesting and helpful topic.. however.. i thought i understood the locked bootloader situation on my droid bionic i could flash any rom i wanted to in conjunction with bootstrap wich i believe to be a bootloader by pass based recovery but no kernals were able to be flashed that is what i understood to be a locked b.l was not overclocking or custom kernals maybe i was wrong this whole time..
Bfitz26 said:
interesting and helpful topic.. however.. i thought i understood the locked bootloader situation on my droid bionic i could flash any rom i wanted to in conjunction with bootstrap wich i believe to be a bootloader by pass based recovery but no kernals were able to be flashed that is what i understood to be a locked b.l was not overclocking or custom kernals maybe i was wrong this whole time..
Click to expand...
Click to collapse
Weird this is how i understood it as well. I'm coming from the Droid X2 and thanks do DK we had cm9 up and running with ICS but the bootloader was locked down. I took it that bootstrap is a recovery tool that works in a way of when your phone is off and you plug it in you boot up to the bootloader. This would allow you to re-flash a rom if your current one was corrupt.
So in my mind you can run different roms and different android versions its just harder to get them on the phone. But from what i've seen you cant flash a new kernal if the bootloader is locked.
Maybe i miss understood this if so i really would like to know fully how this works
On the verizon gs3 the locked bootloader is keeping us from flashing a custom kernel thru odin...we can root and flash a custom rom / recovery but it has to utilize the stock kernel currently. Our bootloader debacle is nothing like moto devices and I wish folks would stop comparing the 2!
droidstyle said:
On the verizon gs3 the locked bootloader is keeping us from flashing a custom kernel thru odin...we can root and flash a custom rom / recovery but it has to utilize the stock kernel currently. Our bootloader debacle is nothing like moto devices and I wish folks would stop comparing the 2!
Click to expand...
Click to collapse
Exactly, what a locked bootloader will allow you to do will vary on different phones and firmwares. I've known some which would not even allow you to flash a recovery.
Sent from my SAMSUNG-SGH-I747 using xda premium
I really hope we get the bootloader unlocked would love to see cm on this phone with some of invisblek's great kernels. btw will I be able to even usrge "set cpu" to overclock and under clock with verizon stock kernal or can this be done with tweaks in the build.prop file, forgive me if this sounds stupid its been a while and I am a samsung's odin first time user.
Sadly this is the outcome of Americans NOT buying a device without a subsidy from the carrier.
Kind of like whining about NOT getting the best Porterhouse steak when buying with food stamps......
I would love to see an end to carrier subsidies.
~~~Sent from the 23rd century, thru a Samsung Onehunglow powered by Walmart brand Higgs Boson particles. (Aisle 27)~~~
I am disappointed in samsung they start to look like Apple can not my apps to my sd card write that they have locked that 2
hello a question to anyone with an understanding on bootloaders,the first question i think i have my answer but then something happened which contradicts it.
1st - is it possble to erase a locked bootloader through fastboot
2nd - if you have a bootloader that fastboot reports as unlocked but when booted android states otherwise and also flashing a cusom boot gives a boot error, which is correct,
3rd - if the answer to the previous question is that its not unlocked then is it possible for the one that reads it wrong to believe its been erased(some missing flag or marker ect
id be really grateful if one of the many talented people who understand all this will answer me, i know that most of you are busy most of the time
thankyou
guessing either no-one knows about this sort of this then or just i mistook xdaforum as somewhere that people are helpful
Hey guys, im new to this forums so first of all, hello everybody.
so, i have this xperia l, and im not new to android devices, and i want to flash a kernel and a rom (more specificly, thunderzcap and ios7)
the problem is, i cant unlock my bootloader. In that screen after you type that weird combination of numbers in the dialer it says that i just cant do it (not allowed). I read it somewhere that i need my simlock code and something else, but according to what i know (and i dont want to believe t) this means it is permantly locked.
So anyone here knows how to solve it? I would defenitly love to unlock the bootloader so i can flash a kernel... or im stuck with my phone? i know there are other roms but it isnt the same thing...
Thanks in advance
If it's locked there is no going around it. So answer is no, if it says on the phone that bootloader is locked you can't unlock it. And there are NO roms that work with locked bootloader. For you to be able to flash a ROM on it you must have unlockable bootloader.
Sorry to give you bad news but that is way things are in your case.
Nothing you can do.................for now.
If we can get CWM going on the phone, we can flash packages. From there, if this can be extended to our phone, http://forum.xda-developers.com/showthread.php?t=2595238 then we can run CM variants on top of stock, and thus there is hope for the locked bootloader people, like myself, hopefully.
Hey guys,
I've been playing around with the firmware on my Moto G and I didn't understand some things related to bootloader/partition table version and I hope someone more knowledgeable can explain me some things, in a more technical way if possible. Links to documentation are also appreciated!
So, apparently you have to keep an eye on bootloader, partition table, and OS versions so they match. You also cannot easily downgrade bootloader versions.
Also, I saw that you can brick your device if you try to flash 5.0.1 ota, then go back to 4.4.2 and flash 4.4.4 ota because of mismatched bootloader versions and will have to wait for official motorola 5.0.1 images.
My first question is why does this happen? If I get stuck on a particular bootloader version (in this case 5.0.1 GPE, right?) why can't I just boot the corresponding OS, why does the device brick (is it incompatible bootloader and partition table, so the bootloader can't find stage 2)?
Second question, apparently you CAN downgrade the bootloader versions, but have to follow some specific steps and use specific files. Why is that? What checks does the devices makes when upgrading bootloaders and what kind of files allow me to downgrade while passing those checks?
Third, why can't you boot older android versions with newer bootloaders? Doesn't the bootloader just initialize some devices and loads the kernel, can't you modify and older kernel to boot with the new bootloader or chainload and older kernel from a newer one? Also why does the boot processes change so frequently when it should be something very stable?
Fourth, what is the rationale behind not allowing you to freely switch bootloader versions?
Well, thats it. Sorry for the long post and thanks to anyone that can help me . Maybe I should post this in android development instead?
I follow .
I believe on Nexus hardware changing Bootloader is an easier process as those devices are deliberately Developer friendly. Motorola are open enough to allow unlocking, but as you have discovered, flashing an older Bootloader is a messy and dangerous process. Perhaps if enough people petitioned for a change, things might be different.
The Bootloader and Kernel are interrelated and that is why newer Bootloader versions break compatibility with previous iterations of Android (each with a unique Kernel.)
It's possible Kernel DEVs could offer a solution, but I suspect the reality is so few people care. The majority of users will get OTA Updates and never go back.
Uh, bump?
Anyone can tell me if there is a more appropriate place to ask question like these?
I hope it will give you some reference in these topics.
http://elinux.org/Android_Booting
http://androidforums.com/threads/android-partitions-kernels-explained.278898/
aryal.subasha said:
I hope it will give you some reference in these topics.
http://elinux.org/Android_Booting
http://androidforums.com/threads/android-partitions-kernels-explained.278898/
Click to expand...
Click to collapse
Thanks, but I already found those in Google and they aren't very useful. Too superficial and both focus on what happens AFTER the kernel is loaded, I'm interested more in the bootloader, how it verifies the signatures, etc.
Anyone?
I have a A125U that I can't unlock the bootloader of. There's no OEM unlock option in the Developer Options, there's no way to unistall system updates to try the date/time thing to get OEM unlock, nothing else I've tried has worked at all. I even tried flashing A125F firmware to no avail, of course. I was thinking, the BL file is the bootloader, is there a way to flash a bootloader that's already unlocked? Or is that not how this works?
If not, does anyone know how to get OEM unlock to show on the A125U? It's been driving me insane.
Not possible unfortunately
no
LOOOOOOOL
This is the biggest lie I've ever seen in my life!!! of course it,s possible ddd. Everything is possible especially this. Trick to your issue, is just that you have to corssflash to the Canadian firmware on your A125U which is the US model. But that doesn't matter, that's nothing because those 2 phones run on the same hardware so the firmware operates with both. Even the SW_REV value doesn't do anything in that situation. You can take the U models and flash it to W(Canada) but that's useless because then you're locked out of natively unlocking the PBL. Just grab the Canadian firmware and crossflash it via heimdall or patched Odin which is the same thing. Erase old NAND.
Also don't think that stuff like this isn't possible, of course it is. You just have to try harder and harder until you get the result you're stasifed with. There is community with a bunch of us enthusiasts (discord server link is on my profile). Don't be scarred to ask here on xda and there in the server. Also you can dm me for help, I'll help you, don't worry.
Hope I helped, be sure to ask if misunderstood or need more help. Also check out some stuff i wrote on this forum. It's very helpful and interesting.
Stay safe,
Krypton