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Why is it so hard to unlock the bootloader for the phone? Why is it so important? Is anyone close to getting past it? Or even working on it?
If you're asking these questions, then it is probably a situation where it won't really matter to you. Not trying to offend, but just from reading through your forum posts, I don't believe that you'll see much difference between safestrap ROMs and full custom kernel ROMs.
The answer as to why it's so hard: Samsung/Verizon/ATT work to prevent the bootloader from being unlocked. As such, the same as soft-modding a game console, an exploit needs to be found within the bootloader. This is the most dangerous area on a phone to mess around with, because it's very easy to permanently brick the phone when playing around with the bootloader. On the original droid that was the leading android development platform for a long time, the motto was, "If you can get to your bootloader, you're not perma-bricked." Screw up on the bootloader, and chances are, you have an expensive coaster.
Why is it so important? Locked bootloaders require signed kernels. Signing custom kernels is not going to be an option as it requires a proprietary encryption that is closed source. This can be thought of akin to MagicGate on the PS2 memory cards. (If you tried to create a device to read a PS2 memory card on any other device, it wouldn't work because of the MagicGate encryption.) It's NOT legal to distribute these encryption keys. As such, even if someone were to discover the key for it, if they distribute it to anyone, Samsung can, and as Sony proved, will go after them legally. Unlocked bootloaders can run any kernel that is made for that device. Unlocked bootloaders also allow flashing things such as a modem update without flashing an official update from the OEM. The primary reason, though, is the kernel. To answer your question from another thread, CyanogenMod requires a CM kernel. It isn't built for an OEM kernel.
Is anyone close to getting past it? Your guess is as good as anyone else's here. Probably not. Each thread that was started has been closed for various reasons.
Is anyone working on it? I believe there are a few devs working on it. If it happens, it'll be posted for sure.
question you didn't ask: Is it worth it? This is the important question you should be asking. Is it worth it to you? This isn't a question that can be answered uniformly across the android community. If you don't understand the benefits of a custom kernel, then you probably won't get much mileage out of an unlocked bootloader. If kexec is fully implemented into safestrap, then custom kernels can be executed giving nearly all the benefits of both worlds (safestrap is a wonderful recovery tool. If you brick w/ safestrap, it is PROBABLY bricked AFTER safestrap). The only real lack you have with kexec vs unlocked bootloader is the flashing of modem updates. This can be overcome by keeping your stock slot updated to the latest OTA (given that it's still rootable).
First of all, I'm not interested in actually going from 4.4.2 to 4.3, I just want to understand why it is only possible on the N900W8.
So, if I get it right, when you update to android 4.4.2 you also flash the new bootloader, which doesn't allow you to go back to the old one and is not compatible with android 4.3. Which makes me wonder:
Why doesn't 4.4.2 work with the older bootloader?
Why doesn't 4.3 work with the newer bootloader?
Since I have root, why I can't just overwrite the new bootloader with the old? Is that particular partition/block/whatever of the eMMC write-protected or the part of the bootloader that needs updating is not on the eMMC?
Why the N900W8 can be downgraded?
dp_alvarez said:
First of all, I'm not interested in actually going from 4.4.2 to 4.3, I just want to understand why it is only possible on the N900W8.
So, if I get it right, when you update to android 4.4.2 you also flash the new bootloader, which doesn't allow you to go back to the old one and is not compatible with android 4.3. Which makes me wonder:
Why doesn't 4.4.2 work with the older bootloader?
Why doesn't 4.3 work with the newer bootloader?
Since I have root, why I can't just overwrite the new bootloader with the old? Is that particular partition/block/whatever of the eMMC write-protected or the part of the bootloader that needs updating is not on the eMMC?
Why the N900W8 can be downgraded?
Click to expand...
Click to collapse
Try Google and XDA search for getting more info on your questions
dp_alvarez said:
First of all, I'm not interested in actually going from 4.4.2 to 4.3, I just want to understand why it is only possible on the N900W8.
So, if I get it right, when you update to android 4.4.2 you also flash the new bootloader, which doesn't allow you to go back to the old one and is not compatible with android 4.3. Which makes me wonder:
Why doesn't 4.4.2 work with the older bootloader?
Why doesn't 4.3 work with the newer bootloader?
Since I have root, why I can't just overwrite the new bootloader with the old? Is that particular partition/block/whatever of the eMMC write-protected or the part of the bootloader that needs updating is not on the eMMC?
Why the N900W8 can be downgraded?
Click to expand...
Click to collapse
You need to read around in the threads related to knox and development probably starting here:
http://forum.xda-developers.com/showthread.php?t=2642207
but as a huge summary of things:
- the boot sequence is secure in all high-end Samsung phones, meaning not any code can be just booted; the bootloader itself is the part most restricted; restrictions are not necessarily identical between Exynos and Qualcomm versions but the idea is the same, the parts of the bootloader must be all cryptographically signed (or similar)
- apparently there are some special version-related restrictions added on top of that by Samsung - the goal is of course to provide a secure environment where knox security is enforced (and can not be circumvented by downgrading to a previous version with a known security bug) and enterprise customers that pay heavy money for that security know that their data is not easy to extract from a phone
- yes, certain parts of EMMC are write-protected before the code-flow leaves the secure bootloader sequence; those regions can only be written from bootloader code (Odin, or maybe some regions could be written from stock recovery, but it must be stock - I think that problem is seen when writing modem files for instance in Mobile Odin Pro).
gee2012 said:
Try Google and XDA search for getting more info on your questions
Click to expand...
Click to collapse
I did, but didn't find any answers. Lots of people trying to downgrade, to flash older bootloaders, etc but nothing explaining what changed as to make 4.4.2 require a new bootloader or why that bootloader is incompatible with 4.3.
Maybe I've been using the wrong terms in my searches, or I'm searching in the wrong place. If you got any link that explains what happened (or points me on where to find that info), please do share it.
xclub_101 said:
You need to read around in the threads related to knox and development probably starting here:
http://forum.xda-developers.com/showthread.php?t=2642207
but as a huge summary of things:
- the boot sequence is secure in all high-end Samsung phones, meaning not any code can be just booted; the bootloader itself is the part most restricted; restrictions are not necessarily identical between Exynos and Qualcomm versions but the idea is the same, the parts of the bootloader must be all cryptographically signed (or similar)
- apparently there are some special version-related restrictions added on top of that by Samsung - the goal is of course to provide a secure environment where knox security is enforced (and can not be circumvented by downgrading to a previous version with a known security bug) and enterprise customers that pay heavy money for that security know that their data is not easy to extract from a phone
- yes, certain parts of EMMC are write-protected before the code-flow leaves the secure bootloader sequence; those regions can only be written from bootloader code (Odin, or maybe some regions could be written from stock recovery, but it must be stock - I think that problem is seen when writing modem files for instance in Mobile Odin Pro).
Click to expand...
Click to collapse
Thanks for the link, I started reading that topic but did not find out what made 4.4.2 incompatible with the older bootloader. Will read the full thread and also the other threads in the development section, thanks.
But, in short, the incompatibility of 4.4.2 is because the samsung bootloader explicitly refuses to load 4.4.2, or some changes in 4.4.2 made it incompatible with the previous boot process? If it is the later, then all devices that were updated to 4.4.2 also had to update their bootloaders, right?
Also, even with the security checks it loads a kernel that isn't necessarily signed right? Then isn't it possible to patch the 4.4.2 kernel to be compatible with the boot process of 4.3 and/or to report like 4.3 so it runs with the older bootloader?
dp_alvarez said:
...
But, in short, the incompatibility of 4.4.2 is because the samsung bootloader explicitly refuses to load 4.4.2, or some changes in 4.4.2 made it incompatible with the previous boot process? If it is the later, then all devices that were updated to 4.4.2 also had to update their bootloaders, right?
Also, even with the security checks it loads a kernel that isn't necessarily signed right? Then isn't it possible to patch the 4.4.2 kernel to be compatible with the boot process of 4.3 and/or to report like 4.3 so it runs with the older bootloader?
Click to expand...
Click to collapse
It IS an incompatibility created on purpose. And yes, all "normal" (N900, N9005) devices that were updated to 4.4.2 have updated bootloaders (the exception is N900W8 and maybe some of the other carrier-specific devices that have bootloaders controlled by themselves and not by Samsung). However there is one extra element - the bootloader itself can not be downgraded since there is 'somewhere' a list that actively prevents that.
On top of that you have the knox warranty flag - each time a kernel or recovery that is not signed is detected that flag is set.
downgrade from 4.4.2 to 4.3
I have note 3 verizon,, I can odin back to 4.3 from 4.4.2,, I have done it several times. Not sure if this is true for all note 3's
ronschuck said:
I have note 3 verizon,, I can odin back to 4.3 from 4.4.2,, I have done it several times. Not sure if this is true for all note 3's
Click to expand...
Click to collapse
'Tis not true for all Note 3s.
xclub_101 said:
It IS an incompatibility created on purpose. And yes, all "normal" (N900, N9005) devices that were updated to 4.4.2 have updated bootloaders (the exception is N900W8 and maybe some of the other carrier-specific devices that have bootloaders controlled by themselves and not by Samsung). However there is one extra element - the bootloader itself can not be downgraded since there is 'somewhere' a list that actively prevents that.
On top of that you have the knox warranty flag - each time a kernel or recovery that is not signed is detected that flag is set.
Click to expand...
Click to collapse
Thanks, I'm starting to understand it a little better now.
Now just one more question if you are still patient enough to put up my quesetions: Why can't we install the 4.4.2 kernel and chainload the 4.3 kernel from there?
I promise I will read better the development threads before I ask questions like these again
dp_alvarez said:
Thanks, I'm starting to understand it a little better now.
Now just one more question if you are still patient enough to put up my quesetions: Why can't we install the 4.4.2 kernel and chainload the 4.3 kernel from there?
I promise I will read better the development threads before I ask questions like these again
Click to expand...
Click to collapse
Hmm, that should be something "doable" as long as you have root in the primary 4.4.2 boot environment, probably that could work in a safestrap-like approach (as long as the Samsung 4.4.2 kernel does not specifically prohibit that somehow, which i doubt). Eventually look after the safestrap threads and ask there.
ronschuck said:
I have note 3 verizon,, I can odin back to 4.3 from 4.4.2,, I have done it several times. Not sure if this is true for all note 3's
Click to expand...
Click to collapse
Are you saying you can odin back to Jellybean from the OTA updated kitkat firmware?
I'd love to see this, can you write up a quick howto? Lots and lots of people would be very thankful for this if it's true...
No not if you take the OTA update,, sorry if I mislead.. I was speaking of running a NC2 rom which is 4.4.2 and then odin back to 4.3..
Hello. Recently I got Galaxy S5. Then after trying to root it I realized it's a chinese clone which haa complicated my life. I tried to root it and put in a wrong version of Clockworkmod. As a result, I fortunately haven't bricked the phone, but my bootloader is not working anymore. It doesn't load up. Only thing that works is the factory mode. Now the problem is - I want to get the phone to it's stock ROM and firmware, but because there is no way to access bootloader, nor download mode, I can't use Odin to do so. Is there any way I could flash the phone with a stock ROM and make the bootloader work again? The OS works fine, only thing that doesn't work is the bootloader. Thank you.
Samsung Galaxy S5 clone (G900S - South Korean), MT6589. Android version 4.4.2 Kit Kat, Kernel version 3.4.5, rooted.
You need to identify what model you have, obtain the stock firmware for that model and restore that. There are forums that concentrate on the clone models, use Google to find them, and they will go into more detail about your options.
Beware that many things on XDA will brick or worse a clone as the apps and advice here are not intended for a clone which is completely different under the hood.
.
fffft said:
You need to identify what model you have, obtain the stock firmware for that model and restore that. There are forums that concentrate on the clone models, use Google to find them, and they will go into more detail about your options.
Beware that many things on XDA will brick or worse a clone as the apps and advice here are not intended for a clone which is completely different under the hood.
.
Click to expand...
Click to collapse
Thank you for your reply. Well tge stock firmware is secondary for me. The problem is with the corrupt bootloader. I think it tries to load the CWM, but due to it's incompatibility it cannot. Is there any way to replace the bootloader only? Without the working bootloader, I can't do anything to fix it or to flash a custom ROM. I haven't find anything related to it. Or at least not yet.
Tom1597530 said:
Thank you for your reply. Well tge stock firmware is secondary for me. The problem is with the corrupt bootloader. I think it tries to load the CWM, but due to it's incompatibility it cannot. Is there any way to replace the bootloader only? Without the working bootloader, I can't do anything to fix it or to flash a custom ROM. I haven't find anything related to it. Or at least not yet.
Click to expand...
Click to collapse
Try to get your money back bro. If it's a chinese clone s5 God only knows what it's running. It's not a Samsung nor an s5 for that matter so the recovery and Odin won't work.
Sent from my SM-G900W8 using Xparent Cyan Tapatalk 2
Well, everything worked well until I tried to flash it. The reason was corrupt GPS. I found a way to fix the GPS but it required root and somehow I clashed it with incorrect CWM and the problem was born :/
Tom1597530 said:
Well, everything worked well until I tried to flash it. The reason was corrupt GPS. I found a way to fix the GPS but it required root and somehow I clashed it with incorrect CWM and the problem was born :/
Click to expand...
Click to collapse
Dude, get out of this forum or you`ll break your device permanently. You don`t have a Galaxy S5 and thuss neither a Qualcomm 801 cpu fow which these roms are build for. Find a forum somewhere for your device. Good luck
A normal (full) software image would include a bootloader. Separating a bootloader is much less common.
And as several people have already warned you.. quite a lot of the advice, procedures, firmware, et cetera on XDA will further damage your clone. Your clone may look like an S5 but it is very different internally. If you truly want a completely unusable phone, a literal paperweight, then continue.
Find another forum that has firmware and advice on how to program your specific clone.
Start here
.
Was the purchase of this clone made inside or outside of the USA?
Ready to sell this phone... tried everything I know how to try... Dev Edition Verizon S5, CAN'T UPGRADE from stock NCG. The most I can do it root... any ROM I flash is nonfunctional on Verizon's network with NO SIGNAL. Replaced SIM, flashed modems, etc etc... I think I'm just not sure how to do it with a dev edition... seriously feel like I'm missing a step. Would like to start from scratch. Does anyone have a stock image of a G900V Dev Edition I could work from, since I'm starting to think the one I've been working from is somehow the incorrect version. Thanks!
http://www.sammobile.com/firmwares/
type g900v in search bar
DSA said:
http://www.sammobile.com/firmwares/
type g900v in search bar
Click to expand...
Click to collapse
I would but I'm trying to avoid locking the bootloader, if possible. Didn't intend on having a developer device, but now that I do, I'd like to try to maintain it's use as one. Bought this phone on swappa, seller didn't give any indication that it was a developer device. Now I'm concerned he did something to it prior to selling that is causing me difficulties. I don't think I should be having these network difficulties, but there could very well be something I'm supposed to be doing with the modem that I'm just unaware of. I figure if I can get back to the way this phone was when it was new (when the original seller bought it) I'd at least have a clean slate to work with.
gatorhater73 said:
I would but I'm trying to avoid locking the bootloader, if possible. Didn't intend on having a developer device, but now that I do, I'd like to try to maintain it's use as one. Bought this phone on swappa, seller didn't give any indication that it was a developer device. Now I'm concerned he did something to it prior to selling that is causing me difficulties. I don't think I should be having these network difficulties, but there could very well be something I'm supposed to be doing with the modem that I'm just unaware of. I figure if I can get back to the way this phone was when it was new (when the original seller bought it) I'd at least have a clean slate to work with.
Click to expand...
Click to collapse
Anything usable in here?
http://www.galaxys5update.com/galaxy-s5-stock-firmware/
kprice8 said:
Anything usable in here?
http://www.galaxys5update.com/galaxy-s5-stock-firmware/
Click to expand...
Click to collapse
I don't think so, but thanks... I think that's the same device firmware that the retail version comes with, which will lock my bootloader. I've actually considered just flashing it anyway and saying the hell with an unlocked bootloader, since I didn't really intend to have one to begin with and apparently there's nothing I can do with it, anyway (none of the unified builds work on my device, anyway) but this is a last-ditch effort to preserve it if i can, and I'm hoping some dev will be willing to help me diagnose my problem.
gatorhater73 said:
I don't think so, but thanks... I think that's the same device firmware that the retail version comes with, which will lock my bootloader. I've actually considered just flashing it anyway and saying the hell with an unlocked bootloader, since I didn't really intend to have one to begin with and apparently there's nothing I can do with it, anyway (none of the unified builds work on my device, anyway) but this is a last-ditch effort to preserve it if i can, and I'm hoping some dev will be willing to help me diagnose my problem.
Click to expand...
Click to collapse
It's not like there's a ton of development going on for Dev edition. I'm loving the retail version of the phone just rooted and running some Xposed. Like it so much, I went out and got one for the wife too and I paid full retail for both to keep my old unlimited data plan. Hers I just left out of the box stock. Will be interested to see how Lolipop looks when it drops to her phone. Sure hope we keep root with Lolipop, I use the heck out of my hotspot, to the tune of about 70gb/mo ...
gatorhater73 said:
I don't think so, but thanks... I think that's the same device firmware that the retail version comes with, which will lock my bootloader. I've actually considered just flashing it anyway and saying the hell with an unlocked bootloader, since I didn't really intend to have one to begin with and apparently there's nothing I can do with it, anyway (none of the unified builds work on my device, anyway) but this is a last-ditch effort to preserve it if i can, and I'm hoping some dev will be willing to help me diagnose my problem.
Click to expand...
Click to collapse
I'm far from a developer, but this may help. I also bought the phone without realizing what it was I was getting into and had similar problems flashing the Optimal rom on my dev edition s5. I could flash but phone would hang on the activation screen with no signal. I eventually succeeded. As near as I can recall this is what I did:
I dirty flashed Beantown 4.4.4 rom (twrp) over my 4.4.2 stock firmware. then flashed n12 firmware (included stock kernel, and modem) from dev edition make an update .tar thread (odin) (http://forum.xda-developers.com/showpost.php?p=56604757&postcount=2). I did a factory reset after flashing. Switched to art. Flashed optimal with clean reset, but did not flash kernel. Later flashed koontsez 4.4.4 kernel. Still running Optimal
Good luck.
JOrkin said:
I'm far from a developer, but this may help. I also bought the phone without realizing what it was I was getting into and had similar problems flashing the Optimal rom on my dev edition s5. I could flash but phone would hang on the activation screen with no signal. I eventually succeeded. As near as I can recall this is what I did:
I dirty flashed Beantown 4.4.4 rom (twrp) over my 4.4.2 stock firmware. then flashed n12 firmware (included stock kernel, and modem) from dev edition make an update .tar thread (odin) (http://forum.xda-developers.com/showpost.php?p=56604757&postcount=2). I did a factory reset after flashing. Switched to art. Flashed optimal with clean reset, but did not flash kernel. Later flashed koontsez 4.4.4 kernel. Still running Optimal
Good luck.
Click to expand...
Click to collapse
Had marginal success using this method... Have been able to maintain a 3G signal, but no LTE after first boot. Rather, when I first booted, I had LTE and thought I was good, but since my first reboot, I can only get 3G and nothing I do can get it back so far.
JOrkin said:
I'm far from a developer, but this may help. I also bought the phone without realizing what it was I was getting into and had similar problems flashing the Optimal rom on my dev edition s5. I could flash but phone would hang on the activation screen with no signal. I eventually succeeded. As near as I can recall this is what I did:
I dirty flashed Beantown 4.4.4 rom (twrp) over my 4.4.2 stock firmware. then flashed n12 firmware (included stock kernel, and modem) from dev edition make an update .tar thread (odin) (http://forum.xda-developers.com/showpost.php?p=56604757&postcount=2). I did a factory reset after flashing. Switched to art. Flashed optimal with clean reset, but did not flash kernel. Later flashed koontsez 4.4.4 kernel. Still running Optimal
Good luck.
Click to expand...
Click to collapse
This happened after I flashed the update.tar (with aboot.mbn removed) and I have note gotten LTE back. Is there something I can do with my aboot.bak that I'm missing?
Its been a few years so i was needing a refreshing (& though simple question, i cant seem to find exact answer).
I have the sm-t337a tab 4. If i plan on rooting it but i also was looking at installing a ROM, which order do i need to (or which do you recommend) do them in???
Thank you for your assistance
gdownloads said:
Its been a few years so i was needing a refreshing (& though simple question, i cant seem to find exact answer).
I have the sm-t337a tab 4. If i plan on rooting it but i also was looking at installing a ROM, which order do i need to (or which do you recommend) do them in???
Thank you for your assistance
Click to expand...
Click to collapse
You always have to root first before you are able to install a custom rom. That said, to the best of my knowledge, there aren't any custom roms available for the SM-T337A. Unfortunately, AT&T and Verizon lock the bootloader on their devices now. This means that you can't have a custom kernel or a custom recovery. Since Cyanogenmod and similar roms based off of it require a custom kernel, you can't have any cyanogen-type roms. That said, a stock based rom (anything capable of running on the stock kernel) should work fine, but as I've said, to the best of my knowledge nobody has made any roms like that for this device yet. Sorry to be the bearer of bad news.
thisisapoorusernamechoice said:
You always have to root first before you are able to install a custom rom. That said, to the best of my knowledge, there aren't any custom roms available for the SM-T337A. Unfortunately, AT&T and Verizon lock the bootloader on their devices now. This means that you can't have a custom kernel or a custom recovery. Since Cyanogenmod and similar roms based off of it require a custom kernel, you can't have any cyanogen-type roms. That said, a stock based rom (anything capable of running on the stock kernel) should work fine, but as I've said, to the best of my knowledge nobody has made any roms like that for this device yet. Sorry to be the bearer of bad news.
Click to expand...
Click to collapse
That sucks. Guess I'll have to be satisfied with just rooting it and maybe a different stock rom, if any available.
I was just searching on here & I'm not sure what instructions are the ones I need for this tab. I saw where someone says they tried towelroot & 1 other but did not work, & other similar posts, then find several posts mentioning that they have rooted it, so I'm not sure what way DOES work to root it. (I also found on another site, which I don't know if Im allowed to post the external link, "Working Tutorial How To Update/Upgrade Samsung SM-T337A To Android 5.1 Lollipop!) Needless to say Im a little unsure of what method I need to root it. ANDROID VERSION: 4.4.2 BUILD: kot49h.t337aucu1ank2
Also Is there a alternative stock based rom (with tutorial) you might recommend ?
gdownloads said:
That sucks. Guess I'll have to be satisfied with just rooting it and maybe a different stock rom, if any available.
I was just searching on here & I'm not sure what instructions are the ones I need for this tab. I saw where someone says they tried towelroot & 1 other but did not work, & other similar posts, then find several posts mentioning that they have rooted it, so I'm not sure what way DOES work to root it. (I also found on another site, which I don't know if Im allowed to post the external link, "Working Tutorial How To Update/Upgrade Samsung SM-T337A To Android 5.1 Lollipop!) Needless to say Im a little unsure of what method I need to root it. ANDROID VERSION: 4.4.2 BUILD: kot49h.t337aucu1ank2
Also Is there a alternative stock based rom (with tutorial) you might recommend ?
Click to expand...
Click to collapse
All you can do is try towelroot. If it comes back as failed, then oh well, it doesn't mess anything up. Towelroot will only work for kernel dates before July 2014 I believe. There are NO custom ROMs, no recovery, no alternatives for this tablet. No developer interest, no carrier support, so no android version beyond 4.4.2. We have been abandoned by AT&T with no way of getting any updates ever again because they locked us out. So we are stuck with a worthless pile of crap tablet that gets more laggy by the day. No more carrier variants of any device for me ever again. International only.
rootng that works
pre4speed said:
All you can do is try towelroot. If it comes back as failed, then oh well, it doesn't mess anything up. Towelroot will only work for kernel dates before July 2014 I believe. There are NO custom ROMs, no recovery, no alternatives for this tablet. No developer interest, no carrier support, so no android version beyond 4.4.2. We have been abandoned by AT&T with no way of getting any updates ever again because they locked us out. So we are stuck with a worthless pile of crap tablet that gets more laggy by the day. No more carrier variants of any device for me ever again. International only.
Click to expand...
Click to collapse
kingroot works perfectly on the T337A tab4