Database Users

Request Rom Manager vs Boot Loader Clarification

Not a Dev, but not a Noob, either. Formerly had a SGH-i897 Galaxy S for 3 years and flashed like crazy on it, while transitioning from Eclair to Froyo to Gingerbread to ICS to Jellybean, mostly using the fine offerings from the AOCP Collective folks. While familiar with Odin, CWM was my usual go-to utility.
Upgraded recently to a SGH-i337 Galaxy S4. Must have owned it for two, maybe three hours, before I rooted it with MotoChopper. This allowed me to re-install Titanium Backup. I left it as merely rooted, while I read up on CWM and some new-fangled thing called TWRP, which I wanted to get installed before casting about for a new ROM. (At the time, AOCP did not have an offering here, or it would have been a no-brainer for me.)
One morning, I turned on the phone and noticed it was doing an OTA update. . . . . . . . .
Mildly curious, I logged onto XDA to read what the community thought about the update, only to discover that I had missed all the dire warnings by a day and my (now) version I337UCUAMF3 ROM had it's boot-loaders locked from a blown Q-Fuse, courtesy of Samsung and AT&T.
Took me a week before I found the rooting solution from jortex, but thankfully, I'm now rooted again.
This background now leads to my questions:
I have ROM Manager Premium (from previous purchase) but have not installed it.
I was aware on my previous SGH-i897 that mixing the Gingerbread and Jellybean boot loaders was like, a Bad Thing when flashing ROMs and would promptly brick the phone.
Does CWM require the ability to load from a boot loader?
I know it creates an update.zip file to restore the original ROM, and usually does so by using whatever ROM is installed at the time.
So wouldn't it just create an update based on the I337UCUAMF3 ROM?
Even if I can't flash new ROMs (unless or until somebody comes up with a Q-Fuse Fix) couldn't I at least have all the recovery and .zip flashing of apps and cache clearing menu choices available to me from CWM?
Or would the act of just installing CWM on a I337UCUAMF3 ROM immediately brick my phone?
In Other Words, how close can I dance to the water's edge?
Been to the ROM Manager web site and they claim I can do any thing at any time.
(Easy for them to say: It ain't THEIR phones!)
Been searching these threads and can't come up with anything explicitly stating yea or nay.
So far, I have been happy enough with the TW stock ROM, but I always felt better being able to boot to recovery to fix things, on those few occasions I got just a leeeeeetle too close to the Bleeding Edge!
What is the consensus out there?
Will CWM 6.0.3.6 bork a I337UCUAMF3? Yes or no?
Would appreciate any thoughts that might enlighten me! :fingers-crossed:

It sure could brick the phone, the only thing you can do at the moment is root. I have seen a couple people try running a recovery on it, and it required a jtag service to restore the device.
Be careful.

TheAxman said:
It sure could brick the phone, the only thing you can do at the moment is root. I have seen a couple people try running a recovery on it, and it required a jtag service to restore the device.
Be careful.
Click to expand...
Click to collapse
Appreciate the response!

This phone is far different from the Captivate. There is no flashing anything on MF3. Basically you are waiting for a work around if that is even possible.
Sent from my SGH-I337 using xda premium

[Q] Bricked AT&T Samsung Galaxy S4

Hello all, if anyone could please help me, I would be extremely grateful.
I updated my Cyanogenmod nightly to the release for December 8th, 2013. The download seemed to be fine, it rebooted into the twrp, and then it rebooted, but then my phone never loaded back up. I tried restarting my phone with the power button, and eventually resulted to the battery pull, but yet my phone still wouldn't load.
I then tried going into the twrp again, and tried to flash a nightly upload that I had used from December 4th, it seemed to of loaded, but again my phone never loaded up.
I tired all day to use Odin to flash the ATT stock firmware, but I kept getting an ODIN FAILED error. I tried several different firmware downloads for ATT, and again, still no luck.
I am really upset over this, and would love to know why the update didn't work, and MORE IMPORTANTLY, how do I fix my device???

Samsung experience shop
Go to a Best buy with a local Samsung Experience center. They can flash the Latest 4.3 software on it from your carrier as long as it turns on and gets to download mode. I did the same thing to mine a month or so back and it saved my phone haha. Its a cool tool they have that i wish i could some how pirate haha
jonathanml86 said:
Hello all, if anyone could please help me, I would be extremely grateful.
I updated my Cyanogenmod nightly to the release for December 8th, 2013. The download seemed to be fine, it rebooted into the twrp, and then it rebooted, but then my phone never loaded back up. I tried restarting my phone with the power button, and eventually resulted to the battery pull, but yet my phone still wouldn't load.
I then tried going into the twrp again, and tried to flash a nightly upload that I had used from December 4th, it seemed to of loaded, but again my phone never loaded up.
I tired all day to use Odin to flash the ATT stock firmware, but I kept getting an ODIN FAILED error. I tried several different firmware downloads for ATT, and again, still no luck.
I am really upset over this, and would love to know why the update didn't work, and MORE IMPORTANTLY, how do I fix my device???
Click to expand...
Click to collapse

I'd still try Odin. If you go to best buy, once you get 4.3 no custom recovery or cyanogen
Sent from my SAMSUNG-SGH-I337 using xda app-developers app

HiTideBlastoise said:
I'd still try Odin. If you go to best buy, once you get 4.3 no custom recovery or cyanogen
Sent from my SAMSUNG-SGH-I337 using xda app-developers app
Click to expand...
Click to collapse
I was actually able to unbrick my phone using the Kies app for Mac. I don't know why I didn't try this earlier. I suppose I was trying to hold onto my root, and ability to flash custom roms onto my phone. Less than 24 hours of stock firmware, and I'm already annoyed. I also ran an update from At&T, and now I'm on 4.3. I'm still a n00b when it comes to the rooting and flashing. Yes, I can manage to follow and read directions to get my phone loaded with custom roms. But here's where I'm at now....
I'm running an unrooted AT&T Galaxy S4 with 4.3. I want Cyanogenmod back, and I want it now!!!
What do I do next????

jonathanml86 said:
I'm running an unrooted AT&T Galaxy S4 with 4.3. I want Cyanogenmod back, and I want it now!!!
What do I do next????
Click to expand...
Click to collapse
PRAY?

hnldriver77 said:
PRAY?
Click to expand...
Click to collapse
ok, but seriously. what can i do? and how do i do it?

you can root it, but that will trip the knox counter to 0x1,
id suggest going into download mode to see if you've tripped the knox counter to 0x1, if not and you want no warranty go to the original dev thread and look for ways on rooting there
if your wanting warrenty, your pretty much hooped then bud...

sopra rsorsifi
hnldriver77 said:
you can root it, but that will trip the knox counter to 0x1, but if thats not a issue then look in the original development thread...
Click to expand...
Click to collapse
What is the overall summary and importance of this knox counter?

Unfortunately at this point, you have root through vroot or kingo and that is all I can say. You cannot install a custom recovery, so no cyanogen
Sent from my SAMSUNG-SGH-I337 using xda app-developers app

[Q] How to install CWM or TWRP?

I have tried many methods to bypass boot loader and install CWM or TWRP on i337 phones, all for which they failed, I am not sure whether because I have NC1 device
My phone is Rooted, NC1, My ultimate objective is to install T mobile Rom, so I can get Wifi-calling on my at&t, what do I need to do in order to that??? I am willing to downgrade or anything to reach my objective.
Here are some guides that I saw at
galaxys4root dot com
"How to Install GT-i9505/T-Mobile Custom ROMs on AT&T Galaxy S4!"
But i couldn't Install cwm or TWRP to proceed. Please Help.

you are post mdl build and can not run cwm or custom twrp only safestrap recovery. surprised you didn't run across that when you rooted and installed safestrap--
as far as wifi calling--don't know, but believe i have read not on an att phone

rugmankc said:
you are post mdl build and can not run cwm or custom twrp only safestrap recovery. surprised you didn't run across that when you rooted and installed safestrap--
as far as wifi calling--don't know, but believe i have read not on an att phone
Click to expand...
Click to collapse
OH right (I did this long time ago so forgot most of it), So if I wanted to install a tmobile s4 custom rom (DARTHSTALKER) on my i337 I could use safestrap, and then flash my kernel using odin for it to work? or that would break the phone?

not sure, i don't use SafeStrap and not familiar with rom
i would make sure it is safestrap compatible and see if any other att folks have flashed it
i do that by skimming last 30 pages and in-forum search for safestrap and att
or you can ask, but have found most times you get no answer on those type of questions. it has to be TW based--

You can get full root access on NC1
devil_2 said:
I have tried many methods to bypass boot loader and install CWM or TWRP on i337 phones, all for which they failed, I am not sure whether because I have NC1 device
My phone is Rooted, NC1, My ultimate objective is to install T mobile Rom, so I can get Wifi-calling on my at&t, what do I need to do in order to that??? I am willing to downgrade or anything to reach my objective.
Here are some guides that I saw at
galaxys4root dot com
"How to Install GT-i9505/T-Mobile Custom ROMs on AT&T Galaxy S4!"
But i couldn't Install cwm or TWRP to proceed. Please Help.
Click to expand...
Click to collapse
It's very hard to achieve what I did in these screen shots... sorta lol I just got the phone delivered yesterday at 2pm and hit Red Bull for 15 hours hacking it... I have full root access in system... knox is frozen by TiBu as you can see SELiniux is permissive, SuperSU Pro in control without a popup warning... I do have a new boot screen though with the unlocked lock lol. Bye bye warranty! I bought the 2 year replacement one and they don't care if it's rooted lol.
Check out the screen captures... I had to slug it out getting one app at a time til I finally figured out how to get TiBu su access... that was the key! I'd have to write a small novel explaining it, and I'm tired as heck lol. Some shots were too big. Point is... its stable I don't think you get this with safe strap do ya? Maybe ya do... but I hacked it lol. Still stock OS with a lot of freezes. If this is something different and ya wanna know reply to the message, but it takes a while and you need to really know your adb commands and be good with terminal emulator because it' s literally all you'll have for most of the 'fight' with Knox... and it really is. Lucky it didn't boot loop lol but I wanted full root access. I'll just deodex it and get rid of the bloatware later. I still wish I could flash CWM though lol. I like AOSP roms

Lt1streconbn said:
It's very hard to achieve what I did in these screen shots... sorta lol I just got the phone delivered yesterday at 2pm and hit Red Bull for 15 hours hacking it... I have full root access in system... knox is frozen by TiBu as you can see SELiniux is permissive, SuperSU Pro in control without a popup warning... I do have a new boot screen though with the unlocked lock lol. Bye bye warranty! I bought the 2 year replacement one and they don't care if it's rooted lol.
Check out the screen captures... I had to slug it out getting one app at a time til I finally figured out how to get TiBu su access... that was the key! I'd have to write a small novel explaining it, and I'm tired as heck lol. Some shots were too big. Point is... its stable I don't think you get this with safe strap do ya? Maybe ya do... but I hacked it lol. Still stock OS with a lot of freezes. If this is something different and ya wanna know reply to the message, but it takes a while and you need to really know your adb commands and be good with terminal emulator because it' s literally all you'll have for most of the 'fight' with Knox... and it really is. Lucky it didn't boot loop lol but I wanted full root access. I'll just deodex it and get rid of the bloatware later. I still wish I could flash CWM though lol. I like AOSP roms
Click to expand...
Click to collapse
Would have been easier on you to use TowelRoot which would give full root access and then use safestrap for its recovery. Could of avoided the 15 hours in about 1 minute with the TowelRoot app

I did try it. Several times. Didn't work at all... It was a lot of fun doing this honestly I haven't had a good challenge in a while lol. I managed to hack knox out of my device using nothing but the device itself and knowledge I have. I really don't want multiple Roms in my device. I just want one ROM like I have in all the others, and that's what I have now and I got CWM installed last night finally... A bit glitchy and not 100% stable yet... It has issues backing up to external SD for some reason. It'll backup to internal though. I used it to flash a small and meaningless update.zip I assembled to test it and it worked with it I'm not sure it would be successful using a backup yet either to restore the device... If I just used towel root I wouldn't have ever figured any of this out, and if I can get it a bit more simplified and figure out which particular steps or combinationof steps allowed me to exploit the system and get it in tthere and I can get it stable... I can tell everyone else how to do it. A friend on XDA is working on a tool now to simple install SuperSU into system... He done it on another device and got cwm installed on a device with a locked boot loader also. I used some of the code to get an idea how to do it on the sgh-i337. Its not impossible... Just hard to figure out I think that's one of the things XDA exist for... To learn and progress and help others... Right?

Lt1streconbn said:
I think that's one of the things XDA exist for... To learn and progress and help others... Right?
Click to expand...
Click to collapse
Sent from my Nexus 5 using XDA Free mobile app
Right, absolutely. Good job. We'll be curious how you do it once you get it figured out.

devil_2 said:
OH right (I did this long time ago so forgot most of it), So if I wanted to install a tmobile s4 custom rom (DARTHSTALKER) on my i337 I could use safestrap, and then flash my kernel using odin for it to work? or that would break the phone?
Click to expand...
Click to collapse
Why a T-Mobile rom on an AT&T phone. Why not use one for an AT&T phone?

tailgunner9 said:
Why a T-Mobile rom on an AT&T phone. Why not use one for an AT&T phone?
Click to expand...
Click to collapse
For t-mobile wifi-calling

Well Great Job then, I do applaud you for your work you done. Hopefully for those that are stuck using safestrap you can get it to the point they could use cwm. That would be awesome.

tailgunner9 said:
Why a T-Mobile rom on an AT&T phone. Why not use one for an AT&T phone?
Click to expand...
Click to collapse
I seriously would not try that using safe strap in i337 @ this point. The ROM would need to be ported as a multicarrier , which is pretty simple in and of itself... A lot of debugging I'd imagine though. You'll only get 2g speed using ATT device on TMO ya know. They have different 3g and 4g LTE bands. It just won't work. If you flash that ROM.. IIt's very likely you'll soft brick or hard brick the device. I have the ATT kernel decomped now working with it... I haven't downloaded any existing ROMS used with i337 yet, but I'll get one and check it out and see what has been done with Knox in it. Just very risky flashing a ROM not specific to your device...

[Q]Want GPE, but can't get custom recovery - Help please! :(

Hey guys... Before I get into this, I would like to say that i'm very new to this whole rooting thing, so please forgive me for my lack of knowledge on various terms and such, and I'm a first time user here at xda.
What's written below might get a little bit complicated so i will try to make it as detailed as possible. Please bare with me here.
So I have a Samsung Galaxy S4 sgh-i337 (AT&T) running on android 4.4.4 (with touchwiz, you guys know the deal). I really wanted stock android lollipop, because I really like the look and feel to it. When I decided to root the phone, I went through many tutorials and I tried many different methods, and none of them worked. The phone still worked fine, but SuperSU was not installed and Root Checker said the phone was not rooted. After scouring the internet, I found one tutorial that had my S4 type and the same version. At that point I realized that my android version was hindering my rooting process. The tutorial used Odin to flash a kernel (NC1), root the phone using towelroot, install SuperSU, (Root Checker too to check if it worked), and then flashing the original kernel again (my original kernel was NJ4). After following this process, my phone was rooted, and everything worked fine.
As I said before, I wanted a GPE ROM, and so I needed a custom recovery. I decided to install CWM, since most GPE ROMs used this specific recovery. Again, I followed many different tutorials, and after each and every one, I would try to go into Recovery mode, and it would just launch the stock recovery. I found another tutorial on another website that involved flashing the recovery from an app in the google play store, so I decided to try it out. I now regret this as it led to more problems. I followed these instructions, and when launching into recovery mode from that point on, I get the yellow triangle with the error message "System software is not authorized by AT&T"
Sure, I could get around it by going into download mode from there, canceling, and it would reboot like normal, and the phone still worked, but I needed to get ride of that error message.
Once again doing my research, I figured out that if I flash a stock firmware specific to my phone, it will reset the phone (the only stock firmware available has android version 4.2.2, which is a really popular version, and is compatible with most custom recoveries and ROMs, so I decided to flash the firmware, as it would also change the version back, right?) When I flashed it using Odin like the directions said, it failed. i then figured out that it failed because my binary counter is not 0. I looked into resetting the binary counter for the AT&T S4, and I found Triangle Away. However, in order to reset your binary counter, you need an unlocked bootloader, and the AT&T S4 (sgh-i337) has a locked bootloader (I don't want to use Triangle Away if it's going to brick my phone, i'd rather unroot and keep touchwiz than brick). In the process of finding this out, I also figured out that the only custom recovery that you could use on a locked bootloader S4 sgh-i337 is SafeStrap. But i heard when using SafeStrap you are limited as far as ROMs go? Would I be able to get a GPE 5.0 Lollipop ROM with SafeStrap? Cause if not I might just unroot using SuperSU and software update my phone (will that fix the error when trying to get to Recovery mode?) Also, if I install Safestrap, will it fix the error message?
Again, sorry for my inexperience in all of this, and thanks for staying with me here. Any help and additional information on what I should do (or any GPE Lollipop ROMs I should use that are compatible with my phone and version and such), as well as any links to tutorials are greatly appreciated (also, keep in mind that all of the vocab I know when rooting is used in this post, I am not aware of most other terms - again, forgive me).

You wrote a lot but I'm not sure what state your device is in right now and what you want to do. But as you've found out, safestrap is the only custom recovery you can use. And touch wiz based roms are the only ones you can use. Afaik there are no 5.0 custom roms you can use at this time.
Sent from my Nexus 9 using XDA Free mobile app

jd1639 said:
You wrote a lot but I'm not sure what state your device is in right now and what you want to do. But as you've found out, safestrap is the only custom recovery you can use. And touch wiz based roms are the only ones you can use. Afaik there are no 5.0 custom roms you can use at this time.
Sent from my Nexus 9 using XDA Free mobile app
Click to expand...
Click to collapse
Oh, thanks for the help! The phone currently works fine, and it is rooted, but when I go into Recovery Mode it gives me the yellow triangle with the error... Will installing SafeStrap fix that? Regardless, thanks for the help, really do appreciate it!

jd1639 said:
You wrote a lot but I'm not sure what state your device is in right now and what you want to do. But as you've found out, safestrap is the only custom recovery you can use. And touch wiz based roms are the only ones you can use. Afaik there are no 5.0 custom roms you can use at this time.
Sent from my Nexus 9 using XDA Free mobile app
Click to expand...
Click to collapse
Also, if i were to update the phone to the next version (i heard there is a way to bump the S4 up in android version) would that reset the error in Recovery Mode? And I also heard that with SafeStrap, you are limited to ROMs on the same android version as the one on your phone? I really like 5.0, but if it's not possible to get it as the moment (and I haven't found any 5.0 ROMs for the sgh-i337 yet - you were right) i might just unroot using SuperSU and just update my version, unrooted and all. I'd rather have my phone be nice and clean than to have root on it with a corrupted recovery mode, and not make use of the root at all (I've seen other ROMs and I prefer 5.0). I might just try to make the phone feel as close to stock as possible by using more google apps and such (keyboard, messages, etc.). Regardless, thanks for the help and additional input, really do appreciate it!

EvilLemon said:
Also, if i were to update the phone to the next version (i heard there is a way to bump the S4 up in android version) would that reset the error in Recovery Mode? And I also heard that with SafeStrap, you are limited to ROMs on the same android version as the one on your phone? I really like 5.0, but if it's not possible to get it as the moment (and I haven't found any 5.0 ROMs for the sgh-i337 yet - you were right) i might just unroot using SuperSU and just update my version, unrooted and all. I'd rather have my phone be nice and clean than to have root on it with a corrupted recovery mode, and not make use of the root at all (I've seen other ROMs and I prefer 5.0). I might just try to make the phone feel as close to stock as possible by using more google apps and such (keyboard, messages, etc.). Regardless, thanks for the help and additional input, really do appreciate it!
Click to expand...
Click to collapse
I would recommend you flash the nb1 tar file in Odin. That'll bring your device to like new. Then you can let it ota nj4. There are root methods for nc1 and nj4. See this
http://forum.xda-developers.com/showthread.php?p=56453100
Sent from my Nexus 9 using XDA Free mobile app

jd1639 said:
I would recommend you flash the nb1 tar file in Odin. That'll bring your device to like new. Then you can let it ota nj4. There are root methods for nc1 and nj4. See this
http://forum.xda-developers.com/showthread.php?p=56453100
Sent from my Nexus 9 using XDA Free mobile app
Click to expand...
Click to collapse
Thanks so much! I followed the instructions and now my phone is back to normal, Recovery mode and all! Really do appreciate it, thanks!

EvilLemon said:
Thanks so much! I followed the instructions and now my phone is back to normal, Recovery mode and all! Really do appreciate it, thanks!
Click to expand...
Click to collapse
No problem. I'm glad you got it working again
Sent from my Nexus 9 using XDA Free mobile app

A bit of guidance please with S4 SGH-I337

I have a S4 Samsung SGH-I337 which is grey import to the UK. It is unlocked for any carrier but still bloated with ATT.
I would like to install and alternative ROM but am getting confused as whether this is possible or not. Have read so many threads and just as I think it is ok, I find another obstacle in the way.
So far I have found that the SGH I337 has a locked bootloader but it can be bypassed by using the loki method. I have now found that this has the MF3 firmware (I337UCUAMF3) and from reading through various threads I am not sure if installing another ROM is possible.
I would welcome some help with this please.

With a locked bootloader, you are limited to flashing tw-based ROMs with safestrap.

audit13 said:
With a locked bootloader, you are limited to flashing tw-based ROMs with safestrap.
Click to expand...
Click to collapse
I have done a lot more reading on SGH I337 MF3 Non Active version running 4.2.2.
It seems that Safeguard will install but the only custom ROMS you can install are the Touchwiz and GED. Having looked at them neither appeal. So will have to give up on this or will end up bricking it.

MF3 is android jelly bean and it is an old OS. May be you prefer jelly beam. If I were you , I would upgrade my phone to Kitkat NB1 , root the phone and debloat the ATT stuff. There are also some cool kitkat custom there though.

sway8966 said:
MF3 is android jelly bean and it is an old OS. May be you prefer jelly beam. If I were you , I would upgrade my phone to Kitkat NB1 , root the phone and debloat the ATT stuff. There are also some cool kitkat custom there though.
Click to expand...
Click to collapse
Thanks, but I don't know if it is possible on this phone because of the AT&T on it, also I am using it in the UK.
I tried Kies and that comes up with "sgh i337 does not support initialising". Don't know if it would help if I did a factory reset. I have backed up everything to Kies.
I have looked at various threads about upgrading the o/s but seems to be the same as installing another ROM and is fraught with the same warnings.

dg2016 said:
Thanks, but I don't know if it is possible on this phone because of the AT&T on it, also I am using it in the UK.
I tried Kies and that comes up with "sgh i337 does not support initialising". Don't know if it would help if I did a factory reset. I have backed up everything to Kies.
I have looked at various threads about upgrading the o/s but seems to be the same as installing another ROM and is fraught with the same warnings.
Click to expand...
Click to collapse
Yes, it is possible for your phone. Here is a guide for the AT&T S4. I used that guide for my i337.
I use kies to check whether I have proper usb driver installed on my pic for the phone. That's it. I did try once to use kies to upgrade the firmware and it did not let me do it. Then again my phone was rooted and I was on a custom rom.
Factory reset will clear your caches. That is all.
The thread I mentioned is a guide to upgrade to lollipop rom . If you do not want to go to lollipop and stay in Kitkat , you could stop after the step one in Post #2. Then use twol root to root the phone.
If you want to stay in Jelly bean just to root the phone, there is a guide near the end of Post #2.
If you want just to root your mf3, here is a guide.

Thanks for the links. I am reading through them slowly.
Need my phone for work tomorrow so will try later in the week.
I have seen mentioned many times about the boot screen showing "Custom" and unlocked padlock. Does this have any effect on the process? Can't remember when it appeared or if it has always been there.

dg2016 said:
Thanks for the links. I am reading through them slowly.
Need my phone for work tomorrow so will try later in the week.
I have seen mentioned many times about the boot screen showing "Custom" and unlocked padlock. Does this have any effect on the process? Can't remember when it appeared or if it has always been there.
Click to expand...
Click to collapse
that "custom" only shows up on the boot screen. I had that once. Has no effect on the operation of the phone. Only that you wont be able to get it fixed under warranty but with a device this old, I doubt you still have warranty.
I used kies to revert back to stock to get rid of the custom boot screen then re rooted. But then again I'm on MDL and I got custom by flashing a recovery that wasn't loki'd.

dg2016 said:
Thanks for the links. I am reading through them slowly.
Need my phone for work tomorrow so will try later in the week.
I have seen mentioned many times about the boot screen showing "Custom" and unlocked padlock. Does this have any effect on the process? Can't remember when it appeared or if it has always been there.
Click to expand...
Click to collapse
The boot screen showing "Custom" and unlocked padlock means you have rooted OS and saying your warranty is void. It will not have any effect on the process. But I have one more information from you that your phone might be rooted. If your phone is rooted you have an admin right.
Download app like Root checker and see whether you have a proper root.
Check your app drawer and see you have app calls superSU installed and properly working.
Since your main concern was AT&T bloatware so you can start debloating those apps.
If you still want to upgrade the phone, follow the guides that I mentioned.