Samsung - Downgrade After Custom ROM ? - Android Q&A, Help & Troubleshooting

Hello everyone.
I am a fan of Android customization, and that's why i installed LineageOS 16 on my Galaxy S7 G930F.
Everything is working fine, but i am now asking myself a question: is it possible to downgrade from that Custom 9.0 to Stock 7.0/6.0 ?
Now that we installed a custom ROM, the Bootloader should be modified, right ? The stock Bootloader blocks Odin from installing older firmwares, but is it now possible ?
I don't want to try, because i have important data on my phone, a really bad internet, and i just want to be sure if it's possible or not.
Thanks to everyone for helping me .

Soriahz said:
Hello everyone.
I am a fan of Android customization, and that's why i installed LineageOS 16 on my Galaxy S7 G930F.
Everything is working fine, but i am now asking myself a question: is it possible to downgrade from that Custom 9.0 to Stock 7.0/6.0 ?
Now that we installed a custom ROM, the Bootloader should be modified, right ? The stock Bootloader blocks Odin from installing older firmwares, but is it now possible ?
I don't want to try, because i have important data on my phone, a really bad internet, and i just want to be sure if it's possible or not.
Thanks to everyone for helping me .
Click to expand...
Click to collapse
Lineage OS does not in any way modify your bootloader. You can flash your stock firmware without any issue. If you intend on keeping the data from apps on lineage os, and using it on stock, it's not going to work.
If you're referring to internal storage, that doesn't need be wiped when returning to stock (unless it's encrypted), only the data partition, system, cache, and dalvik cache need it.
Be aware that if you flash stock firmware using Odin, it will wipe your internal storage unless you use a home csc file. Not all firmwares have them. If you made a backup with twrp, you can restore that without any problems, and avoid worrying about your internal storage.

Thanks for that answer. I read on internet that the bootloader after Android 8.0 was locked at version 4, and did not let older firmwares with different bootloaders being installed with Odin. Of course I can flash the 8.0, but 7.0 and 6.0 does not seem possible because of that "impossibility". We can't use 8.0 bootloader with 7.0/6.0 because some functions will not work suck as vibrator. Flashing a custom firmware made me think that this "lock" would me removed. I already tried downgrading in the paste being on stock 8.0 and I got a fail. Thank for that answer !

Related

Rooting N910CQ AND keeping Android 5.1.1 stock rom - is it possible?

Hi y’all,
Firstly, I’m a newbie. I did some forum reading / reviewing before posting this and I hope I’m posting to correct section (take it easy on newbie ). So anyways, my question is as follows:
I have a N910CQ purchased from Turkey (currently running android 5.1.1). I want to root it but keep stock ROM for two reasons: 1) I am used to touchwiz based stock ROM and I am generally satisfied with it except the bloat ware, and 2) I want to run Cerberus on it... and actually 3) all roms I came by have certain features missing (i.e. camera / pen / fingerprint sensor does not work etc).
But after doing much research (and trial and error for the last 2 days), it seems it is not possible to root a N910CQ device running 5.1.1 android and keep stock rom on it. You can either: 1) root it and flash a 5.0.1 stock rom (and when you later try to upgrade to 5.1.1 you’ll get an error message basically telling you that unauthorized modification was made to OS and therefore you’re no longer entitled to OTA upgrade) OR 2) you’ll have to flash a 5.1.1 rom other than stock rom (such as Team Eos Rom – which has many flaws). But, so far, it seems impossible to root N910CQ and flash 5.1.1 rom.
Do any of you have any recommendations? Thank you.
anybody? any clue???
It looks like your best option would be to install TWRP recovery and use it to flash a custom kernel that auto roots your device such as this http://forum.xda-developers.com/note-4/development/n910c-kernel-5-1-1-stock-tw-permissive-t3206548 The important thing to note is your Build Number as there are many different builds of 5.1.1. You want to make sure the kernel supports the specific build you have installed otherwise you'll soft brick and need to recover either with a nandroid backup or via Odin and the full firmware/OS tar file. Use TWRP to make the nandroid backup before installing any mod so you can easily restore if you run into issues.
es0tericcha0s said:
It looks like your best option would be to install TWRP recovery and use it to flash a custom kernel that auto roots your device such as this http://forum.xda-developers.com/note-4/development/n910c-kernel-5-1-1-stock-tw-permissive-t3206548 The important thing to note is your Build Number as there are many different builds of 5.1.1. You want to make sure the kernel supports the specific build you have installed otherwise you'll soft brick and need to recover either with a nandroid backup or via Odin and the full firmware/OS tar file. Use TWRP to make the nandroid backup before installing any mod so you can easily restore if you run into issues.
Click to expand...
Click to collapse
I did this (except I flashed using Odin) and it totally worked. Thank you!
---
Just for the record though: this kernel triggered "Security Notice Unauthorized Actions Error" and so I had to change it. I'm using SpaceX now, no errors, works smoothly: https://www.androidfilehost.com/?fid=24052804347823851
Cool. I prefer TWRP so I can make backups in case something goes wrong, but whatever works.

Need to dowgrade 6.0.1 to 5.1.1

Hello all, forgive me if this has already been posted somewhere but i cannot find the answers, I am desperately trying to downgrade Marshmallow to Lollipop so I can install CM 12. This phone i had purchased from Amazon so it already had 6.0.1 installed and seems to have already had the bootloader unlocked so I rooted straight out the box without a problem, though I later realized that CM 12 was not compatible with 6.0.1, so then I had "unrooted" (I simply used SuperSU Full Unroot Method) and appears to have been unrooted, I had shifted between using Odin 3.09 and 3.11.1, I dont know if that makes a difference, I had already downloaded what I believe are the STOCK firmwares for 5.1.1, but Odin cannot seem to flash them onto the device.
Here are the device details:
Model Number: SM-G900T
Android Version: 6.0.1
Android Security patch level: May 1, 2016
Baseband version: G900T3UVS3GPK3
Kernal Version: 3.4.0-7500527, [email protected] #1, Thu May 5 16:18:20 KST 2016
Build #: MMB29M.G900TUVU1GPE1
SE for Android status: Enforcing, SEPF_SECMOBILE_6.0.1_008, Thu May 05 16:23:03 2016
Security software version: MDF v1.1 Release 6, VPN v1.2 Release 6.1
KNOX Version: KNOX 2.6, Standard SDK 5.6.0, Premium SDK 2.6.0, Customization SDK 2.6.0, Container 2.6.0, CEP 2.0.1, Enterprise Billing 1.2.0, OTP2.6.0, SE For Android 2.4.0, SSO 2.5.0, Shared Devices 2.6.0, TIMA 3.2.002, VPN 2.2.4
First I rooted using this guide:
https://forum.xda-developers.com/tm...l/root-how-to-root-sm-g900t-firmware-t3358190
Then I simply "Unrooted" using SuperSU.
I had tried using files from here:
https://forum.xda-developers.com/tm.../compilation-s5-g900t-stock-firmware-t3042400
And later Flashed the ROM in this guide using TWRP:
https://forum.xda-developers.com/tm...t/how-to-update-to-g900tof6-5-1-1-pc-t3141404
And ones I have found on sammobile.com
After that I've simply been trying to wipe/reset, and use Odin to downgrade, but it fails everytime, and at one point I used the "recovery" feature when you first initialize the phone as if for the first time and it download all of my apps from my old phone, and somehow it was rooted again(?) Here is a description of what it says in Download Mode:
ODIN MODE
PRODUCT NAME: SW-G900T3
CURRENT BINARY: Custom
SYSTEM STATUS: Custom
FRP LOCK: OFF
KNOX WARRANTY VOID: 0x1 (2)
QUALCOMM SECUREBOOT: ENABLE (CSB)
RP SWREV: S1, T1, R1, A3, P1
SECURE DOWNLOAD: ENABLE
UDC START
SW REV CHECK FAIL : [aboot] Fused 3 > Binary 1
After this I simply reboot the system using the same method to initiate download mode. The boot sequence always hasSecurity Bit: Kernal up at the top when ever I reboot the system.
These are the files I have tried using in Odin 3.09 so far:
G900T3UVU1FOG6_G900T3TMB1FOG6_TMB
> G900T3UVU1FOG6_G900T3TMB1FOG6_G900T3UVU1FOG6_HOME.tar.md5
G900TUVS1FOL1_G900TTMB1FOL1_TMB
> G900TUVS1FOL1_G900TTMB1FOL1_G900TUVS1FOL1_HOME.tar.md5
G900TUVU1DOB1_G900TTMB1DOB1_TMB
> G900TUVU1DOB1_G900TTMB1DOB1_G900TUVU1DOB1_HOME.tar.md5
I have made sure they were complete downloads and have been using these files AS IS, I don't know whether or not I am supposed to rename them or anything.
Up at this point I no longer know what I am doing or what I had even flashed, I really don't know what I did wrong at this point. The biggest reason why I want to downgrade to 5.1.1 and install CM12 is because I have read that it is one the most stable custom ROMS available, hence the dire need to downgrade and REALLY want a good custom rom instead of STOCK android firmware.
If anyone would be kind enough to spend a little bit of your time to point me in the right direction I would greatly appreciate it,
OR if anyone can definitely recommend a VERY STABLE customizable ROM that would also be appreciated, as that would toss out the need to downgrade. Again, forgive me for such a long post, Thank you for your time.
I believe that means you can't downgrade. Not sure why you'd want to anyway. If you want to go to CM, install one of the CM-based Nougat builds, they're stupendous. I'd also stick with Odin 3.09, nothing later than that that I've tried has worked on my T3. Lollipop was the worst ever Android release.
invisiblewave said:
I believe that means you can't downgrade. Not sure why you'd want to anyway. If you want to go to CM, install one of the CM-based Nougat builds, they're stupendous. I'd also stick with Odin 3.09, nothing later than that that I've tried has worked on my T3. Lollipop was the worst ever Android release.
Click to expand...
Click to collapse
Thanks friend, I had now settled and decided to stay on 6.0.1 and just now installed Vanir, barely getting a first impression, I'll see how it goes, and would you say they work on 6.0.1 or would I have to upgrade to nougat? Also I really appreciate your time in reading my post as well as your input.
Iota1942 said:
Thanks friend, I had now settled and decided to stay on 6.0.1 and just now installed Vanir, barely getting a first impression, I'll see how it goes, and would you say they work on 6.0.1 or would I have to upgrade to nougat? Also I really appreciate your time in reading my post as well as your input.
Click to expand...
Click to collapse
Not sure what you're referring to. Would what work? I don't know what Vanir is. As I said before, I would strongly recommend going to a CM-based Nougat rom (I'm on Resurrection Remix), I don't think you'll be disappointed.
invisiblewave said:
Not sure what you're referring to. Would what work? I don't know what Vanir is. As I said before, I would strongly recommend going to a CM-based Nougat rom (I'm on Resurrection Remix), I don't think you'll be disappointed.
Click to expand...
Click to collapse
Apologies for the late reply, Vanir as I've come to find out IS actually one of those nougat based ROMs you speak of, though resurrection remix DOES sounds quite interesting and would like to give it a try, if I wanted to install RR, would I have to uninstall my current rom to get stock OS and THEN flash RR? or could I simply enter Recovery mode and FLASH RR directly without any changes? Also, what can you tell me about custom Kernals?
Thanks.
There are plenty of instructions and tutorials out there, the OP of every rom usually has flashing instructions. Briefly, there's no need to uninstall anything, ever (well, almost). Backup your apps with Titanium (at least the ones for which you want to preserve data), do a full recovery backup, flash the latest stock firmware for your device, let it do a full reboot, then boot back to download mode and flash the new rom and (optionally) the Google apps, then do a full wipe and reboot. After booting, go through the Android device setup, let it restore your apps from the cloud, then restore the apps you backed up. As new versions of your rom are released, just flash them, no wiping, data & google apps will be preserved. With your level of expertise, I'm not sure why you'd want a custom kernel. The Boeffla kernel works on the GS5 and has a lot of customization in it, but with Resurrection Remix you don't need it because there's so much customization in the ROM (for example, the only real reason I flash custom kernels is to control LED brightness at night, but I can do that with RR anyway). The kernel included with RR is just fine.
invisiblewave said:
There are plenty of instructions and tutorials out there, the OP of every rom usually has flashing instructions. Briefly, there's no need to uninstall anything, ever (well, almost). Backup your apps with Titanium (at least the ones for which you want to preserve data), do a full recovery backup, flash the latest stock firmware for your device, let it do a full reboot, then boot back to download mode and flash the new rom and (optionally) the Google apps, then do a full wipe and reboot. After booting, go through the Android device setup, let it restore your apps from the cloud, then restore the apps you backed up. As new versions of your rom are released, just flash them, no wiping, data & google apps will be preserved. With your level of expertise, I'm not sure why you'd want a custom kernel. The Boeffla kernel works on the GS5 and has a lot of customization in it, but with Resurrection Remix you don't need it because there's so much customization in the ROM (for example, the only real reason I flash custom kernels is to control LED brightness at night, but I can do that with RR anyway). The kernel included with RR is just fine.
Click to expand...
Click to collapse
Thank you, this has actually given me a lot more insight on flashing Roms, I'll definitely be giving RR a try, it probably should have been my first choice haha.
Iota1942 said:
Thank you, this has actually given me a lot more insight on flashing Roms, I'll definitely be giving RR a try, it probably should have been my first choice haha.
Click to expand...
Click to collapse
I should have included that after flashing the latest stock firmware, you'll need to re-flash a custom recovery first before you can install the rom (which is flashed from the custom recovery, not from Odin).
I hope I didn't mess up my phone for not doing so (Re-Flashing custom recovery), I had "successfully' and had also updated the ROM to the latest version
"RR-N-v5.8.2-20170304-klte-official"
Android version 7.1.1
Build # RR Nougat 7.1.1_r21 - NOF26W
I had wiped cache, dalvik, system, and dalvik cache and then simply flashed RR and GApps without Installing Stock rom, rebooted, and started as normal, downloaded new RR version, updated, flashed, forgot to download NEW GApps, went through with downloading THEN flashing, and now everything seems to be in order, except not quite, I have tried resetting the APN as well as wiping the cache in recovery, but I can't seem to get my mobile data to work, I have tried looking in many places but can't seem to find the answer, I'm sorry for being such a bother.
invisiblewave said:
I should have included that after flashing the latest stock firmware, you'll need to re-flash a custom recovery first before you can install the rom (which is flashed from the custom recovery, not from Odin).
Click to expand...
Click to collapse
Scratch that, I managed to get it working by reflashing 7.1.1, and I sincerely thank you for your advice, it really has served me well. Cheers

[Guide] How switch to US Nougat ROMs, How to downgrade with Chinese Axon 7

Note: You can try this with EU ROMs but I'm not sure if it will work, and won't be testing to see if it works, since I see no reason to flash EU ROMs anyways.
I knew this from day 1, but was switching between various LOS ROMs so didn't have much inspiration to make a guide. Now i'm switching back to Stock-based ROMs (due to other roms having no dolby, no voice capture,...), I'll be making a guide
I'm not responsible for bricked device.
This is a guide for those who are facing issues when trying to flash US, EU stock and stock-based ROMs on the chinese axon 7 (no signal, no wifi, worse battery, or simply not booting after splash screen). Since downgrading is also a part of this guide, I will also be covering how to downgrade Nougat 7.1.1 ROMs back to 6.0.1 Marshmallow.
Important thing to note:
You must be on B13, 6.0.1 marshmallow with stock recovery, and please, DO NOT UPDATE TO B10 China NOUGAT or anything above ! This will cause a lot of problem, as from what I've deduced, US B19 is based on the China B09 update, anything above B10 won't be backwards compatible. and will cause problems like not booting, (or no wifi, signal etc after you recover the boot partition through recovery)
Now, if you're already on Nougat and want to try this guide, downgrade back to Marshmallow using EDL. Try this guide:
- Download B13 EDL (credits to djkuz from 4pda), extract it
- Download and install the latest Xiaomi MiFlash (stable or beta)
- Turn off your phone, plug it in to your PC, Hold Power + Vol Up + Vol Down, go to device manager, look for the "Port" section, and you will see something like Qualcomm HS-USB QDLoader 9008., if you see it, proceed down below. If not try again.
- right click , open properties on the Qualcomm HS-USB QDLoader 9008, go to port settings, if you see the speed is at 9600 bits per second (bps), change it to 128000 (you can skip this step, but doing it will increase your flashing speed)
- Open MiFlash, press select and pick the folder you extracted a few steps ago.
- Press refresh, if you see your device appearing on the list, press flash. (if some random errors appear, unplug the device, plug it back and immediately press refresh and press flash)
- After flashing you'll be back on B13 China Marshmallow.
REMEMBER, DON'T OTA UPDATE IF YOU WANT A SMOOTH TRANSITION TO US ROMS:
Now, to the good part:
- Download the B09 China OTA package from here (credits to Demons-77)
- put the package into your EXTERNAL sd card, internal won't do.
- reboot to recovery (Power + Vol Up)
- select the option with the word "sd" on it
- now go and pick the package that you just put in
- It will begin flashing and after that, you will have B09 China Nougat
- reboot to bootloader and install recovery (fastboot flash recovery *your file name*)
- after that you can install any roms you like, no need to backup and restore the boot partition every time you flash a US ROM, and you won't encounter strange issues like no boot, no wifi, etc.
TL;DR for those who already know how to do most of these: go back to China Marshmallow through EDL, update to B09 China Nougat with stock recovery, install TWRP and then flash whatever US stock or stock-based roms you want (just like how you would with a US phone)
Does custom kernels work after installing US roms?
I want to have a magisk compatible rom but I don't want to install custom roms other than stock.
Chinese roms doesn't boot with these existing kernels in this forum.
otaconremo said:
Does custom kernels work after installing US roms?
I want to have a magisk compatible rom but I don't want to install custom roms other than stock.
Chinese roms doesn't boot with these existing kernels in this forum.
Click to expand...
Click to collapse
what do you mean by magisk compatible rom? I'm running the latest badboyz with magisk root here, no problems at all
spiwar said:
what do you mean by magisk compatible rom? I'm running the latest badboyz with magisk root here, no problems at all
Click to expand...
Click to collapse
Ok that's great. Last time I tried badboyz, I get issues with my signal keep restarting. I'm currently using chinese B01 mifavor5. all is well, just that I can't use magisk due to the stock kernel.
Thanks for your feedback OP.
Hi, great tutorial, but I got few questions. Now I'm on chinese nougat (B15) and if I downgrade to mm, will still I be able to do this operation? Can I relock bootloader on US rom? Because some apps like android pay, pokemon go and snapchat won't work.
@spiwar Mate I could kiss you right now. But could you just point me to one of the us stock ROMs to flash? (E.g, is this one alright - A2017UV1.1.0B19_StockSystem_by_DrakenFX.zip)
Is it safe to perform ota updates of the USA firmware on Chinese axons? Cheers
Fuilares said:
Hi, great tutorial, but I got few questions. Now I'm on chinese nougat (B15) and if I downgrade to mm, will still I be able to do this operation? Can I relock bootloader on US rom? Because some apps like android pay, pokemon go and snapchat won't work.
Click to expand...
Click to collapse
Downgrading IS a part of this operation if you're already on Nougat (you need to go back to MM before you can go B09 Nougat). Why relock your BL though? Magisk root can work with Android Pay, Pokemon Go AFAIK, not sure though (since I don't use any of those apps)
tigrey said:
@spiwar Mate I could kiss you right now. But could you just point me to one of the us stock ROMs to flash? (E.g, is this one alright - A2017UV1.1.0B19_StockSystem_by_DrakenFX.zip)
Is it safe to perform ota updates of the USA firmware on Chinese axons? Cheers
Click to expand...
Click to collapse
Yes that stock ROM will be okay. Personally I'm using the latest version of BadBoyz ROM.
No you can't. Because OTA updates requires the stock recovery, and your phone probably won't boot if you flash the US Stock recovery
otaconremo said:
Ok that's great. Last time I tried badboyz, I get issues with my signal keep restarting. I'm currently using chinese B01 mifavor5. all is well, just that I can't use magisk due to the stock kernel.
Thanks for your feedback OP.
Click to expand...
Click to collapse
Magisk won't work if you're using B10 Chinese as a base (as mentioned above), if you flash on B10 you'll have to flash the boot portion from the stock Chinese ROM for the US ROMs to even boot, and then you just lose magisk.
I see. Thanks for the tips. But I don't think I'll be coming back to b13 mm for that. I hate restoring data ang all the files in my internal storage.
Hi!
Could you please clarify me a doubt?
To follow this guide, must my device already be rooted?
Thanks!
Well, first part went well. After a lot of effort, because device was recognised as DFU. Anyway, I got it back to B13 with stock recovery.
On second part, when I try installing the FOTA update, it fails, giving me error: status 8. In update history, it says that the system package did not match the phone. Obviously I have A2017.
Any suggestions?

Exploring full ROM options with XT1650-03

So I just unpacked my MOTO Z with great anticipation.
However, I immediately ran into the issue where I can't backup my old phone using TiBU and restore it on my new shining gadget. I was VERY unsuccessful rooting the device.
So I went all in and installed RR which I'm using on all other devices as well. Used this TWRP to do it.
While RR is working well, it doesn't have some of the nice things stock ROM had, like the keyboard adjustability, screen on on hand-over and some adjustments in the camera app. Doesn't really matter, but I'd like to give stock another try before I inevitably commit to RR which will no doubt improve in the mean time as well.
Now, for my problem:
Using the recovery mentioned above, I made a full backup of the phone before I messed with it. Now that same recovery doesn't properly restore that backup: the phone doesn't boot when I restore that backup. it never leaves the bootloader unlocked warning screen.
So I figured: bad backup, let's get a stock image. Eh, again no go: motorola doesn't even publish those. So I grabbed the XT1650-03_GRIFFIN_RETEU... from here.
That one again doesn't even fully flash: I tried partial flash (system partition + recovery partition) - which flashed but didn't boot; then tried full flash, starting with the gpt.bin - but this one didn't even flash. reported some errors and that was it.
So, while not bricked, I'm far from any degree of control over my new phone. I'd like to improve that!
Any advice?
@velis74 to flash firmware you must use adb/fastboot. Is that what you mean by "flashed"?
lollyjay said:
@velis74 to flash firmware you must use adb/fastboot. Is that what you mean by "flashed"?
Click to expand...
Click to collapse
Yes, "flashing" of the "stock image" I tried to do with fastboot - that series of commands flashing one partition after another with images in the archive. I just didn't want to list all those commands in the post because there's more than 20...
If you´ve already updated your Stock, untouched and locked ROM from Marshmallow to Nougat, then you won't be able to Flash back to Marshmallow Stock ROM, because your Bootloader was already updated to Nougat. That's why the whole process fails. Since there's no official RETEU Nougat Stock ROM yet, use the RETBR one. It's practically the same and works as it should: https://firmware.center/firmware/Mo...ubsidy-DEFAULT_regulatory-DEFAULT_CFC.xml.zip
But keep in mind that you won't be able to relock your bootloader, since Motorola/Lenovo haven't released signed Nougat Stock ROMs yet.
doree said:
If you´ve already updated your Stock, untouched and locked ROM from Marshmallow to Nougat, then you won't be able to Flash back to Marshmallow Stock ROM, because your Bootloader was already updated to Nougat. That's why the whole process fails. Since there's no official RETEU Nougat Stock ROM yet, use the RETBR one. It's practically the same and works as it should: https://firmware.center/firmware/Mo...ubsidy-DEFAULT_regulatory-DEFAULT_CFC.xml.zip
But keep in mind that you won't be able to relock your bootloader, since Motorola/Lenovo haven't released signed Nougat Stock ROMs yet.
Click to expand...
Click to collapse
Yep, was just about to post how this thread helped. I'm back at stock and seriously contemplating not rooting. I pretty much only need it for one app where I forgot the password and they make it REALLY hard to reset it

The correct procedure for flashing?

Hi all just after some help. Been using android rooting and flashing ROMs for along time but new to Xiaomi and obviously the new android 10 issues.
To the point:
I've rooted and installed the latest EU rom with TWRP, have been using it happily for a while but I'm keen to try some new ROMs...
1. I've read that people say formatting data is required (which means wiping the internal storage and deleting everything?) Is this needed for EVERY new ROM? Or just if you're coming from miui?
2. Can you actually backup your current rom with settings and data to restore it if you're not happy with the new ROM? God I miss the old way of being a flashaholic...
What is the instructions for correctly flashing a new ROM? As mentioned in currently on miui.
I have read plenty of guides and instructions on here but there's so many variants and I don't want to muck up and risk a brick since there's no patched files available.
Xiaomi note 9s
Appreciate any help or thoughts

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