Develop Bugs

LG G4 boot loop into TWRP

Hello everyone,
yesterday I flashed a new Cyanogenmod 14 nightly (12062016) for my G4 from earlier nightly in TWRP. After reboot the phone keeps going back to TWRP and I can't seem to get it to boot to system..
I tried factory reset, reflashing back to old nightly, flashing stock.. but nothing seems to work.
Also tried doing this in the TWRP terminal:
dd[space]if=/dev/zero[space]of=/dev/block/platform/f9824900.sdhci/by-name/fota
Didn't fix the loop, I guess because it wasn't the OTA update that caused the problem in the first place.
If anyone has an idea, I would greatly appreciate the help!
Thanks.

If you can reach download mode you could try reflashing back to stock then starting again.....Hope you get yours fixed - Sorry to say this but mine did a very similar thing only 24 hours before you posted!!! Only mine was on stock FW and was in use at the time - I've now had to swap it as valuebasket who sold me the phone have ceased trading. If yours is a UK model you may be able to get it replaced under warranty - believe that LG guarantee their phones for 2 years and a ruling by the European court said that flashing a custom rom doesn't invalidate any warranties.

I have the same exact issue, I also flashed the latest CM14 nightly and cannot get the device to boot any rom.
I have even tried flashing stock rom but I get the same problem.
From what I have read, the bootloop issue happens once the device boots but I don't seem to be getting that far.
Any ideas?

Ran into the same problem 3 days ago. This is the first time I have encountered a non-revertible issue in 3 years as a cyanogenmod user. This changes my opinion on how safe it is to make use of a custom ROM. I tried to wipe everything, reinstall TWRP, change TWRP with another recovery, reinstall a safe NAND backup of mine.....nothing.....it went into boot loop. Before I read this post, I was convinced my phone encountered the infamous G4 bootloop problem.....now I see there are other examples, so it shouldn't be the case. Long story short, I had to check my device in at the LG assistance, with 25 days as time forecast.
The guilty nightly was 20161205.
I have never seen anything like this...

This has solved it for me - I installed LG Bridge and flashed the factory firmware using the tool. Now it seems I'm back on stock but at least it's working.

got mine working. I had to install LGUP and flash stock ROM. Once flashed I installed CM14 and I am back up and running again.

I tried LGUP but it could not recognize the device while this was looping.....a bad experience......

I have the same issue. My phone was updated to 20i via the original stock firmware, then I put twrp 3.0.2-0 and cyanogenmod on. I did a cyanogenmod update from within cyanogenmod, which just booted into twrp, then I manually installed the update zip that cyanogenmod had downloaded, then it always boots into twrp. I wonder if initiating the update from within cyanogenmod was the cause. The phone is not detected by LGUP or LG Bridge. I've tried this on a win10 machine, and a win7 vm from linux. I have access to twrp, and download mode by doing the reboot into bootloader from within twrp.
If those people who have fixed this could give more details about how they did it, that would be good. What exact steps did you take? What stock firmware version did you have before installing a custom rom? What OS version were you using? What twrp version?

Well. Mine got stuck in bootloop for the second time today. What is going on? In between the two bootloops I had one good update with CM. Using TWRP 3.0.2.1. Steps to reproduce failure: updating CM from within CM, it autoreboots into TWRP and after that nothing happends, no autoinstall. Then after a manual install of the new CM the bootloop starts.
Resolve the problem:
* Install LGUP 8994 DLL Ver 0 0 3 23, Install LGUP Install Ver 1 14, get the latest KDZ
* Get the phone into download mode with usb cable and after that in firmware update mode
* Startup LGUP and choose refurbish and select the kdz file.
* After that you can boot into your stock LG firmware again, reinstall TWRP an CM. If you want so.

Read that it is advised to manual update cm from within TWRP. TWRP will get an update in the future to solve this bootloop problem.

iankelling said:
I have the same issue. My phone was updated to 20i via the original stock firmware, then I put twrp 3.0.2-0 and cyanogenmod on. After a cyanogenmod update, it always boots into twrp. The phone is not detected by LGUP or LG Bridge. I've tried this on a win10 machine, and a win7 vm from linux. I have access to twrp, and download mode by doing the reboot into bootloader from within twrp.
If those people who have fixed this could give more details about how they did it, that would be good. What exact steps did you take? What stock firmware version did you have before installing a custom rom? What OS version were you using? What twrp version?
Click to expand...
Click to collapse
I second that. Same issue and neither LG Up nor LG Bridge will recognize my device. Looking in device manager there are no serial interfaces. Do I need a special driver that provides a com port for a phone in recovery or fastboot mode?
---Edith 2016-12-12: Found a solution for my issue:
The phone has to be in _download_ mode, not in recovery or fastboot. After realizing that I have to boot the phone in a different manner, it will be recognized by LG UP.
Here is how to boot the pone in download-mode:
- Power off your LG device.
- Press and hold Volume Up button.
- Connect your device to PC with a USB cable while holding the Volume Up button.
- You’ll boot into download mode with “Firmware Update” written on top of the screen.
Now everything is fine again.

croclacrimae said:
Hello everyone,
yesterday I flashed a new Cyanogenmod 14 nightly (12062016) for my G4 from earlier nightly in TWRP. After reboot the phone keeps going back to TWRP and I can't seem to get it to boot to system..
I tried factory reset, reflashing back to old nightly, flashing stock.. but nothing seems to work.
Also tried doing this in the TWRP terminal:
dd[space]if=/dev/zero[space]of=/dev/block/platform/f9824900.sdhci/by-name/fota
Didn't fix the loop, I guess because it wasn't the OTA update that caused the problem in the first place.
If anyone has an idea, I would greatly appreciate the help!
Thanks.
Click to expand...
Click to collapse
I was able to get out of that by also wiping by-name/misc. Don't do that, though, because then your wifi mac address will get messed up and you'll spend all day looking for a permanent fix for that.
I suggest reflashing a stock KDZ using LGUP, as others have said. You can get the usb drivers from LG Bridge.

I will release a fix for that soon. Check the twrp thread for updates on this.

Hi
I also have this problem
I installed cm-14.1-20161201-NIGHTLY-h815 successfully and was running it for almost 2 weeks without issues, today I updated to cm-14.1-20161213-NIGHTLY-h815 from cmupdater and I have been ending up in recovery every time I rebooted.
I tried flashing the latest cm recovery and reflashing the rom, with full wipes but no luck.
Full steps of recovering would be appreciated (for example, there are comments about flashing the latest stock rom, but a link to this rom would be helpful)
Thanks

Good news regarding this:
http://forum.xda-developers.com/showpost.php?p=70082901&postcount=213
The above will fix TWRP bootloop issues as well and I also released a first h811 version which should allow installing CM etc as it should.
Keep in mind that this is a BETA and not an official TWRP release.
Please report back in the above thread!
.

Does your twrp beta really fix the boot loop even it is already happening. What do I have to wipe? I have not managed to get out of the boot loop despite intalling it.
Is using using LG Up to flash to the stock rom really the only option?
Edited 2017-01-25 2:45 pm:
Well, sometimes you just have to be patient. Powered down the phone and when th H815 restarted CM did boot. Great. :good:

Hey, I just want to share a small detail, possibly a fluke that helped me overcome the bootloop.
So...I started with a fresh, stock H815, I don't quite remember the firmware version..it was something like version "20g"..
OK, I looked up several guides and tried to get the newest stable versions of each tool. I went through with the official bootloader unlock, then moved on to rooting: Kingroot didn't work for me so I went on installing twrp in fastboot mode so I could afterwards install supersu and root.
I got there eventually but first I was stuck in bootloop - kept ending up in twrp interface. I found the 2 dd commands but those didn't work for me as the msm_sdcc folder did not exist, but instead there was a "f9824900.sdhci". Tried to overwrite this one ...but as others have stated as well, it didn't work.
At that point, I had nothing to lose, I was starting to accept that I had soft-bricked my precious G4 so..I went on installing the DU 10.6 7.1.1 rom and the stock gapps, wiped dalvik, rebooted and held my breath...not literally
About 12 minutes later, after an endless red, spinning logo, my shiny ping pong paddle showed me a different screen, a fresh start welcome screen .
Almost 24h / 10-12 reboots (twrp included) / 70+ apps installed and removed later, the new OS holds around 2G ram average, a bit better battery life, smoother transitions, flawless navigation, flush streaming over both 3G/LTE & 2.4/5 G wifi.
FYI the reboots were intended, wanted to see consistency in boots - we're in the green . Now testing long term stability with moderate/high usage.
There is 1 aspect I noticed, there are a couple of contexts when the interface burps (several menus, various situations, never in apps) and resets back to homescreen...but I think that's more of a launcher topic than an OS one.
Other than that, so far I'm happy with the mod.
Hope my experience helps others that might be in the same spot I was or at lest boosts their confidence to try out a decent idea they might be pondering.

Swift won't boot into system - straight back to bootloader fastboot mode

I'm trying to be helpful to someone and failing . I've not seen this issue before.
I have a WileyFox Swift that has been unlocked and has TWRP as custom recovery. Internal storage has an installation zip in it so looks like an attempt has been made to flash it. Can't Restore, not sure if a Backup was done. When powered-on it jumps straight to bootloader - fastboot mode. (Start/Power off/Recovery mode/Restart bootloader). Options all work as expected except Start which goes back to bootloader. I can also connect to the handset via usb and receive a response to 'fastboot devices' and other commands.
From TWRP I have installed Lineage nightly rom and the installation has completed successfully. Same for Gapps but the reboot option jumps straight back to bootloader (no sign of a system splash screen). A 'Fastboot continue' command at this point causes a flickering recovery splash screen and then back into bootloader again. I've been in bootloops before but usually a step further on than this. Anybody seen this before - am I missing something obvious?

Hi
Method 1
-if u want to install lineage os
install lineage and reboot it without installing gapps after that install gapps . Hope it works
Method 2
- if method 1 doesn't work for you you need to download and install stock rom for wileyfox swift by adb (fastboot)
See ya

Thanks for the reply. The problem with finding a stock rom is that the Swift shipped with Cyanogen OS 12 (not CyanogenMod). Cyanogen is no more and all links to their website have gone so it's hard to track them down.
I removed the battery from my Swift earlier today and forgot about it for about one hour- I think this has made the difference as I flashed a CyanogenMod 14 rom, rebooted to system and it worked :good:. Went back and flashed Gapps and it worked again :good:. I have an older OS than I want but am fine for the moment.

Good for you

Lineage OS 7.1.2 SuperSu Secure Boot Error [SOLVED]

SOLVED!
So, after just giving up and moving on to another project of trying to flash the ARTX Kernel which didn't work (I'll update this if I find out why it's not working; my phone restarts when im flashing the zip and "2013-2015 [somename ] amurlle.com" pops up in log.) so I researched and found a zip called MrBump.zip which bumps your boot image to get rid of the secure boot check.
How to
Flash SuperSu v2.82.zip via TWRP and then flash MrBump.zip, the phone will reboot after flashing MrBump and then another time for finishing the SuperSu installation.
History
\\
So, I have recently updated from Cyanogenmod 13 to Lineage OS 14.1 as it's faster, pretty, and Xposed was recently released for Nougat.
Installing Lineage wasn't a problem nor Gapps or the su add on package from Lineage which unlocks the OS's own su management service.
I wanted to use SuperSu as it pretty, customization, and better privilege management compared to the option lagging 'Privacy Guard' Lineage uses.
So, I flashed the SuperSu v2.82 zip which gave me a "Secure Boot Error" when rebooting into the system. No partitions seemed to be corrupted or damaged but I assumed
it had to do with the boot.img file as I saw supersu patch the boot image for some stuff I don't know. I decided to research and get my team of arduino super AI's to find
something of an answer of how to fix my problem, stumbling upon an article on XDA from chainfire of a boot image signer. I used Cywgin to create an rsa key and signed my boot image
then figuring out I could use the "BootSigner.zip" to sign the boot image without me creating a rsa key, flashing the zip nothing changed just some other error of where it couldn't read
boot image or the boot image was misdirecting to the system. I then tried fastbooting the signed boot image I made, it didn't work giving me some other ****ty error of mutiny.
I then fastbooted the orginal unsigned boot image I took from my ROM which worked but when booting into the OS SuperSu was still not the active su manager.
I then gave up and am now writing this post in a last option of getting SuperSu on my phone.
I have tried SuperSu 2.78 and kingoroot from the PC hoping that I could then use SuperSuMe
//
Details of my device
\\
LG G3 D855
ARM
Lineage OS 14.1 (20170724)
Gapps 7.1 Micro (20170728)
TWRP 3.1.1-0
//
1 second after turning on the phone the error pops up (the LG logo is visible when the log is onscreen):
ERROR : boot certification verify
[640] --------------------------------------------------
[640]
[640] Secure boot Error!
[640] Cause: boot certification verify
[640]
[640] ---------------------------------------------------
2 seconds later the screen blanks and the LED on my phone blinks blue and red at half second intervals.
Any help would be appreciated, if you need any specifics of my device or screenshots just ask (I can replicate my problems and steps iv'e done if you need me to.)

Eureka!
I did the exact same thing and all the guides that I found assumed that you still had access to the system or had already wiped out download mode. There is a lot of advice out there that really just doesn't work. Anyway, I gave up and decided to do a wipe with suprising results.
boot to stock recovery by holding power+volume down
perform factory reset
phone reboots to TWRP - WHY?!?! I have no idea, but it worked
reinstall your latest lineage image from /data/data/org.lineageos.updater/app_updates/
wipe davlik/cache + reboot
profit!
I don't know why this worked and I stumbled upon this by accident.
Mileage may vary, so please share your results.

XtatX said:
I did the exact same thing and all the guides that I found assumed that you still had access to the system or had already wiped out download mode. There is a lot of advice out there that really just doesn't work. Anyway, I gave up and decided to do a wipe with suprising results.
boot to stock recovery by holding power+volume down
perform factory reset
phone reboots to TWRP - WHY?!?! I have no idea, but it worked
reinstall your latest lineage image from /data/data/org.lineageos.updater/app_updates/
wipe davlik/cache + reboot
profit!
I don't know why this worked and I stumbled upon this by accident.
Mileage may vary, so please share your results.
Click to expand...
Click to collapse
What?
You must've flashed TWRP before, and I don't understand what you mean here. Did you brick your phone trying to flash SuperSu too?
But i'm glad it worked out for you

Bump!

Saterlite said:
What?
You must've flashed TWRP before, and I don't understand what you mean here. Did you brick your phone trying to flash SuperSu too?
But i'm glad it worked out for you
Click to expand...
Click to collapse
Yeah, I had TWRP on it before and got to that point by trying to flash SuperSU on an already installed copy of Lineage. I was really trying to revert to stock and start over when TWRP came up.

LG G4 H815 No TWRP Access

Hello members of XDA,
The issue I'm having is pretty rare and found few or non threads about it, so I will try to be the most precise possible.
Yesterday I decided to change the ROM of my LG G4 H815, I was previously on LineageOS, since LineageOS on H815 wasn't developped anymore. So I asked myself why not trying Android Oreo with CypherOS. Before any changes I was with the latest version of LineageOS for H815 and I had TWRP with the version 3.0.2.1. Bootloader was obviously unlocked.
So I starded to download all the required material to switch to CypherOS 5.3.1, while the download I've made a backup of my actual lineageOS installation on my internal storage. Once every thing was downloaded I tried to install CypherOS I had an error 7 in TWRP install box, so I was pretty worried, scouted XDA threads about the error but i was redirected to the solution where you modify the update binary with txt but still didnt worked. I've found a thread talking about updating firmware of the H815 ( https://forum.xda-developers.com/g4/development/v5-8-5-n7-1-2-resurrection-remix-t3704450) While panicking I've done a wipe of everything (dalvik, data,cache and system) .I applied thge firmware update but I also re-read the thread of CypherOS and figured that I needed a newer version of TWRP, installed it so. THen magically CypherOS installed without any issue.
After installing the Gapps (Arm64 8.1 Nano) I rebooted and the first weird thing appears, after seeing the LG screen while the boot I have another screen telling me that the bootloader has been locked and that i should visit g.co/ABH for more information, then CypherOS initialise, CypherOS worked like a charm. So I wanted to go to my TWRP and make a backup in case. I launched ADB and use the command adb reboot recovery, the phone restarted and had the following events : LG logo, warning message about the bootloader, LG logo again and then a black screen. However I was in recovery mode since adb found me with the command fastboot devices. I had no TWRP logo or anything linked to it. Few minutes later, I had the basic recovery mode where you move yourself with the volume buttons and select with power where the functions are pretty limited.
Then I rebooted the phone with adb (fastboot reboot), CypherOS still working perfectly. Thaught that it was the bootloader which back to scratch when he was blocked, I figured out that he was still unlocked, I used the command "fastboot getvar unlocked" through ADB. THen I thaught i had to install back TWRP, tried through the fastboot mode but I had an error
Code:
FAILED (remote: unkown command)
since i tried everything i could even in the basic recovery mode, the only working command in the recovery is "fastboot flash recovery twrp.img" but still does nothing.
I mean it's not that terrible since I can use my phone and i'm about to change phone in 2 months for a Oneplus but i would really like to be able to install magisk on the phone to grant root access and be able to use TWRP on it like I used to. By the way the backup of lineageOS has been deleted while performing unecessary wipes.

Bennou said:
Hello members of XDA,
The issue I'm having is pretty rare and found few or non threads about it, so I will try to be the most precise possible.
Yesterday I decided to change the ROM of my LG G4 H815, I was previously on LineageOS, since LineageOS on H815 wasn't developped anymore. So I asked myself why not trying Android Oreo with CypherOS. Before any changes I was with the latest version of LineageOS for H815 and I had TWRP with the version 3.0.2.1. Bootloader was obviously unlocked.
So I starded to download all the required material to switch to CypherOS 5.3.1, while the download I've made a backup of my actual lineageOS installation on my internal storage. Once every thing was downloaded I tried to install CypherOS I had an error 7 in TWRP install box, so I was pretty worried, scouted XDA threads about the error but i was redirected to the solution where you modify the update binary with txt but still didnt worked. I've found a thread talking about updating firmware of the H815 ( https://forum.xda-developers.com/g4/development/v5-8-5-n7-1-2-resurrection-remix-t3704450) While panicking I've done a wipe of everything (dalvik, data,cache and system) .I applied thge firmware update but I also re-read the thread of CypherOS and figured that I needed a newer version of TWRP, installed it so. THen magically CypherOS installed without any issue.
After installing the Gapps (Arm64 8.1 Nano) I rebooted and the first weird thing appears, after seeing the LG screen while the boot I have another screen telling me that the bootloader has been locked and that i should visit g.co/ABH for more information, then CypherOS initialise, CypherOS worked like a charm. So I wanted to go to my TWRP and make a backup in case. I launched ADB and use the command adb reboot recovery, the phone restarted and had the following events : LG logo, warning message about the bootloader, LG logo again and then a black screen. However I was in recovery mode since adb found me with the command fastboot devices. I had no TWRP logo or anything linked to it. Few minutes later, I had the basic recovery mode where you move yourself with the volume buttons and select with power where the functions are pretty limited.
Then I rebooted the phone with adb (fastboot reboot), CypherOS still working perfectly. Thaught that it was the bootloader which back to scratch when he was blocked, I figured out that he was still unlocked, I used the command "fastboot getvar unlocked" through ADB. THen I thaught i had to install back TWRP, tried through the fastboot mode but I had an error since i tried everything i could even in the basic recovery mode, the only working command in the recovery is "fastboot flash recovery twrp.img" but still does nothing.
I mean it's not that terrible since I can use my phone and i'm about to change phone in 2 months for a Oneplus but i would really like to be able to install magisk on the phone to grant root access and be able to use TWRP on it like I used to. By the way the backup of lineageOS has been deleted while performing unecessary wipes.
Click to expand...
Click to collapse
It's clearly written on the official website and in the official TWRP support thread for the g4 what you have to do when on Nougat bootloader and want to flash TWRP... and keeping it.
Sent from my LG-H815 using XDA Labs

Yet, this still doesnt help me to solve my issue. Do you think there is a way to fix it or no ? If not, I'll just deal with it for the few months lasting.

Bennou said:
Yet, this still doesnt help me to solve my issue. Do you think there is a way to fix it or no ? If not, I'll just deal with it for the few months lasting.
Click to expand...
Click to collapse
Okay if it doesn't work for you you must do something wrong. It works 100%. If you really want help you should explain in detail exactly which steps you took as otherwise it's all just guessing what you're doing.
Sent from my LG-H815 using XDA Labs

Indeed, I didn't followed the procedure exactly, didn't do the step after flashing TWRP (removing battery and boot manually to recovery). Well thank you, was my bad on that.
Should I do a clean new install of cypheros or should I keep it like that, what would be your advice ? Knowing that at the moment CypherOS works like a charm. I also plan to install Magisk on it to root it.
To help others newbie like me, solution can be found here : https://forum.xda-developers.com/g4/development/recovery-twrp-3-touch-recovery-t3442424

Unable to boot phone once TWRP installed?

Hey guys,
So I've been trying for days to get a custom Ron installed on N975F.
Right now I'm on completely reflashed stock Rom. With stock recovery et al. No root.
I am able to flash Magisk with Odin. No trouble. And my phone continues as usual without issue.
However, once I install TWRP, no matter where or how I install it, once I restart my phone it will boot past the warnings without issue, then go to the screen that just says "SAMSUNG" and the phone will never actually boot up.
I can still boot into TWRP recovery without issue, but system itself will never boot, it will just sit on the "SAMSUNG" screen forever.
In fact, it seems like as long as TWRP is installed to recovery, my system will never boot with any Rom. It can be fixed by reinstalling stock recovery, or by reflashing stock in it's entirety (which I have now done before I try again).
Has anyone got any ideas why this might be occurring or how I can address it? I saw some threads about 'rollback protection' but it seems like that is for people who are not even able to boot into TWRP, or get stuck on the first "Samsung Note 10+", screen rather than the system booting "SAMSUNG" screen.

KiwiNote+ said:
Hey guys,
So I've been trying for days to get a custom Ron installed on N975F.
Right now I'm on completely reflashed stock Rom. With stock recovery et al. No root.
I am able to flash Magisk with Odin. No trouble. And my phone continues as usual without issue.
However, once I install TWRP, no matter where or how I install it, once I restart my phone it will boot past the warnings without issue, then go to the screen that just says "SAMSUNG" and the phone will never actually boot up.
I can still boot into TWRP recovery without issue, but system itself will never boot, it will just sit on the "SAMSUNG" screen forever.
In fact, it seems like as long as TWRP is installed to recovery, my system will never boot with any Rom. It can be fixed by reinstalling stock recovery, or by reflashing stock in it's entirety (which I have now done before I try again).
Has anyone got any ideas why this might be occurring or how I can address it? I saw some threads about 'rollback protection' but it seems like that is for people who are not even able to boot into TWRP, or get stuck on the first "Samsung Note 10+", screen rather than the system booting "SAMSUNG" screen.
Click to expand...
Click to collapse
i am guessing try ADB commands see this link! https://www.koskila.net/how-to-use-twrp-to-flash-an-android-device-that-refuses-to-boot-to-twrp/

Many N975 users have reported this issue and I have forwarded concerned to ian as well. What I believe is formatting on latest (last few) twrp causing issue.
If you have N975/N976 then, visit xda My rom thread - Download area - you will find a folder "for stock rom & bootlooped device" download instructions and follow it, I have wrote guide with or without flashing my rom
Edit :
here is direct link, you will find all required file
https://www.mediafire.com/#0urfw8g1gx630
This guide is stop solution to root/root with twrp/fix Samsung roll back bootloop everything. And yes you don't needs to patch anything yourself, all files available are ready to use

Hi Dr Ketan,
Thanks for the response.
I actually solved the issue simply by using the version of TWRP and following the install instructions on your basic "How to Root and Install TWRP" for Note 10+ guide.
So I think this is a problem relating to Ian's latest TWRP. TWRP linked from your thread
is working fine (but leads to issue with Camera in GSI/Lineage OS ROMs).
I will have a look at your special guide relating to Samsung logo/rollback stuff and see if it will allow me to install latest TWRP from Ian and bypass these issues! Thank you.

KiwiNote+ said:
Hi Dr Ketan,
Thanks for the response.
I actually solved the issue simply by using the version of TWRP and following the install instructions on your basic "How to Root and Install TWRP" for Note 10+ guide.
So I think this is a problem relating to Ian's latest TWRP. TWRP linked from your thread
is working fine (but leads to issue with Camera in GSI/Lineage OS ROMs).
I will have a look at your special guide relating to Samsung logo/rollback stuff and see if it will allow me to install latest TWRP from Ian and bypass these issues! Thank you.
Click to expand...
Click to collapse
Yes, As I said issue is related to newer TWRP only. If you use old TWRP, camera will not work. My above link guide is for latest base and you can get latest TWRP only (Included package are having latest available TWRP & Kernel)