[UNLOCK][UNOFFICIAL][G4] Unlock ANY* LG G4 device with UsU

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අධිරාජ (Adhirāja)

අධිරාජ (Adhirāja)

Senior Member
May 11, 2017
118
10
Anuradhapura
sdembiske said:
I see you still do not how to read thoroughly ... the brick refers to and was only referenced with respect to the Software Update app. If you need an explanation as to the 'why', I suggest, as SteadfasterX has suggested to you already, that you do not unlock or flash a rom ...
Click to expand...
Click to collapse

Ok.

Who said automatically updating firmware will brick?? Have you tried it?? Also if you want to stop app updates, why not just install System App Uninstaller: https://play.google.com/store/apps/details?id=com.kunkunsoft.rootuninstaller&hl=en and uninstall it?? Why making it more complex by going into file systems and entering commands and all??
 
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අධිරාජ (Adhirāja)

අධිරාජ (Adhirāja)

Senior Member
May 11, 2017
118
10
Anuradhapura
adam_s_459_ said:
The update would almost definately carry an aboot image in it which would yeild the same results as flashing a stock based ROM with one. Immediate los of unlock and hard brick.
Click to expand...
Click to collapse

Ok so when you manually flash 6.0 KDZ file, it doesn't carry an aboot image? And also, the phone doesnt automatically software update.. it will tell you that an update is available only. So whats the risk?
 
අධිරාජ (Adhirāja)

අධිරාජ (Adhirāja)

Senior Member
May 11, 2017
118
10
Anuradhapura
dagnusmaximus said:
H815P Tried this and all is working good. Good sound, WiFi, and LTE.
Click to expand...
Click to collapse

Nice:good:

---------- Post added at 03:50 AM ---------- Previous post was at 03:46 AM ----------
dagnusmaximus said:
H815P Tried this and all is working good. Good sound, WiFi, and LTE.
Click to expand...
Click to collapse
How about voice and sms?

---------- Post added at 03:51 AM ---------- Previous post was at 03:50 AM ----------
TheLatios381 said:
Im not clear how you flash twrp. Do you use lglaf? adb? Please tell me
Click to expand...
Click to collapse

Well I flashed 5.1 image using LG UP. I think anything on this phone is flashed using LG UP tool.
 
adam_s_459_

adam_s_459_

Senior Member
Mar 14, 2017
371
89
21
langley
අධිරාජ (Adhirāja) said:
Ok so when you manually flash 6.0 KDZ file, it doesn't carry an aboot image? And also, the phone doesnt automatically software update.. it will tell you that an update is available only. So whats the risk?
Click to expand...
Click to collapse
The 6.0 KDZ has a 6.0 boot stack so that would be ok it's with nougat boot stacks that cause the problems I believe. I stand corrected if I'm wrong
 
H

hey_joe

Senior Member
Oct 28, 2010
1,422
435
Went ahead and flashed a stock-based nougat rom. Everything works ok except there is no sound. From reading everything that's in the Faq, it seems to be related to the modem as the op had said. But flashing N modem and my baseband after didn't fix the sound. Anybody have an idea what else to try? H12 user here.

Thanks
 
grantdb

grantdb

Senior Member
Sep 10, 2011
469
198
grantdb.ca
Great! I had a minute or two of freaking out thinking I bricked when I rebooted into fastboot and didn't have the twrp and baseband files because they were in the download folder on my device! I only have Hotspot wifi through my device for my laptop! lol crossed my fingers and rebooted and was so relieved to boot up no problems! Whew! So now unlocked and rooted on stock MM!
Thanks again for @steadfasterX
 
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keeponjammin

Member
Jun 10, 2015
10
2
steadfasterX

steadfasterX

Recognized Developer
Nov 13, 2013
6,252
15,486
127.0.0.1
OnePlus 7T Pro
N4cr2k said:
Ah, good call on the missing fastboot. I had used an older version of FWUL on a USB drive but persistent mode kept having issues of not staying persistent. So I just went to a full blown installation of Ubuntu and installed SALT manually. lsusb doesn't show any recognized device in any state or any key combo I've tried. With the battery out I get a icon of a red question mark flashing around the outline of a battery.

george@george-Precision-T1600:~$ lsusb
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 058f:6362 Alcor Micro Corp. Flash Card Reader/Writer
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Click to expand...
Click to collapse
This seems like a hard brick then. If you want PM me on that with the subject: unbrick infinity
It will require a windows machine with TeamViewer installed though.

TheLatios381 said:
I decided to say screw it and go back to stock rom (h81220z), but problems mentioned above still exist even after going back. Please help, i do not want to live with this! :crying: :crying: :crying:
Click to expand...
Click to collapse

Flash the lollipop modem partition of your device model nothing else. Then try again

mertklic said:
I will try it on my H815TR
Hope it works!
thanks for the topic sir! :angel:

Edit: sorry for being an idiot but im new to these things :( Does this rom pass your limitations? Is it KDZ/TOT?
https://xdaforums.com/g4/development/rom-h-rom-v30-port-t3672567

Sorry and thank you again!
Click to expand...
Click to collapse

Download it. Open the zip. If you see a modem file in there you have to flash the baseband package after flashing that ROM. If you see a file aboot (very unlikely) do not flash.

TheDerpyLlamas said:
Is there any chance that you could port salt to windows? My pc isn't able to handle virtualbox very well and I don't want to mess with the BIOS settings to use a live usb.
Click to expand...
Click to collapse
Read FAQ 6

keeponjammin said:
Hate to admit it but I believe I broke something.
Good news: fastboot and twrp both work.
Bad news: none of the roms seem to work for me.

1 wipe dalvik, cache, system and data
2. Flash aoscp 5.3, gapps, magisk
3. Flash baseband package
Reboot and after the LG logo with warning a black screen with the text "invalid ram console!!!" greets me.

I assume I made a mistake along the way but tried all combinations and can't seem to figure it out. With modem, without modem, with gapps or without you name it. Any help would be greatly appreciated
Click to expand...
Click to collapse

Flash the latest lollipop version of the modem partition of your device model like described in FAQ 5

adam_s_459_ said:
The 6.0 KDZ has a 6.0 boot stack so that would be ok it's with nougat boot stacks that cause the problems I believe. I stand corrected if I'm wrong
Click to expand...
Click to collapse

Read FAQ 2 which also is true for doing official LG upgrades

th3y said:
Hi, i own a H815P,
Did you use lollipop or MM to do UsU?
after its unlocked, do i need to flash a ROM? or just boot into the actual ROM?
Click to expand...
Click to collapse

Your choice. While it is recommended to boot just once to your current ROM so you know all is working.

TJtheBLueDragon said:
Did you need Linux for this?

Or I can do it in VM?
Click to expand...
Click to collapse
Read FAQ 6 and the OP again

mwahahaa said:
I'm unlocked with TWRP thanks to steadfasterx, now I have to figure out which ROM to flash on my H812...
Click to expand...
Click to collapse
Read FAQ 12

keeponjammin said:
Yep. But maybe at the wrong step. I assumed I would flash it after flashing gapps and then baseband package.
Click to expand...
Click to collapse
Read and follow FAQ 7
 
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adam_s_459_

adam_s_459_

Senior Member
Mar 14, 2017
371
89
21
langley
Haha I was so scared for a second because SALT just closed the unlock process and I thought there was an error, I unplugged my device and it said "CRITICAL ERROR: REFLASH KDZ OR YOU'RE DEVICE WILL BE HARD BRICKED" Turns out it worked perfectly fine and i'm running Oreo now?. Thanks so much @steadfasterX you have made my phone good again.:good:
 
F

fates13

Senior Member
Dec 20, 2014
155
68
Samsung Galaxy Tab S3
OnePlus 8
Hey @steadfasterX, I can't seem to get my lock screen set up on my VS986. I've tried both AOSCP Nougat and Lineage Nougat with multiple downloads and flashes and both force close Settings whenever I try to set up security (pin/pattern/password) on the lock screen. I had to flash the full Lollipop modem for the VS986 in order to get it to boot into Nougat properly. Do you have any clues on why this might be happening? Also, I didn't see this in the OP but are kernels safe to flash after the UsU unlocking process?
 
steadfasterX

steadfasterX

Recognized Developer
Nov 13, 2013
6,252
15,486
127.0.0.1
OnePlus 7T Pro
fates13 said:
Hey @steadfasterX, I can't seem to get my lock screen set up on my VS986. I've tried both AOSCP Nougat and Lineage Nougat with multiple downloads and flashes and both force close Settings whenever I try to set up security (pin/pattern/password) on the lock screen. I had to flash the full Lollipop modem for the VS986 in order to get it to boot into Nougat properly. Do you have any clues on why this might be happening? Also, I didn't see this in the OP but are kernels safe to flash after the UsU unlocking process?
Click to expand...
Click to collapse
Every ROM contains a kernel so of course you can flash any kernel if you like. For your screen lock issue ensure that you wipe the data partition in TWRP . this is not the same than a factory reset so go into the wipe menu and choose format data and try again but keep in mind that this will erase all your personal data on the phone!



Sent from my LG-H815 using XDA Labs
 
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fates13

Senior Member
Dec 20, 2014
155
68
Samsung Galaxy Tab S3
OnePlus 8
steadfasterX said:
Every ROM contains a kernel so of course you can flash any kernel if you like. For your screen lock issue ensure that you wipe the data partition in TWRP . this is not the same than a factory reset so go into the wipe menu and choose format data and try again but keep in mind that this will erase all your personal data on the phone!



Sent from my LG-H815 using XDA Labs
Click to expand...
Click to collapse


Tried out your suggestion and unfortunately it didn't work. I factory reset > formatted data > flashed Lineage 14.1 > flashed modem in TWRP > flashed GAPPS > flashed supersu > wiped cache/dalvik > rebooted and security setting still force closes. :crying:
 
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    steadfasterX
    steadfasterX
    About

    UsU = Unofficial secureboot-off/steadfasterX Unlock


    *works with any G4 model. Even though the h818 can be unlocked as well the touch display does not work anymore (should be possible to resolve but.. read on).
    so I decided to remove it from the UsU unlock. Read the details and process here: h818 topic


    This will "unlock" your bootloader and so enables you to install TWRP and custom ROMS as you like.
    To be honest unlock is not the correct wording but I will still refer to it as unlock as the result is the same:
    UsU will disable "Secure Boot" which verifies signatures on several partitions like: boot and recovery. Disabling secureboot means it will still verify and give you a secure boot error on boot BUT it will ignore and just boot afterwards (similar to a regular unlock).

    This is the outcome of a loooooooong finding process. long? I started with the first attempt in this over 1 year ago. yes.. (think about my nickname heh?!)

    A lot of stuff happend since then which all together helped me to accomplish UsU at the very end (yes all these links are my work including some brave testers ofc! ;) ).

    You wanna know how this big puzzle fits together?
    UsU is not just an unlock! Its a combination of massive changes in TWRP, the G4 kernel and providing all the tools around like FWUL or SALT!

    It was really my biggest project in android development and its not just providing the actual unlock files ;)

    1. Hijacking the boot process via EFIdroid, TWRP in FIsH and FIsH in general
    2. AntiRollback and firehose(!) findings
    3. Partition tables for any G4
    4. mAid (fka FWUL) because I needed a valid base for all my testers (one of the reasons why I started FWUL)
    5. The LG-Up replacement and now unlocking tool SALT ! Without SALT this all would be absolutely crazy risky and absolutely nothing for the average user!
    6. many many unlock methods/theories (and millions of times soft and hard bricked) in my PoC thread
    7. while unbricking I found a way to unbrick even when QFIl fails with my sdcard unbrick method
    8. hard-hard bricked (no other recovery then by LG / chip replacement) for 4 times.. (thanks ILAPO!)
    9. many TWRP tests and changes to detect UsU devices properly


    HINT:
    OPEN THIS THREAD IN A BROWSER!
    NOT IN AN APP!
    THATS THE ONLY WAY TO FULLY SEE EVERYTHING AS IT SHOULD BE


    REQUIREMENTS

    UsU does not care about a country version of a model (e.g. H815 TWN and H815 TUR are all referring to as H815).
    So you will find only the main part of your model listed which means it will work for any of them!

    1) Your device should be one of these (SALT will detect your device and only allows to flash for these variants):

    • LS991
    • F500
    • H810
    • H811 (wth? yes that works but.. you can unlock OFFICIALLY! its just a fastboot command!)
    • H812 (NOTE: firmware: v20x or higher is strictly required before flashing!)
    • H815 - any non EUR
    • H815 EUR (wth? yes that works but.. you can unlock OFFICIALLY! its just a login on the LG website)
    • disabled: H818 (KNOWN ISSUE: TOUCH STOPS WORKING! current state)
    • H819
    • US991
    • VS986

    Note: SALT will tell you which ROM type is compatible with your device within the main screen: GPT compatibility
    Yes there is a way to flash also H815 ROMs on those who do not support it out-of-the-box but this is very risky and requires either a change of the partition table or the ROM build developer need to change the fstab (riskless for you)

    2) ARB less or equal 2
    So ARB 3,4,5,........ WILL NOT WORK!!
    Details:

    Just use SALT to identify your current ARB and read here how to identify and verify: G4 AntiRollback

    * Reason:
    UsU is based on an ARB 2 based aboot (part of the bootloader stack - see FAQ #27) and so ARB > 2 will hard-hard brick your device if you would flash UsU on it. Hard-Hard brick means no way to recover other then sending for repair.

    3) Your device firmware must be MM(keep Requirement #2 in your mind when upgrading to MM)
    which one? I highly recommend the latest MM version for your model --> but again beware of the ARB (not greater then 2)!
    H812 devices need special attention though: v20x or higher is strictly required before flashing!
    Details:
    Yes you can flash and use UsU even when on LP but believe me: you don't want to. You will encounter issues sooner or later when runnin LP so take your time and upgrade your device to MM before proceeding here.



    LIMITATIONS / KNOWN ISSUES
    (bootloader stack is explained and described in FAQ 27)
    • 1) Do not use QFIL or flash any KDZ / TOTs or any ROM containing a bootloader stack (like v29a pure does) ! You WILL loose unlock and may hard-hard-brick your device (at least HARD BRICK)!
    • 2) Do not use QFIL or flash any KDZ / TOTs or any ROM containing a bootloader stack (like v29a pure does) ! You WILL loose unlock and may hard-hard-brick your device (at least HARD BRICK)!
    • 3) Do not flash any MM or N bootloader stack containing the file named: aboot. This will immediately lock your device and so definitively HARD BRICK!
    • 4) If you want to flash a MM or N modem partition (aka firmware) you need to re-flash <model>_UsU_basebands_flash-in-twrp.zip otherwise you will bootloop, stuck on boot or see a blue screen with a modem crash (this may change if I ever get my kernel module working...)
    • 5) If a ROM has no active developer or the developer has not made it UsU compatible you may need to open the ROM zip file on your PC and change the update-script within (just remove the assert line(s) at the top is enough)
    • 6) The fastboot mode coming with UsU will enable fastboot flash but the command fastboot boot will not work (like on the semi-official N bootloader stack)
    • 7) Most important: Once you go this way - there is (maybe) no way back! SERIOUSLY. The only way to make the device exactly like before is replacing the mainboard. If you're scared: good.
      Read the new findings on that part here - some models may be able to revert UsU!
      Think twice and don't complain later if you go on!
    • 8) Do not use QFIL or flash any KDZ / TOTs or any ROM containing a bootloader stack (like v29a pure does) ! You WILL loose unlock and may hard-hard-brick your device (at least HARD BRICK)!
    • 9) video framerates are lowered after flashing UsU. This is due to the fact that required files for high performance video will not load properly anymore and so must be replaced. Replacing those firmware files is a risk and as it is working ok enough for the most users that patch will not be included in any ROM. If you really think you need this patched ensure you read the instructions here thoroughly and understand them 100% before proceeding to apply it: G4-VideoLag-Fix
    YES I REPEATED MYSELF 3 (THREE) TIMES (... for a reason)!

    Code: 
    #include <std_disclaimer.h>
/*
* Your warranty is now (maybe) void (well not really but just for the case...)
*
* I'am not responsible for bricked devices, dead SD cards,
* thermonuclear war, or you getting fired because the alarm app failed. Please
* do some research if you have any concerns about this howto/unlock method
* before using it! ---> YOU <--- are choosing to make these modifications, and if
* you point the finger at me for messing up your device, I will laugh at you.
*
*/


    Downloads

    YES. ALL of them:

    • Latest unlock package by steadfasterX (download the one for your device model only) --> <model>_UsU_unlock.zip (mirror)
    • Latest baseband package (download the one for your device model only) --> <model>_UsU_baseband_flash-in-twrp.zip (mirror)
    • Latest TWRP (PREVIEW-103 or higher!) by steadfasterX
      - Nougat TWRP (if you plan to use + flash Nougat ROMs)
      - Oreo TWRP (if you plan to use + flash Oreo ROMs)
      - Pie TWRP (if you plan to use + flash Pie ROMs)
    • A custom ROM of your choice (see Requirements topic to find a compatible one!) --> e.g. all newer builds here: http://leech.binbash.rocks:8008/
    • Linux: I highly recommend to use mAid . This is an android lovers live ISO which can be booted from an USB stick which has everything needed on board - including SALT!
      Latest mAid *persistent* by steadfasterX (HAVE TO be version 2.6 or later!): maid.binbash.rocks
      only if NOT using mAid:
      Latest SALT version (minimum version: v3.19!) by steadfasterX: SALT
    • Important note about bootloader/modem stuff!
      You will find on several ROM threads the hint that you must have a specific bootloader stack (FAQ #27) in order to make the ROM working properly.
      What in reality is needed on these ROMs is just the MODEM (aka firmware) partition nothing else. Believe me I know this for sure ;)
      1) Flash required modem partition in TWRP or fastboot mode
      2) if using a ROM which is NOT specific an UsU ROM: Flash your baseband package (<model>_UsU_baseband_flash-in-twrp.zip) in TWRP again!! If you don't you will get bootloops, android hanging on boot or modem SoC crashes (blue demigod screen)


    Flash UsU with SALT
    (requires SALT v3.21 / mAid v3.2 or higher)

    Before proceeding ensure that you have read and understood the "Limitations" topic and the "Changes in behavior" topic in this thread!

    If you have a Windows PC the easiest way to get SALT is by flashing mAid v3.2 or higher on an USB stick (if you had read the "Downloads" topic above you should know that already).
    Before you ask if there is a Windows version of SALT: read the FAQ in the SALT thread.

    UsU can be flashed in 3 different ways! Every way will unlock your device the only difference is where you place the UsU files. Choose the one which fits best for you:
    • by an external sdcard (must be VFAT formatted)
    • by using your internal storage
    • by direct flashing (only when available - SALT will show this option only when possible for your device)

    OK enough about all this: LETS UNLEASH YOUR DEVICE!

    • At very first: ensure you are using the LATEST version of SALT!
      SALT contains an internal updater and when a new version has been detected online it will display an upgrade hint. DO THAT if you see any. It doesn't hurt to also trigger the update process even if you see no popup just to be sure that you have the latest version. You can also check the SALT release notes and compare the version with yours (title of the SALT window displays your version).
      That step is really easy but incredible important. Do not miss that!
    • Just to say it again as its crucial important: USE THE SALT UPDATER to ensure you have the latest version!
    • Extract <model>_UsU_unlock.zip and copy the aboot_UsU.img, laf_UsU.img and rawres_UsU.img to either:
      a) your external SDcard (directly on the external sdcard - not in any folder!). The sdcard must be formatted as VFAT.
      or
      b) connect your running Android device with your PC, select MTP mode in Android and copy it to the:
      - "Internal Storage" and folder "Download" (exactly there!)
    • Start SALT
    • If you have not done already: DO A BACKUP NOW I'm serious this is your last chance to grab the important files and it just takes some minutes (in basic mode) but you have all in place if needed!
      If you skip this step no one may can help you later!
    • Notice and WRITE DOWN the "GPT compatibility" info! DO NOT PROCEED IF IT STATES "unknown"
      This part will become crucial important when it comes to which ROM you can flash!
      The only valid information about that can be found in SALT!
      • If you see a "H811" there you have to flash H811 ROMs later (if no specific ROM is available for your model)
      • If you see a "H815" there you have to flash H815 ROMs later (if no specific ROM is available for your model)
      • If you see a "unknown" there you have to STOP and provide the SALT debug log (advanced menu)
    • Open the Advanced Menu
    • Click the "Unlock G4 (UsU)" button and read carefully the popup. Click Unlock, choose your unlock way and follow the instructions
    • If the UsU flashing fails for any reason (SALT will do important pre-checks and validiations before actually flashing):

      If you see a popup about UsU flashing has partially failed do not be scared - just read and follow the instructions!
      If you see a different error: do not reboot or power off the device! Ask for support and provide the debug log in SALT (in Advanced Menu -> Debug Logfile button -> Upload button and share the link)!
    • If the UsU flashing was successful (SALT will validate the flashing) continue:
      Boot your device into fastboot mode (yes UsU has enabled an unlockedfastboot access for you!):
      • take out the battery
      • unplug the usb cable from the PC (not from the device)
      • Insert the battery again
      • wait 2 sec
      • press volume DOWN and while keeping it pressed: plug the USB cable to the device
      • keep volume DOWN pressed until you see the fastboot screen
    • Flash TWRP (yes you can do that now... because of UsU!):
      fastboot flash recovery <twrp.img> (replace <twrp.img> with the real filename)
    • YOU MUST boot to TWRP now (you will notice a secure boot error but TWRP will load!):
      • disconnect USB cable
      • take out battery
      • put battery back in
      • press volume down AND the power button and keep both pressed until.. you see TWRP!
        Gotcha! Try that with a locked phone and you will fail! ;)
    • If you do not boot to TWRP after flashing it it will get OVERWRITTEN and you have to do all the steps for flashing TWRP again!
    • Optional (not needed when you flash an UsU compatible ROM later) Flash the baseband package now: <model>_UsU_baseband_flash-in-twrp.zip
    • While still in TWRP choose REBOOT menu and reboot to RECOVERY (yes again!)
    • Notice: TWRP will show your REAL device model when connected to the PC now.
      If not: SHARE THE recovery LOG (how-to for grabbing the recovery log is written in FAQ #4A)!
    • I would say: its a good time to create a TWRP backup isn't it (ensure you also select "Bootloader" in TWRP backup)?
    • I HIGHLY RECOMMEND to do nothing else now. Just boot into your ROM as it is! Check if everything is working and proceed only if it boots fine and works fine!
    • Optional: just root now. Use Magisk or SuperSU to root your current installed stock ROM to see that it works ;)
    • Done. Do not miss to read the Changes in behavior topic!
    • Whats next? Lol you are FREE! Flash SuperSu, Magisk or a custom ROM. Up to you. Flashing issues? Read the LIMITATIONS/KNOWN ISSUES topic (especially #1, #2, #3).



    Changes in behavior

    Booting to recovery, custom ROM booting (or stock but rooted), booting into download mode

    You will notice a secure boot error ... and it will boot!!
    ... and NO: THIS MESSAGE CAN NOT BE REMOVED! If you can't live with that do not unlock :p


    Fastboot

    After you unlocked your device with this method you will also have an unlocked fastboot mode which can be accessed by a key combo:

    • take out the battery
    • unplug the usb cable from the PC (not from the device)
    • Insert the battery again
    • wait 2 sec
    • press volume DOWN and while keeping it pressed: plug the USB cable to the device
    • keep volume DOWN pressed until you see the fastboot screen
    Now what? You can flash whatever you want here with: fastboot flash <partition> <filename>
    you can NOT: fastboot boot .. as this is blocked like in the semi-official N bootloader stack.


    TWRP/Recovery hardware key combo

    Flashing UsU changes the way the regular factory reset screen key combo is working.
    After flashing UsU we can boot directly into TWRP!
    • power off device
    • unplug the usb cable from the device (if any)
    • press volume DOWN + power button and KEEP THEM BOTH pressed the WHOLE TIME until you see "Recovery loading" or TWRP


    Factory reset hardware key combo

    As written above the regular key combo to get into the LG factory reset screen changes a bit:
    • power off device
    • disconnect any usb cable from the device
    • press volume UP + power button and KEEP THEM BOTH pressed until you see the LG logo the first time! THEN you have to immediately release the power button (ONLY that) and press and keep holding the power button directly again! Keep them pressed until you see the white LG factory reset screen


    Proofs

    Keep in mind: UsU will work for ANY LG G4 model and does not care about country specific ones, too! When I say: ANY, I MEAN any!
    The only device which is a real special one because of different hardware (2 SIM slots) is the H818 which can be unlocked but has issues (see above)
    confirmed:


    Support / Telegram

    Of course in this thread but also by Telegram. I have created a generic group for all stuff around Android : here
    and another one if you want to keep up2date whenever I build something (TWRP, SHRP, LOS, /e/, ...): here



    Model specific ROM threads


    Making the baseband flashing obsolete

    Well time goes by and so things change in the meantime. I have found a way to make the baseband flashing obsolete but that requires to flash either a device model specific ROM or kernel.

    That means:
    • When you flash a full UsU compatible ROM (like those linked above) there is no need anymore to flash the baseband package.
    • When you flash another ROM which is not fully UsU compatible you can flash a kernel with UsU patches and so can avoid flashing the baseband package as well.
      The UsU kernels can be found here.
    • When the ROM is neither fully UsU compatible nor there is no kernel with UsU patches you can or better must flash the baseband package.


    Credits
    • Mohd Saqib for the ls991 userdebug bootloader (https://forum.gsmdevelopers.com/lg-g-series-unified/32523-lg-g4-h811-boot-repair-qfil.html) stack. Without him.. no "unlock"
    • LG for making a faulty mainboard which allowed me to replace it without an issue several times after hard-hard bricking
    • Me - steadfasterX bc I have done all this almost alone (besides the brave testers ofc) AND: just for FUN ! (I *CAN* UNLOCK OFFICIALLY!) and as the the whole guide and method is the result of many many days ... lol noooo *MONTHS* (!!!) of spending my free time on this topic!
    • neutrondev (details about technical understanding + support)
    • uio88 (donator), jasonlindholm (recurring unteachable donator!), pablo103 (donator), britx (donator), ReeS86 (donator), ling751am (donator), 01189998819991197253 (donator), Korpse (donator), decibel_nv (donator), bdasmith (donator), hteles (donator), Leg0V0geL (donator), britx (donator), doop (donator), street_android (donator), ErismaSS (donator), ingcolchado (donator), fauxmight (donator), NwOg1984 (donator), pablogrs (donator), romanofski(donator), nenich78 (donator)
      The overall sum (just for UsU) of donations (as of 2023-04-03): $252 !
      While donations are accepted and appreciated there is NO need for it. I have done all this for fun and I like thx clicks more then money LOL :D

    XDA:DevDB Information
    Unofficial secureboot-off/steadfasterX Unlock, Tool/Utility for the LG G4

    Contributors
    steadfasterX, the_naxhoo (tester), SePhIrOtX (tester), Chebhou (tester), fawadshah33 (tester), DoughMucker (tester), shane87 (tester), Guy Noir (tester), networkkid (tester), ling751am (tester), jmfecon (tester), r3pwn (tester)

    Version Information
    Status:     Stable
    Stable Release Date: 2018-03-08
    Alpha Release Date (PoC): 2017-07-28

    Created 2018-03-08
    View
    72
    steadfasterX
    steadfasterX
    FAQ

    • 0) Is/will UsU be available for ARB 3 or higher?
      no. never.
      Reason:
      UsU is based on an ARB 2 based aboot (part of the bootloader stack) and so any ARB > 2 will hard-hard brick your device if you would flash UsU on it.
      (Hard-Hard brick means no way to recover other then sending for repair)
    • 1) Is UsU reversible?


    • 2a) So I can't flash any KDZ/TOT anymore?
    • 2b) So I can't upgrade my STOCK ROM with the LG updater anymore?
      Have you really read the limitations topic? I guess no.
      You can't! At least for the KDZ flashing part: not yet.
      SALT will allow flashing of KDZ files with the upcoming version 4.0 but until then do not flash with lgup and do not use the LG Android internal updater --> You WILL 100% brick your device.
      Why? Read the above FAQ.


    • 3) Will UsU void my guarantee?
      Sure.

    • 4) I have flashed UsU and now in Android settings and/or in fastboot it shows up as a LG LS991 - WHY?
      The aboot mentioned in FAQ 1) is from a specific device: the ls991. Usually this is nothing which you need to care about. What you see in the Android settings is just parsed from the commandline (means from what aboot is telling) and has no further impacts of nothing. Its just a wrong named "variable" thats it. I still work on a fix to adjust this on boot to your real model but atm of writing it would require a kernel for each model just for this cosmetic thing..
      As the UsU fastboot IS ls991 as written in FAQ #1 you will see it there and this is unchangeable - but nothing you need to care about.


    • 5a) I flashed UsU and now the ROM bootloops
      5b) I flashed UsU and now the ROM does not start
      5c) I flashed UsU and now Android crashes with a blue/purple demigod screen
      5d) I flashed UsU and now I have no SOUND and/or CAMERA anymore
      5e) I flashed UsU and now I have no cell service anymore
      Well there could be 3 reasons why this can happen:
      - Either you have not flashed the baseband package in TWRP
      - you try to boot a ROM which is not compatible with your model (check the GPT compatibility in SALT!)
      - or you have a very sensitive (or strict..) device model
      The first thing you should try is flashing the UsU kernel for your installed ROM.
      If there is no UsU kernel for your ROM install a supported ROM and flash the UsU kernel afterwards.
      If the problem persists or if you still want to use the unsupported ROM: flash the baseband package and the GPT compatibility is ok with the ROM you trying to flash.
      If the problem persists:
      1 )Try to flash the modem partition of your SALT backup before flashing UsU (nothing else!)
      if the problem persists:
      2) Some devices require to flash the full modem partition of Lollipop (instead of flashing the baseband package) in order to work after UsU has been flashed so if you are sure that you flashed the baseband package go here and download the modem or the KDZ file of a 10 (Lollipop) modem.img/modem.bin: codefire if you cant find what you need try that one: storagecow

      Flash the modem file in fastboot mode like this:
      Code: 
      fastboot flash modem modem.img

      or in TWRP like this:
      Code: 
      adb push modem.bin /tmp
adb shell
dd if=/tmp/modem.bin of=/dev/block/bootdevice/by-name/modem
sync
reboot

    • 6) Is there a windows version to flash UsU?
      No and there will be never one. Why? For this FWUL exists. Flash FWUL on an USB stick and boot from it. It's as easy as it sounds.

    • 7) I want to use a custom ROM based on Android Nougat or Oreo. In the ROM OP they say I need the v29a/N bootloader stack. Is this true?
      No. You will find in several ROM threads the hint that you must have a specific bootloader stack in order to make the ROM working properly.
      What in reality is needed on these ROMs is just the MODEM (aka firmware) partition nothing else. Believe me I know this for sure ;)
      If you later want to install custom ROMs based on N or O (any model! and any ARB) --> N modem
      1) Flash G4_29a_N_modem_UsU.zip in TWRP
      2) Flash your baseband package (<model>_UsU_baseband_flash-in-twrp.zip) in TWRP again!! If you don't you will get bootloops, android hanging on boot or modem SoC crashes (blue demigod screen)
      When you have a H815(!!!!) device with ARB = 0 you COULD flash the complete bootloader stack though (if you wish - but as said it is NOT needed. READ MY LIPS: IT IS NOT NEEDED but its possible though ):

    • 8a) I flashed a KDZ with LGUp / LG Flashtools (you really hexedited a kdz/tot just to brick your device? cooool)
      8b) I flashed the non-UsU (see FAQ 7 for the UsU one) v29a bootloader stack on my device
      8c) I have no idea why but i bricked my phone (actually you have but you don't wanna tell)
      You will need an external sdcard or something like the infinity dongle. In theory there is also the way to unbrick by QFIL but this way is incredible dangerous if you use the wrong files (read FAQ #23!!). The external sdcard method will work only when your device is detected in 9008/QDL mode. If you connect your device to the PC and see nothing (Windows: device manager, Linux/FWUL: open a terminal and type: lsusb) then this guide will not work for you. The only chance is to use e.g. infinity or QFIL but there is no QFIL guide out there I would trust..
      For the external sdcard unbrick read and follow the sdcard unbrick guide.
      It is important that you know which bootloader stack you had on your device (in terms of ARB)
      The only difference for UsU devices is that you need to flash:
      the aboot_UsU.img to the aboot partition, the laf_UsU.img to the laf partition and the rawres_UsU.img to the raw_resources partition:
      Code: 
      fastboot flash aboot aboot_UsU.img
fastboot flash laf laf_UsU.img
fastboot flash raw_resources rawres_UsU.img
    • 9a) Will UsU work for my model?
      Yes (h818 has been disabled though)
      9b) Will UsU work for my country/region?
      UsU has no restriction on a specific G4 model or country version.
      9c) Will UsU work for any ARB?
      UsU will work on ARB 0, 1 and 2 ONLY and you will need LP or MM to be able to actually flash UsU.
      Again flashing UsU is a risk always. It happens on your own responsibility!

    • 10a) Will UsU allow me to flash TWRP?
      Yes.
      10b) Will UsU allow me to flash stock ROMs?
      Yes. You will be able to flash stock LP, MM, N
      10c) Will UsU allow me to flash custom ROMs?
      Yes. You will be able to flash any custom ROM of your choice (any android version)
      10d) Will UsU allow me to root my device?
      Yes. Ofc you can root with magisk as usual.

    • 11) I follow your PoC thread since the beginning.. So UsU has no limitations regarding cell service/signal anymore?
      Everything should work (cell service, mobile data, wifi, BT, call, sms, etc). UsU will not replace the complete bootloader stack as it was done in the early implementations.
      By keeping your real bootloader stack the hardware like camera, modem / baseband can be initialized as it should and so no limitations are known (yet).
      Again flashing an unofficial unlock is always a risk. Do not blame me when something is not working as it should.
      You do this on your own responsibility


    • 12) I want to flash a custom ROM but there is none for my model available what now?
      SALT will show a field named GPT compatibility. Just flash a ROM which is compatible with your device. Thats it.
      Read more about the compat check in SALT in the SALT FAQ #15.

    • 13) I want to flash a custom ROM but it says "This ROM is for device xxxx but this device is >.< !! You told that I can flash any ROM so whats wrong here?
      I wrote it in the LIMITATIONS/KNOWN ISSUES topic of the OP but here again:
      Taken from the OP:
      5) If a ROM has no active developer or the developer has not made it UsU compatible you may need to open the ROM zip file on your PC and change the update-script within (just remove the assert line at the top is enough)
      Click to expand...
      Click to collapse
      Here a guide by @sdembiske https://xdaforums.com/showpost.php?p=76405252&postcount=947



    • 14) I have unlocked with UsU and all went fine. I flashed a ROM and it bootloops and now my phone died!! What have you done with my device? It never had this issue before in the last years!?
      Unfortunately this is not UsU's fault. It's yours. Or better its LGs. The g4 is known to have faulty mainboard and when you boot a fresh flashed ROM this is very heavy cpu intensive and so can cause the ILAPO which means the hardware fault occurs. Yes it has not happened to you in the past but how often did you flashed a new ROM in the past? Ask LG for a mainboard replacement (yes even when out of guarantee) or check the bootloop fix it list : https://bit.do/ilapofixg4


    • 15) I flashed the LP modem, but now it wont let me get past lockscreen. Do I need to factory reset?
      background info: the modem partition contains decrypt parts so the screenlock may fail to decrypt.
      Doing a factory reset is one option which will fix this.
      If you dont want to loose your data reset just the password of the screen lock:
      https://xdaforums.com/android/software-hacking/remove-lockscreen-recovery-t3530008


    • 16) I just wanna flash Nougat STOCK. Are there any worry free UsU downloads for it available?
      Sure: here
      After flashing ensure you flash your model baseband package!
      After that and while still in TWRP: Choose Reboot -> RECOVERY ! This should ensure TWRP will not be overwritten on Android boot


    • 17) What is the recommended way to backup with TWRP?
      ONE/FIRST TIME backup. Do this just ONCE --> Select these partitions to backup:
      Code: 
      - Firmware_Image
- EFS
- BL unlock state
- Bootloader
- Carrier

      USUAL/DAILY BACKUP (e.g. to test other ROMs, before an upgrade, etc) --> Select these partitions to backup:
      Code: 
      - Boot
- Recovery
- System
- Data
- Encryption metadata -> when your device is encrypted ONLY
- Firmware_Image
    • 18) I have flashed the bootloader stack of N on my non-H815 device and now I have issues (no cell service, no bluetooth etc)
      There could be 2 reasons why: Either you haven't read the OP guide properly and flashed the bootloader stack or you were one of the "early birds" flashed the full ROM which includes the Nougat bootloader stack.
      H815-ONLY_ARB-0_29a_bootloader_UsU.zip (formerly named: G4_ARB-0_29a_bootloader_UsU.zip)
      H815-ONLY_ARB-0_v29a_FULL-STOCK-ROM_UsU.zip (formerly named: G4_ARB-0_v29a_FULL-STOCK-ROM_UsU.zip)
      The guide in the OP told you to do a SALT backup before flashing UsU.
      If you have followed the guide properly you should have it and the above is one of the reasons why I said its required to do it.
      ( If you lost your backup there is still a way you can go: Follow FAQ #20 )
      Open a terminal in the directory where you SALT backup before flashing UsU (or your extracted KDZ) is.
      Then put your device in fastboot mode and type these commands:
      Code: 
      fastboot flash factory factory.bin
fastboot flash hyp hyp.bin
fastboot flash modem modem.bin
fastboot flash pmic pmic.bin
fastboot flash rpm rpm.bin
fastboot flash sbl1 sbl1.bin
fastboot flash sdi sdi.bin
fastboot flash sec sec.bin
fastboot flash tz tz.bin
      Read the output of the flashing on the screen and in your terminal. Do NOT flash anything else! Just the above - but ALL of the above! (if you miss a single file you will HARD BRICK)
      If something is failing do NOT continue and try to re-do the above commands. if it still fails write in this thread or better come into IRC (when between Monday and Friday)!
      If something failing here it WILL brick your phone.


    • 19) I have flashed UsU but now I always see a secure boot error text at the top of my screen when booting (TWRP, Android, download and fastboot mode). Is it possible to remove that?
      Really? I mean REALLY? Its clearly written in the OP - CHANGES IN BEHAVIOR !


    • 20a)I have flashed UsU and now I want to downgrade/upgrade my bootloader stack. How?
      20b)You were on LP or older MM firmware when you have flashed UsU and now having issues? -> Upgrade your bootloader to MM! Read here how:
      Download a KDZ of your device model.
      Keep in mind that there are frankenstein devices out there (means refurbished devices with mixed hardware inside so you think u have model XXX as it was shown in Android but the mainboard is NOT the same!).
      How to identify a Frankenstein device? Read FAQ #21.
      IMPORTANT: Check the ARB of that KDZ (SALT will show the ARB of a KDZ on extract!) - If you are unsure - DO NOT PROCEED. you can easily hard brick your device if!
      Extract that KDZ with SALT - DO NOT USE ANY OTHER TOOL FOR EXTRACTING! The known windows tools like LG Firmware extract does not extract what we need here and not in the way we need it! So do not use that! You have been warned..
      Open a terminal in the directory where you SALT backup before flashing UsU (or your extracted KDZ) is.
      Then put your device in fastboot mode and type these commands (you have another file extension? read FAQ #24):
      Code: 
      fastboot flash factory factory.bin
fastboot flash hyp hyp.bin
fastboot flash modem modem.bin
fastboot flash pmic pmic.bin
fastboot flash rpm rpm.bin
fastboot flash sbl1 sbl1.bin
fastboot flash sdi sdi.bin
fastboot flash sec sec.bin
fastboot flash tz tz.bin

      Alternative with TWRP (if the above fastboot cmds work for you no need to do this!):
      Code: 
      Boot TWRP
adb push factory.bin /tmp/
adb push hyp.bin /tmp/
adb push modem.bin /tmp/
adb push pmic.bin /tmp/
adb push rpm.bin /tmp/
adb push sbl1.bin /tmp/
adb push sdi.bin /tmp/
adb push sec.bin /tmp/
adb push tz.bin /tmp/
adb shell sync
adb shell "dd if=/tmp/factory.bin of=/dev/block/bootdevice/by-name/factory"
adb shell "dd if=/tmp/modem.bin of=/dev/block/bootdevice/by-name/modem"
adb shell "dd if=/tmp/hyp.bin of=/dev/block/bootdevice/by-name/hyp"
adb shell "dd if=/tmp/pmic.bin of=/dev/block/bootdevice/by-name/pmic"
adb shell "dd if=/tmp/rpm.bin of=/dev/block/bootdevice/by-name/rpm"
adb shell "dd if=/tmp/sbl1.bin of=/dev/block/bootdevice/by-name/sbl1"
adb shell "dd if=/tmp/sdi.bin of=/dev/block/bootdevice/by-name/sdi"
adb shell "dd if=/tmp/sec.bin of=/dev/block/bootdevice/by-name/sec"
adb shell "dd if=/tmp/tz.bin of=/dev/block/bootdevice/by-name/tz"

Download this verify tool to ensure the flashing was successful: [ATTACH]4687157[/ATTACH] ([URL="http://leech.binbash.it:8008/misc/verifyflash.zip"]mirror --> verifyflash.zip[/URL])

Usage:
extract verifyflash.zip
adb push verifyflash.sh /tmp/
adb shell chmod 755 /tmp/verifyflash.sh
adb shell /tmp/verifyflash.sh

      Read the output of the flashing on the screen and in your terminal. Do NOT flash anything else! Just the above - but ALL of the above! (if you miss a single file you will HARD BRICK)
      If something is failing do NOT continue and try to re-do the above commands. if it still fails write in this thread or better come into IRC (when between Monday and Friday)!
      If something failing here it WILL brick your phone.


    • 21)What is a frankenstein device and how can I identify if I have one?
      A so called Frankenstein device shows up different in Android then it is in hardware.
      Often happens on "refurbished" devices and almost everything you can buy on AliExpress is one.
      The only way to identify your REAL model is by disassembling the device.
      No there is NO other way. Everything else can be tricked by software.
      Follow the guide here: https://www.ifixit.com/Guide/LG+G4+Motherboard+Replacement/51202
      now you are able to see the REAL model printed on the front of your mainboard.

      Is a Frankenstein bad? Hell yes. Can you live with one? Up to you. Technically there are good chances that it work as it should - especially when UsU'ing it.
      Main problem here is that some stupid ppl out there take a board (often a h810 or h812 but there is no restriction) and flash a different PBL (primary boot loader) on it to load what they like to load. usually they flash h815 ROMs as that is best for selling as it can be unlocked officially (which NEVER works - as the IMEI and/or serial will never list a Frankenstein as a h815).
      So actually it is not 100% clear what they did with your phone EXACTLY - and that leaves room for bricks when flashing stuff - or even worse: you might encounter partly not working stuff. In most of the Frankensteins I saw they work good when you flash the real models ROMs, bootloader stacks and modem partitions but well there is no guarantee for nothing here!

      Other then that you can use SALT (part of mAid) to determine your model. This with the ARB shown gives you a 80 -90 % clue of your real device model.
      E.g. when you bought a h815 (which is known to NEVER EVER have an ARB higher then 0) and it shows h810 in SALT then you can be 100% sure that it is not a h815 and 90% sure that it is the model shown in SALT instead.
    • 22)I have a H812 and having issues after flashing the N stock ROM / AOSCP Nougat. What can I do?
      Walk throughs:
      Stock N report: https://xdaforums.com/showpost.php?p=75913373&postcount=12 by user @grantdb (consider to show ur appreciation by clicking thx on that post)
      AOSCP N report: https://xdaforums.com/showpost.php?p=75890188&postcount=361 by user @sdembiske (consider to show ur appreciation by clicking thx on that post)
      LineageOS O report: https://xdaforums.com/showpost.php?p=76799406&postcount=1100 by user @sdembiske (consider to show ur appreciation by clicking thx on that post)


    • 23)uhm I wanna / I have flashed with QFIL...

      I wrote millions of times that using qfil is f*** dangerous and shouldn't be used.

      The process of using QFIL with the wrong files can CONVERT your device or blow fuses! Never ever use qfil unless you REALLY understand what files you flash:
      This requires to analyze the files (hexedit) you trying to flash with qfil. which is something 99% of the average user CAN'T.

      Which means: do not use it unless you don't care about damaging your device ofc..

      The only less-dangerous way is of unbricking from the 9008/QDL mode by my sdcard unbrick method but when you already used qfil you may have damaged your device already.

      If you UsU'd your device there is even one more reason to NOT use qfil!
      As said you shouldn't use qfil anyways but when you UsU'd your device it's even more important.

      WHY I say using QFIL is evil?
      Especially on devices which have no ARB >2 firmwares (like h812, h815, h818, h819 and F500) using QFIL is the worst idea you can have.
      Just to be crystal clear: if you have UsU'd or not --> that doesn't matters!

      QFIL is dangerous because:
      • some files you can find around will increase your ARB !
      • Increasing your ARB means you can never flash your original bootloader stack anymore (on devices having no ARB >2 firmwares)
      • If you can not flash your original bootloader stack anymore you can not load parts of the modem partition.
      • If you can not load these parts of the modem partitition you can not get any cell service - full stop. Yes here it ends. You can't go back and so you are stuck with like it is.
      • Well you can still go back by:
        - replacing the mainboard
        - replacing the cpu/whatever chip on the mainboard

      There is ONE single exception to the above: If you have (still) a "nonfusing" device. Nonfusing devices may be able to flash any ARB but beware:
      I had a nonfusing device which suddenly changed somewhen during my UsU hacking sessions.
      I have one user who was able to flash a lower ARB then he had before because his device was stated as a nonfusing device. There is no guarantee but it is a chance for you.

      Read more about the ARB background here: https://bit.do/unlockg4
    • 24)I have a partition file with the extension: [ bin | image | img | mbn ]. How can I convert this?
      The extension is not important. The way how you extract files - is. That's why I say all the time use SALT.
      On Windows the file extension matters a lot which is not the case for Linux/Android.
      There is no need to convert anything as they all are just raw image files.
    • 25a)I have UsU'd but now in TWRP it does not show my model. Instead something like Chinese or strange characters.. How can I solve this?
      25b)I have UsU'd but something went wrong while flashing..! I can still turn on the phone and I see the secure boot error.. What now?
      25c)I have UsU'd but I cannot open the download mode anymore.. What now?

      This can happen when you tried to flash UsU with a completely outdated version of SALT or using an unsupported version of FWUL (like using it in KVM, VMware ,..).

      Ok how to fix this now?

      Boot to fastboot mode.
      Extract the UsU unlock zip file of your model.
      Flash the following from that zip file:

      Code: 
      fastboot flash raw_resources rawres_UsU.img
fastboot flash laf laf_UsU.img

      That's it. TWRP will detect the model now correctly. If not share the TWRP log as described in the TWRP(!) thread FAQ 4a.
    • 26a)How can I identify my bootloader stack from my backup files?
      26b)How can I identify my current installed bootloader stack?

      26a)
      To find out which exact firmware version you had installed before UsU'd can be done easily when you have a backup (which you should have).
      So to grab that info from your backup (requires Linux/FWUL):

      Open a terminal in the directory where you have your SALT backup before UsU'd.
      Then:
      Code: 
      strings misc.bin | grep LG
      It should display a long string containing your model name and the exact firmware version

      26b)
      There is no easy way atm for this. It is MUCH easier to just flash the newest bootloader stack like described in FAQ #20 in this post.
      .. but if you really want something to start with:
      a) do a SALT backup (basic)
      b) extract sbl1 of any(!) KDZ files you can find for your model (you see now what a bad idea that is?)
      c) do a md5sum on sbl1.img/bin (both: on your backup and the KDZ one) and compare. Once you have found a match you know the version.


    • 27) a) What is the "bootloader stack" on the G4?
      27) b) What is the boot process on a Qualcomm device like the G4?

      The bootloader stack is a set of partitions (and optionally a partition table) which MUST be on the exact same firmware and ARB level.
      There are exceptions to this but you really wanna risk a brick?
      Keep the bootloader stack files together otherwise you will brick your device.
      Why is explained in the following topic.

      The LG G4's bootloader stack partitions are:
      • tz (Qualcomm Trust Zone. It performs low-level operations, including working with QFuses (rpmb secured mmc partition))
      • sbl1 (secondary bootloader)
      • sdi (trust zone storage partition. The data which is used by Trust Zone)
      • pmic (power management integrated circuit - related to rpm)
      • rpm (Resource and Power Manager firmware. Firmware for specialized SoC, responsible for resources and power)
      • aboot (<--- replaced by UsU ! so NEVER touch this again after UsU'ing) - Android boot, little kernel, lk, fastboot mode
      • hyp (Hypervisor - Virtual Machine Monitor, related to tz in order to protect the device/kernel - afaik)

      Special partitions (NOT part of the bootloader stack - but either related, optional or as for the PBL - informative):
      The following do not directly belongs to the above stack but it is related. You will never touch PBL, laf or raw_resources and the rest are optional ones.
      • PBL - Built-in ROM Qualcomm primary boot loader (read-only)
      • laf (download mode - can be anything on unlocked / UsU'd devices but for locked devices it MUST match the bootloader stack)
      • raw_resources - contains boot messages read by aboot. Examples: LG logo, bootloader has been unlocked warnings
      • recovery (recovery mode - can be anything on unlocked / UsU'd devices but for locked devices it MUST match the bootloader stack)
      • modem - hardware firmware (sound, baseband, camera, video, ...) accessed and loaded by rpm and Android (kernel, Android) - must STILL match the device's ARB of the bootloader! Otherwise those files cannot be read/loaded (most of them are signed so certificate protected!)

      The boot process on a qualcomm device is as follows:
      All of these partitions are signed by a certificate chain which starts in the PBL (which is read-only so cannot be altered - easily)
      1. pbl  verifies and boots: sbl1 partition
      2. sbl1 verifies and boots: tz, then: aboot
      3. aboot verifies the next boot stage (boot / recovery / laf partition):
        -> for locked devices: enforce verification result (so decline boot when failed)
        -> for unlocked or UsU'd devices: print just a warning (so continue when failed)

      For a graphical view: https://lineageos.org/engineering/Qualcomm-Firmware/ (G4 is: "2013-2016 Era")
    • 28)a) I want STOCK - how can I revert back once I flashed a custom ROM?
      28)b) how can I flash another version of any STOCK rom for my model?

      for Nougat: FAQ #16
      for any other:

      1. extract with SALT system + boot + modem partition of the stock ROM kdz of your choice
        (beware of the ARB!!! SALT will tell you on extracting the ARB and in the main window your device's ARB. do not flash anything higher then what the SALT main screen is showing or you might have a paperweight afterwards!!!! yes, even the system image can blow fuses!)
      2. flash them in fastboot:
        Code: 
        fastboot flash boot boot.img
fastboot flash system system.img
fastboot flash modem modem.img
      3. boot TWRP (if you do not get into TWRP at the first try it gets overwritten. if that happens you must re-flash TWRP in fastboot)
      4. flash the baseband package of your model
      5. factory reset in TWRP (obviously all your data will be lost - so backup before)
      6. if you encounter issues FORMAT data in TWRP (obviously all your data will be lost - so backup before)


    • 29) I have a h810 and an ARB of 3 or higher. I heard there is a way to unlock this specific model somehow?! Is that true? If so how??


      UsU will only work up to and including ARB 2 but the h810 is special as it turns out that its PBL (primary bootloader) SEEMS to be compatible with the h811.
      There are 2 users reported that it worked for them but again this is EXTREMELY risky - especially on Frankensteins (i.e. refurbished models) !!!
      I cannot guide you on that but check out my answer here: https://xdaforums.com/showpost.php?p=80056484&postcount=1857


    • 30) Video framerates are low(er) with UsU?
      As mentioned in the OP above the video framerates might be lowered after flashing UsU.

      This is due to the fact that the required files for high performance video will not load properly anymore and so must be replaced.
      Replacing those firmware files is a risk and as it is working ok enough for the most users that patch will not be included in any ROM.
      If you really think you need this patched ensure you read the instructions here thoroughly and understand them 100% before proceeding to apply it: G4-VideoLag-Fix




    • ZZZ) I have a problem / question not listed here. What should I do?
      All known issues are either fixed or listed above but ofc it can happen that you find something which is not listed here and you want to report it.
      The very first thing you have to do is:
      • Open TWRP
      • Choose the Wipe menu
      • Choose FORMAT DATA (not a factory reset!)
      • Test if your problem is gone
      • ATTENTION:
      This will completely clean your internal storage - all pictures etc everything will be lost so ensure you have a backup!
      HINT: TWRP will not save your internal storage in a backup (read here why) so you have to take care otherwise!
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    55
    steadfasterX
    steadfasterX
    UsU background

    UsU explained (in short words)

    This is just for those want to understand what UsU is in detail and how it works.
    If you are not interested in background information.. well its worth to read anyways ;)

    rawres_UsU.img -> raw_resources partition

    when to be flashed:
    once (part of the unlock ZIP), after flashing another raw_resources partition

    what it is:
    Contains logo for boot, download mode and recovery loading


    laf_UsU.img -> laf partition

    when to be flashed:
    once (part of the unlock ZIP), after flashing another laf partition

    what it is:
    The laf partition holds your download mode. This one is optimized for UsU and SALT.


    aboot_UsU.img -> aboot partition

    when to be flashed:
    once (part of the unlock ZIP), after flashing another aboot partition (which should NEVER happen as it would hard brick your phone)

    what it is:
    The debug/engineering/whatever aboot partition and the heart of UsU. The aboot partition is part of your bootloader stack and besides this it also holds the fastboot mode.
    Its a leaked file originally coming from Mohd Saqib (see credits in the OP) who may even don't know what he provided in his unbrick guide.
    Most important: If you ever flash a KDZ/TOT with one of the windows tools out there it will overwrite this partition and HARD-BRICK your device.
    That's why I write this so explicit in the LIMITATIONS/KNOWN ISSUES topic of the OP!
    For more details refer to the above FAQ #27!

    <model>_UsU_baseband_flash-in-twrp.zip

    when to be flashed:
    once, after flashing another modem partition (e.g. H-ROM still containing the modem partition! which is incredible bad practice btw)

    what it is:
    model dependent baseband / radio / modem files (the stuff needed to make your cell service work).
    I extracted for every model these files and provided a flashable ZIP as this ensures the modem will not crash when on MM or N firmwares.
    To be specific these files are always the latest LP basebands I was able to find/extract for each model and yes its still a kind of hackish this way.
    If I will be able to get the kernel module working this file will be obsolete on newer ROMs but will be necessary on all which do not have that kernel patch.
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    40
    steadfasterX
    steadfasterX
    I think I will take a 1 year vacation now... :rolleyes:


    .
    View
    23
    steadfasterX
    steadfasterX
    Hey we silently reached the amount of more then 100 devices unlocked by UsU ;)

    Thx again for any donator. I just wanted to let everyone know again that donations are NOT needed as I see the thx clicks as my payment ;)

    Nevertheless there are some unteachables ;) mentioned in the OP who donated and I just wanna inform you that I updated the OP (Credits) with the amount spent. I will update that if it changes ofc.
    This is just to let you know that there is one more reason to NOT donate as many ppl already did.

    Cheers
    sfX
    View

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