Develop Bugs

[Q] Trying to downgrade system to unlock bootloader

Hello Everyone. I'm trying to downgrade the software on my Asus Zenfone 2 to version 2.19.40.20 (currently 2.19.40.20) so I can unlock my bootloader. I've heard that the way to do this is following rooting procedure 1 from the main information thread but flashing the version of the files that you want your system to be. However when I download the zip it has the system.img file broken up in some weird way (apparently you need a tool called WinRar to put it back together again but I really don't want to have to go buy a piece of software I'm only gonna need once). Does anyone know how to put the files back together again, have a put together 2.19.40.20 system.img I can use or have some alternative solution to my problem. I'm currently using a Linux system too so if at all possible I would like for any software to be compatible with Linux. If anyone has any insight I would be highly appreciative.

Don't try to flash selectively, as that is very likely to brick your phone. What you want is the correct full ROM package containing a system.img, boot.img/kernel, fastboot (droidboot.img IIRC), IFWI.zip, and some other important partitions whose names escape me. Don't try to extract parts of it (e.g. just the system.img, boot.img, or bootloader), because the components appear to be interdependent. In particular, flashing the wrong version of the bootloader without flashing the corresponding kernel/system image will more than likely brick it. You should be able to supply the full ROM to fastboot (e.g. fastboot update <package_file>). Double check everything and back up before you proceed! @Tuanies should have some pointers for you in case I missed anything, and I would wait to hear from him before you try this.

WinRAR is free. It's a very small program that takes seconds to download and install. It is very simple to put the system image components back together with WinRAR and then you will have that file plus the other three you need. Please try it, I'm sure you'll manage it.

All I suggest is to get the full firmware of 2.19.40.20 and flash the images one by one, and sideload the firmware using adb...
Hope this helps
Good luck.

I'd just download the full package from that's ~1GB and sideload that via recovery in its entirety. If this is too complicated, I'd advise against attempting it.

Seriously it is just about writing 3 lines on adb... Not that hard
Sent from my ASUS_Z008D using Tapatalk

I did finally manage to get WinRar working. I had to go install it on my brother's computer. After I had the files to flash I had no trouble.

This seems like a good place to ask this I was on .22 and tried unlocking boot loader did not seem to work so I went back into my 2.19 folder and flashed back to 2.19 but was still unable to unlock though it appears possibly unlocked on boot loader shows bootloader unk and question marks on last 2 entries, but apparently I am unable to flash over the bootloader in fastboot it says fail cmd err can anyone tell me what that means? And how to get around it, tried flashing non tethered twrp says it wrote it but won't boot to it
Sent from my ASUS_Z00AD using Tapatalk

You must have done something wrong. I had the two question marks before I unlocked mine. When your bootloader is unlocked your boot screen will be white. If you're not sure what I'm talking about then you're not unlocked.

robopilot99 said:
You must have done something wrong. I had the two question marks before I unlocked mine. When your bootloader is unlocked your boot screen will be white. If you're not sure what I'm talking about then you're not unlocked.
Click to expand...
Click to collapse
Okay so I never have gotten the white boot screen and just not sure where to go from here does not seem to want me to flash a droidboot.img and I cannot seem to figure out how to make it take the img I can go back to 4.19 from 4.22 but from there I have tried using adb and terminal emulator to give the commands and after reboot to bootloader it just sits there, so am on 4.22's bootloader and is that why it won't work and would you suggest to get the bootloader unlocked?
---------- Post added at 06:09 PM ---------- Previous post was at 05:58 PM ----------
jimchee said:
Okay so I never have gotten the white boot screen and just not sure where to go from here does not seem to want me to flash a droidboot.img and I cannot seem to figure out how to make it take the img I can go back to 4.19 from 4.22 but from there I have tried using adb and terminal emulator to give the commands and after reboot to bootloader it just sits there, so am on 4.22's bootloader and is that why it won't work and would you suggest to get the bootloader unlocked?
Click to expand...
Click to collapse
The img's I am flashing are from shakalaka, hope thats spelled right
so in fastboot and using adb i did fastboot flash droidboot droidboot.img (enter)
sending droidboot (14410 kb)
Okay (0.622s)
writing "droidboot"
FAILED < Remote: flash_cmds error !
so this is the answer I am getting when trying to flash droidboot
so any ideas would be great

jimchee said:
Okay so I never have gotten the white boot screen and just not sure where to go from here does not seem to want me to flash a droidboot.img and I cannot seem to figure out how to make it take the img I can go back to 4.19 from 4.22 but from there I have tried using adb and terminal emulator to give the commands and after reboot to bootloader it just sits there, so am on 4.22's bootloader and is that why it won't work and would you suggest to get the bootloader unlocked?
---------- Post added at 06:09 PM ---------- Previous post was at 05:58 PM ----------
The img's I am flashing are from shakalaka, hope thats spelled right
so in fastboot and using adb i did fastboot flash droidboot droidboot.img (enter)
sending droidboot (14410 kb)
Okay (0.622s)
writing "droidboot"
FAILED < Remote: flash_cmds error !
so this is the answer I am getting when trying to flash droidboot
so any ideas would be great
Click to expand...
Click to collapse
I had to flash 4 files as it appears you are trying to do. The error is definitely not good. I'm not sure what it means though. Hopefully someone else knows what to do. I'm pretty sure being on this up to date bootloader is your issue. Did you manage to somehow flash the other 3 files?

robopilot99 said:
I had to flash 4 files as it appears you are trying to do. The error is definitely not good. I'm not sure what it means though. Hopefully someone else knows what to do. I'm pretty sure being on this up to date bootloader is your issue.
Click to expand...
Click to collapse
Yep I figure that might be it, just not sure what to do next, every other file flashes whether I am going up or down thinking of trying to flash older than 19 and then hopefully able to its to 2.19, but hopefully someone knows the proper way
Sent from my ASUS_Z00AD using Tapatalk

The files that I flashed I got from here. Don't know if that's where you are getting yours.

What I did is I downgraded to version Z00A_WW_2.19.40.18 of everything (I was warned about flashing different versions of different things so be careful). I then used the bootloader unlock method detailed in section 5 of the resource thread. I think your problem is that the files you are flashing are not pre-rooted. I used the files from section 3.1, method 1 of the same thread. The system.img was broken up in some strange fashion but I can send you the put together version somehow if you would like.

robopilot99 said:
What I did is I downgraded to version Z00A_WW_2.19.40.18 of everything (I was warned about flashing different versions of different things so be careful). I then used the bootloader unlock method detailed in section 5 of the resource thread. I think your problem is that the files you are flashing are not pre-rooted. I used the files from section 3.1, method 1 of the same thread. The system.img was broken up in some strange fashion but I can send you the put together version somehow if you would like.
Click to expand...
Click to collapse
I am using the pre rooted ones from shakalaka and i can get boot, recovery and system to flash but unable to get droidboot to flash and that is what I can't figure out even when i downgrade with all the other files i can't get bootloader unlocked

I couldn't find the files you were referring too. However I really don't know enough about fastboot to really help you resolve the error message. Hopefully someone a little more experienced will come along soon.

robopilot99 said:
I couldn't find the files you were referring too. However I really don't know enough about fastboot to really help you resolve the error message. Hopefully someone a little more experienced will come along soon.
Click to expand...
Click to collapse
They are the same files that you are using from mega.nz and my fastboot knowledge is not great either, so I'll just wait around and see if anyone with more knowledge can help me out, thanks for yoyr help though it's appreciated

@jimchee you are typing the wrong command to flash droidboot. its "fastboot flash fastboot droidboot.img"

Niropa said:
@jimchee you are typing the wrong command to flash droidboot. its "fastboot flash fastboot droidboot.img"
Click to expand...
Click to collapse
Thanks Niropa, I knew there was reason this works now I really appreciate the help

Just a quick note to let everyone know that everything worked without a hitch now have unlocked bootloader and twrp installed.
Sent from my ASUS_Z00AD using Tapatalk

Flash error ?

I wanted to flash MMB29M version downloaded from google factory images official web site, before it comes OTA...
I am using the script "flash-all.bat" and i had this error message while flashing bootloader (same error if i do this step manually) :
fastboot flash bootloader bootloader-bullhead-bhz10k.img
FAILED (remote: device is locked. Cannot flash images)
It is not the first time i flash a rom on a Nexus device, i did that many times on my N4 and my N6, and both were locked and not rooted like my N5X.
With the same process... And I have never had such this error.
So why do I have this error ? What can i do ?

yauyau said:
I wanted to flash MMB29M version downloaded from google factory images official web site, before it comes OTA...
I am using the script "flash-all.bat" and i had this error message while flashing bootloader (same error if i do this step manually) :
fastboot flash bootloader bootloader-bullhead-bhz10k.img
FAILED (remote: device is locked. Cannot flash images)
It is not the first time i flash a rom on a Nexus device, i did that many times on my N4 and my N6, and both were locked and not rooted like my N5X.
With the same process... And I have never had such this error.
So why do I have this error ? What can i do ?
Click to expand...
Click to collapse
From my reading of Heisenburg's guide in the general section, you need to have your bootloader unlocked before you can flash a factory image. Allow "OEM Unlock" in Developer Options then try again.
Sent from my Nexus 5X using Tapatalk

No other choice than erasing my data so...
Thanks for your answer.

yauyau said:
No other choice than erasing my data so...
Thanks for your answer.
Click to expand...
Click to collapse
#1 thing you do when you buy a phone with an unlockable bootloader: unlock it.
You can always wait for the OTA.

You can sideload an OTA update package from stock recovery if you have a locked bootloader, but to flash the partition images using fastboot you absolutely must have an unlocked bootloader.

Error: cannot load 'system.img' When Flashing N Dev 3

Encountered this error message when trying to manually flash the N Dev 3 image, not via the flash-all bat. I'm very familiar when it comes to flashing images on my devices, fwiw.
I tried rebooting my PC, redownloading the image, and updating SDK Tools. No luck.
I've been able to reflash to mtc19t successfully.
My goal was to upgrade to the N Dev 3, then flash the decrypted modified N boot.img from Tigerstown in order to root.

Your fastboot is out of date or you have a bad download.
Sent from my SM-G930V using Tapatalk

Thanks. I'll give this a shot [TOOL]Minimal ADB and Fastboot [4-27-16]:
http://forum.xda-developers.com/showthread.php?t=2317790

bostonirishguy13 said:
Encountered this error message when trying to manually flash the N Dev 3 image, not via the flash-all bat. I'm very familiar when it comes to flashing images on my devices, fwiw.
I tried rebooting my PC, redownloading the image, and updating SDK Tools. No luck.
I've been able to reflash to mtc19t successfully.
My goal was to upgrade to the N Dev 3, then flash the decrypted modified N boot.img from Tigerstown in order to root.
Click to expand...
Click to collapse
You don't need to decrypt or flash a modified boot.img in order to root.

bobby janow said:
You don't need to decrypt or flash a modified boot.img in order to root.
Click to expand...
Click to collapse
Should have mentioned I'd prefer TWRP, too.

I ended up not using the unencrypted boot.img and rooted with CF Autoroot.

had same issue use fastboot from latest sdk

Question about flashing image with fastboot

I'm going to be exchanging my pixel and getting another one. Just curious so I know for the future.. if I flash the full factory image via fastboot does that relock the bootloader? I'm gonna guess that it doesn't but just wanna make sure.
New to adb and fastboot so I've been reading around like crazy trying to learn. Is the only way to lock again to use the actual lock command in fastboot?
Edit: I'm referring to using the flash-all.bat script

Yes, you will have to re-lock the bootloader. Do it with fastboot in the bootloader.
Although, you don't have to re-lock the bootloader before sending your phone back... Especially since it will have the stock image flashed to it.

aholeinthewor1d said:
if I flash the full factory image via fastboot does that relock the bootloader?
Click to expand...
Click to collapse
No. Flashing the factory image does not relock the bootloader. After you have successfully rebooted, return to the bootloader and use the command: fastboot oem lock

cam30era said:
No. Flashing the factory image does not relock the bootloader. After you have successfully rebooted, return to the bootloader and use the command: fastboot oem lock
Click to expand...
Click to collapse
Sorry, I know this has been asked but I've been searching for days and can't find it. Trying to flash latest factory image for 7.1.1 on pixel xl without losing data and can not find a guide to do so. Any help is appreciated

canemaxx said:
Sorry, I know this has been asked but I've been searching for days and can't find it. Trying to flash latest factory image for 7.1.1 on pixel xl without losing data and can not find a guide to do so. Any help is appreciated
Click to expand...
Click to collapse
Right click the flash-all script, and choose edit (or something like that) from the drop down menu. In the last line where it says "fastboot -w update..." delete the "-w". Then just use this flash-all.

cam30era said:
Right click the flash-all script, and choose edit (or something like that) from the drop down menu. In the last line where it says "fastboot -w update..." delete the "-w". Then just use this flash-all.
Click to expand...
Click to collapse
I'm sorry I was looking for the full guide on flashing the factory image with -w removed. But you did answer how to remove the -w so thank you ...is there a link to a guide with the correct commands to use?

canemaxx said:
I'm sorry I was looking for the full guide on flashing the factory image with -w removed. But you did answer how to remove the -w so thank you ...is there a link to a guide with the correct commands to use?
Click to expand...
Click to collapse
This is about the best right now > http://forum.xda-developers.com/pixel-xl/how-to/guide-update-fastboot-t3498187

cam30era said:
This is about the best right now > http://forum.xda-developers.com/pixel-xl/how-to/guide-update-fastboot-t3498187
Click to expand...
Click to collapse
Thank you!! Just to confirm there is only 1 factory image for 7.1.1 in the downloads at the google website, which will work with Verizon correct?

canemaxx said:
Thank you!! Just to confirm there is only 1 factory image for 7.1.1 in the downloads at the google website, which will work with Verizon correct?
Click to expand...
Click to collapse
Correct. Let me ask you, do you have any modifications to your Pixel? Root, TWRP, custom kernel? If not, you'd be better off with ADB sideload.

cam30era said:
Correct. Let me ask you, do you have any modifications to your Pixel? Root, TWRP, custom kernel? If not, you'd be better off with ADB sideload.
Click to expand...
Click to collapse
I have root and that's it. So if I'm understanding correctly, I would put the factory image zip in the platform tools folder and extract it there, open a command window from that folder and run this command fastboot flash-all
Is that correct?

canemaxx said:
I have root and that's it. So if I'm understanding correctly, I would put the factory image zip in the platform tools folder and extract it there, open a command window from that folder and run this command fastboot flash-all
Is that correct?
Click to expand...
Click to collapse
You're on Windows?
Command > fastboot flash-all.bat
Make sure you remove the "-w" first

cam30era said:
You're on Windows?
Command > fastboot flash-all.bat
Make sure you remove the "-w" first
Click to expand...
Click to collapse
Yes I am on Windows. So as long as I do as I stated I will retain data and 7.1.1 will be installed. After boot I can reroot with sr4?

canemaxx said:
Yes I am on Windows. So as long as I do as I stated I will retain data and 7.1.1 will be installed. After boot I can reroot with sr4?
Click to expand...
Click to collapse
In fact, on Windows I think you can just double click the flash-all.bat file (I'm on Linux, so I'm not 100% positive). Yes to your other questions. As long as nothing goes wrong.

canemaxx said:
Yes I am on Windows. So as long as I do as I stated I will retain data and 7.1.1 will be installed. After boot I can reroot with sr4?
Click to expand...
Click to collapse
Been here for about 4 minutes, is that normal?

canemaxx said:
Been here for about 4 minutes, is that normal?
Click to expand...
Click to collapse
Nope. Your fastboot may be out of date. I'd suggest updating your Android SDK.

cam30era said:
Nope. Your fastboot may be out of date. I'd suggest updating your Android SDK.
Click to expand...
Click to collapse
I updated sdk this morning...not sure why it hung there but everything went through and pixel is now booting. Finishing android update is in progress and seems data was retained. Thank you very much for all your help! Just in time too, Dr just decided to induce my wife's labor and my son will be here today!!

canemaxx said:
I updated sdk this morning...not sure why it hung there but everything went through and pixel is now booting. Finishing android update is in progress and seems data was retained. Thank you very much for all your help! Just in time too, Dr just decided to induce my wife's labor and my son will be here today!!
Click to expand...
Click to collapse
Very good.
You sure like living on the edge...

cam30era said:
Very good.
You sure like living on the edge...
Click to expand...
Click to collapse
Haha thanks again for all your help!! 7.1.1 installed and root is back!! This may be the last time I get to update my phone for a while lol

I can't Lock Bootloader (Mediapad M2 10 A01W)

Hi.
I rooted my M2 10 Wifi (A01W) with Kingroot and apparently now it's unroot (Magisk Manager said that). Even I made a factory reset.
I have the _B007 version and when I try to upgrade via OTA to _B008, it always fail and show "Failed to check the update files. Please download the package again".
I've working with ADB, Fastboot... and I could see that it's unroot, but the Bootloader is Unlock and I can't Relock it. Maybe it's the reason because the OTA doesn't work.
So I got a fastboot code with DC-UNLOCKER and tried to relock (fastboot oem relock CODE) and the answer was:
FAILED (Remote: root type is risk)
If I execute "fastboot oem check-rootinfo":
old_stat: RISK
now_stat: RISK
change_time: xxxxxxxxx
Apparently, the Recovery is stock, with EMUI logo showing 3 options:
Reboot, Wipedata/factory reset and Wipe chache partition
I made the factory reset that way.
Any idea? Thanks.

ma2crmam said:
Hi.
I rooted my M2 10 Wifi (A01W) with Kingroot and apparently now it's unroot (Magisk Manager said that). Even I made a factory reset.
I have the _B007 version and when I try to upgrade via OTA to _B008, it always fail and show "Failed to check the update files. Please download the package again".
I've working with ADB, Fastboot... and I could see that it's unroot, but the Bootloader is Unlock and I can't Relock it. Maybe it's the reason because the OTA doesn't work.
So I got a fastboot code with DC-UNLOCKER and tried to relock (fastboot oem relock CODE) and the answer was:
FAILED (Remote: root type is risk)
If I execute "fastboot oem check-rootinfo":
old_stat: RISK
now_stat: RISK
change_time: xxxxxxxxx
Apparently, the Recovery is stock, with EMUI logo showing 3 options:
Reboot, Wipedata/factory reset and Wipe chache partition
I made the factory reset that way.
Any idea? Thanks.
Click to expand...
Click to collapse
Well, I've read that flashing a system.img extracted from the UPDATE.APP I would can restore the Stock ROM... but I don't find a complete Stock ROM for Mediapad M2 10 Wifi (A01W).
I found the OTA in Romfirmware or Fordroid (sorry, I'm new user and I can not post external links). With this I can flash BOOT.img and RECOVERY.img, but the problem persist.
Does someone has any idea... or where can I get the complete Stock ROM?
Thanks!!!

ma2crmam said:
Well, I've read that flashing a system.img extracted from the UPDATE.APP I would can restore the Stock ROM... but I don't find a complete Stock ROM for Mediapad M2 10 Wifi (A01W).
I found the OTA in Romfirmware or Fordroid (sorry, I'm new user and I can not post external links). With this I can flash BOOT.img and RECOVERY.img, but the problem persist.
Does someone has any idea... or where can I get the complete Stock ROM?
Thanks!!!
Click to expand...
Click to collapse
Stokk ROM maybe available through a paid service by easy firmware. Got my LTE Stock ROM frim there. For the Wi-Fi edition you could first take a look here.
Sent from my HTC U11 using XDA Labs

5m4r7ph0n36uru said:
Stokk ROM maybe available through a paid service by easy firmware. Got my LTE Stock ROM frim there. For the Wi-Fi edition you could first take a look here.
Sent from my HTC U11 using XDA Labs
Click to expand...
Click to collapse
Thanks!!! I didn't know that page. It's fine and does not look very expensive.
Just one more doubt.
The firmaware I need (as read on the tablet) is M2-A01w...B008 for West Europe
The firmware that the page shows is M2-A01w...B008CUSTC100D001
Do you know what CUSTC100D001 mean? Could I used it without problems?

ma2crmam said:
Thanks!!! I didn't know that page. It's fine and does not look very expensive.
Just one more doubt.
The firmaware I need (as read on the tablet) is M2-A01w...B008 for West Europe
The firmware that the page shows is M2-A01w...B008CUSTC100D001
Do you know what CUSTC100D001 mean? Could I used it without problems?
Click to expand...
Click to collapse
Glad it helped and yes it is not so expensive regarding the fact that there are all sorts of official firmware (mostly leaked ones) available for a lot of manufacturers.
The CUST reference at the end if the firmware version can be found in settings > about the tablet in the very last line. Mine is in German, So translated this line would state something like adapted/customized version. D001 is definitely Western Europe,this should be fine.
If not familiar how to install it google or search the forum for dload method. It will tell you what to do.
Sent from my HTC U11 using XDA Labs

I've done:
1. Get the correct firmware (version ...B007) and extract the RECOVERY.IMG and UPDATE.APP.
2. Flash the RECOVERY with Fastboot and install the UPDATE with the "dload" in the SD.
3. Reboot in RECOVERY MODE, wipe all and restore factory settings.
4. Then, the tablet was updated via OTA to the ...B008 version.
Then, positive:
1. The OTA works fine.
2. I was abble to install the Nextlix App and the HBO Spain App plays videos. Both didn't work before.
3. If I execute "fastboot oem check-rootinfo":
old_stat: RISK
now_stat: SAFE
Then, negative:
1. I can't relock the Bootloader yet. When I try to relock (fastboot oem relock CODE) and the answer was again: FAILED (Remote: root type is risk)
Well, for normal use that's enough, but... THE RELOCK is becoming personal!!!