Develop Bugs

Moto E4 Guide To Full Stock Firmware Restore and Re-lock Bootloader Any Variant

Note :
Do not erase/flash Bootloader file preloader.img or preloader.bin
fastboot erase preloader
fastboot flash preloader preloader.img
Do not erase/flash partition table file pgpt.img/gpt.img or pgpt.bin/gpt.bin
fastboot erase pgpt or gpt
fastboot flash pgpt or gpt pgpt.img or gpt.img​
About :
With this guide you will restore stock firmware and re-lock your device bootloader.This guide is from Moto E4 Mediatek variant SKU XT1760 but can work with any Moto E4 Variant. Just grab the partition info and partition name in fastboot mode with fastboot command "fastboot getvar all". But this step isn't necessary if you take backup with miracle tool. It will dump whole firmware in scatter format. So, no need to worry if you have a different variant of Moto E4
This guide will give you the following :​
PHP:
<bootloader> : warranty (YES)
<bootloader> : unlocked (NO)
<bootloader> : secure (YES)
>> device unlocked (we cannot remove this warning !)
Requirement :
• Place all the firmware files here:
C:\Program Files\Minimal ADB and Fastboot\HERE
• A laptop/Desktop
• Unlocked Bootloader
• Enabled USB Debugging
• Moto E4 Any Variant
• USB Cable
• Minimal Adb & Fastboot Tool
• Miracle Tool
• Adb & Fastboot Commands
Step 1 : Boot into bootloader mode
Switch off your device
Hold power button and volume down button
When you see START release buttons
This is fastboot mode
Step 2 : Reboot into bootloader
Note : i recommended you to use a laptop than that of desktop. For continuous power supply. Fully charge your laptop battery.
Connect with USB Cable
Open fastboot command window
Type fastboot command:
PHP:
fastboot reboot bootloader
Now your device in fastboot mode
--- Do not disconnect ---
Step 3 : Flashing stock factory images
Type these fastboot commands:
Erasing partitions first
if you have a different variant of Moto E4, just write all the partitions name except bootloader(preloader) in a text file and replace them with the below partition names.​
PHP:
fastboot erase boot
fastboot erase efuse
fastboot erase expdb
fastboot erase flashinfo
fastboot erase frp
fastboot erase hw
fastboot erase keystore
fastboot erase lk
fastboot erase logo
fastboot erase metadata
fastboot erase nvdata
fastboot erase nvram
fastboot erase oem
fastboot erase oemkeystore
fastboot erase otp
fastboot erase para
fastboot erase persist
fastboot erase proinfo
fastboot erase protect1
fastboot erase protect2
fastboot erase recovery
fastboot erase seccfg
fastboot erase secro
fastboot erase tee1
fastboot erase tee2
fastboot erase utags
fastboot erase system
fastboot erase userdata
--- Do not disconnect ---
Now flash stock factory images
PHP:
fastboot flash boot boot.img
fastboot flash efuse efuse.img
fastboot flash expdb expdb.img
fastboot flash flashinfo flashinfo.img
fastboot flash frp frp.img
fastboot flash hw hw.img
fastboot flash keystore keystore.img
fastboot flash lk lk.img
fastboot flash logo logo.img
fastboot flash metadata metadata.img
fastboot flash nvdata nvdata.img
fastboot flash nvram nvram.img
fastboot flash oem oem.img
fastboot flash oemkeystore oemkeystore.img
fastboot flash otp otp.img
fastboot flash para para.img
fastboot flash persist persist.img
fastboot flash proinfo proinfo.img
fastboot flash protect1 protect1.img
fastboot flash protect2 protect2.img
fastboot flash recovery recovery.img
fastboot flash seccfg seccfg.img
fastboot flash secro secro.img
fastboot flash tee1 tee1.img
fastboot flash tee2 tee2.img
fastboot flash utags utags.img
fastboot flash system system.img
--- Do not disconnect ---
Step 4 : Re-lock bootloader
Type this fastboot command
PHP:
fastboot oem lock
Hit volume up button
Again type fastboot command
PHP:
fastboot reboot
Step 5 : Fix for system image sparse chunk
Used only when fastboot command failed to write system in system partition else when you see "sparse chunk error" wait for 10 minutes. you will see 1/20 or something operations. if not or command ended up with chunk error than use this command.​Use this fastboot command:
PHP:
fastboot flash system system.img_sparsechunk.1
fastboot flash system system.img_sparsechunk.2
fastboot flash system system.img_sparsechunk.3
fastboot flash system system.img_sparsechunk.4
fastboot flash system system.img_sparsechunk.5
fastboot flash system system.img_sparsechunk.6
fastboot flash system system.img_sparsechunk.7
fastboot flash system system.img_sparsechunk.8
fastboot flash system system.img_sparsechunk.9
fastboot flash system system.img_sparsechunk.10
fastboot flash system system.img_sparsechunk.11
fastboot flash system system.img_sparsechunk.12
fastboot flash system system.img_sparsechunk.13
fastboot flash system system.img_sparsechunk.14
fastboot flash system system.img_sparsechunk.15
fastboot flash system system.img_sparsechunk.16
fastboot flash system system.img_sparsechunk.17
fastboot flash system system.img_sparsechunk.18
fastboot flash system system.img_sparsechunk.19
fastboot flash system system.img_sparsechunk.20
Step 6 : Do not use this fastboot command
PHP:
fastboot erase preloader
This will wipe bootloader from bootloader partition and your device ended up with permanent Hard brick.
Step 7 : Fix for bootloader(fastboot) drivers
if your device isn't recognized in fastboot mode, Download USB Drivers from below attachment. Select manually "android_winusb.inf" file while updating driver software.
Download Link :
https://drive.google.com/file/d/0B0Oo-yXGY-zUMG1XRG52dFZpV1k/view
Step 8 : How to dump stock firmware
Thread link below:
https://forum.xda-developers.com/moto-e4/how-to/how-to-backup-stock-rom-moto-e4-variants-t3654976
Guide to fix boot_dataerr in miracle tool if it failed to dump stock rom
Look at the log window in miracle tool there in driver part you will see MTK preloader USB COM PORT#7. We don't need Preloader driver right now, we need MTK Android DA USB COM PORT#7. The solution is update your device driver software to fix this problem else you won't able to dump firmware in scatter format also we don't have official factory images. This is the only method to revert on purely unrooted stock firmware.
Step 9 : Minimal Adb & Fastboot download link
https://androidmtk.com/download-minimal-adb-and-fastboot-tool
This is my last thread in Moto E4 forum and i won't support this device anymore.​

Does this work for all variants?

andMego said:
Does this work for all variants?
Click to expand...
Click to collapse
yes, work with all variants.
already mentioned in OP.

kartik verma said:
This is my last thread in Moto E4 forum and i won't support this device anymore.​
Click to expand...
Click to collapse
After you came here and cluttered the forum with a crap load of pointless threads and posts? I love it! Thanks.

amarc78 said:
After you came here and cluttered the forum with a crap load of pointless threads and posts? I love it! Thanks.
Click to expand...
Click to collapse
pointless threads and posts
so my posts are useless. sorry if my posts aren't fit into your expectation.

kartik verma said:
pointless threads and posts
so my posts are useless. sorry if my posts aren't fit into your expectation.
Click to expand...
Click to collapse
Personally I'm very thankful for this post, as I couldn't figure out how to do it myself. I was able to reflash stock and lock the bootloader but it wouldn't boot since it always said it was modified, so I just returned my previous e4 with the bootloader unlocked and the noverify thing flashed.

my phone refuses to verify boot.img

KyleBryant said:
my phone refuses to verify boot.img
Click to expand...
Click to collapse
will it asks for boot.sig or anything else. let me know

I figured it out

KyleBryant said:
I figured it out
Click to expand...
Click to collapse
How?

Motorola doesn't release verified boot images. The reason it wouldn't boot for me is because I forgot to flash the no verity file lol

KyleBryant said:
Motorola doesn't release verified boot images. The reason it wouldn't boot for me is because I forgot to flash the no verity file lol
Click to expand...
Click to collapse
How do I lock the bootloader and get it to verify the boot image?

No idea

andMego said:
How do I lock the bootloader and get it to verify the boot image?
Click to expand...
Click to collapse
fastboot oem lock (relock the bootloader)
their is nothing to do with boot image. verification is for system if you changed something and didn't disable verity " MOUNT FLAG /system ro wait,verify" your device ain't gonna boot into system.
dm-verity can be disabled by two ways either remove "verify" or change the default.prop values "ro.secure=0".

kartik verma said:
fastboot oem lock (relock the bootloader)
their is nothing to do with boot image. verification is for system if you changed something and didn't disable verity " MOUNT FLAG /system ro wait,verify" your device ain't gonna boot into system.
dm-verity can be disabled by two ways either remove "verify" or change the default.prop values "ro.secure=0".
Click to expand...
Click to collapse
Before I returned my other e4 I flashed the stock images with rsdlite and then did fastboot oem lock but then the phone wouldn't boot since it said it was modified so I had to unlock the bootloader again and flash the noverify thing in TWRP. How should I have done it to be able to return the phone with the bootloader locked?

andMego said:
Before I returned my other e4 I flashed the stock images with rsdlite and then did fastboot oem lock but then the phone wouldn't boot since it said it was modified so I had to unlock the bootloader again and flash the noverify thing in TWRP. How should I have done it to be able to return the phone with the bootloader locked?
Click to expand...
Click to collapse
" it said it was modified"
First of all remove all the changes you have done in system else if you don't know where you have done changes wipe system partition and reflash system image in system partition.
don't flash gpt.img, pgpt.img, bootloader.img in fastboot mode also do not erase data in fastboot mode "fastboot erase userdata". your device must be charged upto 80% if you want your device boot after a clean flash.
as i am also facing over discharged problem.

kartik verma said:
" it said it was modified"
First of all remove all the changes you have done in system else if you don't know where you have done changes wipe system partition and reflash system image in system partition.
don't flash gpt.img, pgpt.img, bootloader.img in fastboot mode also do not erase data in fastboot mode "fastboot erase userdata". your device must be charged upto 80% if you want your device boot after a clean flash.
as i am also facing over discharged problem.
Click to expand...
Click to collapse
Kartik dude tell me if this is possible....
To roll back I flash unmodified stock boot image and flash stock recovery through fastboot - reboot system - reset -relock bootloader.....can I able to do this?

drganbds said:
Kartik dude tell me if this is possible....
To roll back I flash unmodified stock boot image and flash stock recovery through fastboot - reboot system - reset -relock bootloader.....can I able to do this?
Click to expand...
Click to collapse
follow this method :
erase partitions only if you have factory images
fastboot erase recovery
fastboot flash recovery recovery.img
fastboot erase boot
fastboot flash boot boot.img
erase system if you done changes in system partition. if not leave this step
fastboot erase system
fastboot flash system system.img

kartik verma said:
follow this method :
erase partitions only if you have factory images
fastboot erase recovery
fastboot flash recovery recovery.img
fastboot erase boot
fastboot flash boot boot.img
erase system if you done changes in system partition. if not leave this step
fastboot erase system
fastboot flash system system.img
Click to expand...
Click to collapse
Excellent then do me a favour buddy I need stock recovery and unmodified boot images of Moto e4 mediatek variant.

drganbds said:
Excellent then do me a favour buddy I need stock recovery and unmodified boot images of Moto e4 mediatek variant.
Click to expand...
Click to collapse
i will upload official factory images when i get free time

Removing chrome and play store from Motorola 7 power

This is for a Motorola XT1955-5 Retail US. I wanted chrome and play store to where the user cant get to them, but other apps can still interact with them. This is a quick and dirty guide in case anyone is in same boat
Install drivers for Motorola g7 power.
Install adb and fastboot tools minimal. Do the portable version
Get the stock firmware from lolinet this person is great!
Flash your phone with the latest firmware. Commands are below. Notice we don't erase user data cuz we don't need to. If it doesn't, work, you can rerun and erase data.
Download the magisk manager app and install on phone
Unpack the stock firmware, and copy the boot.img to the phone
In magisk manager, install magisk (not manager). Select download and install, and select the boot.img
Once it creates the magisk_patched.img, copy that to your computer
Boot the phone to bootloader, and from your computer, run fastboot flash boot magisk_patched.img
Boot the phone normally, and go to magisk manager and see magisk is installed.
Now download the twrp temporary recovery image to your machine.
Boot to the bootloader
Now run: fastboot boot twrp-3.3.1-2-ocean.img
Go to mount. Check the box for system
Now to Advanced -> terminal, and run the commands to remove the system apps from the phone
rm -rf /system/system/app/Chrome
rm -rf /system/system/priv-app/Phonesky
Now boot the phone normally. You will see the play store and chrome are gone!
The trick now is to get a version of the app that we can load, but the user cant touch.
Download chrome and play store from apkmirror.com
Install them on the phone
Now download link2sd and install on phone
Use link2sd with root (it should prompt you for magisk root access), and "freeze" the chrome and play store apps
(Pro tip, make sure the latest version of android web view is installed to pair with latest version of chrome. You don't need to freeze web view)
Now get rid of link2sd.
Now you have a phone where people cant use chrome or play store, but other apps that require it will work.
This is mainly useful if you want a person to use the phone but not install apps on it. The only way around this for them would be to reflash the stock boot.img to the boot partition, or manually copy the app from a usb drive. But if you give someone the phone and say "don't install apps on it" and they don't have other devices, this is the way to do it.
Fastboot commands:
fastboot getvar max-sparse-size
fastboot oem fb_mode_set
fastboot flash partition gpt.bin
fastboot flash bootloader bootloader.img
fastboot flash modem NON-HLOS.bin
fastboot flash fsg fsg.mbn
fastboot erase modemst1
fastboot erase modemst2
fastboot flash dsp adspso.bin
fastboot flash logo logo.bin
fastboot flash boot boot.img
fastboot flash dtbo dtbo.img
fastboot flash system system.img_sparsechunk.0
fastboot flash system system.img_sparsechunk.1
fastboot flash system system.img_sparsechunk.2
fastboot flash system system.img_sparsechunk.3
fastboot flash system system.img_sparsechunk.4
fastboot flash system system.img_sparsechunk.5
fastboot flash system system.img_sparsechunk.6
fastboot flash system system.img_sparsechunk.7
fastboot flash system system.img_sparsechunk.8
fastboot flash system system.img_sparsechunk.9
fastboot flash system_b system_b.img_sparsechunk.0
fastboot flash system_b system_b.img_sparsechunk.1
fastboot flash system_b system_b.img_sparsechunk.2
fastboot flash vendor vendor.img_sparsechunk.0
fastboot flash vendor vendor.img_sparsechunk.1
fastboot flash oem oem.img
fastboot flash oem_b oem_other.img
##fastboot erase userdata
fastboot erase DDR
fastboot oem fb_mode_clear

OP7T softbrick

SOLVED: https://youtu.be/yubl_JTEyJw
Code:
flash-all.bat
@echo off
title Mauronofrio Fastboot Rom Flasher :P
:choice
set /P c=Do you want to wipe all the data ( Reccomended )[Y/N]?
if /I "%c%" EQU "Y" goto :wipe
if /I "%c%" EQU "N" goto :continue
goto :choice
:wipe
fastboot -w
goto :continue
:continue
fastboot flash boot boot.img
fastboot flash dtbo dtbo.img
fastboot flash modem modem.img
fastboot flash reserve reserve.img
fastboot flash recovery recovery.img
fastboot --disable-verity flash vbmeta vbmeta.img
fastboot --disable-verity flash vbmeta_system vbmeta_system.img
fastboot reboot fastboot
fastboot flash abl abl.img
fastboot flash aop aop.img
fastboot flash bluetooth bluetooth.img
fastboot flash cmnlib cmnlib.img
fastboot flash cmnlib64 cmnlib64.img
fastboot flash devcfg devcfg.img
fastboot flash dsp dsp.img
fastboot flash hyp hyp.img
fastboot flash imagefv imagefv.img
fastboot flash keymaster keymaster.img
fastboot flash LOGO LOGO.img
fastboot flash multiimgoem multiimgoem.img
fastboot flash odm odm.img
fastboot flash oem_stanvbk oem_stanvbk.img
fastboot flash opproduct opproduct.img
fastboot flash qupfw qupfw.img
fastboot flash storsec storsec.img
fastboot flash tz tz.img
fastboot flash uefisecapp uefisecapp.img
fastboot flash xbl xbl.img
fastboot flash xbl_config xbl_config.img
fastboot flash system system.img
fastboot flash vendor vendor.img
fastboot flash product product.img
fastboot reboot
pause
Hello! I am having a lot of issues after trying to push a beta update: I couldnt find the zip in the root directory, or more accurately I couldnt place the zip into the root directory, I tried multiple file managers with most recent MAGISK, sooooo
I unpacked the JAR and payload.BIN file using payload_dumper and tried to install the System, Boot, Vendor, and Recovery partition: I couldnt find Radio within the payload.
OnePlus7TOxygen_13.W.08_OTA_008_all_2009072104_5a77f7db9358487c.zip
Sure enough, when it rebooted, i didnt have radio comms: so I tried doing a system wipe from the recovery partition: but now I am in a permanent bootloop after reboot.
I have tried reflashing the most recent stable update using the same method
OnePlus7TOxygen_14.O.18_OTA_018_all_2007240040_77d64cd32274479a
but still no luck. I am trying the MsmDownloadTool V4.0
and cant seem to see my device in the connected devices screen: I see "COM3 N/A Waiting for device"
So at this point, I dont know what to do and would greatly appreciate any help I can get
Thank you

derrickl1990 said:
Hello! I am having a lot of issues after trying to push a beta update: I couldnt find the zip in the root directory, or more accurately I couldnt place the zip into the root directory, I tried multiple file managers with most recent MAGISK, sooooo
I unpacked the JAR and payload.BIN file using payload_dumper and tried to install the System, Boot, Vendor, and Recovery partition: I couldnt find Radio within the payload.
OnePlus7TOxygen_13.W.08_OTA_008_all_2009072104_5a77f7db9358487c.zip
Sure enough, when it rebooted, i didnt have radio comms: so I tried doing a system wipe from the recovery partition: but now I am in a permanent bootloop after reboot.
I have tried reflashing the most recent stable update using the same method
OnePlus7TOxygen_14.O.18_OTA_018_all_2007240040_77d64cd32274479a
but still no luck. I am trying the MsmDownloadTool V4.0
and cant seem to see my device in the connected devices screen: I see "COM3 N/A Waiting for device"
So at this point, I dont know what to do and would greatly appreciate any help I can get
Thank you
Click to expand...
Click to collapse
When you tried to find the ota in root directory did u rename jar file to .zip

SOLVED
https://youtu.be/yubl_JTEyJw
snoopy1e11 said:
When you tried to find the ota in root directory did u rename jar file to .zip
Click to expand...
Click to collapse
Yes, I extracted the jar to a zip, but It failed to copy to the root directory every time

[GUIDE] How to Fastboot Flash without PC for Redmi Note 9

Steps to flash Miui without PC(fastboot flash)
Requirements:
• An OTG cable
• An extra phone
• Working Human brain
Method 1(root):
(1) Download termux(playstore), flash this (https://ghostmirror.hitesh920.workers.dev/0://ADB_&_Fastboot_for_Android_NDK-1.0.41(104107).zip) in magisk, reboot
(2) Download miui fastboot image, extract, in downloads folder, inside the folder, there is a folder called images, move that folder in Downloads folder
(3) Open termux and type
pkg install wget
rm -rf fastboot_flash_no_pc.sh && wget https://mirror.akshaykakatkar.dev/fastboot_flash_no_pc.sh
(If it gives internal server error, simply type again)
su
(4) Connect phone to otg, and type,
chmod +x * && ./fastboot_flash_no_pc.sh
(6) fastboot flash should start and complete after 10-15min
Method 2(non root):
(1) Download This (https://play.google.com/store/apps/details?id=eu.sisik.hackendebug) app
(2)Download miui fastboot rom, extract, inside that folder, there is Images folder, place the images folder in Downloads folder
(3) Open the app, go in fastboot section, and type these commands one by one, and select files from images folder
fastboot erase boot
fastboot flash preloader
fastboot flash logo
fastboot flash tee1
fastboot flash tee2
fastboot flash scp1
fastboot flash scp2
fastboot flash sspm_1
fastboot flash sspm_2
fastboot flash lk
fastboot flash lk2
fastboot flash super
fastboot flash cache
fastboot flash recovery
fastboot flash boot
fastboot flash dtbo
fastboot flash vbmeta
fastboot flash spmfw
fastboot flash md1img
fastboot flash vbmeta_system
fastboot flash vbmeta_vendor
fastboot flash cust
fastboot flash exaid
fastboot flash userdata
fastboot reboot
credits: @Akash23q2 for helping and testing

That's really interesting.
Thank you

Question For those who have flashed International ROM but NFC not working

PS: I know some of the linux thing, but I have no experience in building an Android ROM. Any suggestion and discussion are welcomed
1. Make sure you are on the CN ROM. If not, revert to it.
2. On your CN ROM with magisk/root access, run
Code:
dd if=/dev/block/mapper/vendor_a of=/sdcard/vendor.img
this is to dump the vendor partition where the NFC drivers locate. use vendor_b instead if you are in the b_slot
3. Copy your dumped vendor.img from your phone to your computer with fastboot env.
4. Now flash your internation ROM: AP only
5. run
Code:
fastboot reboot fastboot
get your phone into fastbootd
6.
Code:
fastboot erase vendor_a
fastboot flash vendor_a <path of your vendor.img dumped from CN ROM>
7. reboot to fastboot, run fastboot erase userdata in case the userdata is encrypted
8. restart your phone

Ehh it works, thanks brother!

a723356 said:
PS: I know some of the linux thing, but I have no experience in building an Android ROM. Any suggestion and discussion are welcomed
1. Make sure you are on the CN ROM. If not, revert to it.
2. On your CN ROM with magisk/root access, run
Code:
dd if=/dev/block/mapper/vendor_a of=/sdcard/vendor.img
this is to dump the vendor partition where the NFC drivers locate. use vendor_b instead if you are in the b_slot
3. Copy your dumped vendor.img from your phone to your computer with fastboot env.
4. Now flash your internation ROM: AP only
5. run
Code:
fastboot reboot fastboot
get your phone into fastbootd
6.
Code:
fastboot erase vendor_a
fastboot flash vendor_a <path of your vendor.img dumped from CN ROM>
7. reboot to fastboot, run fastboot erase userdata in case the userdata is encrypted
8. restart your phone
Click to expand...
Click to collapse
What Rom are you using?
Do you have any bugs on it?
Android auto works?

a723356 said:
PS: I know some of the linux thing, but I have no experience in building an Android ROM. Any suggestion and discussion are welcomed
1. Make sure you are on the CN ROM. If not, revert to it.
2. On your CN ROM with magisk/root access, run
Code:
dd if=/dev/block/mapper/vendor_a of=/sdcard/vendor.img
this is to dump the vendor partition where the NFC drivers locate. use vendor_b instead if you are in the b_slot
3. Copy your dumped vendor.img from your phone to your computer with fastboot env.
4. Now flash your internation ROM: AP only
5. run
Code:
fastboot reboot fastboot
get your phone into fastbootd
6.
Code:
fastboot erase vendor_a
fastboot flash vendor_a <path of your vendor.img dumped from CN ROM>
7. reboot to fastboot, run fastboot erase userdata in case the userdata is encrypted
8. restart your phone
Click to expand...
Click to collapse
Is it possible to use this method to change touchscreen drivers? Do you know where it is stored at?
I was having a weird touch screen problem with virtual buttons with an international modified Rom and this touchscreen problem was not present on Chinese stock Rom...

a723356 said:
PS: I know some of the linux thing, but I have no experience in building an Android ROM. Any suggestion and discussion are welcomed
1. Make sure you are on the CN ROM. If not, revert to it.
2. On your CN ROM with magisk/root access, run
Code:
dd if=/dev/block/mapper/vendor_a of=/sdcard/vendor.img
this is to dump the vendor partition where the NFC drivers locate. use vendor_b instead if you are in the b_slot
3. Copy your dumped vendor.img from your phone to your computer with fastboot env.
4. Now flash your internation ROM: AP only
5. run
Code:
fastboot reboot fastboot
get your phone into fastbootd
6.
Code:
fastboot erase vendor_a
fastboot flash vendor_a <path of your vendor.img dumped from CN ROM>
7. reboot to fastboot, run fastboot erase userdata in case the userdata is encrypted
8. restart your phone
Click to expand...
Click to collapse
what img files are excluded in AP flashing process?

doesnt worked for me

How big should the file be "vendor.img"? My has 1,13GB
I try flash it, but get error.
Code:
C:\Users\snego\Downloads\tools_r33.0.2-windows>fastboot erase vendor_a
Erasing 'vendor_a' (bootloader) Permission denied
FAILED (remote: '')
fastboot: error: Command failed
C:\Users\snego\Downloads\tools_r33.0.2-windows>fastboot flash vendor_a vendor.img
Invalid sparse file format at header magic
Resizing 'vendor_a' FAILED (remote: '')
fastboot: error: Command failed
1. Go in fastboot mode
2. fastboot reboot fastboot
3. flash vendor in fastbootD mode.
but still it didn't help. phone won't boot after vendor.img flash