[Android Q&A, Help & Troubleshooting] kaluinos:
I am working on trying to root my Alcatel A50 (nice little phone I picked up on the cheap). In order to install SuperSU to get root access, I need to install a bootloader. By the looks of it, I should be able to make a working bootloader if I have the boot.img file. In order to extract boot.img from the phone, I need root access... a bit of a catch22...

I have so far managed to unlock the bootloader and download an official MBN file via the official Alcatel Windows updater. If I can figure out how to extract boot.img from this MBN file, then I may be able to get around the above3 catch 22.

From this MBN file (3.4 GB in size), I have managed to extract a bunch of apps (see my journal in the hidden section below for details of how I did that). However, part way through the extractor chokes and quits. Based on the size differential of what I am able to extract vs the overall size of the MBN file, I am sure that there is more lurking inside of this file beyond what was extracted - such as the desired boot.img.

What I have gleaned so far in my reading suggests that these MBN files are, in fact, a sort of executable binary file. To that end, I am wondering if anybody has had any luck disassembling these files/fully extracting their contents.

In case it helps (either for my query or some future endeavor in a related vein), here is what I have documented of my quest thus far (follow the directions/links/downloads at your own risk):

https://web.archive.org/web/2017070...bile.com:80/global-en/support/smartsuite/list

Enable OEM Unlock: http://techbeasts.com/how-to-enable-oem-unlock-on-android-nougat/

Install ADB and Fastboot. Go here: https://developer.android.com/studio/releases/platform-tools scroll down to the Downloads section and click on “SDK Platform-Tools for Windows” - it should be a 4-5 MB download. Unzip the files and navigate to the folder via CMD.exe.

As Alcatel seems to have merged with another company, it would appear that links to useful software, drivers etc have all been broken in the midst of their overhaul. I must say I was unimpressed with the limited information/downloads available from their present sites (even checking many of their international sites). At any rate, I managed to find a link to the Alcatel Smart Suite (https://web.archive.org/web/2017070...bile.com:80/global-en/support/smartsuite/list) via Archive.org. I simply selected the newest one and – behold – it downloaded.

Download Smart Suite → Install and load application. Plug in phone to install Alcatel ADB Driver. Reboot Windows

I did run into an issue when running “adb devices” after launching the Smart Suite where it was saying:

adb server version (31) doesn't match this client (40); killing...

could not read ok from ADB Server

* failed to start daemon

error: cannot connect to daemon

I found someone else had a similar issue (https://stackoverflow.com/questions...rsion-31-doesnt-match-this-client-36#38447003). As per the link, I closed Smart Suite and ran the following terminal commands:

adb kill-server

adb start-server

And that seemed to resolve the issue.

You will want to reboot the phone into fastboot mode with this command:

adb reboot bootloader

And verify that you have connectivity by running:

fastboot devices

Then type in this command:

fastboot oem unlock

Your phone will display some text prompting you to unlock the bootloader. Mine says:

Unlock bootloader?

If you unlock the bootloader, you will be able to install custom operating system software on this phone.

A custom OS is not subject to the same testing as the original OS, and can cause your phone and installed applications to stop working properly.

To prevent unauthorized access to your personal data, unlocking the bootloader will also delete all personal data from our phone (a “factory data reset”).

Press the UP/Down buttons to select Yes or No.

Yes: (Volume Up): Unlock (may void warranty)

No: (Volume Down): Do not unlock bootloader.

To continue, Press the Volume Up button on the phone.

Another site suggested I also run: fastboot flashing unlock. I am not sure if that is necessary, but I ran it for good measure. The procedure is the same as above.

Once it finishes, press and hold the power button to power the phone off. Then power it back up. Once it is finished erasing, set up the phone again, enable developer mode and USB debugging.

Next, we will need to obtain root access. To do this, we will install SUPERSU. Unfortunately, at the time of this writing, the official website only gives us XML files when trying to download the files. I did track down an unofficial mirror, though am not 100% sure of its veracity. Download the latest version (the zip file) and use ADB to push it to the phone (adb push filename.zip /sdcard/) and then use the onboard file manager to move it to your external SD card. Then reboot into recovery mode (adb reboot recovery).

Getting Original Firmware

http://www.alcatel-mobile.com/cari/support/softwareUpgrade/list

Download Mobile_Upgrade_S_Gotu2_v5.2.1_Setup.exe

• Install

• Shutdown Phone

• Load software & select 5085O

• Plug in Phone to initiate the downloaded

• (?Unplug phone) and wait for download to complete

• Go into C:\Mobile Upgrade S Gotu2 v5.2.1\download and grab the big file.

Extract Zip → Get MBM File

Either using CYGWIN or running it on Linux directly, execute the following perl script (as per this thread discussion - https://xdaforums.com/android/help/alcatel-pop-4s-help-rooting-installing-t3514186/page9):

cat system.mbn | perl -pe 's/(\xFF{5}\x00{4}\xFF{54})[^\xFF]{10}(\xFF{16})/\1\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\2

/g' | perl -pe 's/(\xFF{32})\xA8\xCF\x56\xCF\xFA\x43\x09\x9F\x79(\xFF{32})/\1\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\2/g' > system.img

On Linux, install simg2img. Use this utility to convert the system.img to system.img.raw (cannot recall where I saw this tidbit)

Mount system.img.raw (mount system.img.raw /mnt/tmp)

sudo cp -R * /home/Downloads/temp/