I wanted to tell you how I could solve the problem when upgrading from Android L 5.1.1 to 6.0.1 in the terminal MM S6 Edge Sm-925i:
"Dm-verity need to check verification failed drk first"
My previous version of android was roteada and under the control of TWRP wanting to update via OTA, told me that my device had been modified and blablabla .... well, as I am a fan of always install the latest system running devices, what I did was upgrade by odin to the latest version ... obviously download the version ARO (in my case of Argentina, is released without operator logos) I downloaded ODIN (recommending me SamMobile) and fly ... did everything well, she cleaned the cell, finished installation and restarted ....
When attempting to load the system error ... dm-verity need to check verification failed drk first //// ufff, well, I started researching in forums, in xda and many sides ... without finding a specific solution point (SamMobile gives, but I'm Argentine and English do not understand much ... so I did not understand very well) then I remembered that once in the preliminary versions of marshallow a developer of xda had launched a custom kernel for android 6 ( 13 cm). Well this is where we started working really ...
It is well known that to install a custom kernel must have equipment with advanced ... then recovery, the first thing to do is this:
1- Install TWRP. I recommend is made by ODIN, we put the team in DOWNLOAD mode with the function keys "VOL - button, HOME, POWER" for 3 seconds and then release. In ODIN, AP load in the recovery, once loaded, with the team in Download mode connect to the PC and we hope to tell us "Added" once that, click on "star" and hopefully finish the process.-. automatically enter the recovery because you can not load the system due to the error you have.
With our team held TWRP already have more features and many options and one of them is to install a modified kernel.
2 - Install KERNEL for MM:
In my case use the kernel "arter97-kernel-g925-13.0" the file I have on my pc and if anyone needs it can go through email, so they can look at xda. here I leave the link: "forum.xda-developers.com/galaxy-s6/samsung-galaxy-s-6--s-6-edge-unified-development/arter97-kernel-galaxy-s6-t3171246" this with all models it supports. I recommend you always use a stable version .. to avoid failures.
because our team does not leave the recovery whatever we do, what I did was save the kernel in a OTG device (our S6 Edge, supports it)
After copying the Kernel to our OTG unit, what we must do is to enter the Recovery, look for the "Install" option then we choose the location (storage / OTG) looking for the file, flasheamos, once finished, we wipe cache ( the option goes right there, not to be found) and with that our Galaxy S6 Edge terminal should start ..
I hope to help who does the same will happen.
Greetings from Argentina.
PS can install the SU if they want to because having a custom kernel everything is permitted.
Sources:
SamMobile
forum.xda-developers
TWRP