[One (M8) General] cimnine:
Hi

You may have followed my previous guide, "How to root m8_dugl", in which I guided step-by-step how to root the m8_dugl.

This guide shall be similiar, just for upgrading your m8_dugl to the latest stock. This guide has been tested with an upgrade to Android 4.4.4, but I think the upgrade to Lollipop will be similar.

Disclaimer

The usual: I am not responsible for anything you do, even if you applied my guide step by step. You are sole responsible for your actions. There's no guarantee that this guide works for you, it just worked for me.

If you encounter problems, don't expect me to help you. Reply with what you did (exactly!), which files you downloaded from where and tell us what went wrong. Be polite and maybe someone will help you out.

Please use the "Thanks" ( :good: ) button if you just want to say "Thank you" or "Great" or "I wanna marry you".

Prerequisites

HTC One M8 Dual SIM (m8_dugl)

A complete backup of your phone! (e.g. with titanium backup)

fastboot installed on your computer

UBS cable

Some time

Warning

Make sure you have a "m8_dugl" device:

Reboot your device to the bootloader (POWER+VOLUME_UP until the screen blacks out, then POWER+VOLUME_DOWN). If it reads there something different than "m8_dugl", then this guide is not for you!

Steps

Download m8_dugl_stock_recovery_1.45.401.12.img

If you have Xposed Framework installed:

Download TWRP_Recovery_2.8.0.5_M8_CPTB.img

Open the "Xposed Installer" app, goto "Framework" and click the "Uninstall" button

Put your phone into fastboot mode (see below on how to).

Connect the phone to the PC

Open a console and type "./fastboot boot path/to/TWRP_Recovery_2.8.0.5_M8_CPTB.img"

Wait for the TWRP recovery to load

Click flash

Make sure you are on the "internal storage"

Navigate to "Android/data/de.robv.android.xposed.installer/files"

Install "Xposed-Disabler-Recovery.zip"

Reboot

Revert any further modifications you have made to system files. (Harman Kardon hacks, ...) (SU is usually not a problem and can stay.)

Put your phone into fastboot mode (see below on how to).

Connect your phone to your computer

Open a terminal and type "./fastboot flash recovery path/to/m8_dugl_stock_recovery_1.45.401.12.img" (you only need to do this if you have flashed a different recovery. When in doubt, skip this step at first and only if the installer fails come back to it, do it and do all the following steps again.)

then type "./fastboot oem lock" (according to a reply this step isn't even necessary. Only do this step if the installer fails!)

then type "./fastboot reboot"

Wait till the phone has booted up

Open Settings, go to "About" > "Software updates". Click "Check now" if it does not start to search right away.

Download the update (or use the notification item to so)

Once the download completed, check "Install now" and click install

Your phone will restart and update itself

When your phone starts, you should see a message like "Your phone has been updated to XXX".

You can verify in Settings > "About" > "Software information" that the update was successful

Troubleshooting

Q: How to put my phone into fastboot mode

A: POWER+VOLUME_UP until the screen blacks out, then press POWER+VOLUME_DOWN. You see some options soon. Use the volume buttons to navigate, the power button to perform the selected action. Select FASTBOOT and press the POWER button.

Q: My phone got stuck when booting into the custom recovery. I cannot restart it.

A: Wait till the battery dies, boot to fastboot once again and flash a different recovery for the one m8 (GSM version!)

Q: The installation of the update failed

A: You, or a app you installed, has probably tampered with system files. The update checks if all system files are as expected. Make sure, all files are back to normal. If you use Xposed, make sure you uninstalled Xposed completly.

Q: I don't have root after the update.

A: That's true. You need to root again. See my guide on how to root the m8_dugl.

Changelog

[2014-01-18] Initial guide

[2015-08-03] Incorperated user feedback about 'oem lock'. Switched to 'fastboot boot recovery.img' instead of 'fastboot flash recovery recovery.img'