This guide is for the T-Mobile HTC One M8. Bootloader Version: 3.16.0.0000
Disclaimer: I am not responsible for your device. You are performing the steps detailed in this post at your own risk. Support for any phone unlocked through this method falls upon you. Assume that this method voids any warranty that may have come with your phone. Also, currently there is no known way to restore the T-Mobile variant to complete stock settings after using HTC Dev Unlock and/or achieving S-Off. Maybe at a later date this could be possible, but not yet. *Please do not quote this post. It's so long.*
Support for recoveries, firewater, or other tools used herein should be asked in their respective thread or forum. Firewater does not work on every T-Mobile M8. If, when running firewater, you see "Whelp, this sucks..." firewater will not work on your phone. Right now firewater is the only method to achieve S-Off on our M8 variant.
There was speculation that the phone's build date might be a reference for who's phone was compatible with firewater. This is not the case. There is no correlation between build date and compatibility. A further explanation is given under the S-Off instructions.
This thread is for people that understand what this whole post means. If you are unsure of the terms, please search. The terminology is readily available and nothing should be difficult to find.
I work and go to graduate school, so this thread will be updated periodically, but I will not be able to provide a lot of support. This guide reflects my steps to achieve root and S-Off, and is just intended to give someone new to the phone an easy to read step-by-step guide of what the process will be.
I also hope we can condense the large amount of information floating around about achieving S-Off on our variant into one thread.
List of devices attached
(after copying the fastboot utility downloaded during the HTC Dev Unlock process to your sdk\platform-tools\ directory, this will tell you if your phone is detected by the computer)
a. At the top of the page, either register for a new account or log in with an existing one
b. Under "Supported Devices" choose "All Other Supported Models"
c. Click "Begin Unlock Bootloader"
d. A prompt will ask you to continue. Read this. If this prompt scares you, stop immediately. Otherwise, press "Yes" to continue
e. Accept the legal terms and conditions.
f. Follow the on-screen steps provided.
After powering down, press Volume Down and while pressing Volume Down, press Power holding both buttons to start the device into Bootloader mode. If you have difficulty, power up normally, go to Settings->Battery and deselect Fast boot. Power down and try again. Step 2
Use the Volume buttons to select up or down. Highlight Fastboot and press the Power button. Step 3
Connect the device to the computer via a usb cable Step 4
Download the fastboot binary for your OS using the provided links
g. Follow the on-screen steps provided
Open a command Prompt: Windows: Start->"cmd" Mac: Applications->Utilities->Terminal.app Linux: Terminal
Type in Command Prompt: fastboot oem get_identifier_token. Step 6
You will see a long block of text. Copy and paste this text into the the token field below (in the Windows command prompt: Right Click > Mark > highlight the block of text > Right click to copy. Mac users can use cmd-option to mark and select text.).
When copying the token, start with this line:
And end with this line:
(Note: Do not copy the INFO or (bootloader) prefix) Step 7
Paste this string of text into the token field and hit Submit in order to receive your unlock code binary file. You will receive this information in your email.
h. After hitting submit, HTC will send you an email. Sender is HTC-Unlockbootloader. Subject is "The key to unlocking your HTC Device."
Attached in this mail is your unlock bootloader key file. To use this file to unlock your device, simply follow the remaining instructions on the website to complete the process and successfully unlock your bootloader.
Please remember that unlocking your bootloader may void all or parts of your warranty and your device may not function as intended by HTC. Unlocking the bootloader is for development purposes only.
* Click here to continue the bootloader unlocking process.
The bootloader unlock key file can only be applied to the device with which you generated the token.
Please do not reply to this email which is auto-sent by server.
If you need to contact us with questions please click here.
Attached to the email is Unlock_code.bin. This is the file you will need to download in order to unlock your bootloader. This file is device specific. You cannot use this file to unlock any other HTC phone. Please do not try as this will probably result in a brick.
Click the link provided in the email to continue the steps to unlock your bootloader
i. Follow the on-screen steps provided
You will receive an email with the attachment: Unlock_code.bin. Save this file in the same folder as your fastboot files (For Example: C:\Android).
If, after a short period of time, you have not yet received the mail, or you have received an email from HTC, but does not contain an attached file, it is possible that more stringent spam filters and anti-virus programs will block this mail or attachment.
In order to ensure that you receive the email with the attachment, we suggest you consider using a non-corporate email server as corporate servers tend to have more stringent attachment policies. If you have not received the email at all, please check your spam folder in your email client to check if the email was filtered out. Step 9
In the command prompt type: fastboot flash unlocktoken Unlock_code.bin. In the command prompt you will see the following message:
On your phone you will now see the disclaimer. Please read this carefully as this action may void your warranty. Use the Volume buttons to highlight your choice, and the Power button to make your selection. If you select Yes, your phone will be reset to its’ factory default settings, and your bootloader will be unlocked. If you select No, your phone will reboot and no modifications will have been made. Step 11
To re-lock your bootloader, in the command prompt, type: fastboot oem lock.
Note: This will not restore the factory default lock, but will simply re-lock the bootloader so no further changes can be made. Furthermore, if you want to unlock your bootloader again, simply repeat step 9 with your original unlock key file to unlock your phone again.
j. Congratulations, your phone now has an unlocked bootloader! If your phone hasn't done so already, reboot it and let it sit at the welcome screen for the requisite 5-10 minutes to settle. Turn off your phone, and reboot to HBOOT with volume down + power button. Select fastboot.
2. Install a custom recovery
As far as I know, there are two recoveries that are fully functional with our M8 variant:
PhilZ Touch CWM
a. Download your chosen recovery from the above links.
b. Rename it recovery.img
c. Drop it in the same folder as your adb and fastboot binaries.
d. After booting to fastboot mode, make sure your device is still plugged in and run the following command in your command window:
Your computer shouldn't have any troubles recognizing your phone since we just went through the bootloader unlock, but it's always best to be safe.
f. Congratulations! You now have a custom recovery installed.
g. I recommend immediately making a backup of your fresh operating system (pre-root) by selecting HBOOT from the fastboot menu, then selecting and booting into recovery
h. After booting into your new custom recovery select backup from your list of options and proceed to select your backup location (internal or micro sd) and continue to the backup. It will be quite large, but this will provide you a good starting point should you ever need to restore to factory settings for any reason.
i. I use TWRP, because it will automatically prompt you to install root and SuperSU upon rebooting from recovery.
I am unsure how to achieve root after flashing PhilZ Touch. If anyone provides the info I will add it to this guide.
3. Achieve S-Off (Hopefully!)
The instructions to attaining S-Off are listed on the firewater s-off page linked above. They are really comprehensive and you should follow them to the letter. Make sure that you read through their prerequisites as well.
Note: On prerequisite number four, it states that you must be "HTCDEV unlocked/rooted." Please read this as you must be HTCDEV unlocked AND rooted.
I didn't want to post the firewater team's instructions here (I didn't ask permission yet), so this section will be more for information regarding the S-Off process that I have gathered from other threads and this one going forward.
Issues seen with Firewater:
Firewater does not work on every T-Mobile M8. If, when running firewater, you see "Whelp, this sucks..." firewater will not work on your phone.
There was speculation that the build date was an indicator of compatibility with firewater's S-Off method. As several people expected, there is no correlation. There are batches of components that HTC purchased from various manufacturers that vary in compatibility with the firewater exploit. At this point there is no known method to determine if your phone will be compatible with firewater. Unfortunately, it's just a shot in the dark. So, if you're comfortable, give it a shot and hopefully you're compatible.
Issue: Firewater hangs but does not give the "Whelp this sucks..." message: Possible Solutions: Your device is likely compatible. You must be persistent. Keep trying.
Hit Ctrl+C to exit the exploit and try again starting from "adb reboot" (from @Fenny)
Unplug your USB cable, reboot your phone manually. Once it boots up, plug in your USB cable (from @epsix)
Plug in your USB cable, adb reboot. Once it boots, go to Developer Options and uncheck and recheck USB Debugging (from @epsix)
Install BusyBox (from @renn9420)
Issue: After running adb reboot command and pushing firewater phone shows up as "offline" Possible Solutions: Make sure that you granted su permissions to your adb shell through SuperSU
I had this happen to me. I would go to run the command and suddenly, the phone is disconnected. I ran through the adb reboot steps a couple of times and finally when executing firewater it ran. Went through the steps 3 times before it ran.
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