Root HTC One M8 without an OS.

[Ibrahim CAKMAK]

Hello,
I had been using TWRP Custom Recovery and a Stock Rom(android lollipop) until 2 days ago, without any problems. After which I reverted TWRP Recovery to a Stock Recovery to get the OTA which was on my notification bar.
I flashed the Stock Recovery using fastboot flash recovery command
Then I booted up, downloaded and installed OTA, without any problems. (usual, restart, phone with a download symbol on it etc..)

Then the problem appeared. Altough I had been waiting for +30mins, it wasn't gonna boot up.(It stuck on the green htc / android logo screen) So I decided to make a factory reset. I did, but it didn't worked as well. I also tried to download and install the RUU which has the same radio number with mine(RUU_M8_UL_L50_SENSE60_MR_HTC_Europe_4.16.401.10_Radio_1.25.214500021.06G_20.68.4196t.01_F_release_417003_signed.exe), but it threw an error. (error [155] unknown error : the rom update utility cannot upgrade your android phone. please get the correct rom update utility and try again.)
I removed my microSD card as a precaution. And I checked my internal storage for capacity, it says 10.4 GB is free out of 10.6GB. (I don't know whether that indicates that there is no OS, or not.)
And I currently have twrp-2.8.7.0-m8.img flashed as my recovery image.

My Bootloader information is :
*** Software status: Modified ***
*** UNLOCKED ***
M8_UL PVT SHIP S-ON
HBOOT-3.19.0.0000
RADIO-1.25.214500021.06G
OpenDSP-v48.2.2-00564-M8974_F0.1211
OS-4.16.401.13
eMMC-boot 2048MB
Aug 4 2015, 19:21:49.0

When I run fastboot oem readcid :
HTC__J15

When I run fastboot getvar version-main :
4.16.401.13

I have checked the thread in which EarlyMon guided through a very similar problem. However I absolutely have no idea which rom I should install. I am planning to make my phone as if it were bought from the store. (Stock rom. No root access. S-ON. Bootloader locked.) But first off, it must boot up.

 

[Ibrahim CAKMAK]

O.k. I successfully managed to install ViperOneM8 Custom Rom. Everything Works perfectly now. Indeed, even though I have my phone S-ON, I didn't need to flash the boot image manually, everything has been done with ease thanks to aromainstaller. And future readers of this topic, I highly recomend ViperOneM8, it provides a handful of new customization features, together with HTC Sense 7.0. It is perfect now. If you have a similar problem I can guide you from here. I'm gonna check this forum once a week, so the worst case scenario is that you get an answer after 7 days.