[One (M8) Q&A, Help & Troubleshooting] geekout:
flashing m8 firmware

Thanks Mike, firmware worked great.

Just wanted to add some info that newbs such as myself may find handy.

My case: M8, , s-off, bootloader unlocked, rooted, att branded, cid: CWS_001, mid: 0P6B12000

I was running cyanogen mod 4.4.4, and decided that I would try lollipop. Flashed lollipop, but wifi went mia because I was running the old firmware. Phone would also hang at HTC boot screen, then go straight to lollipop without any animation in between (thought this to be a little odd).

I read some ware on here that the recovery image could be deleted from the firmware prior to install to prevent having to re-flash a custom recovery after firmware install. I am lazy and had forgotten how to flash a recovery image, so I rather liked that I could leave my custom recovery in place with a firmware upgrade. Note, my mac seemed not to be able to unzip or open the firmware file, so I had to resort to a trusty old pc for this function. Make sure to unzip or open the firmware file, read the included text file to find out if the firmware is compatible with your mid & cid. I found that Winrar would not let me delete files from the firmware while the firmware file was still zipped. Therefore, I unzipped the file, deleted the recovery image from the destination folder, and then re-zipped the contents of the destination folder using normal compression. Note, make sure not to zip the destination folder itself, rather you want to zip the contents of the destination folder by selecting all the individuals files at once and zipping them into a single file. When you are finish, the contents of the new zip file should look like that of the original except for the absence of the recovery image file.

From there, I followed mike's instruction on flashing a firmware file.

I did not realize that flashing new firmware would delete my rom (i.e., lolliop), at least in my instance that was the case. therefore, when I rebooted the phone after firmware install, it simply hung at the htc boot screen (new look to the boot screen by the way). The power button was useless to turn the phone off. So the phone sat at the HTC boot screen for about 20 minutes while I did some research. Some reading revealed that power + volume up would reboot the phone; immediately after the screen goes black you have to release both buttons and then hit power again + volume down button to boot into bootloader, from there to recovery. In recovery, I tried to do a wipe, not yet realizing that the rom had already been wiped, I got an error message to the effect that partitions could not be mounted. I then tried to reboot or boot out of recovery and got a prompt asking if I wanted to reboot with no rom installed. With that realization, and with some luck on my side, as I had the lollipop rom on the external SD, I simple mounted the external SD card from the recovery options (mount) menu, and flashed. Needless to say, the phone booted, I say lollipop boot animation for the 1st time, and wifi is now working great.

by the way, lollipop is simple awesome, it is unfortunate that we have to go through all this, (i.e.,) dogging carriers and manufacturers, to enjoy the intended experience.

Thanks again mike

---------- Post added at 04:20 AM ---------- Previous post was at 04:07 AM ----------

hey man, my phone has the same mid and cid as yours, the firmware ending in 1700 is compatible with our mid and cid, that is what I used, i donT beliEve you have to uPdrade to 4.4.4 or .3, just need the firmware upgrade, then flash lolipop.