For those of you who want to run the latest CM11 ROM Snapshot M10 on your AT&T One X (which I highly recommend as it makes your phone 3 times faster), you will need to update the bootloader on your AT&T One X.
The best way to do is to get S-OFF then run the RUU. By getting S-OFF on your AT&T One X, you will be able to flash the RUU without wiping your internal storage completely.
After getting S-OFF and running the RUU, you can re-install the latest TWRP recovery using fastboot then install the latest CM11 ROM Snapshot M10.
So, here’s the steps:
Step 1. Follow our guide on How to Get S-OFF on HTC Smartphone using Firewater. (If you are having trouble, try installing an older CM11 nightly (which I used in my tutorial) then trying it again.
Step 2. Once you have S-OFF, simply put your phone into fastboot mode and run the RUU. You will need a Windows computer to run the RUU as it only supports Windows.
Step 3. Power off your phone then put into Fastboot Mode by holding down Volume Down and Power buttons together. (When you are in Bootloader mode, select Fastboot and hit Power button which will enter you into Fastboot Mode.)
Step 4. Then connect a micro-USB cable and connect to your computer.
Step 5. Next download fastboot.zip and unzip. Also download latest TWRP recovery and copy into your fastboot folder.
fastboot flash recovery openrecovery-twrp-22.214.171.124-evita.img
Once that’s done, you can simply select “Recovery” in Bootloader menu to install new CM11 ROM. If you have no OS for some reason, see our guide on how to copy files over with no OS.