Moto X - Downgrading the ROM or Bootloader
NOTE: there are MANY threads on XDA Forums from users who have tried to downgrade and have bricked their phones. Many have not been able to recovery them!! This page attempts to give you an understanding of what to look for, and issues that can come from downgrading your phone!
There is discussions on downgrading the bootloader or ROM on the Moto X. This page intends to explain it, why you would want to, and possible issues around it.
There are currently 4 Moto or Stock ROMs for the Verizon, T-Mobile and Sprint Moto X.
4.2.2 as Initially shipped on the X
4.2.2 w/camera update or 1st OTA
4.4 or 2nd OTA
4.4.2 or 3rd OTA
4.4.4 or 4th OTA
To know which one you have on your X, Go App Drawer -> Settings -> About... and take note of the number that SYSTEM VERSION starts with... For Verizon XT1060 they would be as follows... For other carriers, the System Version numbers will be slightly different.
139.10.53 = Initial Shipping 4.2.2
139.15.1 = 4.2.2 w/camera update or 1st OTA
140.45.5 = 4.4 or 2nd OTA
164.55.2 = 4.4.2 or 3rd OTA
212.55.26 = 4.4.4 or 4th OTA
Bootloader Versions... (Note: check by Booting the X into Bootloader/Fastboot mode, and make note of the second line on the screen)
30.70 = original
30.71 = 4.2.2 OTA with camera update
30.B2 = 4.4
30.B4 = 4.4.2
30.B7 = 4.4.4
Why is this important? Due to changes in parts (GPT.BIN and Motoboot.img to name a few) that are included with 4.4.2 and up, under certain circumstances when trying to downgrade (like from 4.4.2 to 4.4 or lower, or 4.4.4 to 4.4.2 or lower), you could either brick your phone, or set it up to brick in the future when you take an upgrade. So it is suggested you just stick with what is on your phone once you get on 4.4.2 or newer.
Why are the Bootloader Versions listed above important to know? Some users have decided to do "tricks" to upgrade or downgrade without touching GPT.BIN and Motoboot.img. Knowing your bootloader version is important to identifiy what ROM or SBF its safe to flash on your phone. For example, if your phone shows 30.B7, then do NOT attempt to flash anyhing but a 4.4.4 rom.
Why would I want to downgrade my Rom or Bootloader? The older root and write protection disable processes for a Moto X with a locked bootloader (like ATT and Verizon) rely on taking advantage of vulnerabilities in the 4.2.2 w/Camera update rom version, or the 4.4 rom. These processes walk you through downgrading your ROM/Bootloader to 4.2.2 w/Camera update and following a set of steps to upgrade which will keep root and disable write protection. It is important to know this information about the different rom versions, and the issues already having 4.4.2 on your phone introduces, to prevent bricking your phone! NOTE: It was safe to downgrade from 4.4. to 4.2.2 w/Camera update when following the SlapMyMoto/MotoWpNoMo processes. But that was the only time it was safe!!!!
Can I use SlapMyMoto/RockMyMoto/etc to root, and MotoWpNoMo to disable write protection on my locked bootloader X? If your X is still on 4.2.2 w/Camera update(1st OTA), or 4.4(2nd OTA), Yes you can. However, because the vulnerabilities that the Slap/Rock/Pwn and MotoWpNoMo processes use to root and disable write protection have been patched in 4.4.2, and the inability to downgrade them, you CAN NOT use those processes to root and disable write protection if you are on 4.4.2 or higher. Another issue is the risks of bricking your phone when you are on 4.4.2 and try to downgrade.
So I'm on 4.4.2 or newer, and I have a locked bootloader, now what? There is no option to disable write protection on 4.4.2 and newer with a locked bootloader at this time. If you can't obtain a bootloader unlock code (from Moto or a 3rd party), then you can't disable write protection unless someone comes up with new exploits and processes for 4.4.2 for disabling write protection. JCASE has released PIE for Motorola Devices. While it roots 4.4.2, it does not disable write protection, so it is a "temporary" root, lost if you power the phone off/on. Because write protection is still enabled, you can't alter /system, /system/bin, etc., so some ROOT type apps will not work. If you want to make use of XPosed, there are some special considerations such as selecting a certain way to install, and only "soft reboot" and such. The Vulnerability used with the PIE exploit process is patched in 4.4.3 and above.
Update: JCASE has updated SunShine to be compatible with the Moto X and a few other devices. It unlocks the bootloader, disables write protection. It can be used on devices with 4.4.2, 4.4.3, and a few, but not many with 4.4.4. There is discussion -> HERE and HERE
Can I downgrade the firmware or bootloader on my phone after I unlock the bootloader?As for downgrading firmware, the same caveats and warnings apply whether your bootloader is locked or unlocked. Due to changes in the bootloader, GPT.BIN and other parts included with 4.4.2 and up, under certain circumstances when trying to downgrade from 4.4.2 to 4.4 or lower, you could either brick your phone, set it up to brick in the future when you take an upgrade, or have issues/problems with the phone if you can download without bricking. So it is suggested you just stick with what is on your phone once you get on 4.4.2. Besides, if you unlocked your bootloader you wont need to downgrade to gain root anymore.
I understand Root, but what is this "Write Protection" you speak of? By default on the Moto X, write protection is enabled. When its enabled, any changes made to "protected" folders/files on the phone (like anything in /system or the like) will not survive power off/on. Its meant to ensure your phone does not get messed up. Consider it a security measure. MotoWpNoMo was a way for users with locked bootloaders to disable write protection. Initially said to be permanent, the 4.4.2 update/rom patched the exploit used and so write protection gets turned back on once 4.4.2 is installed on the phone. NOTE: If you have a phone with an unlockable bootloader, the process of unlocking the bootloader and rooting disables write protection, and MotoWpNoMo is not needed.