Not supported for the Android M, or Android 6.0 Marshmallow, update, the carrier-locked Verizon Moto X 2014 has been officially cleared for unlocking and installing custom ROMs.

Android 6.0 Marshmallow, has been rolling out to Motorola devices like the 2015 Moto X Pure Edition and the third generation Moto G. But if you bought a second-generation Moto X 2014 on Verizon expecting the standard two-year firmware update support that comes with most flagship smartphones, you'd be forgiven for being a little miffed.

That's because while "pure" (or unlocked) editions of the Moto X 2014 were put on the list for an eventual Android M upgrade, Motorola has decided not to give any more update support for the carrier-locked versions of the barely two-year-old device.

It's a very consumer-unfriendly move, and a surprising one for Motorola, which has a reputation for providing prompt Android OS updates -- or, worst case, at least providing Android OS updates at all.

Likely flooded with messages from angry customers, Motorola has attempted to make up for the lack of firmware update support by giving users the option to provide their own, though caveats abound.

Motorola made an announcement on its forums (via TheVerge) that it had "received the green light" to offer codes for customers to unlock the bootloader on their second-generation Moto X handsets.

Unlocking the bootloader allows you to install custom Android ROMs, like those from CyanogenMod. Many custom ROMs are already running some version of Android 6.0 Marshmallow, so Verizon customers (sorry AT&T Moto X owners) now have that option open to them -- if they're capable of flashing custom ROMs and willing to void their warranties.

If you're not familiar with terms like bootloader and flashing ROMs, it's probably best to just stick with your Moto X's official Android 5.0 Lollipop OS. Especially if it's your only smartphone and you can't afford to brick it.

But if you're familiar (or sufficiently curious), here's Motorola's bootloader unlocking portal to get started.