[Atrix 4G Q&A, Help & Troubleshooting] AndyPhreak:
You've stumbled into a bar on the wrong side of town, mi amigo! :eek:

Seriously, before you go trying to actually use any of these menus, you will want to read this post in its entirety:

[Updated 8-2-2011] THE BEGINNERS (N00B) GUIDE!!! N00BS LOOK HERE FOR YOUR HOW TOs

http://xdaforums.com/showthread.php?t=1154600

That being said, here are some notes on how this works on the Atrix 4G.

Fastboot menu

- Power on phone

- Press and hold Volume

Down

key as soon as green power light goes out

- Wait until "Fastboot" appears on Motorola splash screen

- Press Volume Down key to cycle through menu items

- Press Volume Up key to select item

The three most important items in the Fastboot menu for Moto modding are Android Recovery, Fastboot, and RSD:

Android Recovery

- Enter Fastboot main menu and select "Android Recovery"

- Wait until Exclamation mark and Android icons appear on screen

- Tap lower right-hand corner of screen to open system recovery menu (for newer firmware versions, press the Volume Up/Down keys simultaneously)

- Press Volume Up or Volume Down keys or tap menu to select item

- Rotate phone to LANDSCAPE orientation and tap lower corner of screen near "OK" to accept selected item (or press the Volume Up/Down keys simultaneously)

Fastboot protocol support

- Power on phone

- Enter Fastboot main menu (as previously explained) and select "Fastboot"

- Wait until "Starting Fastboot protocol support" appears on screen

RSD protocol support

- Power on phone

- Press and hold Volume

Up

key as soon as green power light goes out

- Wait until "Starting RSD protocol support" appears on screen

- OR -

- Enter Fastboot main menu (as previously explained) and select "RSD"

Android Recovery is a GUI interface for wiping the phone/restoring to factory defaults and applying firmware updates. Recovery packages consist of a zip file containing partition images and a script to tell the recovery program what to do with them. It's common practice to replace the stock recovery program with ClockworkMod (CWM) Recovery. For the Atrix 4G you'll need to use a special version - Tenfar's CWM Recovery Mod for Atrix 4G: http://xdaforums.com/showthread.php?t=1138541

Fastboot protocol requires a USB connection to a command terminal on a PC. Partition .img files are applied directly to the phone memory. You won't want to mess with this until you've read and understood the N00B Guide at the link posted above.

RSD protocol also requires a USB connection. Commands can be issued via a terminal window or a Windows GUI program called "RSD Lite". RSD uses SBF (Single Binary Format) image files instead of the partition image files used by Android Recovery and Fastboot. You also don't want to mess with this until you've thoroughly studied all the info in the N00B Guide.

When you feel you have a basic grasp of how this all works, then here's the easiest method for unlocking your Atrix 4G:

http://xdaforums.com/showthread.php?t=1182871

This all-in-one program will automatically unlock your phone, install Tenfar's CWM recovery, and install su for root access. You won't need to install ADB or RSD Lite or anything else on your PC except for the Motorola USB drivers. I used this one myself after lurking and reading here for about a month. Worked like a charm for me.

Good Luck!