[Atrix 4G General] Tenacious--M:
Ok, finally! I got it done and flashed to CM7. WOW! I love it!

I did notice some differences so I will post my experience here. I will highlight the differences I found that worked for my 2.3.4 Rooted Atrix. Maybe it will help other newbs like me : )

By the way, credit to BriefMobile and the2dcour for the original guide

***I marked the differences I noticed when unlocking my 2.3.4 unlocked At&t Gingerbread***

How To: Unlock the Atrix 4G Bootloader

Prerequisites

• Backed up /data partition

You will lose all of your /data during this process!

• Unlock SBF file [Mirror]

• RSD Lite 5.3.1 or sbf_flash [Download if Atrix is Froyo]

• Fastboot package [Mirror]

Also found in the Android SDK tools folder

Instructions

1. If you’re on Gingerbread, skip to step 13. (I was on 2.3.4 Gingerbread and I also had to do all the steps. Dont skip!!!)

2. Power down your Motorola Atrix

3. Take out your microSD card and SIM card for the flashing process

4. While turning the phone on, hold the Volume Up button until it acknowledges RSD

5. Your device will say “Starting RSD protocol support”

6. Run “RSD Lite” on your computer

7. Press the “. . .” button next to the box labeled “Filename”

8. Load up the SBF file

The SBF file is located inside of the .zip file, you must extract it out before loading it into RSD Lite

Use WinRAR or 7-Zip to extract the .zip file on your computer

9. Plug your device into your computer

Use the USB ports on the back side of your computer for safety

10. RSD Lite should recognize your device and say “Model: NS Flash Olympus” and “Connected…” (Mine said SE Flash Olympus, not NS)

11. Press the “Start” button

12. Be patient while the phone reboots. It will take a long time. (Phone didn’t reboot. It went to a menu and said “5 seconds to select Fastboot”. You have to use Vol down to move in the menu and the Vol up button to select “Fastboot”)

13. Open and extract the Fastboot package from above

14. Open a command prompt window

On Windows, press Start and type “cmd” then press the enter button

15. Type the following command. Your directory will be the folder where you extracted the Fastboot package.

(Example: cd C:\Users\Kenneth\Desktop\fastboot-package) (I extracted mine to the C:\ drive. Then you don’t have to type so much. Just cd C:\fastboot )

cd your directory here

16. Power down your Atrix device

17. Hold the power button and the downward volume button until you see “Fastboot”

18. Let go of the buttons and press the upward volume button once

19. You will now see “Starting Fastboot protocol support”

20. Plug your device into a USB port in the back slot of your computer

Front slots sometimes do not have enough power to stay connected to the device.

21. Type the following command:

fastboot oem unlock

22. You will now receive a warning along with a unique device ID

23. Type the following commands using your unique device ID in place of the ####:

fastboot oem unlock ####

fastboot reboot

24. Wait for your device to reboot. Congratulations! You now have an unlocked bootloader! (Mine said “unlocked” in upper left hand corner, but didn’t reboot. I pulled the battery and restarted. Been working fantastic ever since!)

Source: the2dcour