Unlocked Atrix 4G International Bootloader Available

An international version of the unlocked bootloader for Motorola Atrix 4G is now available through an Orange UK update released recently with support for the service. This release builds upon the existing leaked Gingerbread 2.3 ROM which includes a fastboot-unlockable bootloader, however that leak is only compatible with the USA based AT&T Atrix 4G and not international versions, while this new one comes from an official update, and is compatible with international devices. An official update is expected from Motorola enabling the unlocked bootloader soon, per Motorola's earlier promise.

The unlockability is provided through a french ROM available from Orange UK. This is uploaded to the device via the Windows utility "RSD Lite" or the Linux utility "sbf_flash". Once the ROM is flashed, the bootloader is replaced with a version specifically written to allow "fastboot" unlocking. The method requires the fastboot program provided as part of Google's Android SDK, also available separately at the XDA post. Once run, the user is prompted that unlocking the device can permanently void warranty coverage, and required to re-issue the command with the device's unique ID, acknowledging the warranty issue.

A warning is included not to attempt to use RSD Lite to restore an older version of the system via SBF image, as this may result in a bricked device. The unlocked bootloader provides features that replace SBF flashing and enable more functionality so this should not be a concern as long as the user is aware of it.

Source: XDA Forums (1), (2), (3) 
Via: Engadget