Macbook Pro EFI Firmware Update 2.3
This update fixes several issues to improve the stability of MacBook Pro (early 2011) and MacBook Pro (late 2011) computers and is recommended for all users.
This update includes improvements delivered in MacBook Pro EFI Firmware Update 2.2 that enables Lion Internet Recovery from an Internet connection, resolves issues with Apple Thunderbolt Display compatibility and Thunderbolt Target Disk Mode performance on MacBook Pro (early 2011) models.
The MacBook Pro EFI Update will update the EFI firmware on your notebook computer. Your computer's power cord must be connected and plugged into a working power source. When your MacBook Pro restarts, a gray screen will appear with a status bar to indicate the progress of the update. It will take several minutes for the update to complete. Do not disturb or shut off the power on your MacBook Pro during this update.
Boot ROM or SMC Version Information: After MacBook Pro update has successfully completed, your Boot ROM Version will be MBP81.0047.B24.