Apple has released an EFI firmware update for its entire 2011 Mac line, including the iMac, Mac mini, MacBook Air, and MacBook Pro. While it doesn't offer any new features on the front end, the update (varying in size from 3.7 to 4.2MB depending on your computer) is still one worth downloading, offering fixes to several stability issues. The update also promises to improve the reliability of booting from a network, address an issue that can prevent HDCP authentication after a reboot, and will resolve an issue with boot device selection when a USB storage device is hot-plugged into your machine. If you haven't yet received the prompt, fire up Software Update to install, but be warned: a computer restart is required.