Apple’s patch notes:
- About MacBook Pro EFI Firmware Update 2.7 (4.24MB Download)
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 improves the reliability of booting from the network, addresses an issue that can prevent HDCP authentication after a reboot, and resolves an issue with boot device selection when a USB storage device is hot-plugged.
Boot ROM or SMC Version Information: MBP81.0047.27
- About MacBook Air EFI Firmware Update 2.4 (4.06MB Download)
This update fixes several issues to improve the stability of MacBook Air (Mid 2011) computers and is recommended for all users.
This update improves the reliability of booting from the network, addresses an issue that can prevent HDCP authentication after a reboot, and resolves an issue with boot device selection when a USB storage device is hot-plugged.
Boot ROM or SMC Version Information: MBA41.0077.0F
- About iMac EFI Firmware Update 1.9 (3.07MB Download)
This update fixes several issues to improve the stability of iMac (Early 2011) computers and is recommended for all users.
This update improves the reliability of booting from the network, addresses an issue that can prevent HDCP authentication after a reboot, and resolves an issue with boot device selection when a USB storage device is hot-plugged.
Boot ROM or SMC Version Information: IM121.0047.1F
- About Mac mini EFI Firmware Update 1.6 (4.08MB Download)
This update fixes several issues to improve the stability of Mac mini (Mid 2011) computers and is recommended for all users.
This update improves the reliability of booting from the network, addresses an issue that can prevent HDCP authentication after a reboot, and resolves an issue with boot device selection when a USB storage device is hot-plugged.
Boot ROM or SMC Version Information: MM51.0077.10
You can use the links above to download the firmware update for your specific Mac, but you can also find the update in Software Update.