iMac EFI Firmware Update 1.9
About iMac EFI Firmware Update 1.9
This update fixes several issues to improve the stability of iMac (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: IM121.0047.1F