iMac EFI Firmware Update
The 2.1 version of iMac EFI Firmware Update for Mac is provided as a free download on our software library. IMac EFI Firmware Update for Mac lies within System Tools, more precisely Device Assistants. This free Mac app is an intellectual property of Apple Inc. Our antivirus analysis shows that this Mac download is clean. The size of the latest downloadable installer is 8.3 MB.
From the developer:
iMac (late 2013) EFI Update is recommended for iMac (late 2013) models. This update addresses an issue which may cause a black screen to appear when installing Windows 7 or Windows 8 using Boot Camp Assistant if both an external optical drive and USB thumb drive are connected to the system. This update also ensures that the system will boot by default into OS X after installation of Windows 8.
You may want to check out more Mac applications, such as MacBook EFI Firmware Update, Mac mini EFI Firmware Update or iMac Graphics Firmware Update, which might be similar to iMac EFI Firmware Update.