Apple releases MacBook EFI Firmware Update 1.1

Apple today released MacBook EFI Firmware Update 1.1 which improves the performance and reliability of Intel Core 2 Duo processors and fixes issues with Boot Camp for MacBook computers.

System Requirements:
• Mac OS X 10.4.10 or later
• MacBook (Late 2006)
• MacBook (Mid 2007)

After the firmware is successfully applied to your computer, your BootROM Version will be: MB21.00A5.B07

You can confirm the version of the BootROM installed on your computer using System Profiler.

To complete the firmware update process, please follow the instructions in the updater application (/Applications/Utilities/MacBook EFI Firmware The updater will launch automatically when the Installer closes.

MacBook EFI Firmware Update 1.1 is available via Software Update and also as a standalone installer.

More info and download link (1.7MB) here.

[Thanks to MacDailyNews Reader “GmanMac” for the heads up.]


  1. I just installed, but I didn’t have a smooth experience. It kept asking me about “where is system event?”which I don’t understand. I thought I almost failed the installation, but the system profiler indicates the correct version. So maybe it is.

  2. When updates like this are issued I wish we new more information on them.
    Eg what is performance and reliability of Intel Core 2 Duo processors?
    Can we know exactly what was the issues are?
    I know most people don’t care and all they want is there comp to work, but what about the folks that are interested in the inner workings.

  3. Hanna, I had the same problem several months ago. I don’t remember the specific update, but I do remember thinking how “un-Maclike” that was for a Mac installer. It seemed so PC-ish. I couldn’t locate a “system event” file anywhere, but the installation seemed to work anyway.

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