updated 07:20 pm EST, Wed January 25, 2012
Enables Lion Recovery from an internet connection
Apple this afternoon issued three EFI updates for mid-2010 era MacBooks, MacBook Pros and Mac minis, the sole purpose of which was to enable Lion Recovery from an internet connection. The change allows users who have lost the ability to boot from their hard drive or installed a blank new hard drive and don't have a physical backup to restore Lion by re-downloading it from the Mac App Store.
EFI firmware updates require that the computer be powered by external power at all times during the procedure. The machine will restart with a gray screen and a status bar to indicate progress, and must not be powered down or disrupted during this period, which may take several minutes.
For the MacBook, the mid-2010 model was the last one produced, and appeared in May of that year. It is distinguished from the similar-looking late 2009 model by having an identifier of MacBook7,1, a 2.4GHz Core2Duo processor and an Nvidia GeForce 320M video chipset with 256MB of shared memory. The download file is 3.1MB in size, version 2.1, and the boot ROM or SMC version once completed should be MB71.0039.B0E. The updates for all three machines requires that they be running Mac OS X 10.7.2 already.
The MacBook Pro version (number v2.5) is only for the 13-inch version of the mid-2010 models, the last model to feature an Intel Core2Duo chip. The identifier is MacBookPro7,1 and it featured an Nvideo GeForce 320M only for a video chipset (the larger 15- and 17-inch models had the 320M as well as an additional discrete card for gaming). The EFI update is 3.1MB in size and will end up with a Boot ROM or SMC version of MB71.0039.B0.
The Mac mini mid-2010 EFI version is numbered 1.5 and is the only one of the three to address an additional issue beyond enabling Lion Recovery. It also fixes a problem where the setting of the unit to automatically restart after a power failure isn't retained. The mid-2010 model is the previous-generation model and the last one to feature the Intel Core2Duo chip. Its identifier is Macmini4,1 and is distinguished from the current model by the chip and the presence of a built-in optical drive.
The file size of the EFI update is 3MB and the Boot ROM or SMC version information when complete will be MM41.0042.B03.