Then, 3 times power off automatically in a short period, end up with a normal OS X startup. It got a flashing LED light indicating the firmware was about to be updated. sudo bless -mount / -firmware /MBP91_00D7_B00.scap -verbose -recovery Thus, I've no idea why High Sierra installer failed to update the EFI firmware at the very first time.Īccording to the chapter 2.0 How Does a Mac Update Its EFI Firmware & How Do You Find Your EFI Version of The Apple of Your EFI, with the following command bless, the file MBP91_00D3_B0C_LOCKED.scap extracted from mac2015002efiupdate.dmg, which downloaded from, and the file MBP91_00D7_B00.scap extracted from Install macOS High Sierra.app, it executed successfully. usr/libexec/efiupdater finished with status: 0 Writing firmware update installed cookie (/Volumes/MacSSD/macOS Install Data/.FirmwareUpdateInstalled) Volumes/bless.YdD7/EFI/APPLE/FIRMWARE/MBP91_00D7_B00.scap created successfully If look into previous log of EFI updating, it seems they are quite normal.

Operation: Verify firmware failed, Failure Reason: Error Domain= Code=512 Key info in ia.log is as following.Ĭlearing automation and attempting to rebless.įailed to get disk for UUID specified for rebless.

Here comes the detail.Īttempt 1 - update it by updating macOS from 10.12.6 to 10.13.2įailed with error message 'An error occurred while verifying firmware'. In short, the firmware cannot be updated either by upgrading macOS to High Sierra or by bless manually.

Macbook pro efi firmware