Boot priority and firmware password

Due to the fact that I usually use linux on usb, when i bought a MBP, I set the usb to the primary boot device by entering the start up manager and clicking it while pressing the control key. Even when I detached my usb drive, I was able to boot in to OS X. However, due to the nature of my work, I set a firmware password on my mac. After this, I was unable to boot into OS X unless I manually enter the start up manager and select the disk. Therefore, I was just wondering if I can set a list of bootable devices which will not be affected by the firmware password for the machine to refer to while booting up. Some PCs provide this feature but I am not sure if mac does. Furthermore, I wonder if the bless command can provide such an option. My usb is mbr so start up disk will not work. This will make my work easier and more efficient, any help will be appreciated.

MacBook Pro with Retina display, OS X El Capitan (10.11.1)

Posted on Nov 18, 2015 5:21 PM

18 replies

Loner T

Level 9

59,536 points

Nov 19, 2015 5:46 PM in response to Infinite Niubility

What is the size of the EFI file?

Nov 19, 2015 5:51 PM in response to Loner T

there are many files, from 7 kb to 17 kb, does this have anything to do with the renaming?

Loner T

Level 9

59,536 points

Nov 19, 2015 6:31 PM in response to Infinite Niubility

Unless the renaming changes how the boot loader searches for these files, it should be blessing a folder and look for a default boot.efi file.

For example on my Mac (and this is standard across all Intel Macs)

file /System/Library/CoreServices/boot.efi

/System/Library/CoreServices/boot.efi: PE32+ executable (EFI application) 32-bit

From the man page for bless

--filefile Set this file to be the Mac OS X/Darwin blessed boot file, containing a booter

for EFI-based systems. If this option is not provided, a default boot file is

used based on the blessed directory.

--bootefi [file] Create a boot.efi file in the Mac OS X/Darwin system folder using file as a

source. If file is not provided, a default is used (see FILES), using a path

relative to the mountpoint you are blessing. This attempts to ensure that a

boot.efi is used that is compatible with the OS on the target volume. If --file

is also provided, the new file will be created at that path instead.

What do you get if you run

files EFI

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Boot priority and firmware password