Changing Boot Partition from Terminal to EFI Windows

Discussion in 'Mac Pro' started by monkeybagel, Aug 19, 2016.

  1. monkeybagel macrumors 65816

    Joined:
    Jul 24, 2011
    Location:
    United States
    #1
    For those of us with the cheese grater Mac Pros and have Windows 8+ installed, how do you change the boot partition from either the GUI or Terminal to boot into Windows? I did know how using the Terminal and the 'bless' command, but can't recall what command I used. The Startup Disk in System Preferences does not recognize the volume as a bootable drive, nor does 'BootChamp'. I can hold Option and boot to the volume fine holding Option and selecting EFI Boot, or make it permanent by holding Control when selecting it, but would like to be able to make this change remotely if needed. The Boot Camp Control Panel applet in Windows successfully allows you to select Macintosh HD as the startup disk, but how to select Windows from OS X and reboot remotely has escaped me. There are many articles on the web on how to select a standard BIOS installation and hybrid-MBR of Windows from Terminal, but not an EFI installation. Anyone know how right off?

    Thanks!
     
  2. Kaspin, Aug 19, 2016
    Last edited: Aug 19, 2016

    Kaspin macrumors member

    Kaspin

    Joined:
    Jan 15, 2015
    #2
    either of these should work:

    Code:
    sudo systemsetup -setstartupdisk "/Volumes/Name of Disk"
    
    or

    Code:
    sudo bless -mount "/Volumes/Name of Disk" -setBoot
    
    on my MBP the EFI install is listed as /Volumes/BOOTCAMP/WINDOWS
    I haven't tested on my Mac Pro as my bootcamp there is a BIOS install
     
  3. monkeybagel thread starter macrumors 65816

    Joined:
    Jul 24, 2011
    Location:
    United States
    #3
    I will try that and report back. Did the 2012 MacBook Pro in your signature install native EFI for Windows? I have an Early 2013 MacBook Pro and AFAIK it will not. I haven't tried Windows 10 on it yet.
     
  4. monkeybagel thread starter macrumors 65816

    Joined:
    Jul 24, 2011
    Location:
    United States
    #4

    To follow up, the above commands did not work. The top one looks for a default OS X directory. I ended up using
    Code:
     diskutil mount /dev/disk4s2
    
    which is the EFI partition on the Windows SSD. The volume mounted as /Volumes/EFI.

    I then issued this command:
    Code:
    sudo bless --folder /Volumes/EFI/EFI/Boot --file /Volumes/EFI/EFI/Boot/bootx64.efi -setBoot
    
    This worked fine, but I did have to disable SIP before it would run successfully, as it writes a value to NVRAM that is apparently protected by SIP.
     
  5. Kaspin macrumors member

    Kaspin

    Joined:
    Jan 15, 2015
    #5
    I used a second ssd in place of the optical drive dedicated to windows and it was a native EFI install. I don't know how it works installing to a partitioned osx drive though.
     

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