Booting Windows 10 via EFI on a cMP

Discussion in 'Mac Pro' started by astonius86, May 2, 2017.

  1. astonius86 macrumors newbie

    Joined:
    Apr 25, 2017
    Location:
    Bentonville, AR
    #1
    Yesterday I installed Windows 10 on my 2010 Mac Pro. It was a bit of a pain getting around Boot Camp's limitations, but I finally got it working. Once I'm in Windows 10 everything seems to work perfectly, but I am having a couple of minor issues getting into Windows. I noticed when I use Startup Disk to select the Windows partition and reboot I get the "no boot device available" message, however when I hold down alt/option and boot the Mac I see the Windows partition as "EFI boot". Clicking this "EFI boot" partition starts Windows without a hitch, and running msinfo32 shows that Windows did in fact boot using UEFI. My assumption is that Startup Disk is attempting to boot using simulated BIOS instead of UEFI, and since my disk is running GPT with protective MBR instead of hybrid GPT/MBR it can't find the boot drive.

    Ultimately I have two questions:
    1. Can I force Startup Disk to use UEFI instead of simulated BIOS? I thought about mounting the EFI partition and playing around in there, but I figured I'd ask the community before getting too in the weeds there.
    2. Can I change the "EFI boot" partition name in the boot menu to something more appropriate (such as "Windows")? I already changed it with gdisk in macOS/Windows, but the boot menu is looking at some other identifier.
     
  2. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #2
    1. I could never figure out a way to do that. You can install Boot Champ, which will see the EFI boot properly, but it is deprecated software and you will have to disable SIP.

    2. I don't think so, but consider installing rEFInd. It is VASTLY better than holding down ALT, plus completely configurable. It is also much, much faster. rEFInd intimidated me at first, so I avoided it for months--after installing it I regretted that I hadn't done so on day 1. It's that good.

    rEFInd also has some great themes if you don't want to customize it yourself. Some examples:

    upload_2017-5-2_12-26-13.png
     
  3. astonius86 thread starter macrumors newbie

    Joined:
    Apr 25, 2017
    Location:
    Bentonville, AR
    #3
    Thanks for the rEFInd recommendation. That first theme screenshot looks great! I'll give it a shot this evening.
     
  4. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #4
    Just a word of warning, for that particular theme you'd want to wait to theme it until after you are done configuring everything else.

    rEFInd by default will find and display everything that it thinks is bootable. So you'll see every bootable OS X partition, Windows EFI, Windows BIOS (not bootable), OS X recovery partitions, Windows recovery partitions, etc. You can filter out the ones you don't want, by name, in the config file.

    That particular theme doesn't show the names of the partitions, so you wouldn't know which ones to hide or not--that's why I say apply the theme after configuration.
     
  5. superparati macrumors member

    superparati

    Joined:
    Apr 11, 2016
    Location:
    London
    #5
    Hi astonius86,

    I had the same reflection few months earlier and I ended up by using a command line to switch from OS X to Windows.

    When I did my research it seems that the path of the startup disk bootcamps is the problem.

    The following command line shows me two boot disks:
    • sudo systemsetup -liststartupdisks
    1. /System/Library/CoreServices (macOS)
    2. /Volume/BOOTCAMP/WINDOWS (Windows)

    The boot volume "/Volume/BOOTCAMP/WINDOWS" is not the right one.
    I try this command line:
    • sudo bless -mount /Volumes/BOOTCAMP -setBoot
    • sudo reboot
    And my MacPro reboot properly under Windows 10.
     
  6. astonius86 thread starter macrumors newbie

    Joined:
    Apr 25, 2017
    Location:
    Bentonville, AR
    #6
    This worked beautifully. If only we could figure out how to make that a permanent change.
     
  7. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #7
    Instead of using Bless, would this be permanent? (From the systemsetup MAN pages):

    -setstartupdisk path
    Sets current startup disk to the indicated path. Valid arguments can be listed using "-liststartupdisks"
     
  8. monkeybagel macrumors 65816

    Joined:
    Jul 24, 2011
    Location:
    United States
    #8

    Old post, but I created a bash script to run in Terminal to request my machine to restart in Windows remotely when ssh'ing into it. Also, don't forget, that when holding down the Option key on startup, you can select EFI Boot, and hold down Ctrl and you will see the "Up Arrow" change to a circular arrow, which means that it is going to set that as the Startup Disk moving forward until you manually change it (using Startup Disk in Boot Camp's tray icon, or holding option and booting into OS X one time and changing it in System Preferences/Startup Disk, or using the same method described above (hold Option during startup, select OS X, and hold Ctrl and press Enter).
     

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