Can't use bless/mount EFI partition/use BootChamp

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Level 1

14 points

Can't use bless/mount EFI partition/use BootChamp

After the new macOS 10.13.6 update, my ability to use BootChamp to quickly switch to Windows 10 from macOS via one-time next only boot is gone. After further investigation, I also found I was unable to mount the EFI partition via "diskutil mount disk0s1". I need the ability to use BootChamp back.

What I've already tried:

- Resetting PRAM and NVRAM via command+option+p+r after boot chime

- Resetting SMC via shut down, and then holding control+option+shift+power button for 10 seconds, and then booting up

- Disabling system integrity protection via recovery mode terminal after resetting SMC/NVRAM (SIP was also off before resetting those 2)

- Running

the command "

sudo /usr/sbin/bless --mount /Volumes/BOOTCAMP/ --setBoot --nextonly --verbose" as a suggestion from this link: https://github.com/kainjow/BootChamp/issues/8.The output from terminal I get is this: https://ghostbin.com/paste/67hrc

- Running "/sbin/fsck -fy" from single-user mode

I have not tried First Aid in disk utility or re-installing the BootChamp app yet.

Running "mkdir /Volumes/efi" and then "sudo mount -t msdos /dev/disk0s1 /Volumes/efi" both as root now allows me to mount the EFI partition normally via "diskutil mount disk0s1", but does not fix BootChamp.

FYI holding option at boot does allow me to go to windows. Here is my output for "diskutil list": https://ghostbin.com/paste/amf9z

I am using a 13" 2015 MacBook Pro with Retina display on macOS High Sierra 10.13.6

MacBook Pro with Retina display, macOS High Sierra (10.13.6), Early 2015 model

Posted on Jul 20, 2018 2:45 PM

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Answer 1

Capt Inc Author

Level 1

14 points

Jul 21, 2018 7:44 PM in response to woodmeister50

All the program does is run a built-in system command...anyways I fixed all of my 5 problems caused by the new update by downgrading the OS. 0 problems now

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Answer 2

VikingOSX

Level 10

124,838 points

Jul 20, 2018 3:26 PM in response to Capt Inc

When you run Terminal commands from four years ago that were intended for that older Boot Camp and Windows version, you may have damaged your current Boot Camp partition.

You should not access your EFI partition.

Remove the current Boot Camp partition with Boot Camp itself, create a new Boot Camp partition, install Windows 10/updates, and Apple's Boot Camp Support files for Windows 10.

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Answer 3

Jul 21, 2018 12:03 PM in response to Capt Inc

FWIW, anytime a 3rd party app attempts to accomplish its function

by bypassing/working around the designed operation of any operating

system, it will be subject to breakage with any system updates. This

is something that is all to common in the Windows world and becoming

more common in the macOS world.

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Answer 4

Capt Inc Author

Level 1

14 points

Jul 20, 2018 4:13 PM in response to VikingOSX

The macOS update is what broke it, not running terminal commands. Removing and reinstalling is not exactly practical for me. Need another suggestion, thanks.

Edit: I noticed that I could not access the EFI partition after I noticed BootChamp was broken. I may be wrong, but BootChamp may need to access the EFI partition to do its function

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Answer 5

Capt Inc Author

Level 1

14 points

Jul 20, 2018 6:47 PM in response to etresoft

Holding option at boot is not always possible for me. Additionally, BootChamp was working just fine before the 10.13.6 update, zero problems whatsoever. What changed in 10.13.6 that broke BootChamp? (or specifically, what broke the bless command?)

Edit: also the only reason why BootChamp can't work on El Capitan by default is because thats when SIP was added. If SIP is disabled, BootChamp works just fine on newer macOS versions

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Answer 6

etresoft

Level 9

57,584 points

Jul 20, 2018 8:32 PM in response to Capt Inc

Capt Inc wrote:

what broke the bless command?

I used to have a similar script to quickly boot between different macOS versions. Everything I was doing was by-the-book and using Apple tools, including the "bless" command. I had to stop using it because it would mysteriously corrupt the spotlight archive each time. That was a real hassle back when I had a mechanical hard drive. This was years ago.

Edit: also the only reason why BootChamp can't work on El Capitan by default is because thats when SIP was added. If SIP is disabled, BootChamp works just fine on newer macOS versions

Apparently not.

Apple doesn't allow third party developers to have this kind of low-level access to their operating system. It is common for anyone attempting such access to encounter problems after updates. I'm sorry, but there is nothing you can do about this.

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Answer 7

VikingOSX

Level 10

124,838 points

Jul 20, 2018 6:09 PM in response to Capt Inc

Eyestrain. I overlooked that you were referring to a third-party product named BootChamp. Apologies, but what etresoft has said.

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Answer 8

Capt Inc Author

Level 1

14 points

Jul 20, 2018 6:44 PM in response to VikingOSX

Any explanation as to what in this new macOS update broke BootChamp? Because it was working just fine before installing the update.

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Answer 9

Capt Inc Author

Level 1

14 points

Jul 21, 2018 11:18 AM in response to etresoft

Anyway to downgrade back to macOS 10.13.5? Or at least get the bless command working so I can tell my system to do a one-time alternate boot from the command line?

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Answer 10

etresoft

Level 9

57,584 points

Jul 20, 2018 5:28 PM in response to Capt Inc

Capt Inc wrote:

FYI holding option at boot does allow me to go to windows.

Good. Then do that.

I need the ability to use BootChamp back....I am using a 13" 2015 MacBook Pro with Retina display on macOS High Sierra 10.13.6

Not good. Don't do that.

I'll quote the BootChamp Github site: (emphasis from BootChamp)

BootChamp is not compatible with El Capitan and has been discontinued.

If you follow that link, it takes you to:

http://kainjow.tumblr.com/post/128933657269/bootchamp-and-el-capitan

which describes your problem exactly. If the developer of BootChamp can't make it work, you won't be able to either, nor will we.

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Can't use bless/mount EFI partition/use BootChamp

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