Opencore - Booting into Windows resets default boot option

[ainsleyclark]

Hi there,

As the title suggests, when I boot into BOOTCAMP - Windows from Opencore, it boots absolutely fine, I then restart and and it boots into Windows instead of using macOS.
I have set the default boot option by using Control & Enter at the boot picker. Setting a default startup disk doesn't seem to work, I select macOS, restart and it boots into Windows.
Is Windows resetting NVRAM?

Interestingly when I boot into Windows from Opencore it adds itself into the top boot priority even though I have everything else disabled apart from macOS.

Any help would be appriciated.

Many thanks.

 

[eridian1]

Hello,

I have exactly the same issue. Win10 appears to be changing the BIOS Boot Priority list every time it is started...

Have you found a solution in the meantime?

Best regards,

Eridian

 

[ainsleyclark]

Hi, I needed up creating a script in Windows to run when the computer is loaded to push the Windows boot manager priority to the bottom.
if youwould like I can share it.

 

[eridian1]

Thanks, I found a solution in the meantime: In MacOS I used the StartupDisk Utility to designate my OpenCore/Catalina drive as startup disk, and from that moment on, OpenCore boot menu comes up by default during every boot. I then boot Windows 10 from the OC
selection menu, and even after a Win10 session, the OpenCore drive remains the startup default.

I found this solution in a ****** thread, it was explained there that the MacOS StartupDisk Utility saves your preferred startup drive in an NVRAM setting.

One thing that was different from your setup is that I'm not using BootCamp.

Best Regards,

Eridian

 

[ainsleyclark]

Hi.

That’s good that you got that sorted. I selected startup disk quite a few times from macOS but every time I would boot into windows it hijacked the boot priority and put itself right at the top.
I’m not using boot camp though. Just plain windows 10 on a sata hdd.

If anyone can shed some light on why windows does this annoying thing it would be most useful.

All the best.

 

[ainsleyclark]

@eridian1

what does it say from the opencore picker?As in what’s it name for Windows?

 

[eridian1]

OpenCore Picker in my case looks like this, I have Win10 on M.2 and Catalina on a SATA SSD:

1. Windows
2. SATA_Catalina
3. Recovery 10.15.4 (dmg)
4. OpenShell.efi
5. Erase NVRAM

I never did anything in terms of picker configuration, I also wondered how OC retrieved the names. In case of 2. itis clearly the name of the partition, but in case of 1. I thought as well but it is not so straightforward: I had partitioned the M.2 in diskutility with 500GB ExFAT as a shared data partition and I left 500GB for Windows to take, so diskutility labeled that one "Untitled". Right now it looks like the Volume Name string is empty, maybe OC is "second guessing" from partition type name string?

diskutil info disk0s2
Device Identifier: disk0s2
Device Node: /dev/disk0s2
Whole: No
Part of Whole: disk0

Volume Name:
Mounted: Yes
Mount Point: /Volumes/Untitled

Partition Type: Microsoft Basic Data
File System Personality: NTFS
Type (Bundle): ntfs
Name (User Visible): Windows NT File System (NTFS)

Before I used StartupDisk, I saw exactly the same behaviour as you described: I would enter BIOS config and specify that the SATA containing Catalina should have highest boot priority, in 2nd place I put Windows M.2 and 3rd place I disabled. Then, after booting Win10 and entering again in BIOS I would find Windows M.2 drive in 1st and 2nd place and the Catalina SATA in 3rd.

Have you tested as per OC Vanilla guide that your NVRAM is actually working?

Emulated NVRAM · GitBook

dortania.github.io

Best of luck,

Eridian

 

[konjow]

Can someone tell me how to make OSX boot automatically when Windows disk is above in OC Picker.?
Sometimes I cant even have a picking screen and goes straigt to that ****!

 

[Edhawk]

Do you have the macOS Disk on SATA0 or SATA1 port?

If you set the macOS Disk to SATA0 and Windows to SATA1, SATA2 or SATA3 etc. what difference does it make to the Picker list and default boot option?

System Preferences > Startup Disk should work with OpenCore. It does with my system where I have Catalina, Big Sur and Windows 10 on separate drives, with Catalina set as the default boot option.

Only time it changes from Catalina to Big Sur is when I run an update on Big Sur.