Windows 11 and OpenBSD 7.2 dual boot on GPT EFI based system.

globetrotterdk · 12-08-2022, 01:11 PM

After having tried getting a dual boot system working with Fedora 37 and OpenBSD, I decided to try the recommended dual boot scenario in the OpenBSD FAQ on a computer, namely Windows (11) and OpenBSD.Interestingly, I haven't been unable to find any advise regarding the creation of the partition for OpenBSD. What kind of partition should be used? I ask this because my past experience tells me that it seems to be quite important, as I used a NTFS partition in the following manner:

Code:

$ sudo gdisk /dev/nvme0n1
: t
: 6
: A600
: w

This worked perfectly when Installing OpenBSD 7.2, but proved to be an issue when dealing with Grub 2, as it complained every time an update was run, of a "nested file system". Will this be the case with Windows Boot Configuration Data? How do I avoid this issue?

colorpurple21859 · 12-09-2022, 11:04 AM

Maybe this will help: http://www.h-i-r.net/2021/03/multi-b...10-on.html?m=1

globetrotterdk · 12-09-2022, 04:05 PM

Quote:

Originally Posted by colorpurple21859

Maybe this will help: http://www.h-i-r.net/2021/03/multi-b...10-on.html?m=1

It looks like using a FAT32 partition is suggested. I also completed the process satisfactorily and have the bootx64_openbsd.efi on my Win 11 system(Downloads folder). I installed the free version of EasyBCD, but am not sure how to get the file into the efi partition created by Windows. I also have setup a 500 MB FAT32 efi partition for booting that Windows apparently rejected at install that could possibly be used...

My problems at this point are that neither your link nor the OpenBSD FAQ provides information about where the bootx64_openbsd.efi should reside or how to get it to the proper location. Likewise, I am unsure how to point EasyBCD to the new location for a second entry. In the documentation, there is only talk of booting FreeBSD, so I am thinking that perhaps the OpenBSD FAQ is wildly out of date. The alternative, using rEFInd, is something that I had minimal experience with, years ago...

colorpurple21859 · 12-09-2022, 07:12 PM

Quote:

but am not sure how to get the file into the efi partition created by Windows.

open cmd with administrative privileges, diskpart to assign a letter to the efi partition

Code:

diskpart
list disk
sel disk !
list vol
sel vol ? 
assign letter P: 
exit
P:
cd EFI
mkdir openbsd
copy K:\bootx64_openbsd.efi P:\EFI\openusb\

( ! will be number of windows disk)
(? will be number of efi partition)
(use different letter if P is already in use)
(K will be volume of usb)

globetrotterdk · 12-10-2022, 02:09 AM

Quote:

Originally Posted by colorpurple21859

open cmd with administrative privileges, diskpart to assign a letter to the efi partition

Code:

diskpart
list disk
sel disk !
list vol
sel vol ? 
assign letter P: 
exit
P:
cd EFI
mkdir openbsd
copy K:\bootx64_openbsd.efi P:\EFI\openusb\

( ! will be number of windows disk)
(? will be number of efi partition)
(use different letter if P is already in use)
(K will be volume of usb)

Thanks for that. Your instructions appear to have worked perfectly.

I am relying on the OpenBSD FAQ instructions as the EasyBCD is still a bit of a mystery to me. The first two commands have completed successfully:

Code:

C:\Windows\System32>bcdedit /create /d "OpenBSD" /application bootsector
The entry {66a7496b-7863-11ed-a2b3-28cdc4d81cda} was successfully created.

C:\Windows\System32>bcdedit /set {66a7496b-7863-11ed-a2b3-28cdc4d81cda} device boot
The operation completed successfully.

Unfortunately, it is here that things start going south. This is what I believe the command should look like, however I am pretty sure that the suggested path in the FAQ is incorrect for EFI:

Code:

bcdedit /set {66a7496b-7863-11ed-a2b3-28cdc4d81cda} path \EFI\openbsd\bootx64_openbsd.efi

Then would follow (?):

Code:

bcdedit /set {66a7496b-7863-11ed-a2b3-28cdc4d81cda} device partition=d:

bcdedit /displayorder {66a7496b-7863-11ed-a2b3-28cdc4d81cda} /addlast

globetrotterdk · 12-10-2022, 09:05 AM

I tried the commands as I posted them. Everything was successful, but doesn't work, although I get the boot menu https://i.imgur.com/daNYwQu.jpg, I also get an error messagehttps://i.imgur.com/KtTDgos.jpg. Here is where EasyBCD is useful. EasyBCD makes it possible to easily edit the BCD entries. So I tried editing the OpenBSD entry to Drive: C:\, as it appears that the drive should relate to where the boot loader resides and not the target https://i.imgur.com/qFq1vAr.png. Unfortunately, that didn't work either. So while I am able to boot into Windows 11, OpenBSD appears to be a bridge too far...

globetrotterdk · 12-11-2022, 04:23 AM

OK, well that wasn't going anywhere. I used EasyUEFI to delete the EFI\openbsd directory and used EasyBCD to delete the menu entry "OpenBSD". I visually confirmed this by running bcedit in an admistrator console. Windows 11 boots fine, however I get an irritating prompt from the Windows Boot Manager to choose an operating system, despite there only being one OS - Windows 11, which is what I want to use...

EDIT

The only solution that I found was to use EasyBCD, choose the menu entry and set to "skip the boot menu".

colorpurple21859 · 12-11-2022, 07:02 AM

Deleting the bsd entry with easybcd would have been sufficient enough to remove the extra windows menu entry. If you have the option in the firmware/bios boot menu to boot from a file may allowed booting openbsd bootx64_openbsd.efi file if you didn’t delete the openbsd directory on the efi partition.