I am tasked with upgrading a number of machines to Windows 11. However, some accounting software refuses to work on Windows 11. This is why I need to offer a Windows 10 installation as well. When doing remote administration, I can wake up the system and it will perform a PXE boot (giving me the option to boot into any system remotely). I can chainload bootmgfw.efi which will then continue into one of the Windows installations. It would be very helpful if I had control over which Windows installation is being booted. This article gives a nice overview of the Windows boot procedure in UEFI (via this question).
When examining the efivars, I noticed that bootmgr seems to accept a parameter named BCDOBJECT. It looks like one can specifiy the UUID of the BCD entry bootmgr is to boot.
This mechanism apparently is used to start Windows Recovery. However, I found no clear source of documentation regarding this feature, not even in this detailed post. Is there any option to tell bootmgfw.efi which BCDOBJECT to use via UEFI?
Related questions on askubuntu: https://askubuntu.com/questions/1192128/booting-multiple-copies-of-windows-via-grub and https://askubuntu.com/questions/1328223/getting-rid-of-the-windows-boot-manager-when-dual-booting/1328229
A similar question: Make Linux GRUB run directly multiple Windows systems
