R Pruitt - 2016-04-07

No question here, just information.

Situation: computer with 2 GPT bootable disks. Disk1 has a Windows Boot Manager(WBM) in the canonical location: \EFI\Microsoft\Boot\bootmgfw.efi. Disk0 has rEFInd at \EFI\Microsoft\Boot\bootmgfw.efi and a Windows Boot Manager at \EFI\Microsoft\bootmgfw.efi and a BCD store with the path for {bootmgr} as \EFI\Microsoft\bootmgfw.efi and the partition pointing at Disk0. American Megatrends BIOS.

If you boot Disk0: \EFI\Microsoft\bootmgfw.efi from rEFInd, the following happens:

-the BCD store on Disk0 becomes the system store: https://technet.microsoft.com/en-us/library/dn336950.aspx making it easy to edit the BCD file anyway :)
-booting happens from Disk1: \EFI\Microsoft\Boot\bootmgfw.efi.
-the path and disk of the {bootmgr} in the BCD store on Disk0 are adjusted to point at Disk1: \EFI\Microsoft\Boot\bootmgfw.efi.
-not sure about this one, but I think it just booted the default OS without going into WBM

The Microsoft Windows Boot Manager doesn't behave in the way it was asked to, but is that surprising?

If the WBM on Disk0 is at \EFI\Microsoft\Boot\bootmgfw.efi and the BCD store entry for {bootmgr} points to Disk0:\EFI\Microsoft\Boot\bootmgfw.efi everything works as expected(i.e. booting entirely from Disk0). So if you want to be able to boot from only Disk0, you need to have the Windows Boot Manager at \EFI\Microsoft\Boot\bootmgfw.efi.

All of this is presumably BIOS dependent.

If you want to install rEFInd, you need another way besides putting it at the default WBM location. My BIOS will only boot WBM from the factory installed disk, but on the added disk it will also boot EFI/BOOT/bootx64.efi. So rEFInd can be copied there, the booting entry is UEFI OS (<- you're not going to change this name without the EFI shell) on my system.

Alternatively, you need to follow http://www.rodsbooks.com/refind/installing.html#efishell
noting that the map command is useful for step 2. map -b in the UEFI shell is like map | more. See more https://wiki.archlinux.org/index.php/Unified_Extensible_Firmware_Interface#Important_UEFI_Shell_Commands