Is it possible to use the Windows Boot Manager to chainload another Windows Boot Manager?
For example, (how) can I use a boot manager on
C:\bootmgr that reads
C:\boot\BCD to chainload another boot manager
D:\bootmgr that uses
These tools help you to edit and modify the bootloaders.
BOOTMGR will look for the hive
Your question is, however, very confusing. You state
But then say
In the example you give of what you're trying to achieve, aren't those two different BCD files on two different partitions?
So I'm not sure exactly what you're trying to do. If you're trying to make the legacy BOOTMGR load the same BCD database that the EFI BOOTMGR uses, yes, that would be possible. You'll need to modify the emulation bootrecord on your disk (the fake MBR that's used to stop machines that don't understand GPT from reinitializing disks and losing data) to indicate the presence of at least two partitions, being the ESP and the Windows partition, with the ESP marked as active.
That way, if a BIOS in legacy mode (or a BIOS that doesn't support UEFI) attempts to start your machine from a GPT disk with your modified emulation MBR, it'll see the ESP partition as a "regular" boot partition and load from it (via its bootsector, which you would need to make sure was correctly written with a tool like
To do that:
Get an image of the boot sector of
Hope that helped.
It worked on my Computer, hopefully at yours, too.
You want the first bootmgr to load a secondary bootmgr instead of loading one of the typical OS boot-loaders
"if it works" you should add the following entries to the first C:\boot\BCD
this should create the menu entry "Chainloaded Bootmgr"; when triggered it should load the second bootmgr from D: