Dual Windows EFI boot files

[miharbi91]

In case of a two versions of windows installed, bootmgfw.efi, the efi bootloader of windows, will load a menu to choose from. does anyone know who it works or what are the files loaded for each OS, so i can add them manually to clover?
dunno if this is the correct place to ask, but worth the shot.

PS : windows version are 8.1 and 10, technical preview.

 

[T1hom7as]

In case of a two versions of windows installed, bootmgfw.efi, the efi bootloader of windows, will load a menu to choose from. does anyone know who it works or what are the files loaded for each OS, so i can add them manually to clover?
dunno if this is the correct place to ask, but worth the shot.

PS : windows version are 8.1 and 10, technical preview.

Depends how you boot OS X.
But you could do this for the file names:
- bootmgfw.efi = Windows 8.1
- bootmgfw-orig = Windows 10.

Then Clover should notice the two OS's.

EDIT: You will need the two different bootmgfw.efi files from Win10 and 8.1.

 

[RehabMan]

In case of a two versions of windows installed, bootmgfw.efi, the efi bootloader of windows, will load a menu to choose from. does anyone know who it works or what are the files loaded for each OS, so i can add them manually to clover?
dunno if this is the correct place to ask, but worth the shot.

PS : windows version are 8.1 and 10, technical preview.

In order to boot directly into two separate Windows versions....

- create two separate (small) FAT32 partitions, these will serve as "fake" EFI partitions, one for each Windows install.
- copy the contents of the EFI/Microsoft folder from the main EFI partition to each
- cleanup the BCD on each of these partitions using BCEDIT so it contains data for only the version of Windows that it corresponds to
- create custom entries (in Clover config.plist) for each
- remove the original EFI/Microsoft directory from the main EFI partition

 

[RehabMan]

Depends how you boot OS X.
But you could do this for the file names:
- bootmgfw.efi = Windows 8.1
- bootmgfw-orig = Windows 10.

Then Clover should notice the two OS's.

EDIT: You will need the two different bootmgfw.efi files from Win10 and 8.1.

It won't work. You need to completely separate the Windows bootloader configuration (BCD).

 

[miharbi91]

I wanted to avoid additional System partitions, so here is what i tried :

I added custom entries to clover, setting the Volume to the correct partition, and the path to "Path: \Windows\system32\winload.efi" (this is the bootloader path read by easybcd). I also added the NTFS.efi file system driver so clover can read the file out of an NTFS partition. No luck here.

Later, i tried Setting the default partition in the windows bootloader to windows 10 (with a timeout of 3 seconds, via msconfig), and then copied the EFI/Microsoft to the actual system partition where windows 10 is (copied with linux because BCD was locked in windows), and then restored back the time out to 30 seconds, just to test, later i added an entry to point on the bootloder on the windows 10 partition.
That didn't work either, because the windows bootloader settings are overridden on the EFI partition, so that was also useless.

Conclusion, windows has the worst, inflexible bootloader.

I have a feeling that even with additional EFI partitions, windows bootloader will still save its settings on the first one (after all, accodring to wikpedia windows recommends that it uses the first partition as the EFI one, so no wonder it would scan partitions until it finds the first one and dump all of its **** there).

Nonetheless, adding other "fake" FAT32 EFI patitions might work, and my try maybe didn't work because it's not on a FAT partition, as required by the UEFI specification. i didn't try this yet, i'll leave that for some other time.

Anyway, this is here, in case anyone else is doing this too, would save him some time.

 

[RehabMan]

...
Conclusion, windows has the worst, inflexible bootloader.

Go back and read my suggestion.

I have a feeling that even with additional EFI partitions, windows bootloader will still save its settings on the first one (after all, accodring to wikpedia windows recommends that it uses the first partition as the EFI one, so no wonder it would scan partitions until it finds the first one and dump all of its **** there).

It will work if you do what I suggest.

Nonetheless, adding other "fake" FAT32 EFI patitions might work, and my try maybe didn't work because it's not on a FAT partition, as required by the UEFI specification. i didn't try this yet, i'll leave that for some other time.

FAT32 will work.