Windows 8 Dual boot lost after Fedora upgrade

[Chris Murphy]

On Fri, Jul 3, 2015 at 2:19 PM, g <geleem at bellsouth.net> wrote:
>
>
> On 07/03/15 15:07, Chris Murphy wrote:
>> On Fri, Jul 3, 2015 at 12:42 PM, g <geleem at bellsouth.net> wrote:
>>> did you by chances in creating files and paths create a file with;
>>>
>>>    /EFI/Microsoft/Boot/bootmgfw.efi
>>>
>>> when it should have been;
>>>
>>>    /boot/etc/EFI/Microsoft/Boot/bootmgfw.efi
>>>
>>> thereby causing such an error?
>>
>> /boot/etc/EFI doesn't make any sense.
> .
>
> correct you are. my bad. :-(
>
> should have read;
>
>     /boot/efi/EFI/Microsoft/Boot/bootmgfw.efi

Got it. So the problem there though is /boot/efi/ is a mount point
that only exist once Linux has booted and everything is assembled.
>From the perspective of GRUB it does not exist yet. The location is
actually a specific drive + partition + path. The drive, partition,
and partition scheme is what makes the root to look for hd0,gpt2 in
GRUB speak, and the path is just /EFI/Microsoft/Boot.

But the grub.cfg has this wrong it either looks for hd0,msdos2 or
hd0,msdos4, but what ought to happen is fall back to looking for the
FAT volume fs UUID. But we don't know if that's correct either,
especially if the ESP was reformatted since the 40_custom entry was
created.

So that's why I'm suggestion just remove 40_custom, and let
grub2-mkconfig create the proper Windows menu entry from scratch. It
should find out all of these things and just work.



-- 
Chris Murphy