Incredibly weird windows BOOTMGR.efi filename in EFIbootmgr

Ask Fedora
1

Since installing fedora on my desktop in a partition of one of four disks GRUB only loads fedora, failing on windows and even being unable to boot linux after that error happens.
efibootmgr gives back a very weird looking filename for the windows boot file, will try to mkconfig and see if it fixes itself and ill try to change the filename to the expected one if that doesnt work, but it would still need to be investigated how this happens in the first place (is it even an issue or is it supposed to happen?)

↪ efibootmgr
BootCurrent: 0004
Timeout: 1 seconds
BootOrder: 0004,0000
Boot0000* Windows Boot Manager	HD(2,GPT,fa154a56-9c44-4095-8bc4-518e213d52af,0xfa000,0x32000)/\EFI\MICROSOFT\BOOT\BOOTMGFW.EFI57494e444f5753000100000088000000780000004200430044004f0042004a004500430054003d007b00390064006500610038003600320063002d0035006300640064002d0034006500370030002d0061006300630031002d006600330032006200330034003400640034003700390035007d0000006f000100000010000000040000007fff0400
Boot0004* Fedora	HD(3,GPT,426b6cef-5fdc-4e54-80e4-d926e71bca08,0x36ef0000,0x12c000)/\EFI\fedora\shimx64.efi
2

ok i seem to have gotten confused, the problem lies in GRUB cause i can still boot from my BIOS but this entry still seems different from other dual boot systems ive seen online, what should i be looking to edit/fix/do?

3

Apparently the main issue isnt that efi file entry which seems normal but grub-mkconfig that for some reason takes an 8 digit UUID for the windows partition resulting in a “no such device” error at boot

### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows Boot Manager (on /dev/sdb2)' --class windows --class os $menuentry_id_option 'osprober-efi-1C88-8132' {
        insmod part_gpt
        insmod fat
        set root='hd1,gpt2'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  1C88-8132
        else
          search --no-floppy --fs-uuid --set=root 1C88-8132
        fi
        chainloader /efi/Microsoft/Boot/bootmgfw.efi
}
4

Please provide the output of efibootmgr as well as lsblk -f

The efi partition seems to always use the 8 character UUID as you can see with the output of lsblk. It is fat formatted and must be able to be accessed by the bios and grub.

There is a very slight difference in the entry in mine as you can see. I suspect that may be because I have my bios set to boot uefi only and yours may be allowed to boot either uefi or csm.

### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows Boot Manager (on /dev/nvme0n1p1)' --class windows --class os $menuentry_id_option 'osprober-efi-42F8-BF3E' {
	insmod part_gpt
	insmod fat
	search --no-floppy --fs-uuid --set=root 42F8-BF3E
	chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}

How did you redo the grub config.?
The proper command is sudo grub2-mkconfig -o /boot/grub2/grub.cfg.
If you used a different command please let us know the exact command used.

5

The UUID you see in efibootmgr is the partition UUID which you can display using lsblk -f -o +PARTUUID. It seem that the OP has two ESP partitions, one for Windows and one for Linux. This can bee seen by the UUID being different. It is up to the UEFI implementation if that works or not, although it is not recommended, if not for other reasons, it gets more confusing.

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