On May 30, 2015 2:35 AM, "Adrian Sevcenco" <Adrian.Sevcenco@cern.ch> wrote:
>
> Hi! I know that there is another thread with similar subject but as i tried everything
> i will reiterate the problem with grub2-mkconfig not seeing the windows 8.1 even after
> adding custom entry.
> So, this are my information:
> [root@localhost grub.d]# parted -l
> Model: ATA Corsair Force 3 (scsi)
> Disk /dev/sda: 90.0GB
> Sector size (logical/physical): 512B/512B
> Partition Table: gpt
> Disk Flags: pmbr_boot
>
> Number  Start   End     Size    File system  Name                          Flags
>  8      1049kB  3146kB  2097kB                                             bios_grub
>  1      5243kB  420MB   415MB   ntfs         Basic data partition          hidden, diag
>  2      420MB   693MB   273MB   fat32        EFI system partition          boot, esp
>  3      693MB   945MB   252MB                Microsoft reserved partition  msftres
>  4      945MB   38.2GB  37.3GB  ntfs         Basic data partition          msftdata
>  5      38.2GB  61.3GB  23.1GB  ntfs         Basic data partition          msftdata
>  6      61.3GB  78.5GB  17.2GB  ext4
>  7      78.5GB  90.0GB  11.5GB  ext4
>
> [root@localhost grub.d]# mount | grep ^/dev/
> /dev/sda6 on / type ext4 (rw,relatime,seclabel,data=ordered)
> /dev/sda2 on /boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=ascii,shortname=winnt,errors=remount-ro)
> /dev/sda7 on /home type ext4 (rw,relatime,seclabel)
> /dev/sda4 on /mnt/WIN_C type fuseblk (rw,noatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096)
> /dev/sda5 on /mnt/WIN_D type fuseblk (rw,noatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096)
>
> [root@localhost grub.d]# cat 40_custom
> #!/bin/sh
> exec tail -n +3 $0
> # This file provides an easy way to add custom menu entries.  Simply type the
> # menu entries you want to add after this comment.  Be careful not to change
> # the 'exec tail' line above.
>
> menuentry 'Microsoft Windows 8.1' {
> set root='hd0,gpt4'
> chainloader /EFI/Microsoft/Boot/bootmgfw.efi
> boot
> }
>
> i must say that with both gpt2 and gpt4 (esp partition and C:\ partition) does not work..
>
> [root@localhost grub.d]# ll /etc/grub*.cfg
> lrwxrwxrwx. 1 root root 29 May 30 10:07 /etc/grub2.cfg -> /boot/efi/EFI/fedora/grub.cfg
> lrwxrwxrwx. 1 root root 29 May 30 10:04 /etc/grub2-efi.cfg -> /boot/efi/EFI/fedora/grub.cfg
>
> So, what i am missing? and why? (wasn't fedora tested for efi dual boot situations? i would think
> that is preaty obvious that a HUGE percentage of usage will be on modern efi/gpt windows 8.1 laptops
> and desktops)
>
> Did anyone have a working dual boot EFI installation of Windows 8.1 + fedora 22?
>
> Thank you!
> Adrian
>

A bios_grub partition suggests you do not have a UEFI installation of Fedora. Mixing UEFI and not-UEFI will not work well.  To confirm, can you share the output of `sudo efibootmgr` from your fedora installation?

--Pete