[TIP] How to manually add grub entry for Windows 8 EFI

[Spadge]

Edit /etc/grub.d/40_custom with something like

menuentry "Windows 8" {
    set root='(hd1,gpt2)'
    chainloader /EFI/microsoft/BOOT/bootmgfw.efi
}

Where hd1 is your Windows 8 disk and gpt2 is the partition the EFI stuff is in on that disk.

Run update-grub and reboot.

[Teunis]

gtp2, who would have guessed that one...
I hope my present laptop lives till this (U)EFI stuff gets fully documented!
Thanks

[Guest]

Hello and thank you for the tip. I'm having troubles to make it work properly.

My grub . cfg file has automatically generated entries that uses hd0, so I guess that is the hard drive I should point to (I only have one hard drive after all).
The prefix that it uses for the partitions is "gpt", so if my EFI partition is sda2 I guess I should point to the partition "gpt2".

I have made several trials using variations of those, if I point to hd1 instead of hd0 it tells me:

error: hd1 cannot get C / H / S values.

If I point to hd0 and gpt2 I get something different. I get:

error: invalid signature.