Re: UEFI GRUB boot menu disappears after booting into Windows 8

[Andrey Borzenkov]

В Sun, 13 Jan 2013 16:45:15 -0700
Chris Murphy <address@hidden> пишет:

> 
> On Jan 13, 2013, at 4:38 PM, Joan Jerez <address@hidden> wrote:
> 
> > Hello again,
> > 
> >> GRUB appears, shows you what, before disappearing and booting Windows? Can 
> >> you interrupt this by pressing ESC or SHIFT (some versions apparently stop 
> >> on GRUB with shift, others esc).
> > Don't know what is happening but laptop boot directly to Windows (only 
> > appears manufacturer splash screen and then manufacturer splash screen 
> > loading Windows), bypassing GRUB,
> 
> This suggests to me that the /EFI/BOOT/bootx64efi is a Windows boot loader. 
> When that file is present, it is always used. 

No, it is not. It is default path that is used if EFI boot menu entry
does not include file and points only to device. So if menu entry says
just HDD0 - it will load bootx64.efi, but if it menu entry says
HDD0\EFI\openSUSE\grub.efi - it will load exactly this path.

So it boils down to which EFI menu entry is the default one.

Do not take HDD0 literally here, it is just an example. Actual EFI disk
reference is a bit more complicated.

>                          I'm not certain if going into the firmware boot menu 
> this can be
overridden.
> 

All EFI implementations I have seen so far allow you to either select
specific menu entry or directly select file to load by browsing
filesystem. In the worst case, go into EFI shell and manually run
commands.