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

[Chris Murphy]

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




> (I don't know how can do it if there's no more bootloaders installed and MS's 
> is removed). It seems that GRUB doesn't intervene. I tried pressing n times 
> Esc and in another boot Shift, and don't happens anything.
> 
> When works correctly, appears manufacturer splash screen, GRUB, if you select 
> Ubuntu (black screen until loads) and Windows (manufacturer splash screen 
> loading Windows).

I think your legacy BIOS work around causes UEFI to make a different choice 
when its first used. Maybe it ignores bootx64.efi the first time. It's hard to 
say, there are many UEFI bugs.

> 
> I done workaround again to view GRUB. set command:
> 
> locale-dir=(hd0,gpt7)/boot/grub/locale
> prefix=(hd0,gpt7)/boot/grub/
> root=hd0,gpt7
> (this variable doesn't appears) saved_entry=
> secondary_locale_dir=

And partition 7 in the GPT is presumably the rootfs for Ubuntu?


Chris Murphy