EFI: how to dual boot without esc, F9 ?

[Chris Murphy]

On Jul 14, 2014, at 9:31 PM, sean darcy <seandarcy2 at gmail.com> wrote:

> On 07/14/2014 01:55 PM, Chris Murphy wrote:
>> 
>> On Jul 14, 2014, at 7:45 AM, sean darcy <seandarcy2 at gmail.com> wrote:
>> 
>>> New HP laptop, W 8.1, EFI boot. I've installed F20. The laptop boots to Windows. If I hit ESC and f9, I get:
>>> 
>>> - OS Boot Manager
>>> - Fedora 20 [HDD SERIAL NUMBER]
>>> - Boot from EFI file
>>> 
>>> When I choose Fedora, I get the grub2 manager, which includes a choice for windows.
>> 
>>> F10 in the gives me boot options, but only for devices.
>>> 
>>> How can I get the laptop to boot to the grub2 manager without esc, f9 ??
>> 
>> What do you get for 'efibootmgr -v' ?
>> 
>> What should have happened is the installer calls efibootmgr to set the Fedora boot entry in NVRAM to be first in the bootorder so that the firmware uses GRUB straight away by default. The problem of course is there's a long standing bug with the Windows boot entry in GRUB so I think it doesn't work on Fedora 20. It should work on Fedora 21 (or by manually upgrading f20 grub2-tools to the f21 version, and running grub2-mkconfig).
>> 
>> 
>> Chris Murphy
>> 
> 
> Well that was exciting:
> 
> efibootmgr -v
> BootCurrent: 0003
> Timeout: 2 seconds
> BootOrder: 2001,0000,3000,0002,0003,2002,2003
> Boot0000* Windows Boot Manager HD(2,c8800,82000,b75fbdf8-d691-411e-8c4d-bc2e5b5e8898)File(\EFI\Microsoft\Boot\bootmgfw.efi)(invalid optional data length)
> *** Error in `efibootmgr': double free or corruption (out): 0x00007fff63e991e0 ***
> ======= Backtrace: =========
> /lib64/libc.so.6[0x3f61c75cff]
> /lib64/libc.so.6[0x3f61c7cff8]
> efibootmgr[0x407088]
> efibootmgr[0x402308]
> /lib64/libc.so.6(__libc_start_main+0xf5)[0x3f61c21d65]
> efibootmgr[0x403121]
> ======= Memory map: ========
> ..........
> Boot0001* USB Hard Drive (UEFI) - Generic Flash DiskAborted

File a bug against the kernel. It may turn out to be an efibootmgr bug but my understanding is efibootmgr doesn't do much at all it's mostly all happening between kernel and firmware. Also include the computer make/model, and the firmware version noting if it's current, the above backtrace, the entire contents of dmesg, and a listing of /sys/firmware/efi/efivars.

Give it a week or two, and then if you're feeling adventurous and have a warranty, remove everything from cd /sys/firmware/efi/efivars. At least on Macs it ends up being functionally equivalent of the keyboard shortcut to wipe out NVRAM contents, along with the corruption causing the problem.

> 
> MBR I sort of got. EFI, I know nothing. Is using F21 grub2-tools safe? I'd really hate to brick this machine.

Warranty. But yes grub2-efi and grub2-tools are safe, they don't mess with NVRAM. efibootmgr modifies NVRAM via the kernel. So does poking in sys/firmware/efi/efivars.


Chris Murphy