Detecting running platform (specifically EFI) during runtime?

Detecting running platform (specifically EFI) during runtime?

[Andrey Borzenkov]

Is it possible to check at run-time on which platform we are running.
Specifically, any way to distinguish between EFI and legacy BIOS?

TIA

-andrey

Re: Detecting running platform (specifically EFI) during runtime?

[Keshav P R]

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On Sat, Jan 5, 2013 at 2:58 PM, Andrey Borzenkov <arvidjaar@gmail.com>wrote:

> Is it possible to check at run-time on which platform we are running.
> Specifically, any way to distinguish between EFI and legacy BIOS?
>
> TIA
>
> -andrey
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> https://lists.gnu.org/mailman/listinfo/grub-devel
>

Something like below should work (requires grub 2.00, not 1.99):

[CODE - part of grub.cfg]
if [ "${grub_platform}" == "efi" ]; then
    set _GRUB_PLATFORM="UEFI"

    if [ "${grub_cpu}" == "x86_64" ]; then
        set _UEFI_ARCH="x64"
    fi

    if [ "${grub_cpu}" == "i386" ]; then
        set _UEFI_ARCH="ia32"
    fi

    insmod efi_gop
    insmod efi_uga
fi

if [ "${grub_platform}" == "pc" ]; then
    set _GRUB_PLATFORM="BIOS"

    insmod vbe
    insmod vga
fi
[/CODE]

Regards.

Keshav

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Re: Detecting running platform (specifically EFI) during runtime?

[Colin Watson]

On Sat, Jan 05, 2013 at 05:17:18PM +0530, Keshav P R wrote:
> On Sat, Jan 5, 2013 at 2:58 PM, Andrey Borzenkov <arvidjaar@gmail.com>wrote:
> > Is it possible to check at run-time on which platform we are running.
> > Specifically, any way to distinguish between EFI and legacy BIOS?
> 
> Something like below should work (requires grub 2.00, not 1.99):
> 
> [CODE - part of grub.cfg]
> if [ "${grub_platform}" == "efi" ]; then
>     set _GRUB_PLATFORM="UEFI"
> 
>     if [ "${grub_cpu}" == "x86_64" ]; then

I have now documented the grub_cpu and grub_platform environment
variables in docs/grub.texi in trunk.  (When explaining something not
documented in the manual, please consider whether it would be useful to
propose a documentation patch.)

Cheers,

-- 
Colin Watson                                       [cjwatson@ubuntu.com]