Re: EFI to grub to DOS?

[Jordan Uggla]

On Wed, Jul 18, 2012 at 9:13 AM, Greg Grotsky <address@hidden> wrote:
>   I have a system that has an option in the BIOS to choose boot style as
> "BIOS" or "UEFI". When I choose "BIOS" I can boot to a DOS partition without
> problems. When I choose "UEFI" I can boot to an EFI startup.nsh script
> without problems. I can't however boot to DOS from the "UEFI" boot
> selection.
>
> My question is: can I set the option to "UEFI" and use grub to boot to DOS,
> somehow?

Probably not. grub-efi has an "appleloader" command which can be used
on Intel Macs to boot a drive/partition via Apple's BIOS
implementation but I don't expect that to work with UEFI.

>
>   I've done quite a bit of googling on this question and using this site
> I've been able to create a grub.efi file that I can execute from the EFI
> shell and can point to the DOS partition, but when I try to select it I get:
> "error: invalid EFI file path."
>
>   I have seen a few examples of menuentry blocks that contain options like
> "fakebios" and "loadbios". I have used the method on the link above to
> create vbios.bin and int10.bin, can I use these to simulate the BIOS boot
> option in order to boot to DOS?

No. These options only provide enough to help some Linux graphics
drivers, they will not get you a full BIOS implementation. DOS is
completely dependent on a full BIOS implementation.

For running DOS applications from within GNU/Linux you can use DOSBox.

-- 
Jordan Uggla (Jordan_U on irc.freenode.net)