Re: Using a master grub2 in UEFI

[Bret Busby]

On 29/03/2015, Barry Jackson <address@hidden> wrote:
> Hi,
> In PC-BIOS I have always used a separate partition with it's own install
> of grub2 to boot into core.img of various grub2 based linux installations.
>
> I am now trying to do the same with UEFI and have hit several issues.
>
> grub2-install --grub-setup=/bin/true /dev/sda4
> under PC-BIOS only installs grub2 to the grub2 directory with a copy of
> core.img in grub2/i386-pc/
>
> Under UEFI this also makes changes in the ESP by copying
> /boot/grub2/x86_64-efi/core.efi as /boot/EFI/EFI/<vendor>/grubx64.efi
> overwriting the existing one.
>
> How can I stop this happening?
>
> Also, when I try to boot core.efi from another grub2 menu using
> something like:
>
> menuentry 'Mageia-KDE sda4' {
> search --no-floppy --label --set=root KDEMga4
> multiboot /boot/grub2/x86_64-efi/core.efi
> }
>
> I get an error: no multiboot header found
>
> Any help would be much appreciated.
>
> Thanks,
> Barry
>

Hello.

I have no idea as to whether this will help you in what you seek, but,
please read the message that I posted to this list, on 12 March, in
the thread with the subject
"Query about command line commands"
and possibly the preceding messages in that thread, to get the background.

Basically, the two Linux operating systems (Debian 7 and Ubuntu 14.04
LTS) were apparently installed in the Legacy system, with MS Windows
retained as installed in the UEFI -> Secure Boot mode, and, to choose
which operating system to boot, using the system setup utility, if I
wanted to boot into MS Win8, I would set the Setup Utility to boot
into UEFI -> Secure Boot (which can not be turned off, on that
system), which would then boot into MS Win8, upon booting, and, if I
wanted to boot into one of the Linux distributions, I would set the
Setup Utility to boot into the Legacy mode, which would take me to a
GRUB menu, to choose into which Linux distribution to boot.

The system Setup Utility is supposed to include a third option, the
"dual mode", but it is missing.

It took me over a year to resolve this, and then the hardware of the
computer, failed, so the computer is at present, undergoing
examination, in a warranty claim

I hope that this information is helpful to you.

-- 
Bret Busby
Armadale
West Australia
..............

"So once you do know what the question actually is,
 you'll know what the answer means."
- Deep Thought,
 Chapter 28 of Book 1 of
 "The Hitchhiker's Guide to the Galaxy:
 A Trilogy In Four Parts",
 written by Douglas Adams,
 published by Pan Books, 1992

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