Re: Using a master grub2 in UEFI

[Andrei Borzenkov]

В Sat, 28 Mar 2015 23:27:23 +0000
Barry Jackson <address@hidden> пишет:

> 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

Both arguments are redundant. Install device is ignored on EFI,
grub-setup is never called there either.

> 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?
> 

Currently you can't. Drop a mail to grub-devel with good use case for
it. Workaround is to use --efidir=/tmp (or any other directory). 

> 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
> 

That's correct, this is EFI PE, not multiboot, and you need to use

chainloader /boot/grub2/x86_64-efi/core.efi

Not sure how easy would be to have common multiboot image
under /boot/grub. But it makes sense indeed, to make chainloading
easier.

> Any help would be much appreciated.
> 
> Thanks,
> Barry
> 
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