I have an old-style MBR Grub configuration for F30. Converting the system to UEFI seems like a hassle and doesn't provide an obvious benefit for now (maybe next time I do a full install I'll go for it).
However I also run Windows 10 in a KVM/QEMU virtual machine. This has its own dedicated drive and uses UEFI (OVMF). My BIOS supports UEFI and I've managed to dual-boot a few times by fiddling with the BIOS settings, but switching back and forth is clunky and error-prone, and Windows always wants to "fix" itself before working.
My question is: how can I add this as an option to my Grub configuration to enable dual-boot directly from the Grub menu (i.e. running on metal, not a VM)? In other words, BIOS boots using MBR, invokes Grub, which then (optionally) invokes UEFI to boot Windows. Or is this not possible?
poc
On 9/8/19 6:13 AM, Patrick O'Callaghan wrote:
My question is: how can I add this as an option to my Grub configuration to enable dual-boot directly from the Grub menu (i.e. running on metal, not a VM)? In other words, BIOS boots using MBR, invokes Grub, which then (optionally) invokes UEFI to boot Windows. Or is this not possible?
You can't because the EFI services would not be available.
On Sun, 8 Sep 2019 14:21:59 -0700 Samuel Sieb wrote:
BIOS boots using MBR,
invokes Grub, which then (optionally) invokes UEFI to boot Windows. Or is this not possible?
You can't because the EFI services would not be available.
Could you have a separate grub instance that is UEFI and chainload over to it?
On 9/8/19 2:43 PM, Tom Horsley wrote:
On Sun, 8 Sep 2019 14:21:59 -0700 Samuel Sieb wrote:
BIOS boots using MBR,
invokes Grub, which then (optionally) invokes UEFI to boot Windows. Or is this not possible?
You can't because the EFI services would not be available.
Could you have a separate grub instance that is UEFI and chainload over to it?
It's not grub that provides the services so that wouldn't make any difference. I would expect that the other grub wouldn't even start.
On Sun, 2019-09-08 at 14:21 -0700, Samuel Sieb wrote:
On 9/8/19 6:13 AM, Patrick O'Callaghan wrote:
My question is: how can I add this as an option to my Grub configuration to enable dual-boot directly from the Grub menu (i.e. running on metal, not a VM)? In other words, BIOS boots using MBR, invokes Grub, which then (optionally) invokes UEFI to boot Windows. Or is this not possible?
You can't because the EFI services would not be available.
You mean the EFI services provided by the BIOS wouldn't be available because it's in the wrong mode? Makes sense.
poc
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Patrick O'Callaghan -
Samuel Sieb -
Tom Horsley