Dual Boot Mint 17 and EUFI Windows 8

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gcvisel
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Dual Boot Mint 17 and EUFI Windows 8

Post by gcvisel » Tue Aug 04, 2015 12:43 am

I bought a new laptop that came with Winders 8.1 (yuck!) but I decided to keep it for later upgrade to Win 10, and install Mint 17 beside it.

The instructions I used were not too clear, and I ended up installing it fine in Legacy mode. This works, but to get to either one, I need to go into the BIOS and set/unset the EUFI/Legacy mode. This sure ain't the boot menu I expected, where I just choose one or the other from a menu.

I know I screwed it up, but is there any way that I can now go backwards and get Mint onto the boot menu, without completely redoing it? Can I move GRUB to the EUFI boot partition?

Thanks for any ideas!

Gerry

wayne128
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Re: Dual Boot Mint 17 and EUFI Windows 8

Post by wayne128 » Tue Aug 04, 2015 2:38 am

gcvisel wrote:I bought a new laptop that came with Winders 8.1 (yuck!) but I decided to keep it for later upgrade to Win 10, and install Mint 17 beside it.

The instructions I used were not too clear, and I ended up installing it fine in Legacy mode. This works, but to get to either one, I need to go into the BIOS and set/unset the EUFI/Legacy mode. This sure ain't the boot menu I expected, where I just choose one or the other from a menu.
Since Win8.1 was preinstalled in UEFI mode, and you have installed Mint in legacy mode, you have to use this method of switching back-and-forth to boot two OS installed in two different mode.
I know I screwed it up, but is there any way that I can now go backwards and get Mint onto the boot menu, without completely redoing it? Can I move GRUB to the EUFI boot partition?
It is much easier for you to start from fresh, by booting Mint in UEFI mode and install in UEFI mode.
May be 15-20 minutes away from fresh.


Can you move grub to UEFI boot partition?
Well, to 'repair' this, you need to start from a DVD/USB Mint which boot in UEFI mode anyway, then, verify it is UEFI mode ( just to be sure), chroot to your legacy-installation, then update the repos, install grub-efi, follow by update-grub...
These have a lot more steps and time spent compare with a reinstallation from fresh in UEFI mode.

srs5694
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Re: Dual Boot Mint 17 and EUFI Windows 8

Post by srs5694 » Tue Aug 04, 2015 8:56 am

It's actually not that hard to install an EFI boot loader in a situation like yours -- if you know how. In fact, there are two ways that are fairly painless:
  • Boot Mint or some other emergency medium in EFI mode and run Boot Repair. This should install the EFI version of GRUB and set it up appropriately. There is a danger, though; although Boot Repair usually does the right thing, on occasion it will make matters worse. Also, booting in EFI mode is required to do this right. Check your boot mode by looking for a directory called /sys/firmware/efi. If it's present, you've booted in EFI mode; if not, you've booted in BIOS mode.
  • Disable Secure Boot, then download the USB flash drive or CD-R version of my rEFInd boot manager. Prepare a boot medium and boot from it. This should enable you to boot into Mint, and the boot will be in EFI mode. At this point, you can install rEFInd via the PPA or Debian package; or replace your BIOS-mode GRUB with the EFI-mode version. This method is relatively risk-free (assuming you go for rEFInd at the end rather than EFI-mode GRUB), since if you can boot with rEFInd from the USB drive, a disk-based boot will almost certainly also work.
As wayne128 suggests, re-installing Mint is also an option that's worth considering, particularly if you've invested little time in customization or creating new documents. Re-installing will take more time than installing an EFI-mode boot loader if you're comfortable with the latter procedure and run into no problems; but as a practical matter, many people will make mistakes or be delayed by one issue or another, so re-installing could be faster.

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