Re: Setting up UEFI boot

Mark Fletcher,

You can do EFI installation[1] (grub-efi will recognize others partitions of GPT table), just switch off Secure Boot and reboot, use any DVD/usb linux .iso with EFI (for example: Debian 8.x) and before start installation check if is boot with EFI or legacy (enter with text mode and type [ -d /sys/firmware/efi ] && echo "EFI boot on HDD" || echo "Legacy boot on HDD") the output will display the installation mode.

The output need be EFI boot on HDD , after installation grub-efi will find automatically others partitions of GPT table

If output show Legacy boot.. you followed wrong the steps.

[1] https://wiki.debian.org/GrubEFIReinstall

2016-05-04 8:34 GMT-04:00 Stefan Monnier <monnier@iro.umontreal.ca>:

> How can I set up a machine to boot in UEFI mode when the running kernel was
> booted in legacy mode?

AFAIK it goes something like this:
- Use a GPT partition table, rather than MBR (you can usually convert
from one to the other without reformatting, but that can require tricky
fiddling, so if you can reformat go for it), with an appropriate EFI
system partition mounted to /boot/efi.
- Install grub-efi-amd64 (or grub-efi-i386, of course), and
"grub-install /dev/sda"
- reboot

You may need extra steps to convince your system to boot from Debian's
grub-efi, e.g. copying /boot/efi/efi/debian/grubx64.efi to
/boot/efi/efi/boot/bootx64.efi or selecting debian/grubx64.efi from your
BIOS's boot menu.

IIRC last time I did it, I mostly followed the recipe in
https://tanguy.ortolo.eu/blog/article51/debian-efi

Stefan