I'm running a dual boot Windows 10 and Ubuntu 15.10 on my HP Spectre X360. Everything worked fine until I updated Ubuntu and it asked me to restart the system. After the restart GRUB wouldn't show anymore and my computer would immediately boot into Windows.
I tried the following:
- holding shift during boot: Nothing happens
- Changing the boot order: Only Windows boot manager shows up so I can't change anything
- doing a boot-repair: After running it I got this log http://paste2.org/0Cwwt45W but it didn't fix my problem.
So far I don't know what else to try.
Edit: I can hit esc, then "Boot Device Options" then "Boot from EFI file" then"EFI" then "Ubuntu" then "grubx64.efi" and boot Ubuntu that way.
Now the interesting entries in /var/log/apt/history.log are
Install:
linux-headers-4.2.0-23-generic:amd64 (4.2.0-23.28, automatic)
linux-signed-image-4.2.0-23-generic:amd64 (4.2.0-23.28, automatic)
linux-image-extra-4.2.0-23-generic:amd64 (4.2.0-23.28, automatic)
linux-headers-4.2.0-23:amd64 (4.2.0-23.28, automatic)
linux-image-4.2.0-23-generic:amd64 (4.2.0-23.28, automatic)
Upgrade:
linux-headers-generic:amd64 (4.2.0.22.24, 4.2.0.23.25)
grub-efi-amd64-bin:amd64 (2.02~beta2-29ubuntu0.2, 2.02~beta2-29ubuntu0.3)
grub-efi-amd64:amd64 (2.02~beta2-29ubuntu0.2, 2.02~beta2-29ubuntu0.3)
grub-common:amd64 (2.02~beta2-29ubuntu0.2, 2.02~beta2-29ubuntu0.3)
grub2-common:amd64 (2.02~beta2-29ubuntu0.2, 2.02~beta2-29ubuntu0.3)
linux-signed-generic:amd64 (4.2.0.22.24, 4.2.0.23.25)
grub-efi-amd64-signed:amd64 (1.55.2+2.02~beta2-29ubuntu0.2, 1.55.3+2.02~beta2-29ubuntu0.3)
linux-signed-image-generic:amd64 (4.2.0.22.24, 4.2.0.23.25)
linux-image-generic:amd64 (4.2.0.22.24, 4.2.0.23.25)
linux-generic:amd64 (4.2.0.22.24, 4.2.0.23.25)