The process took hours and when it was finally finished and the pc restarted , it booted directly into W8 without passing through GRUB, "UhOh..."
I immediately went to the internet and found that that GRUB is easy to re-install. I grabbed a copy of live Debian, and made a bootable USB. I could boot from the USB and followed the instructions from the dpkg bot at irc channel #debian-next:
To reinstall boot to your Debian install disk/live CD, switch to the other console (Alt-F2), then mount your root filesystem (mount -t "fs type" /dev/"partition" /target ; mount --bind /dev /target/dev ; mount -t proc none /target/proc ; mount -t sysfs none /target/sys), then chroot into it (chroot /target) and run update-grub && grub-install /dev/"device". Also works for EFI.
I did this and rebooted. Sadly it did not work and I got:
Since then (it has been 3 days! I wish I could sue MS for all the time wasted!) I am trying all suggestions I get that do not look too dangerous. I am about to re-install my Debian, but I am not sure this will solve the problem.
Technical data
Machine: ASUS K55V
It is a UEFI machine but I have
Fast boot [disable]
Secure boot [disable]
Launch in CSM [enable]
PXE OpRom [disable]
As far as I understand this means that I am in BIOS compatible mode.
My Disk was partitioned in the following way (it has a protective MBR strcuture)
EFI partition
Windows partition
Some KiB not allocated
Root partition
Swap
Home partition
This worked fine until the update in question. Following a suggestion from user amphi in #debian-next I added a 1 MiB BIOS Boot partition (shrank the EFI partition by 1 MiB). I thought this did not make sense, cause the system worked for 1 year and half without this partition, but when everything fails, you do what is left. The disk now looks like
EFI partition
BIOS Boot parition
Windows partition
Some KiB not allocated
Root partition
Swap
Home partition
The only effect of this is that my BIOS/EFI now detects 2 windows bootable sectors instead of just one.
Ideas?
Will re-installing Debian solve the problem?
What should I do with the EFI partition? Back it up (it has the bootloaders) and then remove it completely?