I had a weird issue with my HP laptop this morning. It suddently shut down and when I restarted it, it was in some kind of manufacture mode. I managed to get it back to normal boot mode by following official HP informations here but now when I boot, it doesn't find any OS anymore. I checked the harddrive with the HP hardware full check and it seems fine.
I then booted on an old Fedora 21 live usb I have. All my partitions are still here and seems functionnal. I had a multiboot in efi with a grub. I had a Windows and 3 unix on my drive. Everything seems to be still here.
How can I manage to get my grub and all os back without losing everything? Also, before doing anything "dangerous" I would like to make a full save of my disk just in case, how could I perform that?