Stuck at Boot Loader

[andreas85]

@sjyv

so I forced shut down by pressing the power button.

Gently shut down a frozen PC

to minimize the risk of file system corruption and data loss:

[HowTo] reboot / turn off your frozen computer: REISUB/REISUO

Difficulty: ★★☆☆☆ This tutorial was created because people are using a hard power off during freezes, so this will teach you how to turn off your computer when everything is frozen using softer means. So whenever you see someone saying they had to “Power Off” or “Hard Reset” their system without doing a REISUB, please send them here! If you’re reading this in response to a question, please click the green link above this text to bring you to the full unabridged text of the tutorial…

Keyboard shortcuts - ArchWiki

Linux Magic System Request Key Hacks — The Linux Kernel documentation