...@julian-ThinkPad-E550:~$ ls /sys/firmware/efi
ls: cannot access '/sys/firmware/efi': No such file or directory
...-ThinkPad-E550:~$ dmesg | grep efi
[    0.000000] clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645519600211568 ns
[    1.859916] tsc: Refined TSC clocksource calibration: 1995.380 MHz