I uploaded the nodemcu-firmware bu following this tutorial:

http://www.whatimade.today/flashing-the-nodemcu-firmware-on-the-esp8266-linux-guide/

It was pretty straightforward i must say. git-cloned the repo and burned the pre built binaries using the esptool from espressif package (see here: https://nurdspace.nl/ESP8266/First_setup).

Then i used cutecom on /dev/ttyUSB0 (9600 baud) and tried it out. Nodemcu has some nice documentation for what modules are installed and can be used.