[bsder]

OS is not the same level of abstraction as a language.

This is an active problem in embedded. Cheap microcontrollers can have multiple cores that are not even the same architecture.

This means that just to get "blinky" running, you need to choose a (language, OS) tuple. And, given that "language" is generally "C", that means that your abstraction choices for OS are lousy.

Side question: last I checked, FreeRTOS didn't do a great job when multiple microcontrollers were involved--especially if the communication channels or synchronization were hardware-based. Has this changed?