I googled about it and somewhere I read ....
Yes, you can. That is happening in the case of embedded systems
I think NO, it\'s not poss
You can run a program in a system without an Operating System ... and that program need not be an Operating System itself.
Think about all the computers (or processors if you prefer) inside a car: engine management, air conditioning, ABS, ..., ...
All of those system have a program (possibly written in C) running. None of the processors have an OS.
The Standard specifically differentiates between hosted implementations
and freestanding implementations
:
5.1.2.1 Freestanding environment 1 In a freestanding environment (in which C program execution may take place without any benefit of an operating system), the name and type of the function called at program startup are implementation-defined. Any library facilities available to a freestanding program, other than the minimal set required by clause 4, are implementation-defined. 2 The effect of program termination in a freestanding environment is implementation-defined. 5.1.2.2 Hosted environment 1 A hosted environment need not be provided, but shall conform to the following specifications if present. ...