I know that when the source code, in say C++, is compiled, the output from the compiler is the machine code (executable) which I thought were instructions to the CPU directly. Recently I was reading up on kernels and I found out that programs cannot access the hardware directly but have to go through the kernel.
So when we compile some simple source code, say with just a printf() function, and the compilation produces the executable machine code, will each instruction in this machine code be directly executed from memory (once the code is loaded into memory by the OS) or will each command in the machine code still need to go through the OS (kernel) to be executed?
I have read a similar question. It did not explain if the machine code that is generated after compilation is an instruction to the CPU directly or if it will need to again go through the kernel to create the correct instruction for the CPU. I.e., what happens after the machine code is loaded into memory? Will it go through the kernel or directly talk to the processor?