I personally feel that the role of the operating system of embedded systems is to shield the underlying hardware details, you just call the interface provided by the operating system, you can operate the hardware, you can improve the development efficiency, as for the allocation of hardware resources, the operating system will manage for you, do not need to care about how to allocate the hardware resources in the case of hardware complexity, the operating system appears to be particularly efficient!
arm+linux is equivalent to running windows on your intel
cpu. frankly speaking, arm+linux is also a computer, but not as strong as your PC
.