First, what is embedded?
Simple, is embedded in a computer embedded in a variety of devices, it is more versatile than the SCM, but relatively general purpose computer, and is in a private field, having specificity.
SCM is due to the specificity for different purposes, microcontroller developers need to design their own hardware and software platforms.
While embedded with a relatively unified hardware platform, and generally equipped with an embedded operating system, allowing developers to make simple changes and as long as you can make embedded software development applied to specific purposes.
Second, the embedded hardware
Embedded hardware and PC similar to, but will be more conducive to the selection of dedicated hardware.
This introduces the ARM. First ARM is a technology, a processor architecture, is a company, the company responsible for selling IP core, can be understood as "make money by selling drawings." ARM is currently one of the mainstream embedded processor.
Third, the embedded operating system
Real-time operating system : real-time machine is able to react according to external unexpected events, divided into soft and hard real-time real-time . Soft real-time operating system allows event on hold, hard real-time is required to handle emergencies immediately, otherwise it may lead to disaster. Support for hard real-time operating system is called real-time operating system.
[mu] C / OS : This is an application integrated embedded operating system, that is, when you develop, just a bunch of source code for the operating system, you need to put your code and operating system code is written together and functions provided by the operating system (function), then compiled together. This is a real-time operating system, generally do not have a user interface.
Embedded Linux : Linux is not a real-time operating systems, real-time, if desired, can be used RTlinux.