About Real-time and general-purpose operating issue

 Virtualization for embedded systems has many implementations in which two or more operating systems coexist to gain the benefits of each. One approach puts Microsoft Windows and a Real-Time Operating System (RTOS) together.

 

Much is being said about virtualization these days in the softwareworld. Simply stated, virtualization is about getting multiple OSs to run on the same computing platform at the same time. Virtualization has been cited as a key technology for getting the most performance out of the newest multicore processors. But just as not all computing applications are the same, not all virtualization approaches are appropriate for all applications.
Embedded systems have a key requirement that doesn’t normally apply to office and server computers: the need for deterministic response to real-time events. To support the requirement for determinism, embedded applications typically use RTOSs. Embedded applications also employ general-purpose OSs to handle operator interfaces, databases, and general-purpose computing tasks.
In the past, because OSs couldn’t successfully co-reside on computing platforms, system developers employed multiple processing platforms using one or more to support real-time functions and others to handle general-purpose processing. System designers that can combine both types of processing on the same platform can save costs by eliminating redundant computing hardware. The advent of multicore processors supports this premise because it is possible to dedicate processor cores to different computing environments; however, the software issues posed by consolidating such environments require special consideration. Combining real-time and general-purpose operating environments on the same platform (Figure 1) places some stringent requirements on how virtualization is implemented.
1.Paravirtualization
2.Server virtualization
3.Hardware-aided embedded virtualization     
4.Leveraging Intel Architecture
5.Embedded virtualization saves costs

refer: http://embedded-computing.com/articles/real-time-general-purpose-unite-via-virtualization/