The Open C Environment

This section defines the relationship between OCP and the various components in it's Environment. In the following discussion refer to the diagram in Figure 1.1

Figure 1.1: Open C Environment

The diagram as a whole represents a particular implementation of an Open C Layer. The Application, represented as the highest level component, is the body of software that is unique to a given application or service. The CPU/Memory combination, at the lowest level, represents the minimum computing functionality that OCP requires. The Operating System, which may or may not exist on a given computing platform, provides some set of services to OCP. Finally, a particular C Compiler is used to generate machine executable code.

For example, in the case of a Unix workstation, the CPU might be a 64-bit processor with gigabytes of virtual memory. The operating system would provide a wide range of services including disk file I/O, interprocess communication, and network services.

On the other hand, a portable messaging device might use a 16-bit processor with 64 kilobytes of memory while the operating system might be nothing more than a simple task scheduler.

OCP isolates the Application from all of this underlying complexity and variability. Once OCP is ported to a given Open C Environment (CPU/Memory, Operating System, and Compiler) any Application developed under one Open C Environment can easily be ported to another.