Architecture of UNIX Systems
UNIX System Structure
- Operating system interacts directly with Hardware
- Provides common services to programs
- Insulating from Hardware
- Kernel is treated as an operating system
- Programs are independent of the Hardware
- Easy to move on different processing environment
- Programs should be independent of Hardware
- Programs in the upper layer communicate with Kernel using defined set of system calls
- System calls instruct the Kernel to do various operations
- System calls also exchange the data between Kernel and program
- Some Standard programs also fall in this layer i.e. executable files by C compiler
- Top most layer is used for other application programs eg. C compiler (CC)
