What should the system designer do in order to implement system calls, assuming that a system provides the hardware's inbound instructions (for example, "Svc n")? How do users request operating system services?

Job:

1. Write and debug routine subroutines that can realize various functions.

2, write and debug the visit to the pipeline interrupt processing program.

3, constructs the routine subroutine entry Address table.

In the user program, a system call is scheduled where the operating system service needs to be requested. In this way, when the program executes to this command, there will be an interruption, the system from the user state to the pipe state, the operating system's access to the interrupt handler control, it will be called by the system function number, through the routine subroutine entry Address table to the appropriate routine subroutine to perform, after the user needs to complete the service function, Exits the interrupt and returns to the user program's breakpoint to continue execution.

What should the system designer do in order to implement system calls, assuming that a system provides the hardware's inbound instructions (for example, "Svc n")? How do users request operating system services?