Driver programming


Interrupts are not converted to signals or other asynchronous events. They are handled by any C routine which was connected to given interrupt vector by function IntConnect. An interrupt can be handled by application thread, kernel driver is not needed. All interrupt handlers use one common special stack which is prepared by the system during the start-up.

When a task causes a hardware exception such as illegal instruction or bus error, the task is suspended and the rest of the system continues uninterrupted. However, when an ISR causes such an exception, there is no safe recourse for the system to handle the exception. The ISR has no context that can be suspended. Instead, VxWorks stores the description of the exception in a special location in low memory and executes a system restart.