The Frame Scheduler Device Driver Interface

The Frame Scheduler Device Driver Interface

The Frame Scheduler provides a device driver interface to allow any device with a kernel-level device driver to generate the time-base interrupt. As many as 16 different device drivers can support the Frame Scheduler in any one Challenge/Onyx system. The Frame Scheduler distinguishes device drivers by an ID number in the range 0 through 15 that is coded into each driver.

Note: The structure of an IRIX kernel-level device driver is discussed in the IRIX Device Driver Programming Guide (see "Other Useful Books" on page xxiii). The generation of time-base signals can be added as a minor enhancement to a existing device driver. In order to interact with the Frame Scheduler, a driver provides two routines, one for initialization and one for termination, which it exports during driver initialization. After a master Frame Scheduler has initialized a device driver, the driver calls a Frame Scheduler entry point to signal the occurrence of each interrupt.

Device Driver Overview
Exporting the Initialization and Termination Functions
Frame Scheduler Initialization Function
Frame Scheduler Termination Function
Generating Interrupts