BSP and Device Driver Development Guide
The clock driver must supply a handler for the IO control device driver entry point. This functionality is used by other components -- notably the Shared Memory Driver to install a wrapper for the clock interrupt service routine. The following shows the functionality required:
rtems_device_driver Clock_control( rtems_device_major_number major, rtems_device_minor_number minor, void *pargp ) { error check the argument pointer parameter if the command is "ISR" invoke the clock interrupt service routine else if the command is "NEW" install the requested handler }
BSP and Device Driver Development Guide
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