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int_intercept

Usage

   #include <int.h>
   int int_intercept(unsigned vector, int(*funcptr) (struct
                       INT_DATA *pd), unsigned stacksize);

Description

   Note-This function is not available under OS/2.

   int_intercept links a standard C function to an interrupt vector for
   handling the interrupt when the interrupt occurs. The funcptr is a
   pointer to the C function that will handle the interrupt. This function
   must be declared as taking C linkage. The vector argument defines which
   interrupt vector the function will be attached to (0..255). The stacksize
   argument is the number of bytes of memory allocated for the stack within
   the interrupt handler. stacksize should be a minimum of 256 bytes, except
   that if stacksize is 0, no stack is allocated, and the program stack is
   used. This is essential for interrupt routines that are required to be
   re- entrant, such as serial handlers for example.

   If a zero value is returned from the interrupt handler (*funcptr)() then
   the previous interrupt vector for this vector is called else a return
   from interrupt is performed.

   Values in registers can be read/written through the pointer (pd) to the
   INT_DATA struct which is passed to (*funcptr)().

Return Value

   The value returned from int_intercept indicates success or failure. A
   zero is returned on success otherwise -1.