nios_custom interface is used when
the custom instruction needs to be used.
The custom function is called whenever the custom instruction is executed.
See NiosĀ® II processor reference guide page 8-35 for further information about the parameters.
SIM_INTERFACE(nios_custom) {
uint32 (*custom)(conf_object_t *NOTNULL self, uint32 n,
uint32 a, uint32 b, uint32 c, uint32 rA, uint32 rB,
bool readra, bool readrb, bool writerc);
};
#define NIOS_CUSTOM_INTERFACE "nios_custom"