probe(9E)

SunOS 4.1 system:

	int xxprobe(reg, unit)
 	caddr_t reg;
 	int		unit;

SunOS 5.7 system:

	int xxprobe(dev_info_t *dip)

probe(9E) is still expected to determine if a device exists, but now the routine might be called any number of times, so it must be stateless (free anything it allocates).