_init(9E)

static void *xxstatep;
int
_init(void)
{
        int error;
        const int max_instance = 20;    /* max possible device instances */

        ddi_soft_state_init(&xxstatep, sizeof (struct xxstate), max_instance);
        error = mod_install(&xxmodlinkage);
        if (error != 0) {
                /*
                 * Cleanup after a failure
                 */
                ddi_soft_state_fini(&xxstatep);
        }
        return (error);
}

The driver should perform any one-time resource allocation or data initialization during driver loading in _init(9E). For example, it should initialize any mutexes global to the driver in this routine. The driver should not, however, use _init(9E) to allocate or initialize anything that has to do with a particular instance of the device. Per-instance initialization must be done in attach(9E). For example, if a driver for a printer can handle more than one printer at the same time, it should allocate resources specific to each printer instance in attach(9E).

Once _init(9E) has called mod_install(9F), the driver should not change any of the data structures hanging off the modlinkage(9S) structure, as the system may make copies of them or change them.