NAME
device_ids, major, minor, umajor, uminor — calculate device ids
SYNOPSIS
#include <sys/types.h>
#include <sys/systm.h>
int
major(struct cdev *dev);
int
minor(struct cdev *dev);
int
umajor(dev_t id);
int
uminor(dev_t id);
DESCRIPTION
The device_ids family of functions take either the raw device ID, id, or a pointer to the device structure, dev, and return the integer value that is the major or minor device ID as requested.
The actual major and minor device IDs are values masked from of the raw device ID. For details on the actual calculations used to determine the major or minor IDs see the actual source in kern_conf.c.
RETURN VALUES
An integer greater than zero and less than NUMCDEVSW. major() and minor() will return NODEV if the device is invalid.
AUTHORS
This manual page was written by Chad David <davidc [AT] acns.ca>.
BSD June 22, 2004 BSD