Provided by: freebsd-manpages_7.0-2_all
device_ids, major, minor, umajor, uminor - calculate device ids
major(struct cdev *dev);
minor(struct cdev *dev);
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.
An integer greater than zero and less than NUMCDEVSW. major() and
minor() will return NODEV if the device is invalid.
This manual page was written by Chad David 〈email@example.com〉.