MAJOR(9) Kernel Functions MAJOR(9)NAME
MAJOR, MINOR, MKDEV - macros to manipulate device major/minor numbers
SYNOPSIS
#include <linux/fs.h>
#define MAJOR(dev)
#define MINOR(dev)
#define MKDEV(major, minor)
DESCRIPTION
The MAJOR and MINOR macros extract from a device id (of type dev_t) the
major and minor numbers respectively. It is the combined device number
that is found in the struct~file structure.
The MKDEV macro assembles a device number from the supplied major and
minor numbers.
RETURN VALUE
Describe the return values. Enumerate all the distinct values and all
the ranges.
AVAILABILITY
Linux 0.0+
In later kernels (Linux 2.1 and later) there is movement towards using
64bit device numbers. Although it is generally a good idea to not pre‐
sume to know how device numbers are constructed, it is during this
period of transition fundamentally important that you ONLY use these
functions to manipulate device numbers.
SEE ALSOmknod(1)
Also list some source files for the kernel that implement the functions
of the page.
AUTHOR
Stephen Williams <steve@icarus.com>
BUGS
These are macros, so parameters may be evaluated multiple times.
Linux DDI $Date:$ MAJOR(9)