register_blkdev(9) [suse man page]

REGISTER_BLKDEV(9)						   Block Devices						REGISTER_BLKDEV(9)

NAME

       register_blkdev - register a new block device

SYNOPSIS

       int register_blkdev(unsigned int major, const char * name);

ARGUMENTS

       major
	   the requested major device number [1..255]. If major=0, try to allocate any unused major number.

       name
	   the name of the new block device as a zero terminated string

DESCRIPTION

       The name must be unique within the system.

       The return value depends on the major input parameter. - if a major device number was requested in range [1..255] then the function returns
       zero on success, or a negative error code - if any unused major number was requested with major=0 parameter then the return value is the
       allocated major number in range [1..255] or a negative error code otherwise

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010							REGISTER_BLKDEV(9)

MAKEDEV(3)						   BSD Library Functions Manual 						MAKEDEV(3)

NAME

     makedev, major, minor -- device number conversion

SYNOPSIS

     #include <sys/types.h>

     dev_t
     makedev(int major, int minor);

     int
     major(dev_t dev);

     int
     minor(dev_t dev);

DESCRIPTION

     The makedev() macro allows a unique device number to be generated based on its major and minor number.  The major() and minor() macros can be
     used to obtain the original numbers from the device number dev.

     In previous implementations of FreeBSD all block and character devices were uniquely identified by a pair of major and minor numbers.  The
     major number referred to a certain device class (e.g. disks, TTYs) while the minor number identified an instance within the device class.
     Later versions of FreeBSD automatically generate a unique device number for each character device visible in /dev/.  These numbers are not
     divided in device classes.

     On FreeBSD these macros are only used by utilities that need to exchange numbers with other operating systems that may use different encod-
     ings for dev_t, but also applications that present these numbers to the user in a more conventional way.

RETURN VALUES

     The major() macro returns a device major number that has a value between 0 and 255.  The minor() macro returns a device minor number whose
     value can span the complete range of an int.

SEE ALSO

     mknod(2), devname(3), devfs(5)

BSD
								September 28, 2008							       BSD