Hi, rday Thank you for your help. Yes! You did point out my question. I will do read drivers/char/misc.c for a better understanding. Best, 2012/2/12 Robert P. J. Day <rpjday@xxxxxxxxxxxxxx>: > On Sun, 12 Feb 2012, Alexandru Juncu wrote: > >> 2012/2/12 hz hanks <hankshz@xxxxxxxxx>: >> > Hi, all >> > >> > I have a question about major/minor device number. I know that one can >> > use int register_chrdev_region(dev_t from, unsigned count, const char >> > *name); to register a driver with a unique pair of major/minor device >> > number. But what's the difference between two drivers: in one case >> > they have same major device number but different minor device number; >> > on another case they have different major device number but same minor >> > device number. When I searched the Internet, it said that major device >> > number is to identify the driver while the minor device number is to >> > identify specific hardware. But I'm still confused because it seems >> > legal to share the major device number with different drivers. > > you're talking about the "misc" character device driver here, which > allows you to register very simple and independent character drivers > that need only a single minor number all at major number 10. > > look in /dev for how many char device files have major number 10. > that's the perfect example of what you're talking about. see the > source in drivers/char/misc.c. > > rday > > -- > > ======================================================================== > Robert P. J. Day Ottawa, Ontario, CANADA > http://crashcourse.ca > > Twitter: http://twitter.com/rpjday > LinkedIn: http://ca.linkedin.com/in/rpjday > ======================================================================== _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
