every device file in linux has a MAJOR nbr associated with it. The kernel uses this major number to determine what type of device is being opened (see the MACRO's S_IS[CHR/BLK/SOCK..etc] in include/linux/stat.h). then uses this info and the major nbr to index into an array which holds the registered drivers fops structure ex. if u do open(/dev/ttyS0,XX) the kernel figures out it's a char device and then finally uses the major nbr to index an array "chrdevs[]" to get the fops struct (this is the struct that the driver registered via a call to register_chrdev()). HTH, -mandeep On Thu, 2004-09-30 at 17:26, Zeeshan Ali wrote: > Hello, > Whenever i open the device /dev/lpN, the kernel automatically loads > the appropriate driver for that device, as if it has a list of major > number to module mapping. How/where does the kernel do it? > > -- > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
