On Fri, 11 Apr 2008, Mohamed Thalib .H wrote: > > On Fri, 2008-04-11 at 05:56 -0400, Robert P. J. Day wrote: > > i know well enough that, if i write and load a driver that allocates > > a device major number and one or more minor numbers, i can see the > > allocated major number via /proc/devices. but is there a userspace > > way to see the minor number(s)? or, as LDD3 implies, it's my job to > > just *know* what those would have been? thanks. > > > > rday > > -- > > > > ======================================================================== > > Robert P. J. Day > > Linux Consulting, Training and Annoying Kernel Pedantry: > > Have classroom, will lecture. > > > > http://crashcourse.ca Waterloo, Ontario, CANADA > > ======================================================================== > > > > -- > > To unsubscribe from this list: send an email with > > "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx > > Please read the FAQ at http://kernelnewbies.org/FAQ > > > > Check out this command in the user space... > > ls -l /dev > > it gives some thing like this you can find major no is 2 and 7 and minor > are the 23,24,25,37,38,39 etc... > > crw-rw-rw- 1 root tty 2, 23 2008-04-11 19:55 ptyq7 > crw-rw-rw- 1 root tty 2, 24 2008-04-11 19:55 ptyq8 ... snip ... no, it's not that simple -- i'm talking about when you "insmod" a driver and that driver uses, say, alloc_chrdev_region() to register a major number and one or more minor numbers, but you still haven't created any special device files for that driver yet. if you look on p. 47 of LDD3, there's a script called "scull_load" that handles all the bureaucracy of loading a module and checking the major number that's assigned, but it simply assumes minor numbers of 0-3, which just happens to be what the driver asks for. but let's say (theoretically) that you don't know what minor number(s) the driver is going to ask for. is there a way to determine that information from userspace afterwards? i've always assumed there isn't, but i just thought i'd ask to see if there wasn't something i'd just never noticed. maybe something under /sys/module/<whatever>, or something like that. rday -- ======================================================================== Robert P. J. Day Linux Consulting, Training and Annoying Kernel Pedantry: Have classroom, will lecture. http://crashcourse.ca Waterloo, Ontario, CANADA ======================================================================== -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
