[KLUG Members] usb modems and hylafax

[Bert]

Peter Buxton wrote:

>I see in the other mails that you're talking to the ISDN modem.
>
>On Tue, Jan 27, 2004 at 10:56:04AM +0100, Bert was only escaped
>   alone to tell thee:
>
>  
>
>>I did: ln -s /dev/ttyACM0 /dev/modem
>>minicom
>>minicom: cannot open /dev/modem : No such device
>>
>>also tried linking without the -s, but no difference.
>>    
>>
>
>The '-s' option is the difference between a hard link and a symbolic
>link.  Just go ahead and use '-s', because that's what everything else
>uses.
>
>ObRant: When Alan Cox was busy on that kernel for ludicrously under-
>powered machines (FOLKS, right?), he was surprised to note that the code
>to implement symlinks roughly doubled the size of the generic FS code. A
>sure sign that symlinks are a Bad Thing (but not the only one).
>
>  
>
>>I also added with mknod some devices with minor numbers as the address
>>the device is mounted on. No success either. I suppose that that is
>>how it works, the address is the minor device number? right?
>>    
>>
>
>No. Major number 180 is for USB devices, but the minor number defines
>different subtypes of devices.
>
>  
>
are you sure? I have my ttyACMx on major 166.
on 188 are some devices such as usblp0 that indeed make me think of 
something like usb. I wille try some of these devices to get
the usb modem going.

>Device numbers are arbitrary values that define a 'namespace' for
>devices. It's a three-part system:
>
> Device type: block or character
>Major number: Major divisions of devices (SCSI, IDE, ttys)
>Minor number: individual devices or sections, sometimes different devices
>
>Note that:
>
>mknod /dev/THING c 2 0
>mknod /dev/THONG b 2 0
>
>creates two different devices: one is a BSD-style psuedo-tty, the other
>is a floppy disk.
>
>brw-rw----    1 root     floppy     2,   0 Mar 14  2002 /dev/fd0
>brw-rw----    1 root     floppy     2,   4 Mar 14  2002 /dev/fd0d360
>brw-rw----    1 root     floppy     2,   8 Mar 14  2002 /dev/fd0h1200
>brw-rw----    1 root     floppy     2,  12 Mar 14  2002 /dev/fd0u360
>brw-rw----    1 root     floppy     2,  16 Mar 14  2002 /dev/fd0u720
>....
>
>Note how the minor number is used to distinguish between size and
>density.
>
>
>brw-rw----    1 root     cdrom      3,   0 Mar 14  2002 /dev/hda
>
>Major number 3 is the first IDE adapter.
>
>brw-rw----    1 root     disk      33,   0 Mar 14  2002 /dev/hde
>brw-rw----    1 root     disk      33,   1 Mar 14  2002 /dev/hde1
>brw-rw----    1 root     disk      33,   2 Mar 14  2002 /dev/hde2
>brw-rw----    1 root     disk      33,   3 Mar 14  2002 /dev/hde3
>brw-rw----    1 root     disk      33,   4 Mar 14  2002 /dev/hde4
>
>33 is the third IDE adapter, 0 is the disk and 1-4 are the partitions.
>
>
>Someday soon, all these arbitrary numbers will go away. Device numbers
>will be like file descriptors: arbitrary handles generated on the fly.
>Device names will be left as the prime device identifiers, and udev(8)
>or something like it will create them on the fly, at boot and as devices
>are added (i.e., digital cameras).
>  
>
is the /dev directoty than only holding 'active' (present) devices?

>Linux Assigned Names And Numbers Authority: www.lanana.org .
>
>2.4 kernels have devfs, which is like udev but kernel resident. It also
>uses a daemon to update /dev. If you have the option of running it, I
>recommend it highly. You would be past all these "Which device"
>questions and onto device configuration by now.
>
>  
>
how do I run devfs? mount does show a usbdevfs on /proc/bus/usb; how 
does it help me to overcome the "which device" question?
what is the name of the daemon that should be running?


Bert.