How to create the nodes automatically

[Srinivas G.]

Dear All,

I have developed a simple character driver for accessing the custom PCI
board in Fedora Core 3. It is working fine. I am creating the device
nodes manually using the mknod command after inserting my module into
the kernel space. But when I restart the system the nodes are not there.
But the module is present. I have added the MODULE_DEVICE_TABLE in my
module for loading it at boot time. I have read about the
MODULE_DEVICE_TABLE in LDD3. It will add the module name to the
modules.pcimap and modules.dep file. 

My question is: 
Is there any way to create the nodes automatically after restarting the
system if the module exists?

I have heard about devfs. But I did not know about it.
Could any one please respond to my question?

Thanks in advance. 

Regards,
Srinivas G

[Rahul Sundaram]

Srinivas G. wrote:

> Dear All,
>
> I have developed a simple character driver for accessing the custom PCI
> board in Fedora Core 3. It is working fine. I am creating the device
> nodes manually using the mknod command after inserting my module into
> the kernel space. But when I restart the system the nodes are not there.
> But the module is present. I have added the MODULE_DEVICE_TABLE in my
> module for loading it at boot time. I have read about the
> MODULE_DEVICE_TABLE in LDD3. It will add the module name to the
> modules.pcimap and modules.dep file. 
>
> My question is: 
> Is there any way to create the nodes automatically after restarting the
> system if the module exists?
>
>   
>  
Try creating the nodes in /etc/udev/devices

> I have heard about devfs. But I did not know about it.
> Could any one please respond to my question?
>   
>  
Devfs is deprecated and mostly removed out of the recent kernels.

-- 
Rahul 

Fedora Bug Triaging - http://fedoraproject.org/wiki/BugZappers

[Mikkel]

Srinivas G. wrote:
>  Dear All,
>  
>  I have developed a simple character driver for accessing the custom PCI
>  board in Fedora Core 3. It is working fine. I am creating the device
>  nodes manually using the mknod command after inserting my module into
>  the kernel space. But when I restart the system the nodes are not there.
>  But the module is present. I have added the MODULE_DEVICE_TABLE in my
>  module for loading it at boot time. I have read about the
>  MODULE_DEVICE_TABLE in LDD3. It will add the module name to the
>  modules.pcimap and modules.dep file. 
>  
>  My question is: 
>  Is there any way to create the nodes automatically after restarting the
>  system if the module exists?
>  
>  I have heard about devfs. But I did not know about it.
>  Could any one please respond to my question?
>  
>  Thanks in advance. 
>  
>  Regards,
>  Srinivas G
>   
You will need to write a udev rule that create the /dev entries
when it sees the hardware. You could create a static rule that
creates them every time the system boots, but a better way would
be to have them created when the module is loaded.

See http://fedora.redhat.com/docs/udev/ for more information about
udev and links about writing rules.

Mikkel
-- 

  Do not meddle in the affairs of dragons,
for thou art crunchy and taste good with Ketchup!