On Tue, Jul 10, 2012 at 11:01 AM, Philippe Gerum <r...@xenomai.org> wrote:

> On 07/10/2012 01:23 PM, Sunetra Sashi wrote:
>
>>
>> What is the recommended methodology for kernel space modules to
>> communicate with each other across the Linux-Xenomai space?
>>
>
> There is no recommended methodology for this: kernel space should run
> within the linux domain only, or within the Xenomai domain only via the
> inter-driver RTDM interface, or should communicate with user-space only via
> a driver interface. rt <-> nrt within kernel space can be done using a low
> level mechanism, but there is no high level IPC for this.
>
> Again, if your kernel space code is actually an application, spare
> yourself a lot of pain, and move it to userland.
>

That is interesting. So if I have a linux kernel module, say a network
device driver. And another Xenomai kernel module that needs to run real
time. Since we want to deal with IP packets, we need our linux module to
run in the kernel space. Is it safe to assume that communication between 2
such drivers is not possible in the kernel?



>
>> I corrected the rtipc rtdm device as a protocol device (I must have
>> changed it in error) and I am able to load the xeno_rtipc.ko now.
>> However, the socket open still fails with the same error code.
>>
>> Thanks
>>
>>
>>                  I am making these calls from within the kernel, not
>>         from user space.
>>                  Hence I ended up using rtdm calls instead
>>
>>
>>
>>              /dev/rtp0 is a non-real-time user-space endpoint for the
>>              communication, between a regular linux application and a
>>         real-time
>>              component. It does not make sense to open it from kernel
>> space.
>>
>>
>>         My intent here is to set up something similar to xddp-echo.c
>>           (RT - Non
>>         RT communication) but in kernel space instead. How should I go
>> about
>>         creating the Linux endpoint for XDDP in the kernel?
>>
>>
>>     There is no direct way for that, this device/protocol is not
>>     intended for this purpose. This is a regular linux application to
>>     Xenomai real-time communication path, nothing else. Regular linux
>>     applications live in userland, only.
>>
>>     We don't recommend building applications in kernel space.
>>
>>
>>
>>
>>
>>
>>
>>                           Do I need to install any specific xenomai
>>         modules for
>>                  this to work?
>>
>>
>>                       Obviously, yes. Check IPC drivers in the "Drivers"
>>         sub-menu
>>                  of the
>>                       Xenomai configuration. You need to have
>>                       CONFIG_XENO_DRIVERS_RTIPC_XDDP enabled.
>>
>>
>>                  I already checked this in the configuration, It is
>> enabled.
>>                  Should this
>>                  also be set to y? CONFIG_XENO_DRIVERS_RTIPC. In my
>>         configuration
>>                  it is
>>                  set to m.
>>
>>
>>              Did you load the xeno_rtipc module then?
>>
>>
>>         It is not loaded. But I got an error when I did that.
>>         Xenomai: assertion failed at /.../kernel/xenomai/skins/)
>>         Xenomai: RTDM: missing open handler
>>
>>
>>     It does not make any sense. This assertion can only trigger for a
>>     named device, not a protocol device. RTIPC is a protocol device.
>>
>>     - did you change any of the driver code?
>>     - what command did you use to load the module, verbatim?
>>
>>         insmod: error inserting 'xeno_rtipc.ko': -1 Invalid parameters
>>
>>
>>
>>                  Should I see any modules loaded in
>>                  /proc/xenomai/rtdm/protocol___**__devices?
>>
>>
>>              Yes.
>>
>>
>>
>>
>>                           Thanks
>>                           Shweta
>>
>>           ______________________________**_______________________
>>
>>
>>                           Xenomai mailing list
>>         Xenomai@xenomai.org <mailto:Xenomai@xenomai.org>
>>         <mailto:Xenomai@xenomai.org <mailto:Xenomai@xenomai.org>>
>>                  <mailto:Xenomai@xenomai.org
>>         <mailto:Xenomai@xenomai.org> <mailto:Xenomai@xenomai.org
>>         <mailto:Xenomai@xenomai.org>>>
>>         
>> http://www.xenomai.org/______**mailman/listinfo/xenomai<http://www.xenomai.org/______mailman/listinfo/xenomai>
>>         
>> <http://www.xenomai.org/____**mailman/listinfo/xenomai<http://www.xenomai.org/____mailman/listinfo/xenomai>
>> >
>>
>>                  
>> <http://www.xenomai.org/____**mailman/listinfo/xenomai<http://www.xenomai.org/____mailman/listinfo/xenomai>
>>         
>> <http://www.xenomai.org/__**mailman/listinfo/xenomai<http://www.xenomai.org/__mailman/listinfo/xenomai>
>> >>
>>
>>
>>           
>> <http://www.xenomai.org/____**mailman/listinfo/xenomai<http://www.xenomai.org/____mailman/listinfo/xenomai>
>>         
>> <http://www.xenomai.org/__**mailman/listinfo/xenomai<http://www.xenomai.org/__mailman/listinfo/xenomai>
>> >
>>                  
>> <http://www.xenomai.org/__**mailman/listinfo/xenomai<http://www.xenomai.org/__mailman/listinfo/xenomai>
>>         
>> <http://www.xenomai.org/**mailman/listinfo/xenomai<http://www.xenomai.org/mailman/listinfo/xenomai>
>> >>>
>>
>>
>>
>>                       --
>>                       Philippe.
>>
>>
>>
>>
>>
>>              --
>>              Philippe.
>>
>>
>>
>>
>>
>>     --
>>     Philippe.
>>
>>
>>
>>
>
> --
> Philippe.
>
>
>
_______________________________________________
Xenomai mailing list
Xenomai@xenomai.org
http://www.xenomai.org/mailman/listinfo/xenomai

Reply via email to