RTEMS lwIP porting

Joel Sherrill joel.sherrill at oarcorp.com
Mon Aug 10 17:28:31 UTC 2015



On 8/10/2015 12:25 PM, ragu nath wrote:
> Hi Daniel,
>
> Most of the  work comes from  your/marcos port.  The aim was to
> integrate a working lwIP port to RTEMS Source Builder.
> I took the port & understood what has been done. Then I wrote  an
> application that uses lwip stack on RTEMS.
> I ran into some issues and fixed them. Now with the changes,  the
> application works.

To repeat myself.. the port needs proper attribution and to be submitted
upstream as soon as possible. Then changing the RSB pointers is easy.

> I discussed with chris on how to integrate the changes to RSB. As per
> his suggestion, the idea is to separate lwip base and drivers. The
> lwip base is compiled as a library using RSB and driver will be
> compiled as a separate library .  The application can then link to it.
> The driver is also from your port with some fixes.

And just to throw it out there, Chris and I would love to see the
current stack moved out of the RTEMS tree and into a separately
buildable package. That would let a user choose from one of three
stacks.

Hopefully the network applications and services would be largely
independent of the stack chosen. The RSB should help with this.

> I am not aware of the issue with POSIX API. Once we get this working,
> I am ready to implement with native api in the future.

It results in slightly larger applications. If the porting layer hasn't
changed a lot, the link I provided in the other email may have a great
chunk of the work in it. But that code is 10 years old and they could
have changed the porting layer. I just don't know.

> Thanks,
> Ragunath
>
>
> On Mon, Aug 10, 2015 at 9:50 PM, Daniel Gutson
> <daniel.gutson at tallertechnologies.com> wrote:
>> On Mon, Aug 10, 2015 at 10:48 AM, Joel Sherrill
>> <joel.sherrill at oarcorp.com> wrote:
>>>
>>>
>>> On 8/9/2015 4:57 AM, ragu nath wrote:
>>>>
>>>> Hi All,
>>>>
>>>> I have sent the patches for building lwIP from RSB.  First patch
>>>> contains changes for RTEMS Resource Builder. The second patch is RTEMS
>>>> specific changes that will be applied to lwIP base.This patch contains
>>>> only lwIP sources. I will be sending another patch for the driver to
>>>> be used with lwIP. The application can then link to both of the
>>>> libararies (lwip & driver).
>>>>
>>>
>>> Has the LWIP patch been submitted upstream to the LWIP maintainers?
>>>
>>> And where do drivers come from? From what I have seen, LWIP seems
>>> to not have a unified base of device drivers. Would this just be to
>>> build the basic stack and then it is the users responsibility to
>>> find and compile a driver?
>>
>> Also, what from these comes from our work? Sorry that I'm a little bit
>> confused and arrived late to the
>> subject. BTW, there is still work to do, since the state we left
>> working LWIP is using the posix layer,
>> which we observed introduces important overhead, so a further step is
>> to reimplement the LWIP's HAL
>> using the RTEMS native API instead. Any plan for that?
>>
>> Thanks!
>>
>>      Daniel.
>>
>>>
>>> What is your RTEMS configuration so I can try it?
>>>
>>> I will try to build it today.
>>>
>>> --
>>> Joel Sherrill, Ph.D.             Director of Research & Development
>>> joel.sherrill at OARcorp.com        On-Line Applications Research
>>> Ask me about RTEMS: a free RTOS  Huntsville AL 35805
>>> Support Available                (256) 722-9985
>>>
>>> _______________________________________________
>>> devel mailing list
>>> devel at rtems.org
>>> http://lists.rtems.org/mailman/listinfo/devel
>>
>>
>>
>> --
>>
>> Daniel F. Gutson
>> Chief Engineering Officer, SPD
>>
>> San Lorenzo 47, 3rd Floor, Office 5
>> Córdoba, Argentina
>>
>> Phone:   +54 351 4217888 / +54 351 4218211
>> Skype:    dgutson
>> LinkedIn: http://ar.linkedin.com/in/danielgutson
>
>
>

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill at OARcorp.com        On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
Support Available                (256) 722-9985


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