Re: [ECOS] Problem with MGETHDR

[Gary Thomas <gary@mlbassoc.com>]

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On Mon, 2005-06-13 at 19:41 +0530, Rupesh Kumar wrote:
> Hi Gary,
> 
> I am running the http server Published on MLB site.Target Board is ARM
> (ARM926EJS) Board.
> 
> what i am assuming is MGETHDR will get the kernel buffers,does it has
> any thing to do with application buffers.(Correct me if i am wrong).

This is true - the network stack has its own set of buffers which are 
manipulated via MGETHDR, etc.  However, since eCos has a flat, 
unprotected memory model, your application can easily mess things up
so that that pool is no longer managed properly.

As I said in a previous email, verify that your network driver is
working properly first, then investigate what's going wrong.  

One thing that's always a good idea is to enable assertions in the
eCos kernel.  This can help find problems quickly, even elusive ones
like stack overflows.  To enable this, enable CYGPKG_INFRA_DEBUG

> 
> Regards
> rupesh
> 
> On Mon, 2005-06-13 at 19:25, Gary Thomas wrote:
> > On Mon, 2005-06-13 at 19:14 +0530, Rupesh Kumar wrote:
> > > Hi all,
> > > 
> > > I am running the http server on eCos (MLB HTTP Server).
> >                                         ^^^^^^^^^^^^^^^
> > There is no such thing;  there is a sample HTTP server setup on the MLB
> > website which uses standard eCos with a publicly available HTTP server.
> > I'm sure this is what you meant :-)
> > 
> > > 
> > > In my ethernet driver eth_drv_recv function in in ISR Context.
> > > After Receving some packets eth_drv_recv function is failing.so i am not
> > > able to receive any more packets.
> > > 
> > > I have found that eth_drv_recv() is failing at MGETHDR Macro call.At the
> > > time of failing it is not even entering the macro call.(this i found by
> > > putting some traces in the MGETHDR Macro Call).
> > 
> > What platform/target?
> > 
> > Most likely, something is going wrong in your application code,
> > possibly a stack overflow, etc.  
> > 
> > -- 
> > ------------------------------------------------------------
> > Gary Thomas                 |  Consulting for the
> > MLB Associates              |    Embedded world
> > ------------------------------------------------------------
> > 
-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------


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