Re: [ECOS] Thread-aware debugging w/ Redboot on ARM?

[Alex Schuilenburg <alexs at ecoscentric dot com>]

Paul D. DeRocco wrote:
> > From: Gary Thomas
> >
> > Which platforms support this is merely a function of which ones
> > have it configured in, i.e. it's platform independent.  Note: I
> > do see that some platforms have this explicitly disabled.  This
> > is possibly just for size reasons (I'm not sure)  At first glance,
> > it appears that most of the ARM platforms do enable it.
>
>
> Also for remote debugging, the thing that interprets the remote debug
> protocol must have thread support built in. Redboot does, but the JTAG
> debugger I've used doesn't.


It is not so much as the JTAG debugger not having support but the 
debugger being able to extract the thread info out of the target.  GDB 
also knows nothing about eCos threads, it just knows how to ask for 
information about threads from the target. The debugger itself has no 
idea where to find or extract eCos thread info from the target.  So the 
target has to interpret the thread info requests from the debugger, 
extract the thread info from the running system by doing some local 
on-chip processing, and then return this to GDB.  When debugging using 
JTAG/ICE/BDM or simulators, the target is halted. Nothing runs. So this 
info cannot be extracted unless the debugger is RTOS aware and knows 
where to look for this info.  However, if you debug using RedBoot, it 
knows how to extract this info from eCos. This is why you need a running 
target.

HTH
-- Alex


> --
>
> Ciao,               Paul D. DeRocco
> Paul                mailto:pderocco@ix.netcom.com


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