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

[Alex Schuilenburg]

Paul D. DeRocco wrote:
>>From: Roland Caßebohm (by way of Roland Caßebohm
>>
>>Maybe you could make your sourcecode available? I'm thinking
>>about porting a jtagtool like "jtager" to eCos as host and as
>>a result I want to have one day an JTAG adapter which could
>>in the first step only burn FLASH via JTAG, but in a second
>>step could also debug the target.
>>
>>Therefor it should talk the gdb remote protocol. Having
>>special support for operating systems for multi threading
>>would be perfect.
> 
> 
> The question is this: how does a JTAG debugger manipulate threads, without
> duplicating the knowledge of the thread structure layout in the JTAG
> interface? Is it possible for the JTAG debugger to initiate a subroutine
> call through the virtual vector to the eCos thread function, and trap the
> return?

Yes. That is exactly how a gdb server would use JTAG to extract the 
thread info and return it to the gdb client.  However, it is also a lot 
more than just that. For true threead support you would need to be able 
to set thread breakpoints, switch threads to extract register contexts 
and so on.

-- Alex


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