Hi Mathieu,
I was just about to leave!
However this is a quick question to answer.
When decoding STM traces, how is the library aware of the masterIDs present on the system?
Master and channel IDs are represented as packets in the STPv2 stream. So the packet processing part of the OpenCSD decoder will render these packets as they appear. The additional work we mentioned on Weds IRC chat - an extra STM decoder layer in OpenCSD to generate generic output packets will present data blocks to the library clients in the form of Master+Channel+Payload+(optional Marker).
It will be up to the higher level client of the library to know what channels are associated with which sources, and clients will have to key on channel ID rather than master ID.
So the stack should look like:-
User-Application [assigned channel N] -> writes(payload) data to Linux Generic Software Trace Module -> writes data to Linux ARM STM driver
On the output side
Trace Extracted Pushed into -> OpenCSD.STM decoder -> internally recognises packets -> outputs-> Generic SWTracePacket[M,N](payload). -> consumed by -> Decoder Application that has association information to associate channel N with User Application.
So the OpenCSD decoder is Master / Channel agnostic - it is the higher level decoder that also understands the nature of the (payload) data that needs to be master/channel aware.
Have a good weekend.
Mike
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-----Original Message----- From: CoreSight [mailto:coresight-bounces@lists.linaro.org] On Behalf Of Mathieu Poirier Sent: 05 February 2016 17:07 To: coresight@lists.linaro.org Subject: STM trace decoding
Good afternoon/evening Mike (or anyone else in a position to answer),
I wish we could have that conversation on IRC as I am sure my question will be inaccurate. I'm also well aware the weekend has started in the UK so it could also wait until Monday. But I'll try to be as precise as possible....
When decoding STM traces, how is the library aware of the masterIDs present on the system? I suppose there is an external way of passing that information to the decoder... The metadata contained in the perf.data file is irrelevant when dealing with STM traces.
Some clarification would be appreciated.
Many thanks, Mathieu _______________________________________________ CoreSight mailing list CoreSight@lists.linaro.org https://lists.linaro.org/mailman/listinfo/coresight
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