On Tue, Dec 11, 2018 at 2:02 AM Mathieu Poirier <mathieu.poir...@linaro.org> wrote: > > Good day Adrian, > > On Sat, 8 Dec 2018 at 05:05, Lei Wen <adrian.w...@gmail.com> wrote: > > > > Hi Mathieu, > > > > I am enabling etmv4 coresight over one Cortex-A7 soc, using 32bit kernel. > > And I am following [1] to do experiment regarding the addr_range feature. > > That wiki is very old and after reading it again I seriously consider > removing it. It is still accurate but there are better ways to do > things now, i.e perf. The main openCSD documentation page [2] > contains everything you need to know about the integration with perf. > > [2]. https://github.com/Linaro/OpenCSD/blob/master/HOWTO.md > > > The default addr_range is set as _stext~_etext, and it works fine with > > etb as sink, > > and etm as source. I could see there are valid kernel addresses using > > OpenCSD. > > I'm really curious about how you use openCSD to validate your traces - > can you expand more on that?
I just manually replace the cstrace.bin in the decoder/tests/snapshots/juno-ret-stck/. And modify the register data according to my platform. Then produce the decode result by below command: ./decoder/tests/bin/builddir/trc_pkt_lister -ss_dir decoder/tests/snapshots/test -decode -logfilename 2.ppl > > I think the results are misleading you since the openCSD library can't > readily be used to decode sysfs trace sessions. The wiki doesn't > mention using openCSD to decode traces either. The only integrated > way to use openCSD to decode CoreSight traces is via perf. Again, the > link above will give you all the information you need to do that. > > > > > But while I try to store one small range of address pair, which contain > > only one > > kernel function. It doesn't behavior like what said in [1], the write > > pointer would > > grows rapidly with the read pointer. And I dump the etb buffer and parse it > > with > > openCSD, finding that there is no I_ASYNC packet in the dump and is fulled > > with > > I_NOT_SYNC. > > > > So my question is why ETB continue to grow when there is no trigger at all? > > Is it normal? I could provide more info if you need it. > > I am dubious about the validation process and as such can't comment on > this. Please share your results using the perf integration and then > I'll be able to have a better idea of what is going on. I see... I would try use perf to get more result and get back here. > > Taking a step back I am curious about the ETMv4/ETB combination... Is > the ETB the only sink you have to work with? Moreover, are you sure > it is not a TMC-ETF? The ETMv4/ETB match seems a little odd to me > since they belong to two different era of the CoreSight architecture. > Usually with an ETMv4 we will see a TMC-ETR, which as a lot more > capabilities. ETR is supported. I use ETB as it is mentioned in that old wiki page. Thanks, Lei
