> On March 26, 2012, 3:23 a.m., Andreas Hansson wrote: > > Is it not possible to use the Ruby sequencers for all the connections to > > the DMA devices, i.e. config, pio and dma? > > Nilay Vaish wrote: > I think Ruby, as of now, cannot allow pio accesses to flow through it. I > have talked to Brad > about this before, and it seems to me that current implementation would > have to be enhanced. > I don't know what config port is about. > > Andreas Hansson wrote: > I was just thinking...if the config and pio request and responses do not > go through Ruby, then can we not do the same for the dma port requests and > responses? Since Ruby does not do general memory-mapped requests/responses > for the former, we could simply connect also the dma port to the bus that is > used for the config and pio port, could we not? > > Nilay Vaish wrote: > I believe we can, but I don't have a say on what should be preferred. > > Nilay Vaish wrote: > Andreas, can you comment on how these three types of accesses differ from > each other? > With a better picture, I might be able to able to allow pio and config > requests to go > through Ruby.
The pio and config port are memory-mapped slave ports (much like a memory), but instead of storing data they read/write to registers that affect the behaviour of the device. Hence, they receive requests and send out responses. The dma port is a master port (much like a CPU inst/data port), and it sends out read/write requests and expects them to be routed to a slave based on the address, and responses to come back when necessary. Let me know if there is more information you would like about their functionality and the assumptions. - Andreas ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: http://reviews.gem5.org/r/1102/#review2378 ----------------------------------------------------------- On March 24, 2012, 1:27 p.m., Nilay Vaish wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > http://reviews.gem5.org/r/1102/ > ----------------------------------------------------------- > > (Updated March 24, 2012, 1:27 p.m.) > > > Review request for Default. > > > Description > ------- > > Changeset 8918:e1988ccf8001 > --------------------------- > Ruby X86: problem in setting DMA port, related to the changeset 8850 > I think since the dma port is assigned twice (once in SouthBridge.py, > and once by Ruby somewhere) an extra port gets created which has no > peer port. This results in a segmentation fault when a simulation is > started. The posted patch solves the problem, but it is not the > solution I am looking for. Andreas, do you have some idea how to > handle this issue? > > > Diffs > ----- > > configs/common/FSConfig.py 7d95b650c9b6 > src/dev/x86/Pc.py 7d95b650c9b6 > src/dev/x86/SouthBridge.py 7d95b650c9b6 > > Diff: http://reviews.gem5.org/r/1102/diff/ > > > Testing > ------- > > > Thanks, > > Nilay Vaish > > _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
