On Thursday, 26 September 2019 21:19:04 UTC+2, ce...@tuta.io wrote: > > Sep 26, 2019, 17:53 by mib.ho...@gmail.com <javascript:>: > > > I'm probably the wrong guy to answer this question as I'm a noob into > how sw os's work, but regarding linux memory access from the fpga: > > > Thanks. Sorry for probably idiotic questions, I am noob about FPGA > development. > > Ok :-)
> > > > A (hw) function in fpga (also with dma channels), can address any linux > memory location (even sw restricted ones). > > > > If needed it is also possible to setup say like a 64KB dual port shared > memory block inside the fpga fabric and have both fpga and linux access to > that. > > > Are both solutions useful for this scenario? I imagine that the frequency > of change will be lot higher on FPGA side than on Linux side. For example > the encoder counter will be updated almost constantly. > > Cern. > > Well on the fpga side you don't have any cpu-like structure that governs every thing, only clock signals, and flags and every function you implement runs on it's own simultaneously (in parallel) (think 1 sw core for every function) on every clock cycle. > > > > > > On Thursday, 26 September 2019 15:48:35 UTC+2, ce...@tuta.io wrote: > > > >> Sep 26, 2019, 01:29 by >> mib.ho...@gmail.com <>>> : > >> > >> > Well current state is that PR (Partial Reconfiguration) is brand new > to the OS (Open Source) world, > >> > as > IntelfPGA (former Altera) "just" have promised it for their 19.1 > release (no lite version out yet), <>> https://github.com/>> > machinekit/mksocfpga/issues/>> 100 < > https://github.com/machinekit/mksocfpga/issues/100>>> > > >> > on the contrary Xilinx have sneaked it out very quietly with their > Vivado 2019.1 release this summer <>> https://github.com/>> > machinekit/mksocfpga/issues/>> 100 < > https://github.com/machinekit/mksocfpga/issues/100>>> > > >> > > >> > So while the idea has had time to settle in this old thread, the > possibility of implementation here in Machinekit is brand new.... :-) > >> > Michael B > >> > > >> Well, > >> and how it is with the memory? And with the bus connection between hard > ARM processor and FPGA fabric? Because now we have the HAL memory block > locked into RAM with HAL library enabled allocating and memory (alignment) > management from Linux side. But I presume that for FPGA-side components, > that would not be good enough and this memory block will have to be > directly in FPGA fabric so the components can use this space as a > "register", right? Will then be possible to atimically access this memory > (or variables there stored) both from Linux running on an ARM core and > component in FPGA fabric? (I mean as a direct memory access, zero-copy, not > some memory synchronization.) > >> > >> Cern. > >> > >> > > >> > On Wednesday, 25 September 2019 20:49:04 UTC+2, >> ce...@tuta.io > <>>> wrote: > >> > > >> >> I am late to the party, I know, sorry, but this idea is very > interesting to me. As I know that perspectives and opinions change, I would > like to inquire about the current state. If all in this thread is still > valid or if it was redacted in some way? > >> >> > >> >> I need to wrap my head around this concept, but fundamentally > speaking, I see no reason why it should not be possible and even how it is > that much different from the current state. Because, currently the > operation on HAL is discrete and sequential. But only up to the point. As I > see it, the basic structure of HAL is the input and output of each block > (component). What is happening inside the component is a black box and of > no particular interest to the user or a system. That "happening" is enabled > by so called threads or tasks (on the Linux OS side), but actually from > theoretical point of view are also of no importance. > >> >> > >> >> Given the dawn of multicore, we can have multiple threads running > independent on each other on different isolated CPU/cores all reaching the > same memory. There is still the limit that threads on one instance has to > be run in increments of the first one, but I am not sure if that is real > limit or just something nobody changed from LinuxCNC days. (Because really, > it is nonsense.) > >> >> > >> >> If you can somehow pass-through the memory (I/O) from FPGA-side HAL > to Linux-side HAL, I think you are pretty much done and you have HAL in > FPGA. (HostMot2 FPGA firmware is also a HAL type, but you have the ugly > read/write functions. I call it the LinuxCNC way of thinking about it.) > >> >> > >> >> Because then it will be the same old, same old. > >> >> > >> >> And that opens up some very interesting possibilities. > >> >> > >> >> BTW, I have only very rough understanding about FPGA development. > But that SystemC looks extremely promising. > >> >> > >> >> Cern. > >> >> > >> > > >> > > >> > > >> > -- > >> > website: > >> http://www.machinekit.io <http://www.machinekit.io>>> > <>> http://www.machinekit.io <http://www.machinekit.io>>> >> blog: > >> > http://blog.machinekit.io <http://blog.machinekit.io>>> <>> > http://blog.machinekit.io <http://blog.machinekit.io>>> >> github: > >> > https://github.com/machinekit <https://github.com/machinekit>>> <>> > https://github.com/machinekit <https://github.com/machinekit>>> > > >> > --- > >> > You received this message because you are subscribed to the Google > Groups "Machinekit" group. > >> > To unsubscribe from this group and stop receiving emails from it, > send an email to > >> machi...@>> googlegroups.com <>>> <mailto:>> > machinekit+>> unsub...@googlegroups.com <javascript:> <>>> >> . > >> > To view this discussion on the web visit > >> > https://groups.google.com/d/>> msgid/machinekit/a9420e6d->> > 4f39-46e2-97c1-d4f7af69c89e%>> 40googlegroups.com < > https://groups.google.com/d/msgid/machinekit/a9420e6d-4f39-46e2-97c1-d4f7af69c89e%40googlegroups.com>>> > > <>> https://groups.google.com/d/>> msgid/machinekit/a9420e6d->> > 4f39-46e2-97c1-d4f7af69c89e%>> 40googlegroups.com?utm_medium=>> > email&utm_source=footer < > https://groups.google.com/d/msgid/machinekit/a9420e6d-4f39-46e2-97c1-d4f7af69c89e%40googlegroups.com?utm_medium=email&utm_source=footer>>> > > >> . > >> > > >> > >> > > > > > > > > -- > > website: > http://www.machinekit.io <http://www.machinekit.io>> blog: > > http://blog.machinekit.io <http://blog.machinekit.io>> github: > > https://github.com/machinekit <https://github.com/machinekit> > > --- > > You received this message because you are subscribed to the Google > Groups "Machinekit" group. > > To unsubscribe from this group and stop receiving emails from it, send > an email to > machi...@googlegroups.com <javascript:> <mailto: > machinekit+unsubscr...@googlegroups.com <javascript:>>> . > > To view this discussion on the web visit > > https://groups.google.com/d/msgid/machinekit/b430e32c-13cc-47d2-ab88-3da6aa31a293%40googlegroups.com > > < > https://groups.google.com/d/msgid/machinekit/b430e32c-13cc-47d2-ab88-3da6aa31a293%40googlegroups.com?utm_medium=email&utm_source=footer>> > > . > > > > -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. 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