Once you get it working on the old stuff, come back and ask how to get it moved forward. It is pretty easy once you know your PRU code is working.
With the remote-proc driver, you can throw the built .elf files into /lib/firmware and trigger them to load by the kernel, without needing to have a library or line of your own C code. You can still mmap() the shared memory to have your userspace app communicate with the PRUs. There are some other good sets of documents out here, but I'll agree that nothing is as complete as Derek Molloy's book. On Wed, Mar 1, 2017 at 12:15 PM Justin Pearson <justin.pear...@gmail.com> wrote: > Hi Mike, > > As Greg said, PRU development is severely hampered by incomplete, > out-dated, and mutually-exclusive sets of instructions. Derek Molloy's book > may be based on an older Beaglebone Black, but at least it's self-contained > and consistent. I struggled for a long time to get the PRU working on a > "modern" (4.4?) kernel. Eventually I gave up and installed the > 3.8.13-bone80 kernel, which runs all Derek's examples fine. That is the > direction I suggest for you. > > I never would've gotten my PRU setup working without Derek's book -- I'd > still be recompiling kernels and randomly applying patches according to > contradictory Internet documentation. > > BTW, your seg faults may be caused by not loading the PRU device-tree > overlay. Derek provides a device-tree overlay and instructions for > compiling it on page 510. The actual .dts file is on GitHub here: > > https://github.com/derekmolloy/exploringBB/tree/master/chp13/overlay > > Good luck, > Justin > > > On Tuesday, February 28, 2017 at 8:01:44 AM UTC-8, Greg wrote: > > Hi Mike- > > > There are several possible paths. Since you mentioned Derek Molloy's > book, here is my project which was inspired by his chapter on the PRU: > > https://www.hackster.io/Greg-R/beaglebone-pru-adc-a42a71 > > If you look at this, you will see that I used the RemoteProc framework. > This framework is relatively new and experimental. I have found that TI is > supporting this quite well and for the most part it worked well in the > limited project space I have worked in at this time. > > There is also the UIO based framework which is more mature and has many > successful projects developed with it. > > With regards to getting up and running, you need to be aware of some > set-up you will have to do whatever route you chose. > Here is another project I have published which includes documentation to > guide you through the set-up of RemoteProc framework. > There are some details which I think would also be useful if you go the > UIO route: > > > https://www.hackster.io/Greg-R/pru-pid-motor-speed-controller-with-beaglebone-green-ccb805 > > I am still working on the above project to re-implement the web interface > using a Node based server. Or maybe Python. Not sure yet. > > In general if you Google search on the PRU, you are going to find many > paths which lead you down a dead end. > There is a huge amount of obsolete data information out there. Even a lot > of the TI stuff which is outdated was still out there the last time I > looked. > For example, there are a lot of projects based on the PASM compiler. This > is the original compiler for the PRU. That old compiler is good and used > by many successful project, but it is no longer supported by TI. The new > C compiler (which also compiles assembly) is supported, and though similar > to the instruction set of PASM, there are some differences. So that is > another decision node. > > So that's what I know, good luck with your project! > > Regards, > Greg > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/261e8b4f-928e-4b33-bf37-47fd5385b423%40googlegroups.com > <https://groups.google.com/d/msgid/beagleboard/261e8b4f-928e-4b33-bf37-47fd5385b423%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CA%2BT6QP%3D_edrhykQYwv4DN%3DxS4jzon7AisdL%2BDCKHBPNemLbZ8w%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
