I'm back to working on getting all 10 pru0 pins working for my final design. Rather than loading a new version and hoping for the best, I'd like to use this as a learning opportunity for better understanding of how device trees, overlays, pin-config, uBoot all work together.
* Is there a recommended (organized) source for this type of information? I find that currently I'm finding fragmented information requiring me to piece it together for a complete understanding (which I sometimes do incorrectly). I'd be very happy to be able to read and learn on my own rather than ask for help - questions which may be obvious or simple for those that have the complete picture. * on the elinux.org BeagleBone pages I read that "kernel overlays are going bye-bye" and "too many bugs, no dev interest...". So does this mean that exactly one dtb is loaded at boot and is immutable? Or that a "base" dtb with additional overlays can be used, but all must be specified at boot time and cannot change thereafter? I thought there was a lot of excitement about (and promotion of) the concept of using a cape overlay system to change the system configuration. (Piecing together fragments here) was the final analysis that on-the-fly hardware configuration changes are not really frequent, so boot-time reconfiguration was a reasonable trade-off for simplifying the overall system? * I still don't know why my current configuration only allows me to configure some pru pins using config-pin. (Example: I can configure P9-27 and P9-30 as pruout but not P9-25.) I've looked at the config-pin output, and the tables/information contained in the script itself, and all seem to show the pins properly defined as having a pruout mode - yet it doesn't work. I'm using the reference by Derek Molloy compiled to a convenient table format (here: http://exploringbeaglebone.com/wp-content/uploads/resources/BBBP9Header.pdf) which indicates each of these pins are allocated for use by mcasp_0. * I looked at the source RCN linked below (bb.org-overlays) but don't know what I need to build: is it a new .dtb, or config-pin script? On my system I see that there is no "state" file for the pins I cannot configure for pruout. I see cape-universala (and cape-universaln and cape-universal) in /lib/firmware, but when I use config-pin attempting to load it that fails. It seems my system is incorrectly configured... Note that I am using uio_pruss drivers and a workable solution must be compatible with this. On Wednesday, December 20, 2017 at 2:34:48 PM UTC-8, RobertCNelson wrote: > > On Wed, Dec 20, 2017 at 4:29 PM, ags <[email protected] <javascript:>> > wrote: > > Thank you Robert. In the long term I will certainly do as you suggest. > Is > > there no way to "downgrade" or use an overlay for pin configuration that > is > > in sync with my current (4.4.30) kernel version? > > Yes, source is available: > > https://github.com/beagleboard/bb.org-overlays > > > > > If that is not possible, will the 4.4.91 version you recommend support > > uio_pruss? I will have to review my notes, but my recollection is the > > remoteproc/uio driver debate was raging when I decided on this route, > and it > > took some effort for me to figure out how to make it work. > > You said you were using uio_pruss, so i gave you specific directions > for uio_pruss with v4.4.x-ti. ;) > > > > > Finally, if I must move to 4.4.91, would you kindly state how I can > > accomplish this with all pinmux/helper/config/overlay items also being > > synced without disrupting uio_pruss? > > I presume this: > > > > cd /opt/scripts/tools/ > > git pull > > sudo ./update_kernel.sh > > sudo reboot > > > > > > will result in the latest kernel version (4.9.x??) which is not what I > > want... > > Nope, if you have v4.4.x-ti installed, that ^ will install the latest > v4.4.x-ti.. > > Regards, > > -- > Robert Nelson > https://rcn-ee.com/ > -- 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/fef93045-439c-4fd8-b7a2-5d431067dc7a%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
