Re: Serial UART on RPi3

[Dustin Marquess <dmarquess%gmail.com@localhost>]

I did.  I even tried enable_uart=0 and that didn't seem to have any
effect, eg dmesg still shows:

[     1.000003] com0 at simplebus1: BCM AUX UART, working fifo
[     1.000003] com0: console

And I still see output on the GPIO pins, but now there appears to be
some baud mismatch or something as the output is garbled, but it's
still there.

-Dustin

On Sat, Dec 22, 2018 at 1:24 PM Jared McNeill <jmcneill%invisible.ca@localhost> wrote:
>
> Did you remember to remove enable_uart=1 from /boot/config.txt as well?
>
> On Sat, 22 Dec 2018, Dustin Marquess wrote:
>
> > [ Resending in plain text, sorry about that ]
> >
> > Sorry if this is already documented somewhere.  I didn't see anything
> > obvious on http://wiki.netbsd.org/ports/evbarm/raspberry_pi/ and my
> > searching didn't find an answer either.
> >
> > I have an Uputronics GPS "HAT" on my RPi3 running a GENERIC64 build of 8.99.28.
> >
> > I got gpiopps and everything working, the last piece is the actual
> > NMEA/U-Blox data feed.  I believe I have two particular problems:
> >
> > 1) I can't seem to figure out how to get the kernel to use the
> > HDMI/wsdisplay/wscons as the system console instead of com0.  I've
> > tried tinkering with /etc/ttys & /etc/wscons.conf and nothing.
> > /boot/cmdline.txt already has "console=fb".
> >
> > 2) I have a feeling that the system is using the default of mapping
> > GPIO 14/15 to the BCM AUX UART instead of the ARM PL011 UART.  Since
> > overlays don't seem to work, do I need to modify
> > /boot/bcm2837-rpi-3-b.dtb to accomplish this? I'm assuming so.  If so,
> > that part I've done before.
> >
> > Thanks!
> > -Dustin
> >
> >