Re: Boot stops at loader after build/install cycle

On Thu, Mar 30, 2023 at 12:24:13AM +0000, Marcin Cieslak wrote:
> On Wed, 29 Mar 2023, bob prohaska wrote:
> 
> > If not maybe try  different hardware (cables, usb-serial adapters,
> > power supplies and so on) with an eye to any changes of behavior.
> > At this stage making the problem worse might be more useful than
> > making it better. Disconnecting the serial-end ground might be
> > worth a try. If the connection still works it suggests you have
> > multiple grounds, which can cause trouble. I ended up lifting
> > the ground on one of my serial connections. AFAIK both Ethernet
> > and USB power supplies are floating, so multiple grounds are very
> > unlikely. But something might be faulty.
> 
> The characters look too regular to me, just like a normal terminal
> codes, not a line noise. I test the device now powered from the
> same USB hub as the USB-serial converter. Rockchip needs 1500000 bps
> console, pretty fest.

OK, then let's assume your serial cables & hoods etc. are OK for the
moment. What does serial console config on the rpi look like?

When I specified the rpi4 serial console speed in the config to match my
serial terminal server, rather than let it "float" (default 9600), my
loader interruptions stopped, and no more stray characters on the serial
console after boot either.

> Also, uboot autoboot prompt never gets interrupted.
> 
> I also noticed that "resizewin" complains about not getting
> information about the terminal upon login on the serial console
> while being in the vt(4) text mode.
> 
> Looks like the bootloader tries to send/receives some terminal control
> sequences and this fails, interupting the autoboot.

It may be something along those lines. When I was getting loader stops
during reboot on my rpi4, my guess was the default FreeBSD speed 9600
vs. my serial terminal server setting of 115200 was causing stray
characters on the line during boot, loader interpretted that as a
keystroke, so it stopped.

Cheers,
sr.