Re: Boot stops at loader after build/install cycle

From: Mark Millard <marklmi_at_yahoo.com>
Date: Fri, 14 Apr 2023 04:49:50 UTC
On Mar 30, 2023, at 10:40, Warner Losh <imp@bsdimp.com> wrote:

> On Thu, Mar 30, 2023 at 9:27 AM bob prohaska <fbsd@www.zefox.net> wrote:
> On Wed, Mar 29, 2023 at 06:09:00PM -0700, Steve Rikli wrote:
> > On Thu, Mar 30, 2023 at 12:24:13AM +0000, Marcin Cieslak wrote:
> > > 
> > > 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.
> 
> Where are you setting the serial console to 9600 baud? AIUI the
> Pi defaults to 115200, can it be set in config.txt?

[FYI: my context is 115200 based throughout.]

> The sequence ending in R is indeed "report cursor location" so it's the result
> of resizewin not reading it and leaving that around maybe? Or something else
> sending the Query Cursor Location and then not reading it.
> 
> https://www.cse.psu.edu/~kxc104/class/cmpen472/11f/hw/hw7/vt100ansi.htm

FYI: I just booted a 2023-Apr-13 snapshot and saw the behavior
for the first time: "0;200R" at the boot prompt (the window
being 60 lines by 200 columns). I had not seen this with the
Apr-06 snapshot or before, although normally my snapshot
updates have been very rare, not two weeks in a row.

I deleted the 0;200R text and typed boot to manually continue
the boot. (Yes: the "6" was not present.)

A "shutdown -r now" sequence did not get the problem.

It leaves me wondering about varaibility in the u-boot
to FreeBSD-loader transition's handling of things or
other sources of variability in the handling in the
loader.

I'll see if I can get a capture of the byte stream with
an example of the extra text (apparently via power-on).

===
Mark Millard
marklmi at yahoo.com