Re: serial console device, and installboot vs. /boot.cfg

[Steve Rikli <sr%genyosha.net@localhost>]

On Thu, Feb 08, 2024 at 08:22:32AM -0500, Greg Troxel wrote:
> Some brief hints that may help:
> 
>   Read boot(8) after knowing that the first-stage boot blocks load /boot
>   which loads the kernel.  You need the first-stage ones to use the
>   right console to get good diagnostics.

OK, I believe that matches my experience; I didn't see boot messages or
menus etc. on serial console until re-configuring "Primary bootstrap" as
installboot(8) describes, no matter what I added to /boot.cfg .

>   I am 98% sure that the console from the first-stage boot is passed to
>   /boot.

I tend to agree based on my results, since /boot apparently followed my
console settings for the first-stage/primary boot blocks.

> about:
> 
> 4) what is "-o console=auto" intended to do with installboot? I tried
> 
> I think it's 'do some kind of default' which is sort of useful when you
> have no idea about the system hardware and no idea what somebody might
> want.  It does not seem like a good choice for someone who knows what
> they want.

Well, what I really want :-) is to be able to switch between a COM serial
port and a Pc keyboard without re-configuring NetBSD, and that's what I
was hoping for with auto.

"auto" activates the serial console in my config, but the Pc keyboard+VGA
sees no boot messages or menus, which feels like "auto" and "com0" are
effectively the same in my setup. More experiments warranted.

> FWIW on a pcengines apu2 (on which I run amd64 not i386 but I don't
> think that matters) I run:
> 
>   installboot -v -o console=com0 -o speed=115200 /dev/rwd0a /usr/mdec/bootxx_ffsv1

That looks close to what I did; I separately tried both these:

  installboot -v -o console=com0,speed=115200 /dev/wd0a /usr/mdec/bootxx_ffsv2
  installboot -v -o console=auto,speed=115200 /dev/wd0a /usr/mdec/bootxx_ffsv2

with the same (working) results as near as I can tell. installboot(8)
says options are comma separated, so I used my syntax rather than
multiple "-o" like in your example. Apparently equivalent?

> and my boot.cfg is unchanged from the install.  (Of course, don't copy
> this because your disk might be different and it might be ffsv2.)

Yes, I ended up with an unchanged /boot.cfg as well, since it didn't
seemm to be a determining factor in activating serial console vs. the
primary boot blocks config.

However, I also see in another message where martin@ describes different
syntax for consdev from what I had tried in /boot.cfg, so I'll check that
out as well.

Cheers,
sr.