Frederick Bruckman <fb@enteract.com> writes:

> I'm trying to set up a 486 to use a real vt420 as a serial console.
> I've compiled and installed the boot-blocks, and it pretty much works,
> except it started doing something strange. After
> 
> 	root on sd0a dumps on sd0b
> 	root file system type: ffs
> 
> it just sits there. After hitting break to get into the DDB, then "c",
> it goes right on into multi-user. Any ideas?
> 
> Another thing. What's the difference between CONSDEV_COM0KBD and
> CONSDEV_COM0? The boot_console man page talks about CONSDEV_COM0, the
> Makefile in stand/biosboot suggests CONSDEV_COM0KBD. They both seem to
> do something. Could anyone explain the difference?
Since I did the change, I can explain.  CONSDEV_COM0 means use com0; If
there is no com0, you lose.  CONSDEV_COM0KBD means try com0, print out
a "challenge", if you get a response, use com0, otherwise use the 
machine's keyboard (KBD).  (Imagine having a laptop that you may take home
and not have a serial line to, iff its on the road.)  In spirit,
CONSDEV_COM0KBD is much like CONSDEV_AUTO.  The problem with the
latter is that it will try all serial lines and if it finds a serial
mouse or something else bad, you never come up.