On Sat, 23 Jun 2001, Jun-ichiro itojun Hagino wrote:

> >For sparcs, 38400 seems to be the upper limit.  How about i386, can we go
> >ahead and put a baud rate of 115200?  If we put 115200, does it mean we have
> >to compile a custom bootloader, or does "biosboot_com0.sym" automagically
> >determine the baud rate and all that matters is "/etc/ttys"?
>
> 	dunno.  never tried any other speeds than default (9600).

NO! "/etc/ttys" is only for the getty. If you want a _console_ (boot
prompt, boot messages, debugger) yes, you must recompile for a
terminal speed that is not the default. What I would do is create a
new directory in /usr/src/sys/arch/i386/stand (say biosboot_115200),
copy ./biosboot_com0/Makefile into that directory, edit to taste
(change to "BASE= biosboot_115200" and "CPPFLAGS+= ...
-DCONSPEED=115200", at least) then either "make" or "make obj; make"
in that directory.

You can avoid the risk of making your system unbootable by testing the
new bootblocks on a floppy, first. Basicly,

  y | fdformat > /dev/null # no output if OK
  /usr/mdec/installboot -f -b 200 ./biosboot_115200.sym /dev/rfd0a

Reboot. If you can see the boot menu, and catch the prompt with the
space bar, it works. To complete the boot, you _must_ catch the boot
prompt, or it will try to boot the (nonexistent) kernel on the floppy.
At the prompt, type

  boot hd0a:netbsd

Before you go with a console speed of 115200, you might check that the
debugger works, too. Try sending a "break", then at the debugger
prompt, type

  ps
  c


Frederick