Nicolas Saurbier wrote:
> Hi,
> 
> you should change line "tty00 ...." for com0, "tty01. ...." for com2, etc.
> in "/etc/ttys". The std.115200 represents the line-speed (here 112500Baud).
> The last keyword "local" is just a comment, you can leave this out.

No, the word "local" is not a comment.
Read the manpage ttys(5). :-)
"local" tells getty to ignore the modem signal lines for the tty.

And the "std.115200" is not really the speed, but a string, which is 
matched to /etc/gettytab. As it happens, "std.115200" is a set of 
settings which just sets the serial speed to 115200... :-)
(But it could set it to 300 bps instead if it wanted to, and set all 
kind of other stuff as well.)

> I don't know how to activat changes without reboot, but after a reboot you'll
> have serial console.

As Jukka Salmi pointed out. This is not a console line, but simply a 
normal serial login terminal line. And a SIGHUP to the init process will 
force it to re-read the ttys file.

> For a Kernel that outputs to serial console, you'll need
> to recompile the kernel an set following params:

That is what a serial console is. The console is where the system 
outputs system information. Serial or otherwise.
A login process is totally unrelated to the console.

:-)

	Johnny