Forcing a serial console for the kernel

["STEPHEN JONES, W0TTY" <smj%cirr.com@localhost>]

Is it possible to force a serial console for the install kernel  
available in
ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-5.0.2/*/binary/kernel/netbsd- 
INSTALL.gz ?

At the boot prompt defining consdev does not seem to have any affect.

The particular machine is several thousand miles away, so I do not  
have access to
a floppy or cd drive.

For a kernel that I've built, if I've set the option:

options        CONSDEVNAME="\"com\"",CONADDR=0x2f8,CONSPEED=9600

Is there anything else I need to use?  Shouldn't setting consdev at  
the boot
prompt allow any kernel with com support to redirect to the serial  
port anyway?

I've also looked using the new boot.cfg file and also installboot,  
but there does
not see to be a well documented method for setting up serial console  
support.