How to have quieter bootup messages?

[Jose Marin <jose@ma.hw.ac.uk>]

No, I don't mean the messages from the init scripts (I guess you can use
the VERBOSE variable in /etc/default/rcS for that);  I mean the bootup
messages from the _kernel_, the ones you can read again with dmsg. 

I searched the file /usr/src/linux/Documentation/kernel-parameters.txt
and the BootPrompt-HOWTO, but I'm still not sure how to do this.  Would
you set the console kernel parameter to /dev/null or is that too drastic?
Maybe /dev/ttyS0?

I guess what I really want is something like "dmesg -n 1" to be applied
during bootup time.  Can I specify "console_loglevel" as a kernel
argument?  It's mentioned in the HOWTO but not in kernel-parameters.txt.

TIA,

Jose

PD:  If you wonder why I want this:  I have some machines which dual-boot
on an automatic schedule between Linux and NT, and they do so via LILO
_and_ Linux.  I just don't want the people using NT to realize that
they're being booted for a couple of seconds into Linux before they're
really booted into NT.