Linux boot with NO writes?

Is it possible to boot Linux without writing to media?

Let me explain. Knoppix and the like boot from a CD but they create a
RAM drive to write the boot log and other information. What if I didn't
want to make a boot log for whatever reason? Like, the RAM size was
limited and I didn't want to use it up with log data.

Another way to ask it is: Can the log and ALL other writes at boot time
be piped to /dev/null? I assume in would be a pain simply because each
service started in the boot would have to be redirected or have the log
disabled.

In answering the question, it would be safe to assume that this is a
specialized environment, like an embedded application.

Alan