Subject: Re: Using other Kernels
To: Jorge Ivan Rodriguez <yod@uclink4.berkeley.edu>
From: Bill Studenmund <wrstuden@loki.stanford.edu>
List: port-mac68k
Date: 04/07/1996 18:42:07
> 
> What is the proper procedure for installing a new kernel.  Do I simply cpin
> it to root and make sure it is named netbsd?  Is that all there is to it or
> do I need to somehow "sync" the kernel to my binaries?

Maybe. If the difference between the new kernel and the kernel for your
user-land binaries is limited to improvements of drivers, etc, then
you should be able to just use the new kernel. If, however, new features
have been added, you might need to re-compile certain binaries. Exactly
which ones need changing depends upon the differences between the kernels.

That said, I think the kernels everyone's distributing now should be fine;
keeping /netbsd pointing at the right thing is all you need.

Note: Don't forget to copy any working kernels you have before installing
a new kernel. Also, you can boot from a kernel named something other
than /netbsd. Maybe copy the kernel in as /netbsd.new, and tell the booter
to boot off of it.

Once booted, the kernel on disk is not read by the running kernel (which
is why the kernel can be on a MacOS disk). The kernel on disk is read by
certain programs which need to spy on the running kernel. By looking in
the one on disk, they can find where to look in the kernel's memory
space to find things like what processies are running, or what network
routs are active.

What I do is to have a couple of kernels lying around (netbsd.dist -
the 1.1 kernel - netbsd_new2, netbsd_new3, etc) and link the running
one to netbsd (ln -f /netbsd_new5 /netbsd). If I don't do much before
making /netbsd point to the right place, then I can boot off the new
and then change the link while the new one is running (while /netbsd
points to the wrong kernel).

Good luck!

Bill