option for "boot to kernel.old"

[Paul Herman]

On Sat, 13 Nov 2004, Matthew Dillon wrote:

   And, even better... if someone does a 'make installkernel' more then once
   without rebooting it shouldn't overwrite kernel.old the second time, and
   if someone does a 'make installkernel' while *running* kernel.old it
   shouldn't overwrite kernel.old either.
While we're throwing out ideas...  :-)

I've always had on my wishlist a way to optionaly have /kernel 
"expire" in such a way that if the timestamp on /kernel is older 
than, say, 10 minutes, then boot from /kernel.old.

The option to "testboot" /kernel would be enormously useful if you 
don't have physical access to a machine and the newly installed 
kernel for some reason doesn't boot.  Just have someone hit the 
reset button 10 minutes later.

I think the only real hacking needed would be to make /boot/loader 
aware of the CMOS clock.  It's been something I've been looking to 
do, just haven't gotten around to it.

-Paul.