First let me say I had this idea about 2 years ago after learning about
Recoverable Virtual Memory and doing persistant databases. I eventually
came to the conclusion that it was a great idea provided only one OS was
involved.
> The Tadpole Sparc notebooks would dump all of the state machine to
> either a special file or swap (can't recall which) and then just load
> that machine image. It would, I believe, tell each device to
> shutdown. On reload it would reinialize everything. I'm pretty sure
This is at least what would have to be done to get the machine back into
the state it was in, but what happens to things like cache controllers
etc..
As for the running programs what happens if my calendar program has just
finished displaying my appointments for the day and issues a sleep for
24hrs I then "dump" the whole OS and don't restart for 3 days, the
calendar program then sleeps for 23hrs 59minutes and shows me the
appointments for 2 days ago.
Okay this is bad way to implement a calendar program but is serves a
purpose to demonstrate that dates etal could get seriously screwed up with
this sort of boot strategy.
> totally chaotic. Open files were still open, however, and programs
What if one of the open files was on your mounted dos partition and the
user switched to dos and used the file, eg deleted appended... This could
cause major problems!
Please don't let me put you off this, I think it's a great idea but it has
many considerations if your intention is to switch between different OSes.
Personally I just leave my machine in Linux and only reboot to play games
in dos (which is all that is on my other partiton other than games - ie no
windows or anything else!), the other reason I leave my machine on is my
CMOS battery is flat and at 13quid I would spend less electricity leaving
it on than to buy a new battery :-)
-- Darren J Moffat