Re: [9fans] ok, *init* is running on ts7200

[Charles Forsyth <forsyth@terzarima.net>]

>>Oh my goodness that's stupid. I wonder why they did that?

it's certainly annoying.  for x86 fans (and those processors
often need big fans) i should explain that
at least real mode in the powerpc, which sets you back
to the instruction before you enabled vm, isn't as bad as `real'
mode on the x86, which sets you back about 25 years.
the powerpc at least is much the same processor but with
VM switched off (but you've got to jump through a few
hoops to put it on again).  one popular way to switch the mmu back on
is to do a return-from-interrupt back into the trap handler,
having saved the state.  one reason is that just setting
the appropriate bits in the MSR might cause trouble (or might not).
either way, to save the state you've got to
address the appropriate kernel save area.
are those memory accesses cached in that state?
well ... it depends.