Lab3: 3.2 Context switch register

[Victor Wu]

For 3.2, the problem doesn't specify which type of target machine to run
the g-cache modules. When I tried it on the tango x86 machines, simics
would complain:

simics> run-command-file add-twolevelcache.simics
[cpu0 info] instruction-cache-access-trace can not be used with an x86
processor. Using instruction-fetch-trace instead.
Traceback (most recent call last):
File "add-twolevelcache.simics", line 69, in ?
@conf.phys_mem.timing_model = conf.id
AttributeError: 'module' object has no attribute 'phys_mem'

And if ran it anyway, no statistics would ever be collected.

However, when I run it for the bagel machine of the past labs, there are
no problems with attaching the cache but I can't find the context
register cr3. I'm guessing this specific register was for the x86
machine, so does anyone know which register handles the context switch
for the bagel machines?