nathan binkert wrote: >> How does switching in and out of PAL mode work? Could we take advantage >> of that somehow? I don't have a really good idea of how that might help. >> I'm just throwing the idea out there. >> > Basically, the callpal instruction is like a branch, but it also sets > the mode bit (and enables the pal shadow registers and stores the > return address in a different place). rti (return from interrupt, I > think that's what it is called) is like a normal ret, but it undoes > everything. We could certainly record somewhere the pal state. We > don't have to only store it in the PC. It does need to remain in the > PC though because my guess is that some of the PAL code would depend > on that bit being there. > > Nate > _______________________________________________ > m5-dev mailing list > [email protected] > http://m5sim.org/mailman/listinfo/m5-dev >
It might work to make callpal and rti SerializeAfter if they aren't already (or we may have to force a flush) and have them set a PAL bit in some control reg somewhere. Then the TLB can use that and ignore the PC. That would probably make those instructions perform worse, though. Gabe _______________________________________________ m5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/m5-dev
