Hi folks. A minor issue we ran into with some of the work we're doing at Google is that on an ARM CPU, the CNTFRQ register needs to reflect the clock rate of the timer, and that timer seems to run at the CPU clock rate, at least how things are set up for us.
The problem is, there doesn't seem to be anything that updates that register on clock changes. We have things set up so that when the system first starts the clock "changes" to its initial value, but that isn't reflected in the CNTFRQ register. There may be some bit of setup code we're missing somewhere which should handle this initial setup for us (I'll take a look for it shorly), but I was wondering how this is supposed to work in general. Is there a mechanism or plan for one that I'm not aware of? I suspect in a real system there would either be hardware which orchestrates the clock rate change and then lets firmware know with an interrupt, or a bit of firmware which is called into to change the clock which, as part of its executing, would update that register. We have a workaround at the moment which should get things going for us, but I'd like to keep in line with existing code as much as possible. Gabe _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
