On 06/08/2017 11:23 AM, Noam Camus wrote: > > > *> From:* Vineet Gupta <Vineet.Gupta1 at synopsys.com> > *> Sent:* Thursday, June 8, 2017 7:38 PM > > >> > >> With simulator we just turn this configuration on, so we redirect the Legacy > >> Synopsys L2 ISR from nSIM into machine check. > >> This way we end up just like with silicon ? > > >This doesn't make sense :-) > >In simulation (where L2 interrupt is asserted), you need to handle it as such - > >say reading out the banked regs for L2 interrupt. What you are doing here is > >handling it like an exception which won't work . I really don't see the point of > >this "alignment" - hardware and simulation are different. simulation semantics are > >already supported by generic ARC code. And for silicon case, the existing vector > >woudl MachineCheck would work for both K and U. So I'm not sure what we are trying > >to achieve here ! > With EZsim we try to simulate NPS400 CTOP core and not ARC core, and as such we > strive to have similar echo system for both silicon and its simulator. Right, but if you are using nSIM which generates L2 interrupt for user mode error - then it is already different from silicon and needs to handled as such. > If we could, we would alter nSIM to behave just like our silicon. > So in current situation where we lack doing so we suffice in single pretty small > adjustment in OS (platform specific code). You are saying contradicting things here. Above u want EZSim to simulate CTOP (i.e. generate machinechk for U errors) but here you claim u use nSIM which will generates L2 intr. So I'm still grossly confused. What does EZSim (based on nSIM) do when bus error is triggered from User mode - does it raise (A) L2 interrupt or (B) MachineCheck ? If it is (A) the the existing common code in ARC will work - mem_service() -> do_memory_error() -> panic() if it is (B), again the common machinecheck handler will be called and will panic. I don't see the need to mix both (A) and (B) i.e. use mem_service() which is a L2 interrupt, but then handle it in MachieChekc which is for exceptions ? How is that supposed to work ! -Vineet
