On Sunday 08 June 2008, Maciej W. Rozycki wrote: > On Sun, 8 Jun 2008, Luke -Jr wrote: > > the bcm63xx patches OpenWrt has that I'm using as a base for this... > > It would be best if the patches you are referring to got merged with the > mainline. Otherwise whoever uses them is essentially on their own -- > people lack the resources needed to chase random changes out there in > general. Is merging with mainline something I can help with, being a beginner in this area generally and not having any part in writing them? > > > That's grossly wrong. If you need to preset it for the time being > > > till you debug calibration, then for a MIPS processor assume one > > > instruction per clock tick and two instructions per loop -- that may > > > not be entirely correct, but is a good approximation. Otherwise you > > > risk peripheral devices are not driven correctly with all sorts of the > > > nasty results. > > > > Meaning this? > > preset_lpj = loops_per_jiffy = 2; > > Not exactly. Try harder -- this is simple arithmetic and you've got all > the data given above already. :) 200 / 2? I'm not really sure what a 'jiffy' is.. > > > and (b) control being transferred to a block of memory that isn't > > > actually code, as can happen if exception vectors or global > > > pointers-to-functions aren't set up correctly, or if the kernel stack > > > is being corrupted. When you say "the instruction in question is a > > > store word", how do you know that? > > > > The RI error spits out a bunch of info, including epc which presumably > > points to the instruction causing the problem: ac85ffc0; this is 'sw > > a1,-64(a0)' > > I have seen that already and wrote these stores in __bzero are protected. > Perhaps the fixup fails for some reason, but you need to investigate it > and this is why I suggested to see how the RI handler is reached. Since > this is a known point the failure leads to, you should be able to work > backwards from there quite easily. Ah, so what you're saying is that perhaps the 'sw' is triggering a TLB exception, and the handler for *that* is causing the RI problem? Thanks, Luke
