On Wed, Jun 24, 2009 at 03:18:24PM -0700, Kaz Kylheku wrote: > From: Kaz Kylheku <KKylheku@xxxxxxxxxxxxxxxxx> > Date: Wed, 24 Jun 2009 15:18:24 -0700 > To: Aurelien Jarno <aurelien@xxxxxxxxxxx>, linux-mips@xxxxxxxxxxxxxx > Subject: RE: Broadcom Swarm support > Content-Type: text/plain; > charset="us-ascii" > > Aurelien Jarno wrote: > > Hi all, > > > > I am still trying to get a Broadcom Swarm boot on a recent kernel. I > > have made some progress, but I am now stuck on another problem. > > > > I am using a lmo 2.6.30 kernel, using the defconfig > > [ snip ] > > > | Kernel panic - not syncing: Attempted to kill init! > > | Rebooting in 5 seconds..Passing control back to CFE... > > What kernel were you running prior to trying 30? > > When I migrated from 2.6.17 to 2.6.26, on a Broadcom > 1480 based board, I discovered that there is some kind > of instruction cache problem, which causes userland to > fetch garbage instead of code from its mmap-ped executables. > I could not get init to execute successfully. > > Sorry, I can no longer remember whether this problem was > SMP specific or not (like what you're experiencing); > it might have been. > > At some point in the kernel history, Ralfie decided that > the flush_icache_page function is unnecessary and > turned it into a MIPS-wide noop. But the SB1 core, which has > a VIVT instruction cache, it appears that there > is some kind of issue whereby when it > is handling a fault for a not-present virtual page, > it somehow ends up with bad data in the instruction > cache---perhaps an inconsistent state due to not having > been able to complete the fetch, but having initiated > a cache update on the expectation that the fetch > will complete. It seems that the the fault handler > is expected to do a flush. > > Anyway, see if you can work this patch (based on 2.6.26) > into your kernel, and report whether it makes any difference. The functionality of flush_icache_page() is being handled update_mmu_cache. The SB1 isn't the only MIPS CPU featuring VIVT caches - there are also the MIPS 20K and 25K CPUs and the virtually identical SB1A core. I've tested Linux on 20K and 25K just days ago and I get months of uptime on my BCM1480 box. What type of boot devices are you using, is it the onboard IDE controller by any chance? Ralf
