From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3B4F5BE9.6258498B@mvista.com> Date: Fri, 13 Jul 2001 16:36:57 -0400 From: Dan Malek MIME-Version: 1.0 To: Adam Wozniak Cc: linuxppc-embedded@lists.linuxppc.org Subject: Re: mmu problems References: <3B4F412F.99A14D9E@comdev.cc> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Adam Wozniak wrote: > I suspect there's something about the MMU that's not being configured > properly, but I don't really know where to start. Everyone assumes there are bugs in things they don't understand. While there is always the possibility of something wrong, there are lots of 8260s running Linux without trouble. The same MMU code is used on all 6xx platforms, which includes lots of Macs that have been running for years. I suspect you have a memory controller or other hardware design problem with your board. I have worked with many hardware engineers debugging memory interface problems once Linux is running. There just aren't any diagnostics that exercise a system like Linux does. The combination of cache, burst cycles, dma, and other simultaneous resource uses always show design/implementation bugs you have never seen before. You are describing the classic symtoms some of us have seen many times before. Adam Wozniak wrote: > NIP: C0005F80 XER: 00000000 LR: C000CF9C SP: C3417D30 REGS: c3417c80 > TRAP: 0700 MSR: 00089032 EE: 1 PR: 0 FP: 0 ME: 1 IR/DR: 11 You forgot the most important function from System.map, the one at NIP. Also, that MSR is bogus. Somewhere, something was fetched from memory that had bit 12 set. We never do this in software, and the hardware should always have it cleared. -- Dan ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/