I should mention that our SDRAM is connected to the 8540's DDR controller, not LocalBus.
Aaron -----Original Message----- From: Cordes, Aaron M Sent: Thursday, August 12, 2004 2:34 PM To: 'wd at denx.de' Cc: linuxppc-embedded at lists.linuxppc.org Subject: RE: Linux 2.4.27-pre6-bk hangs on MPC8540 board Is there a way in Linux or the 8540 to prevent burst accesses, in order to test whether they are the problem? I scanned the processor's reference manual, but I didn't see anything that would let me do this. Thanks Aaron Aaron Cordes -----Original Message----- From: wd at denx.de [mailto:[EMAIL PROTECTED] Sent: Thursday, August 12, 2004 9:08 AM To: Cordes, Aaron M Cc: linuxppc-embedded at lists.linuxppc.org Subject: Re: Linux 2.4.27-pre6-bk hangs on MPC8540 board In message <EE7CAF713952AC4A970DD7CD8B4C12A042DCA7 at emss09m06.us.lmco.com> you wrote: > > We are bringing up an 8540-based board, and are getting hangs at > random spots when booting Linux. Sometimes the hangs occur while the > kernel is initializing, sometimes the boot gets far enough where I can > log in and run a couple of programs. Eventually the board locks up > with no oopses or panics. If I connect to the board with a debugger, > the processor is usually stopped in the Data miss exception handler, > and there is usually memory corruption in the kernel code. That's it: memory problems. > I ran memory tests using both Edink and U-boot and they all passed, so > I'm reluctant to blame hardware for the memory corruption. Has anyone > seen similar behavior, or have any suggestions of things I might try? All those memory tests only can test simple read and write accesses; they all fail to access burst mode accesses, which will happen when Linux starts runing, and which are failing. Your SDRAM initialization is bad, and the system crashes when it tries to fetch instructions from RAM. Note that simple read and write accesses may still work, it's the burst mode that is failing. It is NOT sufficient to program the memory controller of your CPU; each SDRAM chip also requires a specific initialization sequence which you must adhere to to the letter - check with the chip manufacturer's manual. Best regards, Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de If this is a service economy, why is the service so bad? ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
