From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <38EE0267.FB881499@embeddededge.com> Date: Fri, 07 Apr 2000 11:44:39 -0400 From: Dan Malek MIME-Version: 1.0 To: Pavel Roskin CC: "Wohlgemuth, Jason" , "'linuxppc-embedded@lists.linuxppc.org'" Subject: Re: Software Emulation Exception... References: Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: > > "Software Emulation %s/%d NIP: %lx *NIP: 0x%x code: %x" So, decode the address/instruction and see if it makes sense. > The problem has gone after upgrading to the Montavista kernel (from their > CDK 1.0) Since I know something about both of your custom board designs, I can say that the software is unlikely to be the trouble, although it could affect the problem. This exception is typical of custom designs that haven't properly designed the external device interfaces to the 8xx bus. I strongly suspect one of the external devices isn't working correctly, and when the processor is executing code from DRAM it gets some trash from the bus instead of the proper instruction. After something like this occurs, dump the memory at this address and check to make sure what the processor claims to have executed is really there. > However, I have no idea what caused the problem and whether it has been > fixed. If you haven't attached a logic analyzer, tripped the error, and verified the bus timing you will never know what caused it. Things like this don't fix themselves :-). These problems are sensitive to the instruction stream (the instruction pointer, the instruction itself, and access to the device). Moving the code around may appear to "fix" the problem, but it is still there waiting to happen once the product is shipping...... -- Dan ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/