From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3A42057C.6449819F@nexus-tech.net> Date: Thu, 21 Dec 2000 08:28:28 -0500 From: Kyle Harris MIME-Version: 1.0 To: Jerry Van Baren CC: linuxppc-embedded@lists.linuxppc.org Subject: Re: Software Emulation error References: <4.3.2.20001221073632.00bb81f0@falcon.si.com> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Jerry Van Baren wrote: > > Scrogged memory, bad code. You are trying to execute a floating point > instruction and your processor doesn't support floating point (or it is > disabled). Memories like to go to 0xFFs and that is a floating point > instruction. Most floating point instructions are 0xFE and the 'D' > field supplies the remaining '1' bit. I don't see any valid > instructions for 0xFFFFFFDA (they all have a reserved field of '0's in > them), but the op-code causes a floating point trap if you don't have > floating point available/enabled. > > I assume memcp/44 is line 44 in memcp. I would check the parameters to > the memcp() call to make sure you aren't copying garbage over > yourself. If you can look at the assembly code and registers, make > sure the destination wasn't 0x398c8d84 (next instruction pointer - 4). > > How was my guess? Did I win $1,000,000 :-)? It would be easier if you > tell us the processor and more about your system. Sorry, I guess more detailed info would be helpful. I'm running a 2.2.13 kernel on a TQM823 board. I have seen this error when using dd to write to flash. But it's not consistent (sometimes dd works, sometimes it doesn't). Then I wrote a program using the times() function and it always fails. I went back and tried this with the original kernel and it works! I recompiled with and without MATH_EMULATION, but essentially get the same error. I've tried rebuilding the kernel to what I think are default settings, but still no luck. What other kernel configs are relevant? I'll put your name in the drawing for the $1M. :) Thanks, Kyle. > At 09:20 PM 12/20/00 -0500, Kyle Harris wrote: > > >Hi, > > > >I've encountered the following error several times while running various > >programs. This one comes from a process attempting to call the times() > >function. > > > >Software Emulation memcp/44 NIP: 18424a0 *NIP: 0x398c8d88 code: ffffffda > >Illegal Instruction > > > >Can anyone give me a clue as to why this happens? > > > >Thanks, Kyle. > > > ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/