4 Replies Latest reply on Jan 11, 2012 4:41 PM by tedk

    debugging tool for SCC - P54C registers dump for Xen port

    peter.strazdins

      I have a summer scholar (its summer here down under ) investigating on porting Xen to the SCC (big task for a summer project!). Low-level debugging support  is going to be needed. So whule  sccDump dumps the SCC-specific registers, is there any tool which will  dump the P54C registers?

       

      Any other hints for this rather ambitious summer project are welcome!

        • 1. Re: debugging tool for SCC - P54C registers dump for Xen port
          tedk

          Debugging on the cores is a challenge. Here are some posts that might prove helpful. People have run gdb on a signle core. Many-core debugging is more problematical, but there is research in that area.

           

          http://communities.intel.com/message/138247#138247

          http://communities.intel.com/message/131244#131244

          http://communities.intel.com/thread/22876

           

          A while back I heard something about a Xen port to SCC being attempted in China, but I haven't heard anything in a while.

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          • 2. Re: debugging tool for SCC - P54C registers dump for Xen port
            tedk

            Looking at the new 1.4.2 beta I came across this statement .... and noticed the reference to gdb. I'll try it out. I'm thinking that with this xen port you might be interested in 1.4.2.

            • The Linux console contains serial ports “/dev/ttyS0” to “/dev/ttyS3” that are connected to “/dev/crbif0rb0cNNttyS0” to “/dev/crbif0rb0cNNttyS3” of the MCPC where NN is the core number. So the MCPC has 4x48 serial ports to the SCC cores.
              The crbif driver has been modified (new release, that comes with new sccKit) in order to provide the serial connections. They can be used e.g. to connect the core via minicom or telnet. They can also be used to attach a gdb remotely…
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            • 3. Re: debugging tool for SCC - P54C registers dump for Xen port
              peter.strazdins

              Many thanks for the tips Ted.  I thnk that writing to the serial ports is the best approach.

               

              I'm unsure of how to use gdb for this purpose as it requires OS services which wont be available before the hypervisor is up (correct me if I am wong).  

              • 4. Re: debugging tool for SCC - P54C registers dump for Xen port
                tedk

                To remote debug with gdb, you will need sccKit 1.4.2. And yes I think you may have to build a custom  SCC Linux. 1.4.2 is in beta.

                Do you have your own hw? We're setting up a 1.4.2 system here for people to login to to try out the beta or you can install it yourself on your own hw if you have it. The SCC Linux with 1.4.2 has what they've called virtual serial ports. I've tried them out with mnicom to see the console messages appear on the MCPC when booting SCC Linux. I haven't tried remote debugging yet ... if you can help with that, that woudl be great.

                 

                But if you are going to go with using serial ports, I'd recommend getting involved with the beta and the discussion about building a custom SCC Linux. The procedure has changed a lot since 1.4.1.3. sccLinux code will be on github. To get on the SCC Data Center 1.4.2 beta file a bug on our bugzilla under the product ADD ME to the SCCKIT BETA 1.4.2.

                http://marcbug.scc-dc.com/bugzilla3/

                 

                Message was edited by: Ted Kubaska: words left out