3 Replies Latest reply on Dec 3, 2018 11:43 AM by jafoste4

    How to read files from SD to DDR

    cattaneo.riccardo

      Dear all,

      I'm trying to design a ZedBoard based application exploiting partial reconfiguration.

      The system is FSBL based and runs a simple application which reads a full bitstream from SD, copy some partials into DDR and reconfigure a single partition as required.

      Unfortunately, while I can read and successfully configure the PL reading the full bitstream from SD card, I seem to be unable to read any other file into DDR.

      To do this, I used the "SD_TransferPartial" from the SW shipped with XUP1159 App Note.

      Specifically, I do the following:
      1) boot ("done" led on Zedboard is steady blue, PL is successfully configured)
      2) initialization of the addresses where the partials are going to be placed
      3) dump of these addresses. the initialization is successful
      4) invocation of SD_TransferPartial. The function does _not_ return any error
      5) dump of the addresses. They are still initialized with the original values
      6) invocation of the operation on the (reconfigurable) core instantiated on the PL with parameters 8 and 5, read the result which is 13 (the core is a simple adder). Success
      7) invocation of the partial reconfiguration (with a multiplier instead of an adder) reading the partial from the previous address. The function does _not_ return any error
      8) invocation of the operation on the (reconfigurable) core instantiated on the PL with parameters 8 and 5, read the result which is 13 (the core is _still_ a simple adder). Fail (it should be 5*8=40)

      So the problem is that the function is not placing any useful bit in the DDR. However, it opens successfully the file (I placed a xil_printf after the f_open function and it does work).

      Do you know how to address this issue?

      Best regards

      Riccardo

        • Update
          cattaneo.riccardo

          Hi,

          I managed to get a full log of the execution. Here it is



          ---PARTIAL RECONFIGURATION FOR ZEDBOARD---

          [START INITu2026]
          Address of adder: 9437184
          Allocated 59196 bytes for adder.
          Address of mult: 3145728
          Allocated 59196 bytes for mult.
          Executing a memset of the relevant address space with 'a'
          [INIT DONE!]

          [DUMP ADDER 9437184 FOR 59196 BYTES]
          a a a a a [u2026u2026u2026] a a a a a a
          [END DUMP OF 9437184 FOR 59196 BYTES]

          [DUMP MULTIPLIER 3145728 FOR 59196 BYTES]
          a a a a a [u2026u2026u2026] a a a a a a
          [END DUMP OF 3145728 FOR 59196 BYTES]

          [TRANSFERRING PARTIALS]
          Transfer Adderu2026 transferred!
          Transfer Multiplieru2026 transferred!

          [DUMP 9437184 FOR 59196 BYTES]
          a a a a a [u2026u2026u2026] a a a a a a
          [END DUMP OF 9437184 FOR 59196 BYTES]

          [DUMP 3145728 FOR 59196 BYTES]
          a a a a a [u2026u2026u2026] a a a a a a
          [END DUMP OF 3145728 FOR 59196 BYTES]

          [MEMORY MANIPULATION: SUCCESS.]

          [TEST FULL BITSTREAM FUNCTIONALITIES: ADDER]
          Execute additionu20268 and 5, result: 13
          [STARTING PARTIAL RECONFIGURATION...DONE]
          [TEST BITSTREAM FUNCTIONALITIES: MULTIPLIER]
          Execute multiplication...result: 13
          result: 13
          result: 13
          result: 13
          result: 13
          result: 13
          result: 13
          result: 13
          result: 13
          result: 13


          As you see:
          1) the memory is memset before the execution of the transfers
          2) the memory is dumped - the memory results memsetted correctly
          3) the memory is then loaded with bitstreams
          4) the memory is dumped again - the memory is still loaded with initialized values, so no actual transfer has been done
          5) execute functionality of the full bitstream (add 8 and 5, result is 13 as expected)
          6) reconfigure with partial whose location is expected to be at the declared address (3145728)
          7) execute multiple times the multiplication between 8 and 5, but result is still 13 (an addition and nt a multiplication)

          Conclusion: the SD_TransferPartial is not working in this case. While the function fails if the file is not found (I tried this) it does not fail when transfer fails. I also tried to read byte by byte but it still seems not to work correctly.

          Best regards

          Riccardo

          • Hi,
            samimalik

            Hi,
            I'm working on similar project. Can you give me little more detail of how you transferred your data from SD-Card to DDR and then from DDR to PL. And can you share .c file or related material because I'm beginner on zedboard...

            Thanks,
            Sami Malik

            • Hi Sami,
              jafoste4

              Hi Sami,

              For educational support, you will find better assistance asking for help at the Digilent support forum.

              Also, seeing at the previous post is near 5 years old, i'm unsure if you will receive a further response.

              -Josh