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SW-EK-TM4C129EXL: Boot Serial Example not Working

Part Number: SW-EK-TM4C129EXL
Other Parts Discussed in Thread: UNIFLASH, EK-TM4C1294XL


I am using the boot_serial example from the SW-EK-TM4C129EXL and have followed the procedure outlined in the document Getting Started with TivaWare for C Series ( Literature Number SPMU373 of March 2021). I am using Code Composer Studio  version and LM Flash Programmer build 1613. I am following the procedure described by the documentation referenced in Chapter 6 TivaWare Boot Loader. I have gotten example projects from the Project Wizard example explorer in a fresh works space. I performed the modification to the APP_BASE to 0x00004000 to account for the difference in the procedure between the chapter 6 example of TM4C123 and TM4C129. I have compiled the boot loader and flashed the Device using the ICDI with CCS. Switched over to the LM Flash Programmer and followed the steps to set up the code manually according to the specifications of the documentation account for the larger size of the Memory pages in TM4C when setting the Program Address Offset (0x) 4000. At this point I get this error.

To verify as much as possible I loaded up the boot loader using the LM Flash Programmer, used Uniflash to verify the code was in the correct memory location and this was confirmed. I can also use Uniflash to download all of the Flash contents of the Device to verify that I can load both the boot loader serial and the hello world program together without deleting their memory contents.

At this point I am faced with the wall that most documentation is insufficient or has been removed from the locations stated here. I also cant find good enough documentation on the board model to help specify how to configure the board correctly with the jumpers. I am using the available documentation of Tiva C Series TM4C1294 Conected LaunchPad Evaluation Kit  (literature number SPMU365C) and TM4C Series TM4C129E Crypto Connected LaunchPad Evaluation Kit ( literature number SPMU372A).  I also noticed a issue with the configuration file of the device based on the documentation. The Flash page size is being set to 1kB instead of the aforementioned 16kB stated in the SPMU373 documentation.

Note: There are warnings in the boot loader when compiling. If I change the project compiler version then that warning disappears but the other two remain. I have tried to download the version of the compiler this was made with. With no success.

Best regards,

Stephen G

  • Hello Stephen,

    I have to deeply apologize here.

    It looks like the wrong image was used for Section 6.2 which shows how to configure LM Flash Programmer.

    I will see that this gets addressed promptly and the image is correctly updated.

    These are the setting you should be using for the boot loader:

    I expect that once you use these corrected settings with the boot_serial example for EK-TM4C1294XL, you will be able to connect to the boot loader.

    Best Regards,

    Ralph Jacobi

  • Hi Ralph,

    I tried the configuration based on the picture you sent and I still think this is still not working. The solution I found is to CHECK the Disable Auto Baud Rate Support. This is already disabled in the example bl_config.h file and is using the Fixed Baud Rate of 115200.

    The transfer size therefore has no impact. For example I set it to 20 in trying to understand its interaction with the #define BUFFER_SIZE 20.

    I configured some probes to monitor the RX and TX on the defined GPIO pins PA0 and PA1 respectively. I was able to see that when in Auto Baud rate configuration for the boot_serial the TX pin is being driven to 0.

    Can you comment on the issue I mentioned about the page/sector size?

    Best regards

    Stephen G

  • Hi Stephen,

    I'm really making us look incompetent it seems.

    It was 100% my intention to have that box checked but I was testing all iterations to confirm it was required to disable Auto Baud support and managed to post the wrong configuration.

    Auto Baud should be disabled and it is 100% correct to check that box to disable it.

    I haven't tinkered with transfer size much or the interaction with the buffer size so I can't shed much light there - I've always used 32. In general the buffer size would be important more at higher speeds. We use a larger buffer and transfer more packets for example using 460800 baud because the speed of the transfer then shows a tangible difference by sending more bytes per packet. I believe for 115200, the time between transfer is slow enough that the buffer gets emptied before it is fully filled and therefore 32 on transfer vs 20 in the buffer works fine. You can always set that higher up to the listed maximum if you want. I may consider putting an 'improvement' suggestion in to visit 20 vs 32 as a default given LM Flash defaults to 32.

    The Flash page size is being set to 1kB instead of the aforementioned 16kB stated in the SPMU373 documentation.

    That should be 0x4000 yes, I will have to go back through our bug logs because I had thought this was address in a prior TivaWare update so I need to see what occurred there. In any case I'll submit a bug ticket so that is address in any future update we do.

    Best Regards,

    Ralph Jacobi