• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 31 subscribers
  • Views 445 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Best Practices ??? for Custom USB Memory Stick bootloader for TM4C129ENCPDTI3

Bill Sousan
Intellectual 380 points

We have developed a custom bootloader program that copies a application bin files off of a USB memory stick and into the flash memory area above the custom bootloader memory area.  Everything seems to work well. 


My question is if others have done something similar and if so, did they use any of the processor's mechanisms for "locking" out the flash memory area where the custom bootloader resides?  Or are there other considerations I need to be aware of when using a custom boot loader (in order to prevent the processor from ever getting "bricked")

Thanks,

Bill

  • 0
    TI__Guru**** 244440 points

    Hello Bill,

    There is a Flash protection mechanism on TM4C which allows Execute Only. However for literal access the CPU needs to do a Read, which causes a Bus Fault. Though it will not brick the part, it would surely not let the boot loader run correctly.

    The simplest (and perhaps the only) mechanism that is available is to lock out the debug port by the boot loader in production release. This way the user cannot look at the Flash or any other peripheral making the device as a black box.

    Regards

    Amit