Debugging your Model T Using GDB

• At the top of the directory run the following in terminal:

openocd -f interface/jlink.cfg                      \
        -f target/stm32f2x.cfg                      \
        -f stm32f2x-setup.cfg                       \
        -c init                                     \
        -c "reset init"                             \
        -c halt                                     \
        -c "stm32f2x.cpu configure -rtos auto"

• In another terminal run:

arm-none-eabi-gdb build/app_mt/app_mt.elf                   \
                      --eval-command "target remote:3333"   \
                      --eval-command "monitor poll"         \
                      --eval-command "monitor reset halt"

You can now debug in the gdb window. Some useful commands:

• monitor reset halt
  • Resets the device and stops it so you can setup a new session
• info threads
  • Shows a list of the current ChibiOS threads, their states and current program counters
• thread <#>
  • Where <#> is the thread id from the 'info threads' list
  • switches to that thread context
• thread apply <#> bt
  • Shows a backtrace for a given thread
• Printing dbg_panic_msg should help narrow down which error happened
• If a hard fault exception is generated, you can inspect the registers that are dumped to stack variables in the handler
• PC (program counter) and LR (link register) will be of most interest Information on those registers is in the .map file