Nucleo-L433RC-P: Debug fails on first attempt but works on second

[freeflyer]

I am developing software on the Nucleo-L433RC-P board but have a strange situation when debugging.

The first time I debug, the software does not run and I get the following error...

Break at address "0x1fff2ce8" with no debug information available, or outside of program code.

Break at address "0x1fff2cd6" with no debug information available, or outside of program code.

As shown in the screenshot below...

However, the second time I debug it works correctly.

Why does it not work correctly on the first debug, but then works correctly on the second debug ?

I have tried two different boards (one of which is brand new and never been used) but the behaviour is the same, so it must be a software issue.

[michaeljyti]

second attempt. Here's how:

1. Software System Reset ensures the MCU starts correctly in user flash, avoiding the debugger halting in system memory (like 0x1fff2ce8).

2. BOOT0 LOW guarantees the MCU boots from your code in flash, not the bootloader.

3. Updated ST-Link firmware fixes known bugs that cause unreliable initial debugging behavior.

   <ul>
   <li>Set the <strong>Reset Mode</strong> in Debug Configurations to <strong>Software System Reset</strong>.</li>
   <li>Ensure <strong>BOOT0</strong> is pulled <strong>LOW</strong> to boot from flash memory.</li>
   <li>Update <strong>ST-Link firmware</strong> via STM32CubeIDE to ensure stable debugging.</li>
   </ul>

[michaeljyti]

1. Lines 11–15 likely have no impact and using malloc/free can risk heap corruption or stack overflow from unexpected interrupts.

2. Check that _Min_Heap_Size and _Min_Stack_Size are set correctly, and verify stack usage using stack painting methods.

<p>Removing lines 11–15 and avoiding <code>malloc/free</code> is wise, as heap misuse or stack overflow may be the real issue.</p>
<p>Ensure <code>_Min_Heap_Size</code> and <code>_Min_Stack_Size</code> are properly set, and verify stack usage with stack painting techniques.</p>