Mbed Studio padding J-Link serial number with leading zeros, breaks pyocd

Mbed Studio Bugs
1

Hi,

Mbed studio appears to be padding the Serial number of J-Link’s when attempting to run pyocd.

For example:

Mbed studio is calling:

pyocd flash --uid 000123145678 --target k64f --erase=chip

For a j-link with a SN of 12345678. pyocd will wait for that j-link to connect for ever, where as

pyocd flash --uid 123145678 --target k64f --erase=chip

Will work properly.

Is there a way to work around this?

2

Hi Kyle,

Thanks for the feedback, this is unexpected behaviour. Would you mind sharing your log file using the feedback link in mbed studio so we can investigate?

Kind regards,

Rob

3

Sent

4

I’m aware this is a but of a thread from the dead but was there a resolution? As I’ve just hit this very issue in Mbed studio 1.4.3. I’m running on Windows 10 for my sins.

I have worked around this by adding a quick ‘fix’ to
\Mbed Studio\mbed-studio-tools\python\Lib\site-packages\pyocd\core\helpers.py

I added:

        if unique_id is not None:
            unique_id = unique_id.lstrip('0')

at the start of ‘get_all_connected_probes’ and all comes to life.

1 Like
5

Hi Tom,

Actually, this is still an issue for me. I don’t see that path on either my Mac OS nor my Windows Mbed Studio installs. Can you potential elaborate on where that file is?

6

Hi Kyle, on my windows install it is:
C:\Users<user>\AppData\Local\Mbed Studio\mbed-studio-tools\python\Lib\site-packages\pyocd\core

Not sure about on Mac.

7

Got this working on my mac! Path is:
/Library/Application Support/Mbed Studio/mbed-studio-tools/python/lib/python3.7/site-packages/pyocd/core/helpers.py

Someone should probably make a pull request on pyocd to fix this. Do you want to do it?

8

Looking at the pyocd github page this is a known issue:
PyOCD incorrectly truncates device Serial Numbers starting with ‘0’ · Issue #917 · pyocd/pyOCD (github.com)

Maybe they need some prodding to address it. I am guessing not many people are using the jlink probes due to the cost. I’m only using it because we have a box of them left over from legacy projects that used IAR and Keil.