Windows 10, ERROR:ChipWhisperer Target:Target did not ack

[fipio]

Hi
I have a problem with the errors and warnings that appear:

• “ERROR:ChipWhisperer Target:Target did not ack”
• “Warning: Device failed to ack”

I use software:
I tried ChipWhisperer 5.5.2 versions: Windows Installer and Virtual Machine (VirtualBox). The error shows up in both.

I use hardware from the Level 2 Starter Kit (SCAPACK-L2):

• CW308 UFO Board
• ChipWhisperer-Lite (Model: CW1173)
• STM32F board (sticker F303) - STM32F303RDT6

The USB cable is directly connected to the PC. I tried several USB cables, different USB inputs (3.2, 2.0).

The error appears when executing the code in Jupyter Notebook, e.g .:

• SOLN_Lab 3_1 - Large Hamming Weight Swings
• SOLN_Lab 3_3 - DPA on Firmware Implementation of AES

+--------------------------------------------------------
+ Built for platform CW308T: STM32F3 Target with:
+ CRYPTO_TARGET = TINYAES128C
+ CRYPTO_OPTIONS = AES128C
+--------------------------------------------------------
Detected unknown STM32F ID: 0x446
Extended erase (0x44), this can take ten seconds or more
Attempting to program 6383 bytes at 0x8000000
STM32F Programming flash...
STM32F Reading flash...
ERROR:ChipWhisperer Target:Target did not ack
Verified flash OK, 6383 bytes
---------------------------------------------------------------------------
Warning                                   Traceback (most recent call last)
~/work/projects/chipwhisperer/jupyter/courses/sca101/Lab 3_3 - DPA on Firmware Implementation of AES (HARDWARE).ipynb in <module>
      9 key, text = ktp.next()
     10 
---> 11 target.set_key(key)
     12 
     13 N = 2500

~/work/projects/chipwhisperer/software/chipwhisperer/capture/targets/SimpleSerial.py in set_key(self, key, ack, timeout)
    533             if ack:
    534                 if self.simpleserial_wait_ack(timeout) is None:
--> 535                     raise Warning("Device failed to ack")
    536         else:
    537             target_logger.debug("Key unchanged, skipping send")

Warning: Device failed to ack

---------------------------------------------------------------------------
Warning                                   Traceback (most recent call last)
<ipython-input-2-3902592a4978> in <module>
      1 if VERSION == 'HARDWARE':
----> 2     get_ipython().run_line_magic('run', '"Lab 3_3 - DPA on Firmware Implementation of AES (HARDWARE).ipynb"')
      3 elif VERSION == 'SIMULATED':
      4     get_ipython().run_line_magic('run', '"Lab 3_3 - DPA on Firmware Implementation of AES (SIMULATED).ipynb"')

~/.pyenv/versions/3.7.7/envs/cw/lib/python3.7/site-packages/IPython/core/interactiveshell.py in run_line_magic(self, magic_name, line, _stack_depth)
   2342                 kwargs['local_ns'] = self.get_local_scope(stack_depth)
   2343             with self.builtin_trap:
-> 2344                 result = fn(*args, **kwargs)
   2345             return result
   2346 

~/.pyenv/versions/3.7.7/envs/cw/lib/python3.7/site-packages/decorator.py in fun(*args, **kw)
    230             if not kwsyntax:
    231                 args, kw = fix(args, kw, sig)
--> 232             return caller(func, *(extras + args), **kw)
    233     fun.__name__ = func.__name__
    234     fun.__doc__ = func.__doc__

~/.pyenv/versions/3.7.7/envs/cw/lib/python3.7/site-packages/IPython/core/magic.py in <lambda>(f, *a, **k)
    185     # but it's overkill for just that one bit of state.
    186     def magic_deco(arg):
--> 187         call = lambda f, *a, **k: f(*a, **k)
    188 
    189         if callable(arg):

~/.pyenv/versions/3.7.7/envs/cw/lib/python3.7/site-packages/IPython/core/magics/execution.py in run(self, parameter_s, runner, file_finder)
    722             with preserve_keys(self.shell.user_ns, '__file__'):
    723                 self.shell.user_ns['__file__'] = filename
--> 724                 self.shell.safe_execfile_ipy(filename, raise_exceptions=True)
    725             return
    726 

~/.pyenv/versions/3.7.7/envs/cw/lib/python3.7/site-packages/IPython/core/interactiveshell.py in safe_execfile_ipy(self, fname, shell_futures, raise_exceptions)
   2829                     result = self.run_cell(cell, silent=True, shell_futures=shell_futures)
   2830                     if raise_exceptions:
-> 2831                         result.raise_error()
   2832                     elif not result.success:
   2833                         break

~/.pyenv/versions/3.7.7/envs/cw/lib/python3.7/site-packages/IPython/core/interactiveshell.py in raise_error(self)
    329             raise self.error_before_exec
    330         if self.error_in_exec is not None:
--> 331             raise self.error_in_exec
    332 
    333     def __repr__(self):

    [... skipping hidden 1 frame]

<ipython-input-2-cd2a822a193f> in <module>
      9 key, text = ktp.next()
     10 
---> 11 target.set_key(key)
     12 
     13 N = 2500

~/work/projects/chipwhisperer/software/chipwhisperer/capture/targets/SimpleSerial.py in set_key(self, key, ack, timeout)
    533             if ack:
    534                 if self.simpleserial_wait_ack(timeout) is None:
--> 535                     raise Warning("Device failed to ack")
    536         else:
    537             target_logger.debug("Key unchanged, skipping send")

Warning: Device failed to ack

[Alex_Dewar]

Hi,

The device should acknowledge each serial message we send to it. Typically, if this doesn’t happen, it means serial isn’t working for some reason.

Can you try uncommenting the

putch('h');
putch('e');
putch('l');
putch('l');
putch('o');

line in chipwhisperer/hardware/victims/firmware/simpleserial-aes/simpleserial-aes.c. Then rebuild the firmware, reprogram the STM32F3, and run the following code:

print(target.read())

This just causes the target to print a “hello” message after boot so we can confirm that the device is starting up, serial is working, the baud rate is correct, etc.

Alex

[fipio]

Thanks for your reply.
I uncommented lines from putch (). Then I rebuilt the firmware, reprogram STM32F3 and print.
Unfortunately, the “hello” text did not appear.

[Alex_Dewar]

Hi,

Can you verify that J3 is jumpered on HS2/OUT and that the VCC3.3 LED is on? Also, if you try building with PLATFORM=CWLITEARM, do any of LED1-3 turn on?

Alex

[fipio]

Thanks for your reply.

yes, J3 was jumpered on HS2/OUT.
3.3V LED is on - (LED 5 is on, LED8 is on).
LED2 and LED3 are on when the program prints ‘hello’.
LED2 and LED3 are turned off when the program does not print ‘hello’.

I tried again today and it printed hello.
“<ihello”
… I did not change the jumpers, USB.

The problem with the error (Target did not ack) and not writing ‘hello’ sometimes occurs.

To get rid of the error I did:

• disconnect the USB cable from Chipwhisperer Lite
• close the current tab in the browser
• In Jupyter, the Running tab, click “Shutdown” of the active Notebook
• open target file
• click ‘Kernel -> Restart and Clear Output’
• plug the USB cable to Chipwhisperer Lite
• executes the necessary instructions and cw.program_target ().
  The text “hello” appears

Now when I click ‘Cell-> All Output-> Clear’ or ‘Kernel-> Restart & Clear Output’ and execute the code again (cw.program_target ()) the error sometimes reappears. Something gets stuck somewhere, I don’t know if it’s in Jupyter or on the PCB.

[Alex_Dewar]

One last thing to try: can you try replacing cwlite.py at chipwhisperer/software/chipwhisperer/hardware/firmware with the one at this link? https://raw.githubusercontent.com/newaetech/chipwhisperer/5.1.3/software/chipwhisperer/hardware/firmware/cwlite.py.

Alternatively, you can run this block in one of the notebooks in the jupyter folder:

%%bash
cd ../software/chipwhisperer/hardware/firmware
git checkout 5.1.3 cwlite.py

Then try rerunning the capture. This replaces the current FPGA bitstream with an older one that handles clocking more reliably.

EDIT: Also, we can just do a replacement if easier. Let me know

Thanks,

Alex