Fault 1_1: 'ext_offset' is not in list

Embedded Security ChipWhisperer Hardware
1

Hi everyone,

I just started with hardware hacking (both the book and the jupyter notebooks) and I ran into a small issue on the first exercise.

I tested this with the CWLITEXMEGA (old version) and the CWHUSKY and the error comes up no matter what hardware I use.

So I managed to get working firmware on both CWs as well as the XMEGA and CW313(SAM4S) targets. I set all the scripts and nothing weird comes out until I try and run the actual loop part, then this error message pops up every time:

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I tried starting over, but it always comes up (checking earlier steps, I can see that ext_offset is there and set to 0, so I wonder why it tells me that ‘ext_offset’ is not in list.

Anyone ran into this before? I tried running the solution script to see if it was my loop giving the exception, but it seems to be at the beginning of the python code and not related to my part of the code or even the device itself.

My setup is a Windows PC with an up to date Kali Linux machine where I run Jupyter Notebook. Checked that my CW is properly hooked and I do get an ack.

I’m a bit at a loss here and unable to keep going with that part of the tutorials. I’ll jump to 1_2 for now and see if I can keep going, but still curious about why I get this error when I can see the variable being called in an earlier block.

2

There is no gc.set_range("ext_offset") here. Maybe you made some changes, or your repository is out of date?

The corresponding “solution” notebook does use ext_offset - I’m pretty sure the only reason that’s different is that we run those internally periodically to make sure nothing is broken and wanted to speed things up.

The solution notebook shows how you could add ext_offset to the list of parameters that are swept by the glitch controller: it needs to be added to the parameters list when you instantiate the glitch controller:
gc = cw.GlitchController(groups=["success", "reset", "normal"], parameters=["width", "offset", "ext_offset", "tries"])

1 Like
3

Hi JP,

Thanks for the reply! I had indeed not add ‘ext_offset’ in that chunk of code. Got a bit lost as to if or where I had to add it.

Bit of a skiddie when it comes to HW and CW. Thanks again for the help!