Agree. Absolutely awesome article except for this one little line:
> Ensure the patches to the calibration values are safe before using.
How would you do that? I've worked on both ends of steering on VW Bugs and Golfs (steering column fixes and tie rod replacements). You don't want to mess either of these up either, but the repairs are (a) well documented and (b) relatively easy to verify you did them correctly.
By contrast, I've seen software break catastrophically in the past from "harmless" updates like changing the number of commas in a version string. In this case it's not the kinda doesn't work problem but hitting an unexpected corner case on the freeway that would worry me.
The calibration values were discovered through static analysis, so the code referencing those values can be followed to determine if unexpected side effects may be present. Obviously this process is imperfect, but it's not like blindly throwing bytes in and hoping something comes out.
I'm not a big advocate for comma/OpenPilot or EPS patching stuff in general, but I thought the patch in this example was fairly benign and reasonable as these things go - it was a data patch to the calibration area rather than a code patch, and the altered calibration contained relatively straightforward values with clear references and obvious effects.
> Ensure the patches to the calibration values are safe before using.
How would you do that? I've worked on both ends of steering on VW Bugs and Golfs (steering column fixes and tie rod replacements). You don't want to mess either of these up either, but the repairs are (a) well documented and (b) relatively easy to verify you did them correctly.
By contrast, I've seen software break catastrophically in the past from "harmless" updates like changing the number of commas in a version string. In this case it's not the kinda doesn't work problem but hitting an unexpected corner case on the freeway that would worry me.