> Not entirely true, publishing the code isn't the same as allowing its modification. Code signing can be used to limit which versions are allowed to run.
If I can't run my home-compiled versions of your code - whether because of code signing restrictions or because of federal law prohibiting firmware that hasn't been certified - it's not free[0]. So without without reproducible builds, providing the source code for the firmware provides very little benefit (since I have no way to prove that the code corresponds to what's actually running on the device, nor any legal way to install and run it on the device myself.)
Reproducible builds could in theory work, but actually getting builds to be bit-for-bit reproducible is not an easy feat. I'd be very surprised if firmware were capable of this.
[0] This is a great example of why a free software license doesn't necessarily mean that the software is free. It means that the author has waived his/her ability to restrict your freedom to use/modify/distribute the software, but that doesn't mean that third parties (ie, the government, or a patent troll) have done the same.
Not free, but open. I'd argue the latter is significantly more important than the former if you're trying to protect against the code working against you. At least if the code is open, you can inspect it and verify its operation.
If I can't run my home-compiled versions of your code - whether because of code signing restrictions or because of federal law prohibiting firmware that hasn't been certified - it's not free[0]. So without without reproducible builds, providing the source code for the firmware provides very little benefit (since I have no way to prove that the code corresponds to what's actually running on the device, nor any legal way to install and run it on the device myself.)
Reproducible builds could in theory work, but actually getting builds to be bit-for-bit reproducible is not an easy feat. I'd be very surprised if firmware were capable of this.
[0] This is a great example of why a free software license doesn't necessarily mean that the software is free. It means that the author has waived his/her ability to restrict your freedom to use/modify/distribute the software, but that doesn't mean that third parties (ie, the government, or a patent troll) have done the same.