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P2 Executable file validation — Parallax Forums

P2 Executable file validation

ke4pjwke4pjw Posts: 1,169
in Propeller 2

Is there something like a CRC included in the Binary file generated by proptool?

I am writing an "over the air" firmware updater for my light controller, and to validate the file it downloaded from the internet I would like to use a CRC or an MD5 hash. This is just to make sure that the file is accurate. I can manually add a CRC to the document it checks for updates, but I would rather not, if I can get away with it.

Thanks,
Terry

Comments

  • Wuerfel_21Wuerfel_21 Posts: 5,106

    IIRC no, there's no checksum in the binary, the serial loader computes and appends it on the fly. That checksum is just a sum of longs, which isn't as good as CRC.

  • ke4pjwke4pjw Posts: 1,169

    So, after fighting (and losing) with my web hosting provider to try and disable SSL redirects, I decided to just use Azure Blob Storage to distribute updates. It's free for up to 5GB. It is fortuitous that blob storage provides a base64 encoded MD5 hash of the file in the http response headers. So that looks like the best route as a whole. I won't have to manually create the validation hash. W00T!

    Pretty sure there are base64 decode and MD5 objects for spin1 already out there.

  • VonSzarvasVonSzarvas Posts: 3,487

    Ha! Edge hosting an Edge !

  • ke4pjwke4pjw Posts: 1,169

    It's real now. Over the air updates by Monday morning or bust!

  • ke4pjwke4pjw Posts: 1,169

    Looks like a bust for today. I am able download a manifest file, parse that file and download the files in the manifest. I can check for and create a DOWNLOAD and BACKUP folder on the SD card. The problem is I cannot figure out how to get the FAT32 driver to open files for writing, or capture the actual error. I need to study more about how abort works. A simple return value would have been easier IMHO, but I suspect they wanted to be able to bubble an error all the way up and abort is a way to do that.

    So, this is progress from the weekend:

  • VonSzarvasVonSzarvas Posts: 3,487

    :) Neat! And not really a full bust, as you've figured so much along the way ! :smiley:

  • ke4pjwke4pjw Posts: 1,169

    I sat up right out of bed this morning realizing I didn't create the file before attempting to write to it. As we say in the south, I was "stuck on stupid". I will update the code and try it this evening.

    Further updates to this will be in the "Blitzen 24" E1.31 Pixel Light Controller Updates thread. thread

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