[Suit] manifest18 review

["Rønningstad, Øyvind" <[e-mail]>]

Hi everyone, here is another list of questions, suggestions, and clarifications for the manifest.


  *   (I've mentioned this before, but can't recall that we have properly discussed it) I feel the spec is missing a "write" directive for writing very small values (e.g. 32-bit configuration values). The only way to do this now would be to add the 4 bytes as a payload (possibly integrated), and have a digest check in the manifest followed by a copy. This is obviously a lot of wasted bytes and cycles. Can we add a suit-directive-write directive with a bstr argument that will be written directly to the current component?
  *   I think the envelope should have a suit-envelope-version analogous to suit-manifest-version, since it is the top-level type, and therefore needs to be correctly decoded before the suit-manifest-version can be checked.
  *   In Table 1 "run" is described as "run(current)" and "run sequence" is described as "exec(arg)". I suggest renaming "run sequence" to "execute sequence" in the whole document to avoid confusing the two concepts (which are quite different). Another source of confusion is that "the run sequence" can apply to the "run" command sequence in the manifest.
  *   I suggest renaming "common sequence" to "shared sequence" since it is less similar-sounding to "command sequence", and arguably slightly more descriptive.
  *   Is "false" a valid value for IndexArg (6.5 seems to imply no)? If not, the CDDL should be changed from "IndexArg /= bool" to "IndexArg /= true".
  *   6.7 (The section on parallell processing) states "To isolate each sequence from each other sequence, each sequence MUST begin with a Set Component Index directive with the following exception: when the index is either True or an array of indices, the Set Component Index is implied. Any further Set Component Index directives MUST cause an Abort". Does this restriction on Set Component Index inside Run Sequence always apply, or only when Strict Order is False in the surrounding context?
  *   In directive-try-each, if one sequence succeeds, should the try-each end, or should all sequences in the try-each be executed regardless?

BR, Øyvind