pkg: cncbor: misc fixes

[kaspar030]

Contribution description

Testing in #8467 was limited to native. This PR fixes some problems on ARM:

1. cn-cbor uses unaligned ntoh[sl](), causing hard faults on ARM. -> added an alignment safe implementation

2. the unittests parse_hex() had faulty malloc+sscanf. replaced with fmt.

Issues/PRs references

#8467. @

[kaspar030]

@lorenz9314 can you take a look at this?

[nmeum]

Did you consider also submitting these patches upstream?

[kaspar030]

Did you consider also submitting these patches upstream?

The original code has a comment like "if you cannot do unaligned accesses, fix these:", so I assumed upstream is not interested. Then again, as is, noone ever used that code on ARM before...

[jnohlgard]

I see that upstream code comment as more of a "feel free to provide a PR if you need alignment", not a wontfix

[kaspar030]

I see that upstream code comment as more of a "feel free to provide a PR if you need alignment", not a wontfix

cabo/cn-cbor#47

[lorenz9314]

@kaspar030 Yep, sure. I pretty much took the parse_hex() function from the original cn-cbor tests. This however seems much more elegant (and functioning) anyway.

[kYc0o]

Got the same problem while testing cbor related things.

Should we wait for upstream merge?

[kYc0o]

Tested ACK. However maybe it's good to wait for upstream changes.

[kYc0o]

AND, we didn't spot this because Murdock doesn't build unittests separately, and while building the whole unittests the module posix is added for other tests, so it gets magically imported.

I think we should provide a fix for that. I think @kaspar030 was working already on something like that while doing #8801 ?

[kaspar030]

I suggest we merge this, upstreaming might take time. We can remove the patch easily later. Also, this PR includes some other fixes to the package.

[kaspar030]

• squashed

[kYc0o]

Then go!