sys/suit/storage/vfs: initial import

[fjmolinas]

Contribution description

This PR extends suit/storage units with vfs. It also makes suit/storage use xfa to allow for easy declaration of storage units, e.g.: backup filesystem storage can be added:

XFA_USE(char*, suit_storage_files_reg);
XFA(suit_storage_files_reg, 0) char* _slot0_file = "/sda/SLOT2.txt";
XFA(suit_storage_files_reg, 0) char* _slot1_file = "/sda/SLOT3.txt";

Testing procedure

I'll adapt the suit/example_update examples to run on native and use this storage unit once #16771 is in.

Issues/PRs references

Somewhat related to #17962
Depends on #17941
Could use #16771

[benpicco]

Nice addition, just one question: How are the different SUIT storage backends identified?

[fjmolinas]

Rebased to get the suit changes in

[fjmolinas]

I adapted the examples/suit_update test to also run on native... although I don't think murdock is able to run it.

[benpicco]

I think the Readme needs an update too, it only tells me how to load a file to RAM. (Also: s/suit coap/suit fetch coap/g)

I adapted the examples/suit_update test to also run on native... although I don't think murdock is able to run it.

It won't be able to create the tap device - but with gcoap_fileserver and socket_zep we should be able to run it on CI, just like tests/gnrc_rpl

[chrysn]

The PR title and some commit messages are unclear about whether this is SUIT specific (sys/suit/storage) or not (sys/storage). Appears to be the former from a quick glance.

[fjmolinas]

The PR title and some commit messages are unclear about whether this is SUIT specific (sys/suit/storage) or not (sys/storage). Appears to be the former from a quick glance.

fixed

[fjmolinas]

I think the Readme needs an update too, it only tells me how to load a file to RAM.

@benpicco is addressing the missing README enough to get this in? Or will you want to wait for you to add the gcoap_fileserver based test?

[benpicco]

Having a test for this is entirely orthogonal, I just want the readme update so I can test it myself.

[fjmolinas]

Having a test for this is entirely orthogonal, I just want the readme update so I can test it myself.

Sorry I missed this comment, will address next week, sorry for the delay.

[fjmolinas]

Having a test for this is entirely orthogonal, I just want the readme update so I can test it myself.

@benpicco I just updated the README, there is actually very little to adapt from the regular RAM workflow in the README, only the install-id.

[benpicco]

Why limit this to native?

[fjmolinas]

I'm just adding this storage for native in the test, same question can be asked for RAM storage

[benpicco]

Looks good to me, feel free to squash.

[fjmolinas]

squashed

[fjmolinas]

Rebased to get the pthon fix in.

[benpicco]

Hm I think you only squashed and didn't rebase - the python test is still failing.

[fjmolinas]

All green here @bergzand @benpicco!