Capabilities and slots

Mark Shuttleworth mark at
Wed Jan 20 17:41:25 UTC 2016

On 20/01/16 14:08, Rick Spencer wrote:
> I assume that as a developer I would somehow also have to map the snap to
> the actually GPIO pin in order to grant the snap permission to use that
> hardware.

As a *developer* you would not; you would want to say that your snap
either needs or can take advantage of a "bool-file" thing. The *user*
would map a bool-file thing provided by one of the system snaps to your

So as a developer you are describing generically what capability you
need, as a user you are specifying which of the things on the system
that match should be assigned to that snap.

The underlying mechanism (/sys/class/gpio) would be managed by snappy.
So as a user you have no need to know or understand /sys/class/gpio, you
just say "connect this snap to the red light".


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