Which interfaces are important today to define a time-hardware snap interface

[Eric S. Raymond]

Christian Ehrhardt <christian.ehrhardt at canonical.com>:
> Hi,
> I'm back from PTO and continued on the snap packaging of ntpsec.
> Background details on interfaces:
> https://github.com/snapcore/snapd/blob/master/docs/interfaces.md
> 
> Based on grep -Hrn '\/dev\/' | awk '{gsub(".*/dev/", "/dev/"); print $1}' |
> sort |uniq
> I tried to summarize what an "time-hardware" interface for snappy might be.
> 
> TL;DR - think of it as a list of things allowed to be accessed
> 
> I streamlined the list a bit for readability.
> I removed some on my own like /dev/kmem being the opposite of isolation :-)
> But please let me know if I forgot something.
> 
> /dev/acts%d+
> /dev/cuaa%d+
> /dev/device%d+
> /dev/dumbclock%d+
> /dev/gps%d+
> /dev/gpspps%d+
> /dev/hpgps%d+
> /dev/icom
> /dev/jjy%d+
> /dev/neoclock4x-%d+
> /dev/oncore.pps.%d+
> /dev/oncore.serial.%d+
> /dev/palisade%d+
> /dev/pps%d+
> /dev/refclock-%d+
> /dev/spectracom%d+
> /dev/trimble%d+
> /dev/true%d"
> /dev/zyfer%d+
> 
> - Do we also need like /dev/ttyS%d+ ?

For full generality we need /dev/ttyS%d+ and /dev/ttyUSB%d+.  These might
be referenced by a refclock path option.

You also need to add /dev/refclockpps-%d+, the generic driver requires it.

> - I hope you could suggest if we could drop some of these by being no more
> important today or in general?

You can certainly drop /dev/icom, that was used only by the
now-removed audio drivers.  Also /dev/palisade%d+, that was the old
name for /dev/trimble%d+.
 
> FWIW - if in doubt I'd prefer to better keep the list short.

So would I, but we can't if the snapified version is going to
support refclocks.
-- 
		<a href="http://www.catb.org/~esr/">Eric S. Raymond</a>