[yocto] update mechanisms (was: Re: [meta-swupd][PATCH] bsdiff: update to latest version)

[Patrick Ohly]

On Wed, 2016-11-30 at 17:19 +0000, André Draszik wrote:
> On Wed, 2016-11-30 at 15:59 +0100, Patrick Ohly wrote:
> > I've started a Wiki page
> > https://wiki.yoctoproject.org/wiki/System_Update - rudimentary at the
> > moment, but might as well be mentioned already now.
> > 
> > Perhaps you can say a few words about your usage of swupd and what you
> > liked or didn't like about it? Note that performance will become better
> > with the upcoming update.
> 
> In the wiki or here? I'll be out for the next week, but when I come back I
> will write some more.

Let's discuss here and if necessary, summarize in the wiki.

> BTW, you probably know this: 
> https://lists.linuxfoundation.org/pipermail/automotive-discussions/2016-May/002061.html

I might have seen it at some point, but I hadn't paid that much
attention then and it's a good, timely reminder. I'll link to it from
the Wiki page.

> I liked swupd for its ability to be used both for initial provisioning

You mean installing from the update repository? That's something that
Clear Linux OS can do with their installer, but nothing like that has
been tried with a Yocto-based build. That doesn't mean that it can't be
done, it's just work.

>  as
> well as for incremental updates. The latter being important when you have
> *loads* of devices, where it doesn't seem to make sense to download a full
> image for a tiny change to each device (think cellular!),

That's indeed one of the strengths of swupd. OSTree comes close in terms
of some key characteristics (file-based, persistent /etc and /var). It
would be interesting to know how efficient updating via OSTree is.

-- 
Best Regards, Patrick Ohly

The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.