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Re: Kernel Configuration

On Thu 27 Mar, Ken Emmons, Jr. wrote:
> Hello,
> I have browsed some of the archives and I have noticed that there has
> been a lot of ta lk and discussion about investing a lot of design work
> into a kernel configuration sys tem. 
> I fail to see how this has anything to do with a distribution, embedded
> or otherwise.  The hard part about installing GNU/Linux is getting all
> the various libraries and appl ications installed without some kind of
> dependency nightmare or compiling your own cod e. Compiling a custom
> kernel (if you should need one...) is the least of your problems . 

>So am I missing something, or is there some validity to these statements? 

Yes, you are missing something. The configuration system is important for
the configuaration of the filesystem, as well as the kernel. The idea (of
emdebsys at least) is to make sure that you make a kernel and filesystem
that match up and contain all the parts needed, but nothing else. We used
the kernel configuration systems for two reasons. 1) they already exist as
general-purpose config systems, and 2) a fair number of things in a system
need to match up between kernel and fs (modules, kernel options to match
networking tools, proc if some of your tools need it etc) so configuring
both together makes sense.

I agree that kernel config on it's own is a solved problem.

> I guess my point is that an embedded debian kind of system should jsut be
> packaging a  root filesystem (which debian already does out of the box
> for several architectures... ) and then just have special tools to
> assemble this filesystem onto flash media. Of course that is a quite
> simplified outlook, but at the core that is all you need to do. 
> Of course, you have to strip down a lot of the packages, but it seems
> that the folks at emdebian already have some tools to do this already. 

No - that's the part we haven't got. Well not in a general sense. Embedsys
knows which files you actually _need_ from some packages and just takes
those, ignoring the rest of the package, but we don't have a
general-purpose package-shrinker yet, so emdebsys is no use for stuff it
doesn't know about (altough it's easy to add new rules). I'm not sure if
anyone does has a good package-minimising scheme. I know the familiar
people have thought about this a fair amount, and there's udebs, and I
remember someone writing a paper about a next-gen packagaing system that
would get you some of this for free (can someone remind what that is if
they recognise the description please - I looked for it recently and
realised I couldn't remember enough about it to find it)


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