Re: recipe for kernel build...
On Thu, Jan 26, 2006 at 06:38:34AM -0800, Kenward Vaughan wrote:
> > I have just done my first Debian install, and one of the things I
> > want to do before I declare it complete is to make sure I can
> > recreate the kernel from source so that I know I have the source
> > for what I am running on hand..
>
> It can also help when you decide to optimize the kernel for what is
> specifically in your machine... :)
You have no idea how much will power it took to resist the
temptation to make a few changes.....
But I know that would be very imprudent - if I make changes now
and it doesn't work (or worse, is unstable) I won't know if it
was my change that did it, or if there was some procedural error
in the way I built the kernel....
So my policy is to rebuild as close as possible to what the install
gave me, and then run it for long enough to give me some confidence
that it is stable...
Then when I do attempt some customization, I will have some justification
for believing that nothing has changed except what I intended to
change...
> > The problem at this point is working out how the current kernel
> > binary was configured. In my previous Linux distributions (SuSE
> > and gentoo), I could copy /proc/config.gz which was garanteed
> > to be the configuration of the running kernel, but my new Debian
> > system doesn't seem to have that. Is there a different mechanism?
>
> Config files are normally found in /boot. It seems that your other
> system kernels were compiled with the option to have the config file
> also carried within the kernel, which is a neat trick if you feel you
> need it.
Not so critical once I have started to build my own kernels, but it
is comforting to have in a binary obtained from some external source
so that I really know what config was used to build it..
After all, even if the install was good, it is always possible for
a careless sysadmin to wind up with unmatched files in /boot...
> > Can I assume that if I don't run menuconfig etc that the default
> > kernel configuration installed from the source tarfile will be
> > what was used to produce my running kernel?
>
> It'll certainly use what is there, which likely won't match a chunk of
> what you need for your laptop.
I discovered that there was no .config at all until I had copied
the one from /boot. Hopefully that was all that was needed to
duplicate the original config.
> > Anything else I should know when building in a Debian system?
>
> Only everything you can piece together about you own system.
>
> Kernel-package is a very nice way to piece together the parts of your
> recompilation into a Debian package. The instructions are quite good,
> too.
Not what I am used to, but I'll have a read and give the 'debian way'
a try..
> If all you are tying to do is recompile the image, then use the config
> file in /boot. But I'm curious why you want to do that, since the
> package is there already... ???
All in good time.... when I know I can build a stable kernel
from source in the original configuration, then I'll start
customizing things for my particular machine...
Thanks for your comments,
Regards,
DigbyT
--
Digby R. S. Tarvin digbyt(at)digbyt.com
http://www.digbyt.com
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