[Wylug-help] kernel

[Shaun Laughey]

On Wed, 2007-07-25 at 18:18 +0100, linux at sh2515.plus.com wrote:
> hi
> 
> i am currently compiling a new kernal as an experiment.
> 
> question:
> is there a way of finding out exactly what a computer is using or uses? as
> there were parts which i didn't know if i should take them out or leave
> them.
> 
> anyway will find out soon if i should of left them in.
> 
> regards
> 
> scott

My word Scott, you are a glutton for punishment - but to answer your
question most distro's compile almost everything as a module and then
load them dynamically during boot using autodetection or serious hinting
via /etc/modules, /etc/modules.conf, /etc/modprobe* etc. there are as
many schemes for this as there are distros and probably a few spare.

Ubuntu uses /etc/modules to force modules to be loaded on boot.

lspci is the console equivalent of the gnome hardware tool - both list
the stuff in your machine quite well. 

When you are running a stock kernel lsmod will tell you what you have
loaded which is normally a good hint as to what you should ensure you
should have compiled at the least as a module.

If you read the Debian readme there's info on copying the config of a
working configuration into /usr/src/linux as .config or make oldconfig
etc. and that can be a good jumping off point.

Personally I've given up compiling my own kernels as the gains are
minute compared to the hours of compiling/recompiling/installing/
recompiling/installing especially as you use an nvidia card and I assume
you are using the closed source binaries which Ubuntu doesn't quite
handle with the same finesse as SuSE and Mandriva do where they
automagically "recompile" for your new kernel on boot.

To make matters more fun you also need a mini kernel with just enough
driver stuff compiled in not as modules to boot the rest of the kernel.
The stock one works fine but my make initrd always messes it up for some
reason and end up with missing file systems or squealing sound cards.

So to keep your sanity make sure you know how to reboot in the event of
a kernel screwing up - copy your existing initrd.gz and vmlinuz
somewhere in /boot so they don't get flattened by your kernel. Grub
makes recovery easy if you have those two safe and you know what they
are called.

Good luck.

Shaun Laughey.