Hi,
The answer to the real question is that you just need to install the
kernel-unsupported rpm to get the pwc kernel module.

   yum install kernel-unsupported
or if you have multiple cpu's
   yum install kernel-unsupported kernel-smp-unsupported

How could you have found that out?
By using yum, and specifically 'yum provides'
   yum provides pwc
or
   yum provides pwc.o

But, to answer the questions you asked.

Laurent Aphecetche wrote:
> Hi,
>
> I'd like to make a custom kernel (to include the pwc driver for a logitech
> webcam), but would like to be sure I'll end up with a working one.
> My first guess was to use the file /boot/config-2.4.21-27.0.1.EL during make
> xconfig, but :
> a) the kernel compilation fails if I use this file
> b) this file has CONFIG_USB_PWC=m but I cannot locate the pwc.o anywhere on
> my system
> so I conclude that this was not the config file used to produce the kernel
> available in kernel-2.4.21-27.0.1.EL rpm
>
> So my first question is : "is there a way to get the configuration of a
> SL-distributed kernel ?"
>

Well, your first guess was right, in that /boot/config-2.4.21-27.0.1.EL really
is the config file used to make the kernel.  But RedHat seperated the kernel
modules into those that they would accept buzilla reports for, and those they
wouldn't accept bugzilla reports for.

Personally, I think this is a bit goofy.

Scientific Linux 3.0.4 will install kernel-unsupported by default, to avoid
these types of confusions.

> And next, after some trials, I was able to compile a custom kernel, but I
> miss an openafs module for that one. How could I make a custom openafs module ?
>
> Thanks,

How to make a custom openafs module.  I'm going to tell you the easy way, and
the way that I build my modules.

Easy way.
You haven't really changed anything, so the module for the regular kernel
should work.  Just copy
   /lib/modules/2.4.21-27.0.1.EL/kernel/fs/openafs/openafs.o
to
   /lib/modules/<my custom kernel>/kernel/fs/openafs/openafs.o

Harder way.
Get the src.rpm for our openafs.
ftp://ftp.scientificlinux.org/linux/scientific/303/SRPMS/openafs-1.2.11-15.9.SL.src.rpm
And then I run
rpmbuild --rebuild openafs*src.rpm --define "build_userspace 0" --define
"build_modules 1" --define "kernel X.Y.Z" --target i686
an example would be
rpmbuild --rebuild openafs-1.2.11-15.5.SL.src.rpm --define "build_userspace 0"
--define "build_modules 1" --define "kernel 2.4.21-15.0.3.EL" --target i686

Troy
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Troy Dawson  [log in to unmask]  (630)840-6468
Fermilab  ComputingDivision/CSS  CSI Group
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