re: New "Creating Custom Kernels" newbiedoc
On Wed, 26 Mar 2003 kjmck@bellatlantic.net wrote:
> Thank you for your feedback.
>
> >1) The pcmcia option merits special mention, since by default it is
> >turned on (at least for the kernels I have used) and you explicitly
> >need to turn it off if you aren't using it, otherwise the compilation
> >will halt before it begins. You could give directions on how to turn
> >it off.
>
> I don't understand what you mean here. A kernel won't refuse to compile just
> because you have included an option and you don't have the hardware for it.
>
> By way of discussing "Third-party modules" I used PCMCIA as an example. I
> mentioned that PCMCIA kernel support must be turned off to use the pcmcia-cs
> package.
>
> Or did you mean something else entirely? If so please let me know.
I guess I was not precise enough. :-)
What I meant to say was that by default PCMCIA support is turned on, but
apparently you still need to pick some more specific suboption or
something (I don't use this option so I'm not sure what it is). So, when
compiling the kernel, if you are not using PCMCIA, it will halt for
further user input at this stage unless PCMCIA is turned off completely,
which can be very confusing to someone who doesn't know what it means. It
keeps happening to me (with the standard Debian sources). I'm surprised
that you haven't (unless you actually do use PCMCIA).
Hmm. Strange. I am not currently able to reproduce this problem with
either the 2.4.17 sources or the 2.4.19 source (which is what I have
installed currently), though I have run into it repeatedly in the past.
Ok, please ignore the above comment.
> >2) By the way, isn't it better to do the kernel image and the third
> >party modules separately? Usually I do a
>
> >fakeroot make-kpkg modules-clean
>
> >before
>
> >fakeroot make-kpkg modules-image
>
> >which is what the kernel-package README recommends.
>
> That may have been true at one time; I actually do it all at once. I've done
> dozens of kernels on several machines and never had it hiccup for that reason.
This is probably true if you are only doing it once. But if you are
recompiling the kernel after changing options (whether using the same
kernel sources or different kernel sources) and using the same module
sources, you need in general to clean the modules directory in between,
otherwise old object files etc. can mess things up.
So in general I think it is best to add the modules clean option. If you
don't agree, you could ask Manoj what he thinks.
> >3) You could mention the --added_modules option in 8.3 for use with
> >modules-image or modules-clean. It is in the man page, but I didn't
> >notice its existence for quite some time.
>
> I may do that. The idea is to cover "just enough, but not too much"; I'm
> looking for that balance point.
True, you don't want to try to cover every possibility. But it is no big
deal. If you are talking about compiling third party modules, you could
just mention that you can select which of the modules to compile by using
the option. It is only one extra line.
A couple of extra things.
1) You could mention in section 2.2 that you can use different versions of
gcc to compile, and that you can set the CC environment variable to choose
which version of gcc to use. This is relevant because of the upcoming gcc
transition to 3.2. Some people may prefer to continue using 2.95 for a
bit.
2) Also, it might be worth seeing if you can get your tutorial distributed
officially with kernel-package. The only thing is I am not sure how Debian
feels about the GNU FDL, but I think there are issues.
Faheem.
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