[Tfug] Ubuntu Gutsy Compiling Kernel

[Jude Nelson]

What is the chipset of your NIC?  You may have to supply the vanilla kernel
a chipset-specific patch as well as the RTAI one.

I'm not sure the RTAI patch will work with 2.6.23 as well as
2.6.22.xx...theCompletely Fair Scheduler in
2.6.23 I heard hampers the ability to have real-time responses from the
kernel, because the CFS distributes CPU time to all processes equally (and
there isn't a config option to turn it off).

Kind Regards,
Jude Nelson

On 10/25/07, Andrew Ayre <andy at britishideas.com> wrote:
>
> Hi Jude,
>
> Thanks for the reply. Here is the problem though:
>
>   - with the Ubuntu version of the kernel, the kernel won't compile with
> the RTAI patch
>
>   - with the vanilla kernel ethernet doesn't work for some reason
>
> I am patching version 2.6.22.9 with the RTAI 2.6.22.9 patch. When I did
> a diff between the vanilla kernel and the Ubuntu kernel, there are a lot
> of changes.
>
> The RTAI documentation recommends only patching vanilla kernels.
>
> My only thought at this point is to give the vanilla 2.6.23 a try, but
> that takes me even closer to the bleeding edge...
>
> Any suggestions on how to proceed? I looked at the syslog after booting
> with the vanilla kernel and didn't see anything obviously wrong.
>
> Thanks for the help!
>
> Andy
>
> Jude Nelson wrote:
> > To find out how to kernels differ, get the vanilla one and the Ubuntu
> one
> > and do this:
> >
> > diff -u /path/to/vanilla/kernel /path/to/Ubuntu/kernel >
> > /path/to/convenient/patchfile
> >
> > That'll give you a source patch file that will contain all the patches
> > applied to the Ubuntu kernel from the vanilla.
> >
> > To set up RTAI, you'll need to know what kernel version(s) the RTAI
> patch in
> > question requires.  Just grab the one you want and the corresponding
> > kernel.  Unpack the kernel, cd into the kernel's root source directory,
> and
> > execute this command*:
> >
> > patch -Np1 < /path/to/RTAI/diff
> >
> > (fill in the blanks as needed).
> >
> > *If you want to add Ubuntu's patches to the vanilla kernel, then apply
> the
> > patch you created above BEFORE the RTAI diff.
> >
> > Now, do a make menuconfig to load in the config options (you don't need
> to
> > feed it the Ubuntu kernel config--the script is smart enough to do that
> > itself).
> >
> > If you don't feel like looking through all the options, just abort and
> have
> > a look inside the .config file in the root directory of the kernel.
> > Somewhere, there should be an RTAI option.  You may need to enable it
> > manually.  Chances are, the CONFIG_xxx key/value pair will have the
> string
> > "RTAI" in there somewhere, so you can easily use vi to locate it.
> >
> > After that, just a "make-kpkg --initrd --bzimage kernel_image
> modules_image"
> > command should create a kernel deb and any additional out-of-tree
> modules
> > you may need (you'll need module-assistant, fakeroot, make-kpkg, etc. to
> do
> > this).  If you don't want an initrd, then omit the "--initrd" option.
> >
> > Hope this helps,
> > Jude
> >
> > On 10/25/07, Glen Pfeiffer <glen at thepfeiffers.net> wrote:
> >> I don't have any answers, but am posting this to start it as a new
> thread.
> >>
> >> -- andy at britishideas.com wrote:
> >>> I'm running Ubuntu 7.10 Gutsy on my desktop PC and I want to patch the
> >>> kernel with RTAI. However my knowledge of patching and kernels is
> >>> limited... Here is what I tried:
> >>>
> >>> I grabbed the Linux source from the Ubuntu gutsy repos and found it to
> >>> be 2.6.22.9. I built it and installed the package and it worked fine.
> I
> >>> used /boot/config-2.6.22-14-generic as the .config file.
> >>>
> >>> Next I grabbed 2.6.22.9 from kernel.org. I built it in the same way
> and
> >>> installed the package. It works except Ethernet is broken. I again
> used
> >>> /boot/config-2.6.22-14-generic as the .config file.
> >>>
> >>> In both cases I didn't configure the kernel - I simply built it.
> >>>
> >>> So I am assuming that something was patched in the Ubuntu version to
> fix
> >>> some kind of problem.
> >>>
> >>> eth0 appears to be ok, but there are no packets in or out.
> >>>
> >>> Does anyone have any pointers on how do I find out what patch is
> missing
> >>> from my vanilla kernel? It seems Gutsy ships with 2.6.22.14, but
> nothing
> >>> beyond 9 is available from kernel.org. So I'm guessing the Ubuntu team
> >>> made a few revs of their own.
> >>>
> >>> I posted on ubuntuforums.org but haven't received any replies on this.
> >>>
> >>> thanks, Andy
> >>>
> >>> -- Andy
>
> --
> Andy
> PGP Key ID: 0x67090A54
>
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