[klibc] version compatibility between linux and klibc

[Sam Ravnborg]

On Thu, Jul 08, 2010 at 10:23:36PM -0400, Phil Howard wrote:
> On Tue, Jul 6, 2010 at 2:29 PM, Sam Ravnborg <sam at ravnborg.org> wrote:
> 
> > The above is wrong - klibc today should be built using exported headers.
> > I tried with latest klibc + kernel.
> >
> > This worked for me:
> > cd $KERNEL
> > make headers_install
> > cd $KLIBC
> > make KLIBCKERNELSRC=$KERNEL/usr
> >
> >
> > Note that "headers_install" install the userspace ready headers in $KERNEL/usr
> > which is why this dir is specified as argument to KLIBCKERNELSRC.
> 
> I got a short chance to try this, this evening.  I had the kernel
> install the headers in a directory right next to where the kernel tree
> itself was extracted.  Then I symlinked "linux" to that install target
> directory instead of the kernel extraction directory.  A few probably
> minor compile warnings on occaisional files, but it seemed to
> basically finish OK.  I did not use the patch.
There are basically two approaches.
One is to use the kernel headers direct - which requires the patch I posted.
And another is to use the exported headers from the kernel.
Rather than messing with symlinks you can say:

    make KLIBCKERNELSRC=path/to/exported/headers

I would prefer that option rather than maintaining symlinks - as it
is much more obvious how the files are pulled in.

> 
> I'll do some testing this weekend to be sure, and refine the script
> that does the whole build and post that.  Then it's on to my early
> user space ideas to be coded up.  I'm on the mailing list now, so I'll
> watch and see if there's anything I can contribute to in the future.

Thanks for testing and providing feedback!

	Sam