[oe] [oe-commits] Roman I Khimov : (e) glibc-package: fix kernel version passed to qemu

[Tom Rini]

On Mon, May 18, 2009 at 08:37:09PM +0100, Phil Blundell wrote:
> On Mon, 2009-05-18 at 19:54 +0100, Phil Blundell wrote:
> > On Mon, 2009-05-18 at 22:42 +0400, Roman I Khimov wrote:
> > > Now, I think that this should be fixed on target level. OLDEST_KERNEL should 
> > > be something sane. Global 2.4.0 from bitbake.conf is good enough for most 
> > > targets, but if we know that none of ARM EABI works with kernel versions prior 
> > > to 2.6.14, we should set OLDEST_KERNEL to 2.6.14 for that targets. Or higher, 
> > > of course, if target needs/wants that. If that's OK with all, I'm doing a 
> > > patch.
> > 
> > I'm still not convinced this is either practical or desirable.  The
> > kernel versions you mentioned are the minimum required for the
> > particular version of glibc you were looking at, but different libcs or
> > different versions of the same libc will have different minimum kernel
> > requirements even for the same target.  (As an obvious example, the m68k
> > port has been supported in glibc since its inception and clearly didn't
> > require a 2.6.18 kernel to start with.)
> 
> The other thing to say about OLDEST_KERNEL is that it was intended to be
> controlled by the DISTRO, not by the MACHINE.  In other words, it's a
> policy control ("kernel x.xx is the earliest one we care about; it's
> okay to omit the compatibility bits for older ones") and not a target
> attribute ("kernel x.xx is the minimum required for correct
> functionality").  We don't currently have a variable with the latter
> semantics and nor am I very convinced that it would be a good idea to
> introduce one.

I've re-read most of the thread, and I think what we need to do is:

- Acknowledge we've not set OLDEST_KERNEL in a sane way for a while.
  Except in some _machines_ we just use the 2.4.0 default, and glibc
  corrects it up.

- Acknowledge this is a GLIBC / EGLIBC only variable and move it over,
  with weak assignments to sane values in glibc.inc / eglibc.inc.  We
  might have to have some other possibilities commented out explaining
  what they do.  For example, arm-linux (oabi), non-nptl x86, etc.

-- 
Tom Rini