[yocto] Yocto 2.2 minimum kernel requirement

[Paul Eggleton]

On Mon, 31 Oct 2016 15:36:24 Khem Raj wrote:
> > On Oct 31, 2016, at 2:59 PM, Paul Eggleton <paul.eggleton at linux.intel.com>
> > wrote:> 
> > On Mon, 31 Oct 2016 09:37:07 Khem Raj wrote:
> >>> On Oct 31, 2016, at 7:37 AM, Vuille, Martin (Martin) <vmartin at avaya.com>
> >>> wrote:
> >>> 
> >>> We are looking at upgrading from Yocto 1.8 to 2.2.
> >>> 
> >>> Yocto 2.2 has a minimum kernel requirement of 3.2.0.
> >>> 
> >>> This isn’t an issue for our target (ARMv5, Linux 4.4) but may be
> >>> an issue for our automated build machines (x86, Linux 2.6.32—CentOS 6.)
> >>> 
> >>> However, there is a note that says
> >>> “For x86 and x86_64, you can reset OLDEST_KERNEL
> >>> <http://www.yoctoproject.org/docs/2.2/mega-manual/mega-manual.html#var-O
> >>> L
> >>> DEST_KERNEL> to anything down to 2.6.32 if desired.”
> >>> 
> >>> Is it possible to configure things such that we can keep supporting the
> >>> old kernel for the SDK while we support a more up-to-date kernel for the
> >>> target?
> >> 
> >> I think that should be the default. We do not set it for x86/nativesdk
> >> case. File a ticket if thats not the case.
> > 
> > SDK_OLDEST_KERNEL is the variable that's supposed to be controlling this,
> > but I noticed a couple of weeks ago that we aren't feeding
> > SDK_OLDEST_KERNEL into glibc for nativesdk, so we should fix that - I've
> > filed a bug [1] and will sort that out. I think we should probably set
> > the SDK_OLDEST_KERNEL default for x86 to 2.6.32 at the same time - I
> > assume there are no objections?
>
> Yes, its for nativesdk/glibc, I think for target x86 we should keep 3.2

Right, I'm not proposing changing the target value.

It turns out setting SDK_OLDEST_KERNEL in an arch-specific manner is a little 
awkward since there aren't overrides that can be used for the SDK value, but 
we can do it from conf/machine-sdk/*.conf though.

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre