[Openembedded-architecture] who should set default tunes?

[Mark Hatle]

On 5/2/17 2:41 PM, Phil Blundell wrote:
> On Tue, 2017-05-02 at 08:01 -0500, Mark Hatle wrote:
>>
>> I disagree.  The DISTRO sets the various flags and options, but
>> shouldn't have anything to do with the ABI. 
> 
> I'm not quite sure what "flags and options" you're referring to here.

distro name, version...

PACKAGECONFIG...

DISTRO_FEATURES...

...etc...

> But, contrary to the second half of your statement, selecting the ABI
> is one of the primary competencies of the DISTRO.  Only the DISTRO is
> in a position to know:
> 
> - what the set of hardware is that it wishes to support;

What about distros that are hardware specific?  All of mine distributions are
hardware agnostic, Poky is, the oe-core 'nodistro' is, etc.

> - how it plans to configure its kernel(s);

Again, I consider this project or BSP specific.. different kernels for different
hardware.

> - what filesystem layout it plans to use (which can have implications
> on, for example, the name of the interpreter which gets burned into its
> binaries);

Things like merged /usr, path names, etc.. I agree this is DISTRO.

> - what tradeoffs it wishes to make between optimisation for one
> platform at the expense of another;
> 
> - how many different variants of the same binaries it wants to support,
> and how it wants to do that (DL_HWCAP, multiple binary packages, ...)
> 
> - how many different images it wishes to ship, and what machines it
> wishes to support with each;
> 
> - what pre-existing binaries, and/or other distributions, it might want
> to maintain compatibility with;

The above I've always handled with either the BSP or the local project
configuration.  Again my view is the distribution is platform agnostic.

> - what upgrade and/or downgrade paths it wants to provide;
> 
> - what political considerations (e.g. around endianness) it might have
> to take into account;
> 
> - and no doubt many other things that might influence binary
> compatibility in one way or another.

local project or BSP (via the tunes) is what I use to set these.  My
distributions don't have these concerns.

It doesn't care if it's mips, arm, ppc, etc etc etc...  I only care I have a
consistent userspace.  The kernel, Linux configuration, and processor types are
set above this in the BSP and/or the project local.conf.

--Mark

> p.
>