[OE-core] how to pass or set specific gcc flags?

[Kumar Gala]

On Aug 8, 2011, at 9:55 AM, Richard Purdie wrote:

> On Sun, 2011-08-07 at 12:08 -0500, Kumar Gala wrote:
>> We'd like to pass:
>> 
>> --enable-targets=all
>> 
>> on ppc when we target a 64-bit platform but happen to build a 32-bit
>> toolchain & rootfs, its useful to still have 64-bit support in the
>> compiler to build a 64-bit kernel if desired in this scenario.  Also,
>> this seems useful for the multilib situation.
>> 
>> Wondering what the best way of doing this.  Adding something into the
>> tune-ppcFOOBAR file but not sure how to do that so it gets picked up
>> by the right toolchain pass.  And what do we even override?  I
>> suggested adding a GCC_EXTRA_OECONF.
> 
> I'd caution against this since we don't currently handle packaging of
> toolchains directly using multilibs and I suspect the compiler wouldn't
> bootstrap properly either.
> 
> Its not the compiler itself I worry about but pieces like libc and
> libgcc.

I dont think they have any issue with --enable-targets on ppc.

The issue is I'm trying to look at this based on our customer view point.  The majority of our customers that would utilize 64-bit are going to want to start with a 32-bit rootfs and than add some 64-bit bits to it.  Rather than the other way.

This is one reason I'm asking about how to deal with tune-ppce5500.inc and 32-bit vs 64-bit.

Now it might be ok short term since we have 2 toolchains, etc for multilib.  However at some point (shortly) we have to address this.

I think the 2 toolchains is UGLY and confusing to customers/users.  While I understand it from the point of view on how to take steps to get multilib going it doesn't mean we shouldnt start thinking about how to address these issues.

- k