[U-Boot] [PATCH 1/2 v6] Make libgcc inclusion from common Makefile overridable by platform config file

[Wolfgang Denk]

Dear Dirk,

In message <4A59F95A.6060803 at googlemail.com> you wrote:
> 
> > I really hesitate to do that. It seems that not  using  the  compiler
> > provided library is not such a clever thing to do. The compile writes
> > probably  know  better  what  a  specific  version  of GCC needs that
> > anybody else.
> 
> Yes, you are basically right. But ;)
> 
> But, as Jean-Christophe mentioned above, it's a pain with the various 
> ARM tool chains floating around. Some are older, some are newer, some 
> are configured for EABI, some not, some are configured for software 
> floating point, some for hardware floating point, etc., etc.

Right. And each of these is supposed to come with it's own version of
libgcc, configured exactly for  the  requirements  of  this  specific
version and configuration of GCC.

And it turns out that the majority of architectures works  just  fine
with  such  a setup, just using libgcc for functions required for and
provided by the compiler.

If the compiler provided functions cannot be used,  this  is  IMO  an
indication  of  a  broken toolchain, which should either be fixed (if
it's under some form of maintenance) or abandoned (because  you  will
have the same problems again in other situations outside of U-Boot).

> While I as developer might be able to find a recent tool chain with a 
> libgcc compatible with U-Boot, I think we should avoid this pain for 
> our users. Users which like to "just compile U-Boot" and then we tell 
> them "well, your tool chain you seem to be happy with doesn't link 
> U-Boot, for U-Boot you have to install an other one" I think wouldn't 
> make them happy.