Re: [RFC] Get rid of SUBARCH

[David Daney]

On 08/22/2013 01:41 PM, Rob Landley wrote:
> On 08/22/2013 07:58:26 AM, Geert Uytterhoeven wrote:
> > On Wed, Aug 21, 2013 at 9:51 PM, Sam Ravnborg <sam@xxxxxxxxxxxx> wrote:
> > >> > The series touches also m68k, sh, mips and unicore32.
> > >> > These architectures magically select a cross compiler if ARCH !=
> > SUBARCH.
> > >> > Do really need that behavior?
> > >>
> > >> This does remove functionality.
> > >> It allows to build a kernel using e.g. "make ARCH=m68k".
> > >>
> > >> Perhaps this can be moved to generic code? Most (not all!)
> > cross-toolchains
> > >> are called $ARCH-{unknown-,}linux{,-gnu}.
> > >> Exceptions are e.g. am33_2.0-linux and bfin-uclinux.
> > >
> > > Today you can specify CROSS_COMPILE in Kconfig.
> > > With this we should be able to remove these hacks.
> >
> > The correct CROSS_COMPILE value depends on the host environment, not
> > on the target configuration.
>
> Actually it depends on _both_.

I think the important issue is not the exact dependencies of the value 
of CROSS_COMPILE, but rather that it varies enough that automatically 
choosing a value based on SUBARCH often gives the wrong result.

Removing SUBARCH and setting CROSS_COMPILE either from the make command 
line (or environment) or the config file, is a good idea because it 
simplifies the build system, makes things clearer, and yields more 
predictable results.

David Daney

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