[Buildroot] [PATCH 1/2] arch/csky: restrict ck610 to the C-SKY gcc port

[Yann E. MORIN <yann.morin.1998@free.fr>]

Guo, All,

On 2019-07-16 00:02 +0800, Guo Ren spake thusly:
> On Sun, Jul 14, 2019 at 5:54 PM Yann E. MORIN <yann.morin.1998@free.fr> wrote:
> >
> > As Guo explained, upstream gcc does not support abi-v1 (only abi-v2), but
> > ck610 needs abi-v1 [0] [1]
> >
> > To simplify things, we make the whole C-SKY architecture require gcc-9
> > or later, and add a single exception in gcc to force the ck610 to use
> > the C-SKY port.
> >
> > [0] http://lists.busybox.net/pipermail/buildroot/2019-July/254386.html
> > [1] package/Makefile.in#73
> >
> > Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
> > Cc: Guo Ren <guoren@kernel.org>
> > Cc: Arnout Vandecappelle <arnout@mind.be>
> > Cc: Romain Naour <romain.naour@gmail.com>
> > ---
> >  arch/Config.in             | 3 +++
> >  arch/Config.in.csky        | 2 ++
> >  package/gcc/Config.in.host | 3 +++
> >  3 files changed, 8 insertions(+)
> >
> > diff --git a/arch/Config.in b/arch/Config.in
> > index d8d841b1a2..9d1a06872d 100644
> > --- a/arch/Config.in
> > +++ b/arch/Config.in
> > @@ -78,6 +78,9 @@ config BR2_aarch64_be
> >  config BR2_csky
> >         bool "csky"
> >         select BR2_ARCH_HAS_MMU_MANDATORY
> > +       # Most variants are support by gcc-9+, except one that is handled as a
> > +       # special exception in package/gcc/Config.in.host
> > +       select BR2_ARCH_NEEDS_GCC_AT_LEAST_9
> We recommand using  BR2_GCC_VERSION_CSKY not BR2_GCC_VERSION_9_X. I
> don't want GCC_9 as default for buildroot user and they could select
> it by themself.

This new 'select' does not change the pereferred gcc version. It just
limits which ones are available.

By selecting BR2_ARCH_NEEDS_GCC_AT_LEAST_9, we ensure that any version
of gcc below 9.x are not visible.

But the C-SKY specific gcc version, BR2_GCC_VERSION_CSKY, is not
impacted by this restriction.

So, with this patch, when BR2_csky=y:

  - with ck610, only BR2_GCC_VERSION_CSKY is available, labelled "gcc
    csky" in the gcc version selection, in menuconfig;

  - with any other variant, BR2_GCC_VERSION_CSKY and BR2_GCC_VERSION_9_X
    are both available, and BR2_GCC_VERSION_CSKY is the dfault.

Does that explanations address your concerns? If so, I can respin the
series with an expanded commit log.

Thanks for the review! :-)

Regards,
Yann E. MORIN.

> >         help
> >           csky is processor IP from china.
> >           http://www.c-sky.com/
> > diff --git a/arch/Config.in.csky b/arch/Config.in.csky
> > index 4bdfbfae4b..2cf31c88c6 100644
> > --- a/arch/Config.in.csky
> > +++ b/arch/Config.in.csky
> > @@ -5,6 +5,8 @@ choice
> >           Specific CPU variant to use
> >
> >  config BR2_ck610
> > +       # Not supported by upstream gc <= 9, and handled as a special
> > +       # exception in package/gcc/Config.in.host
> Acked.
> 
> >         bool "ck610"
> >
> >  config BR2_ck807
> > diff --git a/package/gcc/Config.in.host b/package/gcc/Config.in.host
> > index 8b563c8f27..adc12e95ea 100644
> > --- a/package/gcc/Config.in.host
> > +++ b/package/gcc/Config.in.host
> > @@ -89,6 +89,9 @@ config BR2_GCC_VERSION_9_X
> >         # powerpc spe support has been deprecated since gcc 8.x.
> >         # https://gcc.gnu.org/ml/gcc/2018-04/msg00102.html
> >         depends on !BR2_powerpc_SPE
> > +       # C-SKY sk610 needs abiv1, which is not supported in
> > +       # upstream gcc
> > +       depends on !BR2_ck610
> Acked.
> 
> >         select BR2_TOOLCHAIN_GCC_AT_LEAST_9
> >
> >  endchoice
> > --
> > 2.20.1
> >
> 
> 
> -- 
> Best Regards
>  Guo Ren
> 
> ML: https://lore.kernel.org/linux-csky/

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