Re: [PATCH 1/2] m68knommu: create config options for CPU classes

[Greg Ungerer <gerg@snapgear.com>]

Hi Geert,

On 03/06/11 21:15, Geert Uytterhoeven wrote:
> On Fri, Jun 3, 2011 at 08:43,<gerg@snapgear.com>  wrote:
>> From: Greg Ungerer<gerg@uclinux.org>
>>
>> There are 3 families of CPU core types that we support in the m68knommu
>> architecture branch. They are
>>
>> . traditional 68000
>> . CPU32 (which is a 68020 core derivitive without MMU)
>
> derivative ... and without bitfield instructions.

My spelling never was too good :-)
I'll fix up the comment and add mention of bitfields.


>> . ColdFire
>
>> It will be useful going forward to have a CONFIG_ option defined for
>> each type. We already have one for ColdFire (CONFIG_COLDFIRE), so add
>> for the other 2 families, CONFIG_M68000 and CONFIG_MCPU32.
>
> I'm wondering whether it would help to have Kconfig symbols for the
> instruction capabilities as well.
> Then you have to document these capabilities in the kconfig definition only,
> and can use single (e.g.) #ifdef CONFIG_CPU_HAS_BITFIELDS tests everywhere
> else, instead of duplicating the logic at every #ifdef.

Yes, that sounds like a reasonable idea. I won't add them in this patch
though. I'll add it to the bitops.h merge patch - which is the only
one that would be effected/helped by a bitfield Kconfig option right
now.

Thanks
Greg


>> Signed-off-by: Greg Ungerer<gerg@uclinux.org>
>> ---
>> áarch/m68k/Kconfig.nommu | á 52 ++++++++++++++++++++++++++++++++++++++++------
>> á1 files changed, 45 insertions(+), 7 deletions(-)
>>
>> diff --git a/arch/m68k/Kconfig.nommu b/arch/m68k/Kconfig.nommu
>> index fc98f9b..b004dc1 100644
>> --- a/arch/m68k/Kconfig.nommu
>> +++ b/arch/m68k/Kconfig.nommu
>> @@ -14,6 +14,33 @@ config GENERIC_CLOCKEVENTS
>> á á á ábool
>> á á á ádefault n
>>
>> +config M68000
>> + á á á bool
>> + á á á help
>> + á á á á The Freescale (was Motorola) 68000 CPU is the first generation of
>> + á á á á the well known M68K family of processors. The CPU core as well as
>> + á á á á being available as a stand alone CPU was also used in many
>> + á á á á System-On-Chip devices (eg 68328, 68302, etc). It does not contain
>> + á á á á a paging MMU.
>> +
>> +config MCPU32
>> + á á á bool
>> + á á á help
>> + á á á á The Freescale (was then Motorola) CPU32 is a CPU core that is
>> + á á á á based on the 68020 processor. For the most part it is used in
>
> without bitfield instructions.
>
>> + á á á á System-On-Chip parts, and does not contain a paging MMU.
>
> Gr{oetje,eeting}s,
>
> á á á á á á á á á á á á Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> á á á á á á á á á á á á á áá áá -- Linus Torvalds
>
>
>


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