Re: CPU_BIG_ENDIAN in generic code (was: Re: [PATCH v3 3/7] arch/sparc: Define config parameter CPU_BIG_ENDIAN)

[Max Filippov]

On Wed, May 24, 2017 at 3:18 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Wed, May 24, 2017 at 11:59 AM, Geert Uytterhoeven
> <geert@xxxxxxxxxxxxxx> wrote:
>> I guess the time is ripe for adding (both) symbols to all architectures?
>
> Good idea. I think we can do most of this by adding a few lines to
> arch/Kconfig:
>
> config CPU_BIG_ENDIAN
>         bool
>
> config CPU_LITTLE_ENDIAN
>        def_bool !CPU_BIG_ENDIAN
>
> This way, we only need to add 'select CPU_BIG_ENDIAN' to the
> architectures that are always big-endian, and we don't need to
> change anything for the ones that have a single 'CPU_BIG_ENDIAN'
> option.
>
> The three architectures that have a 'choice' statement (mips, ppc and
> sh) will have to convert, and m32r will have to replace the
> option with the opposite one, which could break 'make oldconfig',
> but nobody really cares about m32r any more.

Xtensa may have either endianness and for xtensa we define
CONFIG_CPU_BIG_ENDIAN or CONFIG_CPU_LITTLE_ENDIAN
in the arch/xtensa/Makefile based on the value of the compiler builtin
macro.

-- 
Thanks.
-- Max