Re: [PATCH 01/18] powerpc: Add ability to build little endian kernels

Josh Boyer
2010-10-01T11:40:52Z

On Fri, Oct 1, 2010 at 3:05 AM, Ian Munsie <imunsie@au1.ibm.com> wrote:
> diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
> index d361f81..074ff12 100644
> --- a/arch/powerpc/platforms/Kconfig.cputype
> +++ b/arch/powerpc/platforms/Kconfig.cputype
> @@ -329,3 +329,19 @@ config CHECK_CACHE_COHERENCY
>        bool
>
>  endmenu
> +
> +config ARCH_SUPPORTS_LITTLE_ENDIAN
> +       bool
> +
> +config CPU_LITTLE_ENDIAN
> +       bool "Build little endian kernel"
> +       depends on ARCH_SUPPORTS_LITTLE_ENDIAN && EXPERIMENTAL
> +       default n
> +       help
> +         This option selects whether a big endian or little endian kernel will
> +         be built.
> +
> +         Note that if building a little endian kernel, CROSS_COMPILE must
> +         point to a toolchain capable of targetting little endian powerpc,
> +         while the toolchain specified by CROSS32_COMPILE must be capable of
> +         targetting *BIG* endian PowerPC.

Have you tested this support with a userspace containing floating
point instructions? I wonder if CONFIG_MATH_EMULATION is going to
need work at all, and if the boards with an actual FPU (440EP, 440EPx,
460EX, etc) would have issues.

josh