On 8/15/14 9:52, Max Filippov wrote:

On Fri, Aug 15, 2014 at 5:47 AM, Max Filippov [off-list ref] wrote:

quoted

Hi Chen,

On Thu, Aug 14, 2014 at 8:54 PM, Chen Gang [off-list ref] wrote:

quoted

Normal architectures:

 - Big endian: avr32, frv, m68k, openrisc, parisc, s390, sparc

 - Little endian: alpha, blackfin, cris, hexagon, ia64, metag, mn10300,
                  score, unicore32, x86

 - Choose in config time: arc, arm, arm64, c6x, m32r, mips, powerpc, sh

Special architectures:

 - Deside by compiler: microblaze, tile, xtensa.

 - Deside by building host: um

 - Next, need improve Kbuild to probe endian to deside whether need mark
   __BUILDING_TIME_BIG_ENDIAN__ before real config.

Please check this comments, thanks.

quoted

[...]

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diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 3a617af..a3e8f7e 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig

@@ -22,6 +22,8 @@ config XTENSA
        select HAVE_IRQ_TIME_ACCOUNTING
        select HAVE_PERF_EVENTS
        select COMMON_CLK
+       select CPU_BIG_ENDIAN if __BUILDING_TIME_BIG_ENDIAN__
+       select CPU_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
        help
          Xtensa processors are 32-bit RISC machines designed by Tensilica
          primarily for embedded systems.  These processors are both

I've tested this part and it doesn't select neither CPU_BIG_ENDIAN,
nor CPU_LITTLE_ENDIAN. And looking into the Kconfig/Kbuild I cound't

Correction: it always selects CPU_LITTLE_ENDIAN, regardless of the
compiler endianness.

Yeah, at present, it always select CPU_LITTLE_ENDIAN, next, Kbuild need
be improved for it, just the comments said.

If this patch can be pass checking, I shall improve the Kbuild for it,
also will modify some individual drivers to use CPU_*_ENDIAN.

I guess, we need Cc to kbuild for getting more ideas, suggestions, or
completions.



THanks.
-- 
Chen Gang

Open, share, and attitude like air, water, and life which God blessed