On 8/15/14 9:52, Max Filippov wrote: > On Fri, Aug 15, 2014 at 5:47 AM, Max Filippov <jcmvbkbc@xxxxxxxxx> wrote: >> Hi Chen, >> >> On Thu, Aug 14, 2014 at 8:54 PM, Chen Gang <gang.chen.5i5j@xxxxxxxxx> wrote: >>> 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. >> >> [...] >> >>> 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