On 8/13/14 13:08, Sam Ravnborg wrote: > On Wed, Aug 13, 2014 at 06:48:35AM +0800, Chen Gang wrote: >> x86 and ia64 are always little endian. And another architectures may be >> little endian: mips, sh, powerpc, and m32r (may mark CPU_LITTLE_ENDIAN >> explicitly); also arm(64) and c6x (which may be !CPU_BIG_ENDIAN). >> >> Some drivers (e.g. some of "drivers/isdn/hisax") may only support little >> endian (CPU_LITTLE_ENDIAN), and some drivers may only support big endian >> (!CPU_LITTLE_ENDIAN). >> >> So export all little endian architectures within kernel wide, so can let >> Kconfig easier for the modules which only support little endian or only >> for big endian (assume !CPU_LITTLE_ENDIAN is same as CPU_BIG_ENDIAN). > We need to cover three cases here: > - An arch supports only little endian > - An arch supports only big endian > - An arch may be both little and big endian > Yeah, we need. > The solution you suggest assumes that an arch is either little or big endian. > But we cannot ignore the hybriads that can do both. > For the architectures which can do both, for me, they are: sh, powerpc, m32r, and mips (may mark CPU_LITTLE_ENDIAN), also are: arm/arm64, and c6x (may mark !CPU_BIG_ENDIAN). For the architectures which only support little endian: x86, and ia64. The left, I assumes they are big endian (no any 'ENDIAN' can be found in their Kconfig files). In my memory, except related with Intel, all are (or support) big endian. Thanks. -- Chen Gang Open, share, and attitude like air, water, and life which God blessed -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
