On Mon, 2015-08-31 at 19:56 +0800, Boqun Feng wrote: > On Mon, Aug 31, 2015 at 09:19:26PM +1000, Michael Ellerman wrote: > > On Mon, 2015-08-31 at 15:53 +0800, Boqun Feng wrote: > > > On Mon, Aug 31, 2015 at 04:52:38PM +1000, Benjamin Herrenschmidt wrote: > > > > On Mon, 2015-08-31 at 14:44 +0800, Boqun Feng wrote: > > > > > Hi all, > > > > > > > > > > I hit a strange build error on v4.2, when I try to build a LE kernel > > > > > with a slightly modification of the ppc64_defconfig. What I did is > > > > > just > > > > > make ppc64_defconfig and make menuconfig to set CPU_LITTLE_ENDIAN=y, > > > > > and > > > > > then build the kernel. > > > > > > > > > > I did a little research myself, and found out the error is because of > > > > > trying to build a LE kernel with CONFIG_PPC_PS3=y. So a simple way to > > > > > reproduce is: > > > > > > > > First, LE isn't supported on PS/3 :-) It's only supported on POWER8 > > > > machines (and *some* P7 machines and only when running as KVM guest). > > > > > > Got it, thank you ;-) > > > > > > So should we modify Kconfigs of all the platform to reflect this? > > > > Yes. Maybe something like this? > > > > diff --git a/arch/powerpc/platforms/Kconfig.cputype > > b/arch/powerpc/platforms/Kconfig.cputype > > index c140e94..c359f72 100644 > > --- a/arch/powerpc/platforms/Kconfig.cputype > > +++ b/arch/powerpc/platforms/Kconfig.cputype > > @@ -415,9 +415,13 @@ config VDSO32 > > big endian. That is because the only little endian configuration > > we > > support is ppc64le which is 64-bit only. > > > > +config CHOOSE_ENDIAN > > + bool > > + > > choice > > prompt "Endianness selection" > > default CPU_BIG_ENDIAN > > + depends on CHOOSE_ENDIAN > > help > > This option selects whether a big endian or little endian kernel > > will > > be built. > > diff --git a/arch/powerpc/platforms/powernv/Kconfig > > b/arch/powerpc/platforms/powernv/Kconfig > > index 604190c..32d5661 100644 > > --- a/arch/powerpc/platforms/powernv/Kconfig > > +++ b/arch/powerpc/platforms/powernv/Kconfig > > @@ -18,6 +18,7 @@ config PPC_POWERNV > > select CPU_FREQ_GOV_ONDEMAND > > select CPU_FREQ_GOV_CONSERVATIVE > > select PPC_DOORBELL > > + select CHOOSE_ENDIAN > > IIUC, we can actually set PPC_POWERNV=y and PPC_PS3=y at the same time, > right? > > So this can't prevent PPC_PS3 && CPU_LITTLE_ENDIAN from being true.
Yeah true. So that's probably not a good solution. cheer _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
