| Message ID | 1441019966.31779.1.camel@ellerman.id.au (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
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. > default y > > config OPAL_PRD > diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig > index 54c87d5..182f485 100644 > --- a/arch/powerpc/platforms/pseries/Kconfig > +++ b/arch/powerpc/platforms/pseries/Kconfig > @@ -21,6 +21,7 @@ config PPC_PSERIES > select HOTPLUG_CPU if SMP > select ARCH_RANDOM > select PPC_DOORBELL > + select CHOOSE_ENDIAN > default y > > config PPC_SPLPAR > > > > > > But the specific problem you are having looks like a differnet issue > > > with the PS3 boot wrapper. > > > > > > > But could the reason of this be that the building process of the PS3 > > boot wrapper assumes the kernel is BE? > > It looks more like we're getting confused between 32-bit and 64-bit, from your > log: > > ld: powerpc:common64 architecture of input file `arch/powerpc/boot/ps3-head.o' is incompatible with powerpc:common output > > Which says it has a .o which is 64-bit but it's trying to produce 32-bit output. > > That's probably related to the PPC64_BOOT_WRAPPER stuff. Probably, and just FYI, I build a 64bit BE kernel, the dtbImage.ps3 is ELF 32-bit MSB executable. Regards, Boqun
On Mon, 2015-08-31 at 21:19 +1000, Michael Ellerman wrote: > Yes. Maybe something like this? I would have done it the other way around with endian at the top and only the supported platforms displayed based on the endian... But I don't care *that* much either way >diff --git a/arch/powerpc/platforms/Kconfig.cputype >b/arch/powerpc/pl atforms/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 > default y > > config OPAL_PRD > diff --git a/arch/powerpc/platforms/pseries/Kconfig > b/arch/powerpc/platforms/pseries/Kconfig > index 54c87d5..182f485 100644 > --- a/arch/powerpc/platforms/pseries/Kconfig > +++ b/arch/powerpc/platforms/pseries/Kconfig > @@ -21,6 +21,7 @@ config PPC_PSERIES > select HOTPLUG_CPU if SMP > select ARCH_RANDOM > select PPC_DOORBELL > + select CHOOSE_ENDIAN > default y > > config PPC_SPLPAR > > > > > > But the specific problem you are having looks like a differnet > > > issue > > > with the PS3 boot wrapper. > > > > > > > But could the reason of this be that the building process of the > > PS3 > > boot wrapper assumes the kernel is BE? > > It looks more like we're getting confused between 32-bit and 64-bit, > from your > log: > > ld: powerpc:common64 architecture of input file > `arch/powerpc/boot/ps3-head.o' is incompatible with powerpc:common > output > > Which says it has a .o which is 64-bit but it's trying to produce 32 > -bit output. > > That's probably related to the PPC64_BOOT_WRAPPER stuff. > > cheers >
On Tue, 2015-09-01 at 06:40 +1000, Benjamin Herrenschmidt wrote: > On Mon, 2015-08-31 at 21:19 +1000, Michael Ellerman wrote: > > > Yes. Maybe something like this? > > I would have done it the other way around with endian at the top > and only the supported platforms displayed based on the endian... > > But I don't care *that* much either way Yeah, I figured folks are not really caring so much about endian when configuring they're primarily thinking about the platform. But if we do it this way we *also* need to make PS3 etc. depend on BIG_ENDIAN, so they don't get enabled on multi-platform LE builds, so we should probably just do it that way. cheers
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
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 default y config OPAL_PRD diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig index 54c87d5..182f485 100644 --- a/arch/powerpc/platforms/pseries/Kconfig +++ b/arch/powerpc/platforms/pseries/Kconfig @@ -21,6 +21,7 @@ config PPC_PSERIES select HOTPLUG_CPU if SMP select ARCH_RANDOM select PPC_DOORBELL + select CHOOSE_ENDIAN default y config PPC_SPLPAR