Messages in this thread Patch in this message | | | From | Michael Ellerman <> | Subject | Re: Error: invalid switch -me200 | Date | Mon, 16 Nov 2020 17:06:21 +1100 |
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Christophe Leroy <christophe.leroy@csgroup.eu> writes: > Le 14/11/2020 à 01:20, Segher Boessenkool a écrit : >> On Fri, Nov 13, 2020 at 12:14:18PM -0800, Nick Desaulniers wrote: >>>>>> Error: invalid switch -me200 >>>>>> Error: unrecognized option -me200 >>>>> >>>>> 251 cpu-as-$(CONFIG_E200) += -Wa,-me200 >>>>> >>>>> Are those all broken configs, or is Kconfig messed up such that >>>>> randconfig can select these when it should not? >>>> >>>> Hmmm, looks like this flag does not exist in mainline binutils? There is >>>> a thread in 2010 about this that Segher commented on: >>>> >>>> https://lore.kernel.org/linuxppc-dev/9859E645-954D-4D07-8003-FFCD2391AB6E@kernel.crashing.org/ >>>> >>>> Guess this config should be eliminated? >> >> The help text for this config options says that e200 is used in 55xx, >> and there *is* an -me5500 GAS flag (which probably does this same >> thing, too). But is any of this tested, or useful, or wanted? >> >> Maybe Christophe knows, cc:ed. >> > > I don't have much clue on this.
Me either.
> But I see on wikipedia that e5500 is a 64 bits powerpc (https://en.wikipedia.org/wiki/PowerPC_e5500) > > What I see is that NXP seems to provide a GCC version that includes aditionnal cpu (e200z0 e200z2 > e200z3 e200z4 e200z6 e200z7): > > valid arguments to '-mcpu=' are: 401 403 405 405fp 440 440fp 464 464fp 476 476fp 505 601 602 603 > 603e 604 604e 620 630 740 7400 7450 750 801 821 823 8540 8548 860 970 G3 G4 G5 a2 cell e200z0 e200z2 > e200z3 e200z4 e200z6 e200z7 e300c2 e300c3 e500mc e500mc64 e5500 e6500 ec603e native power3 power4 > power5 power5+ power6 power6x power7 power8 powerpc powerpc64 powerpc64le rs64 titan " > > https://community.nxp.com/t5/MPC5xxx/GCC-generating-not-implemented-instructions/m-p/845049 > > Apparently based on binutils 2.28 > > https://www.nxp.com/docs/en/release-note/S32DS-POWER-v1-2-RN.pdf > > But that's not exactly -me200 though. > > Now, I can't see any defconfig that selects CONFIG_E200, so is that worth keeping it in the kernel > at all ?
There was a commit in 2014 that suggests it worked at least to some extent then:
3477e71d5319 ("powerpc/booke: Restrict SPE exception handlers to e200/e500 cores")
Presumably there was a non-upstream toolchain where it was supported?
AFAICS the kernel builds OK with just the cpu-as modification removed:
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index a4d56f0a41d9..16b8336f91dd 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -248,7 +248,6 @@ KBUILD_CFLAGS += $(call cc-option,-mno-string) cpu-as-$(CONFIG_40x) += -Wa,-m405 cpu-as-$(CONFIG_44x) += -Wa,-m440 cpu-as-$(CONFIG_ALTIVEC) += $(call as-option,-Wa$(comma)-maltivec) -cpu-as-$(CONFIG_E200) += -Wa,-me200 cpu-as-$(CONFIG_E500) += -Wa,-me500
# When using '-many -mpower4' gas will first try and find a matching power4
So that seems like the obvious fix for now.
I tried booting the resulting kernel in qemu, but I get:
$ qemu-system-ppc -M none -cpu e200 -kernel build\~/vmlinux Error: Trying to register SPR 574 (23e) twice !
Which is not related AFAIK and indicates the qemu support is broken.
Unless we hear from someone that they're using mainline on an e200 then it seems like it's a candidate for removal.
cheers
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