Re: [PATCH v3] powerpc/boot: Don't always pass -mcpu=powerpc when building 32-bit uImage
From: Pali Rohár <pali@kernel.org>
Date: 2022-11-01 22:13:04
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On Sunday 09 October 2022 13:06:52 Pali Rohár wrote:
On Monday 29 August 2022 10:54:51 Pali Rohár wrote:quoted
On Sunday 28 August 2022 17:43:53 Christophe Leroy wrote:quoted
Le 28/08/2022 à 19:41, Pali Rohár a écrit :quoted
On Sunday 28 August 2022 17:39:25 Christophe Leroy wrote:quoted
Le 28/08/2022 à 19:33, Christophe Leroy a écrit :quoted
Le 28/08/2022 à 11:56, Pali Rohár a écrit :quoted
When CONFIG_TARGET_CPU is specified then pass its value to the compiler -mcpu option. This fixes following build error when building kernel with powerpc e500 SPE capable cross compilers: BOOTAS arch/powerpc/boot/crt0.o powerpc-linux-gnuspe-gcc: error: unrecognized argument in option ‘-mcpu=powerpc’ powerpc-linux-gnuspe-gcc: note: valid arguments to ‘-mcpu=’ are: 8540 8548 native make[1]: *** [arch/powerpc/boot/Makefile:231: arch/powerpc/boot/crt0.o] Error 1corenet64_smp_defconfig : BOOTAS arch/powerpc/boot/crt0.o powerpc64-linux-gcc: error: missing argument to '-mcpu=' make[1]: *** [arch/powerpc/boot/Makefile:237 : arch/powerpc/boot/crt0.o] Erreur 1 make: *** [arch/powerpc/Makefile:253 : uImage] Erreur 2Seems like in fact, E5500_CPU and E6500_CPU are not taken into account in CONFIG_TARGET_CPU, and get special treatment directly in arch/powerpc/Makefile. This goes unnoticed because of CFLAGS-$(CONFIG_TARGET_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU)) I think we need to fix that prior to your patch.It looks like that CONFIG_TARGET_CPU is broken. $ make ARCH=powerpc corenet64_smp_defconfig CROSS_COMPILE=powerpc64-linux-gnu- ... # configuration written to .config $ grep CONFIG_TARGET_CPU .config CONFIG_TARGET_CPU_BOOL=y CONFIG_TARGET_CPU_BOOL is set but CONFIG_TARGET_CPU not!Yes, because there is no default value for E5500_CPU and E6500_CPU. We need to add one for each.I see... Will you prepare this fixup for your previous patch? And I think that following construct $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU)) should be changed just to -mcpu=$(CONFIG_TARGET_CPU) Because if user specified that want build for specific target CPU, it should not be silently ignored.Christophe, should I do something in this area?
Christophe, any input from your side?