Thread (30 messages) 30 messages, 2 authors, 2023-02-20

Re: [PATCH v3] powerpc/boot: Don't always pass -mcpu=powerpc when building 32-bit uImage

From: Christophe Leroy <hidden>
Date: 2022-12-07 13:39:41
Also in: lkml


Le 26/11/2022 à 17:30, Pali Rohár a écrit :
On Wednesday 02 November 2022 14:05:35 Christophe Leroy wrote:
quoted
Le 01/11/2022 à 23:12, Pali Rohár a écrit :
quoted
On Sunday 09 October 2022 13:06:52 Pali Rohár wrote:
quoted
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 1
corenet64_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 2
Seems 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?
Hi, sorry I was on holiday until today. I'll try to have a look in the
coming days.
Ok, Did you have a time to look at it?
I just sent a patch for it.

Christophe
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