Re: [kvm-unit-tests PATCH v1 3/5] arm64: Implement the ./configure --processor option

[Andrew Jones <andrew.jones@linux.dev>]

On Fri, Jan 10, 2025 at 01:58:46PM +0000, Alexandru Elisei wrote:
> The help text for the ./configure --processor option says:
> 
>     --processor=PROCESSOR  processor to compile for (cortex-a57)
> 
> but, unlike arm, the build system does not pass a -mcpu argument to the
> compiler. Fix it, and bring arm64 at parity with arm.
> 
> Note that this introduces a regression, which is also present on arm: if
> the --processor argument is something that the compiler doesn't understand,
> but qemu does (like 'max'), then compilation fails. This will be fixed in a
> following patch; another fix is to specify a CPU model that gcc implements
> by using --cflags=-mcpu=<cpu>.
> 
> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
> ---
>  arm/Makefile.arm    | 1 -
>  arm/Makefile.common | 1 +
>  2 files changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arm/Makefile.arm b/arm/Makefile.arm
> index 7fd39f3ada64..d6250b7fb686 100644
> --- a/arm/Makefile.arm
> +++ b/arm/Makefile.arm
> @@ -12,7 +12,6 @@ $(error Cannot build arm32 tests as EFI apps)
>  endif
>  
>  CFLAGS += $(machine)
> -CFLAGS += -mcpu=$(PROCESSOR)
>  CFLAGS += -mno-unaligned-access
>  
>  ifeq ($(TARGET),qemu)
> diff --git a/arm/Makefile.common b/arm/Makefile.common
> index f828dbe01d33..a5d97bcf477a 100644
> --- a/arm/Makefile.common
> +++ b/arm/Makefile.common
> @@ -25,6 +25,7 @@ AUXFLAGS ?= 0x0
>  # stack.o relies on frame pointers.
>  KEEP_FRAME_POINTER := y
>  
> +CFLAGS += -mcpu=$(PROCESSOR)
>  CFLAGS += -std=gnu99
>  CFLAGS += -ffreestanding
>  CFLAGS += -O2
> -- 
> 2.47.1
>

Reviewed-by: Andrew Jones <andrew.jones@linux.dev>