[U-Boot] [PATCH] Makefile: Introduce ARCH_PLATFORM_LIBGCC variable

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hi Tom,

On Fri, 11 Oct 2013 16:13:03 -0400, Tom Rini <trini@ti.com> wrote:

> In some cases, such as arm multi-lib hardfloat (hf) toolchains, we will
> have multiple libgcc.a's available, and the arch needs to provide
> additional logic to determine the right file to use
> (-print-libgcc-file-name contains no CFLAG parsing logic).
> 
> Cc: Albert Aribaud <albert.u.boot@aribaud.net>
> Signed-off-by: Tom Rini <trini@ti.com>
> ---
>  Makefile           |    4 ++++
>  arch/arm/config.mk |   11 +++++++++++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/Makefile b/Makefile
> index b09bfcc..13b396f 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -357,8 +357,12 @@ else
>  PLATFORM_LIBGCC = -L $(USE_PRIVATE_LIBGCC) -lgcc
>  endif
>  else
> +ifneq ("$(ARCH_PLATFORM_LIBGCC)","")
> +PLATFORM_LIBGCC := -L $(shell dirname $(ARCH_PLATFORM_LIBGCC)) -lgcc
> +else
>  PLATFORM_LIBGCC := -L $(shell dirname `$(CC) $(CFLAGS) -print-libgcc-file-name`) -lgcc
>  endif
> +endif
>  PLATFORM_LIBS += $(PLATFORM_LIBGCC)
>  export PLATFORM_LIBS
>  
> diff --git a/arch/arm/config.mk b/arch/arm/config.mk
> index d0cf43f..e1d0dec 100644
> --- a/arch/arm/config.mk
> +++ b/arch/arm/config.mk
> @@ -19,6 +19,17 @@ LDFLAGS_FINAL += --gc-sections
>  PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections \
>                       -fno-common -ffixed-r9 -msoft-float
>  
> +#
> +# When we use a hardfp toolchain if there are both 'libgcc.a' (hardfp) and
> +# 'arm-linux-gnueabi/libgcc.a' (softfp) we need to use the latter.  We
> +# cannot always build with a hardfp-only toolchain.

What does this last sentence mean exactly?

> +ARCH_PLATFORM_LIBGCC := $(shell \
> +	X=`$(CC) -print-file-name=arm-linux-gnueabi/libgcc.a`; \
> +	if [ -f $$X ]; then echo $$X ; \
> +	else $(CC) -print-file-name=libgcc.a ; \
> +	fi)
> +
>  # Support generic board on ARM
>  __HAVE_ARCH_GENERIC_BOARD := y

Amicalement,
-- 
Albert.