[Buildroot] [PATCH 1/3] arch/config.in.arc: Introduce the ARC optimized hs38 config

[Thomas Petazzoni <thomas.petazzoni@bootlin.com>]

Hello,

+Arnout for legacy handling.

On Fri,  8 Nov 2019 09:41:10 -0800
Vineet Gupta <Vineet.Gupta1@synopsys.com> wrote:

> This corresponds to -mcu=hs38 with mpy-option=9 (64-bit multiplier)
> 
> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
> ---
>  arch/Config.in.arc | 21 ++++++++++++++-------
>  1 file changed, 14 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/Config.in.arc b/arch/Config.in.arc
> index c65bb01f1f4f..284951b82cee 100644
> --- a/arch/Config.in.arc
> +++ b/arch/Config.in.arc
> @@ -11,13 +11,19 @@ config BR2_arc750d
>  config BR2_arc770d
>  	bool "ARC 770D"
>  
> -config BR2_archs38
> +config BR2_archs
>  	bool "ARC HS38"
>  	help
>  	  Generic ARC HS capable of running Linux, i.e. with MMU,
> -	  caches and multiplier. Also it corresponds to the default
> +	  caches and 32-bit multiplier. Also it corresponds to the default
>  	  configuration in older GNU toolchain versions.
>  
> +config BR2_archs38

This re-use of an existing name is a bit annoying. Indeed, all existing
users of Buildroot that have a configuration with BR2_archs38 will now
be building for a ARC system with a 64-bit multiplier, while they were
previously building for a 32-bit multiplier.

I see that what you have done is to try to be consistent between the
BR2_ options and the gcc options. I'm hesitating between keeping the
consistency but making the migration a bit annoying for users, or
breaking the consistency to make the migration smooth for users.

Since I think the number of affected users will probably be quite
small/limited, I think I would be fine with merging your patch as-is,
but I'd like to hear from others.

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com