[Buildroot] [PATCH 2/2] toolchain: Add support for Cortex-M4 processor

[Douglas RAILLARD <public.douglas.raillard@gmail.com>]

Hi Chris,

On 17/09/2015 09:21, Chris Wardman wrote:
> This patch adds support for the Cortex-M4 processor. Cortex-M4 is almost
> completely identical to the Cortex-M3 processor. Cortex-M4 uses the same
> Thumb2/Thumb instruction set. Not sure if the extra M4 DSP instructions are
> currently supported.
> 
> Signed-off-by: Chris Wardman <cjwfirmware@vxmdesign.com>
> ---
>  arch/Config.in.arm | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/Config.in.arm b/arch/Config.in.arm
> index 4d10f4c..5055cb5 100644
> --- a/arch/Config.in.arm
> +++ b/arch/Config.in.arm
> @@ -156,6 +156,11 @@ config BR2_cortex_m3
>  	bool "cortex-M3"
>  	select BR2_ARM_CPU_HAS_THUMB
>  	select BR2_ARM_CPU_HAS_THUMB2
> +config BR2_cortex_m4
> +	bool "cortex-M4"
> +	select BR2_ARM_CPU_HAS_THUMB

It is not clear if selecting BR2_ARM_CPU_HAS_THUMB for Cortex M is
relevant or if this leads to other problems:
http://article.gmane.org/gmane.comp.lib.uclibc.buildroot/126372

> +	select BR2_ARM_CPU_HAR_THUMB2
> +	select BR2_ARM_CPU_ARMV7M

If adding the BR2_ARM_CPU_ARMV7M option is okay, this could also be used
to preset some options for uClibc-ng.

>  config BR2_fa526
>  	bool "fa526/626"
>  	select BR2_ARM_CPU_HAS_ARM
> @@ -419,6 +424,7 @@ config BR2_GCC_TARGET_CPU
>  	default "cortex-a12"	if BR2_cortex_a12
>  	default "cortex-a15"	if BR2_cortex_a15
>  	default "cortex-m3"	if BR2_cortex_m3
> +	default "cortex-m4"     if BR2_cortex_m4
>  	default "fa526"		if BR2_fa526
>  	default "marvell-pj4"	if BR2_pj4
>  	default "strongarm"	if BR2_strongarm
> 

Best regards,

Douglas
-- 

Douglas RAILLARD