[U-Boot] [PATCH] ARM1136: Align stack to 8 bytes

[Martin Krause]

Hi Vitaly,

the exact same problem applies to ARM1176. Maybe you could update
your patch and add the same line to /arch/arm/cpu/arm1176/start.S.
I am currently not working on an top-of-tree U-Boot, so it would
be not so easy for me to create a separate patch for ARM1176.

Regards,
Martin

u-boot-bounces at lists.denx.de wrote on Tuesday, June 15, 2010 12:52 PM:
> The ARM ABI requires that the stack be aligned to 8 bytes as it is
> noted in Procedure Call Standard for the ARM Architecture:
> http://infocenter.arm.com/help/topic/com.arm.doc.ihi0042d/index.html
> 
> Unaligned SP also causes the problem with variable-length arrays
> allocation when VLA address becomes less than stack pointer during
> aligning of this address, so the further 'push' into the stack
> overwrites first 4 bytes of VLA.
> 
> Signed-off-by: Vitaly Kuzmichev <vkuzmichev at mvista.com>
> Signed-off-by: George G. Davis <gdavis at mvista.com>
> ---
>  arch/arm/cpu/arm1136/start.S |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/cpu/arm1136/start.S
> b/arch/arm/cpu/arm1136/start.S index 957f438..d0c5717 100644
> --- a/arch/arm/cpu/arm1136/start.S
> +++ b/arch/arm/cpu/arm1136/start.S
> @@ -185,6 +185,7 @@ stack_setup:
>  #endif
>  	sub	sp, r0, #12		/* leave 3 words for abort-stack    */
>  #endif	/* CONFIG_PRELOADER */
> +	bic	sp, sp, #7		/* 8-byte alignment                 */
> 
>  clear_bss:
>  	ldr	r0, _bss_start		/* find start of bss segment	    */