[U-Boot] [PATCH] arm: lib: memcpy: Do not copy to same address

[Alexander Holler]

Am 23.05.2011 11:06, schrieb Matthias Weisser:
> In some cases (e.g. bootm with a elf payload which is already at the right
> position) there is a in place copy of data to the same address. Catching this
> saves some ms while booting.
>
> Signed-off-by: Matthias Weisser<weisserm at arcor.de>
> ---
>   arch/arm/lib/memcpy.S |    3 +++
>   1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/lib/memcpy.S b/arch/arm/lib/memcpy.S
> index 3b5aeec..f655256 100644
> --- a/arch/arm/lib/memcpy.S
> +++ b/arch/arm/lib/memcpy.S
> @@ -60,6 +60,9 @@
>   .globl memcpy
>   memcpy:
>
> +		cmp	r0, r1
> +		moveq	pc, lr
> +
>   		enter	r4, lr
>
>   		subs	r2, r2, #4

The standard clearly say to both memory regions should not overlap when 
memcpy() is used, so I would say this is the wrong place to fix that.

Regards,

Alexander