[U-Boot] [PATCH v2] arm: Tegra2: Fix ELDK42 gcc failure with inline asm stack pointer load

[Tom Warren]

On Fri, Feb 17, 2012 at 9:01 AM, Tom Warren <twarren.nvidia at gmail.com> wrote:
> The 4.2.2 gcc in the ELDK42 release doesn't like the direct SP
> load using a constant in tegra2_start. Change it to use a load
> thru another reg using mov sp, %0 : : "r"(CONST).
>
> Tested on my Seaboard T20-A03, U-Boot loads and runs OK. Also
> compiled all tegra2 builds with both gcc 4.2.2 and 4.4.1 OK.
>
> Signed-off-by: Tom Warren <twarren at nvidia.com>
> ---
> V2: Change 4 mov/orr's to single mov sp as per Marek Vasut
>
>  arch/arm/cpu/armv7/tegra2/ap20.c |   10 +++++-----
>  1 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/cpu/armv7/tegra2/ap20.c b/arch/arm/cpu/armv7/tegra2/ap20.c
> index 4c44bb3..f0450f4 100644
> --- a/arch/arm/cpu/armv7/tegra2/ap20.c
> +++ b/arch/arm/cpu/armv7/tegra2/ap20.c
> @@ -298,11 +298,11 @@ void tegra2_start(void)
>                writel(0xC0, &pmt->pmt_cfg_ctl);
>
>                /*
> -               * If we are ARM7 - give it a different stack. We are about to
> -               * start up the A9 which will want to use this one.
> -               */
> -               asm volatile("ldr       sp, =%c0\n"
> -                       : : "i"(AVP_EARLY_BOOT_STACK_LIMIT));
> +                * If we are ARM7 - give it a different stack. We are about to
> +                * start up the A9 which will want to use this one.
> +                */
> +               asm volatile("mov       sp, %0\n"
> +                       : : "r"(AVP_EARLY_BOOT_STACK_LIMIT));
>
>                start_cpu((u32)_start);
>                halt_avp();
> --
> 1.7.7.1
>

Ack? Nak? Can I get some love here?

Albert/Wolfgang - did anyone try this to ensure that it really fixes
the 6 Tegra2 failures?

Tom