[U-Boot] [PATCH 2/2] sunxi: Set the AUXCR L2EN bit for sun4i/sun5i in FEL boot mode

[Hans de Goede]

Hi,

On 07/18/2014 07:09 PM, Siarhei Siamashka wrote:
> This is needed to have feature parity with the normal boot mode,
> where the L2EN bit in the CP15 Auxiliary Control Register is set
> by the BROM code right from the start.
>
> If this is not done, the Linux system ends up booted with the L2 cache
> disabled.
>
> Signed-off-by: Siarhei Siamashka <siarhei.siamashka at gmail.com>
> ---
>   arch/arm/cpu/armv7/sunxi/board.c | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
>
> diff --git a/arch/arm/cpu/armv7/sunxi/board.c b/arch/arm/cpu/armv7/sunxi/board.c
> index 49c9448..86cf4c9 100644
> --- a/arch/arm/cpu/armv7/sunxi/board.c
> +++ b/arch/arm/cpu/armv7/sunxi/board.c
> @@ -69,6 +69,18 @@ void s_init(void)
>   		"mcr p15, 0, r0, c1, c0, 1\n");
>   #endif
>
> +#if defined(CONFIG_SPL_FEL) && (defined(CONFIG_SUN4I) || defined(CONFIG_SUN5I))
> +	/* For ARM Cortex-A8 based hardware (sun4i and sun5i), the L2EN bit is
> +	 * set by the BROM code in the "normal" mode, but not in the "FEL" mode.
> +	 * Here we fix this inconsistency in the Auxiliary Ctl reg by also
> +	 * setting the missing L2EN bit.
> +	 */
> +	asm volatile(
> +		"mrc p15, 0, r0, c1, c0, 1\n"
> +		"orr r0, r0, #2\n"
> +		"mcr p15, 0, r0, c1, c0, 1\n" : : : "r0");
> +#endif
> +

Wouldn't it be better to do this in the start_fel.S file you've introduced in
the first patch of this series ?

Regards,

Hans