[U-Boot] [PATCH] ARMv7: start.S: stay in HYP mode if u-boot is entered in it

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hi Andre,

On Tue,  2 Apr 2013 17:43:36 +0200, Andre Przywara
<andre.przywara@linaro.org> wrote:

> The KVM and Xen hypervisors for the Cortex-A15 virtualization
> implementation need to be entered in HYP mode. Should the primary
> board firmware already enter HYP mode (Calxeda firmware does that),
> we should not deliberately drop back to SVC mode.
> Since U-boot does not use the MMU, running in HYP mode is just fine.
> 
> Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
> ---
>  arch/arm/cpu/armv7/start.S | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
> index 36a4c3c..95c8a95 100644
> --- a/arch/arm/cpu/armv7/start.S
> +++ b/arch/arm/cpu/armv7/start.S
> @@ -126,11 +126,15 @@ IRQ_STACK_START_IN:
>  reset:
>  	bl	save_boot_params
>  	/*
> -	 * set the cpu to SVC32 mode
> +	 * disable interrupts (FIQ and IRQ), also set the cpu to SVC32 mode,
> +	 * except if in HYP mode already
>  	 */
>  	mrs	r0, cpsr
> -	bic	r0, r0, #0x1f
> -	orr	r0, r0, #0xd3
> +	and	r1, r0, #0x1f		@ mask mode bits
> +	teq	r1, #0x1a		@ test for HYP mode
> +	bicne	r0, r0, #0x1f		@ clear all mode bits
> +	orrne	r0, r0, #0x13		@ set SVC mode
> +	orr	r0, r0, #0xc0		@ disable FIQ and IRQ
>  	msr	cpsr,r0
>  
>  /*

Applied to u-boot-arm/master, thanks!

Amicalement,
-- 
Albert.