[boot-wrapper PATCH v2 4/8] aarch64: Prepare for EL1 booting

[Andre Przywara]

On Fri, 21 May 2021 18:48:03 +0800
Jaxson Han <jaxson.han at arm.com> wrote:

> When booting from EL1, add a check and skip the init of
> sctlr_el2 in jump_kernel
> 
> Signed-off-by: Jaxson Han <jaxson.han at arm.com>

Reviewed-by: Andre Przywara <andre.przywara at arm.com>

Cheers,
Andre

> ---
>  arch/aarch64/boot.S | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S
> index ee9886b..b8f9e4e 100644
> --- a/arch/aarch64/boot.S
> +++ b/arch/aarch64/boot.S
> @@ -144,10 +144,14 @@ jump_kernel:
>  	ldr	x0, =SCTLR_EL1_RESET
>  	msr	sctlr_el1, x0
>  
> +	mrs	x0, CurrentEL
> +	cmp	x0, #CURRENTEL_EL2
> +	b.lt	1f
> +
>  	ldr	x0, =SCTLR_EL2_RESET
>  	msr	sctlr_el2, x0
>  
> -	cpuid	x0, x1
> +1:	cpuid	x0, x1
>  	bl	find_logical_id
>  	bl	setup_stack		// Reset stack pointer
>