Re: [kvm-unit-tests PATCH v2 2/9] arm64: efi: initialise SCTLR_ELx fully

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 29/05/2025 14:55, Joey Gouly wrote:
> Don't rely on the value of SCTLR_ELx when booting via EFI.
> 
> Signed-off-by: Joey Gouly <joey.gouly@arm.com>
> ---
>   lib/arm/setup.c | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/lib/arm/setup.c b/lib/arm/setup.c
> index 67b5db07..0a22dbab 100644
> --- a/lib/arm/setup.c
> +++ b/lib/arm/setup.c
> @@ -349,6 +349,11 @@ efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo)
>   {
>   	efi_status_t status;
>   
> +
> +	// EFI exits boot services with SCTLR_ELx.M=1, so keep
> +	// the MMU enabled.
> +	write_sysreg(INIT_SCTLR_EL1_MMU_OFF | SCTLR_EL1_M, sctlr_el1);

minor nit: Given this is in a common file for arm/arm64, may be worth 
adding a helper function that does this on arm64. I understand EFI
cannot enabled for arm32, still keeping this file generic would be
cleaner. e.g.,

mmu_on(); or even  setup_sctlr();

Suzuki