Re: [PATCH 1/2] sunxi: boot0.h: allow RVBAR MMIO address customisation

["Jernej Škrabec" <jernej.skrabec@gmail.com>]

Dne sreda, 05. april 2023 ob 16:27:30 CEST je Andre Przywara napisal(a):
> To switch the ARMv8 Allwinner SoCs into the 64-bit AArch64 ISA, we need
> to program the 64-bit start code address into an MMIO mapped register
> that shadows the architectural RVBAR register.
> This address is SoC specific, with just two versions out there so far.
> Now a third address emerged, on a *variant* of an existing SoC (H616).
> 
> Change the boot0.h start code to make this address a Kconfig
> selectable option, to allow easier maintenance.
> We make this address user-visible (even though it shouldn't be), to
> allow putting this in defconfig. This is needed because there are
> apparently revisions of the H616 SoC out there using different
> addresses, so this becomes a per-board decision.
> 
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>

Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej

> ---
>  arch/arm/include/asm/arch-sunxi/boot0.h |  7 ++-----
>  arch/arm/mach-sunxi/Kconfig             | 12 ++++++++++++
>  2 files changed, 14 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/arm/include/asm/arch-sunxi/boot0.h
> b/arch/arm/include/asm/arch-sunxi/boot0.h index 46b7e073b59..59ea75a96b5
> 100644
> --- a/arch/arm/include/asm/arch-sunxi/boot0.h
> +++ b/arch/arm/include/asm/arch-sunxi/boot0.h
> @@ -39,11 +39,8 @@
>  	.word	0xf57ff06f	// isb     sy
>  	.word	0xe320f003	// wfi
>  	.word	0xeafffffd	// b       @wfi
> -#ifndef CONFIG_SUN50I_GEN_H6
> -	.word	0x017000a0	// writeable RVBAR mapping address
> -#else
> -	.word	0x09010040	// writeable RVBAR mapping address
> -#endif
> +
> +	.word	CONFIG_SUNXI_RVBAR_ADDRESS	// writable RVBAR mapping 
addr
>  #ifdef CONFIG_SPL_BUILD
>  	.word	CONFIG_SPL_TEXT_BASE
>  #else
> diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
> index 6417aee944b..b46667ce01e 100644
> --- a/arch/arm/mach-sunxi/Kconfig
> +++ b/arch/arm/mach-sunxi/Kconfig
> @@ -110,6 +110,18 @@ config SUNXI_SRAM_ADDRESS
>  	Some newer SoCs map the boot ROM at address 0 instead and move the
>  	SRAM to a different address.
> 
> +config SUNXI_RVBAR_ADDRESS
> +	hex "RVBAR address"
> +	depends on ARM64
> +	default 0x09010040 if SUN50I_GEN_H6
> +	default 0x017000a0
> +	---help---
> +	The read-only RVBAR system register holds the address of the first
> +	instruction to execute after a reset. Allwinner cores provide a
> +	writable MMIO backing store for this register, to allow to set the
> +	entry point when switching to AArch64. This store is on different
> +	addresses, depending on the SoC.
> +
>  config SUNXI_A64_TIMER_ERRATUM
>  	bool