Re: [PATCH] sunxi: a133: adjust TF-A load address

[Paul Kocialkowski <paulk@sys-base.io>]

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Hi Andre,

On Fri 30 Oct 26, 00:37, Andre Przywara wrote:
> When development of the Allwinner A133 TF-A port started, BL31 was put
> in SRAM, like on the similar H6 SoC. Consequently we used the same SRAM
> address as the H6 in the Kconfig stanza of the A133 U-Boot port.
> 
> Later we realised that the SRAM space will become too tight, in fact it
> was already spilling over into SRAM C, which we cannot use any more at
> runtime, once the display engine is used. So the mainline TF-A port
> eventually put BL31 in DRAM, which of course requires a different load
> address.
> 
> Adjust the BL31 load address to use the same DRAM location as the (almost
> SRAM-less) H616, by just adjusting the match pattern, to not let the A133
> fall through to the SUN50I_GEN_H6 symbol.
> This allows U-Boot to use the now merged mainline TF-A port for the A133.
> 
> This is unfortunately a breaking change, but there is not much we can do
> about it, and since U-Boot packages TF-A in our booting scheme, we have
> that under control.

Thanks for submitting this! I agree this is the right thing to do.

Also note that I've been using the 0x104000 SRAM address as base for the
crust SCP firmware, which will be submitted once crust support is there.

Another aspect is that I'm not sure we actually lock down the address in
the TZC, so it's likely that Linux could still overwrite the TF-A code.
But that's a TF-A problem, not a U-Boot problem.

Reviewed-by: Paul Kocialkowski <paulk@sys-base.io>

All the best,

Paul

> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  arch/arm/mach-sunxi/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
> index b0c5d3cd903..b7ee14c6678 100644
> --- a/arch/arm/mach-sunxi/Kconfig
> +++ b/arch/arm/mach-sunxi/Kconfig
> @@ -267,7 +267,7 @@ config SUNXI_RVBAR_ALTERNATIVE
>  config SUNXI_BL31_BASE
>  	hex
>  	default 0x00044000 if MACH_SUN50I || MACH_SUN50I_H5
> -	default 0x40000000 if MACH_SUN50I_H616
> +	default 0x40000000 if MACH_SUN50I_H616 || MACH_SUN50I_A133
>  	default 0x00104000 if SUN50I_GEN_H6
>  	default 0x00054000 if MACH_SUN55I_A523
>  	default 0x0
> -- 
> 2.46.4
> 

-- 
Paul Kocialkowski,

Independent contractor - sys-base - https://www.sys-base.io/
Free software developer - https://www.paulk.fr/

Expert in multimedia, graphics and embedded hardware support with Linux.

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