Re: [PATCH 4/4] ARM: dts: stm32mp: add bootrom serial (DFU) reboot mode

[Sascha Hauer <sha@pengutronix.de>]

On Tue, Aug 09, 2022 at 08:29:38AM +0200, Ahmad Fatoum wrote:
> The same register we use for the reboot mode communication between Linux
> and barebox is also sampled by the bootrom. If the lowest 16 bits of it
> are 0x00FF, the bootrom will enter DFU mode. Add the appropriate
> reboot-mode, but with a barebox, prefix, so Linux doesn't automatically
> provide it to userspace along with the existing loader and recovery
> modes.

Why do we need to prevent Linux from providing dfu mode to userspace?
Isn't that a vlid usecase?

Sascha

> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>  arch/arm/dts/stm32mp151.dtsi | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/dts/stm32mp151.dtsi b/arch/arm/dts/stm32mp151.dtsi
> index ed7cf6192bea..ac6536a556a9 100644
> --- a/arch/arm/dts/stm32mp151.dtsi
> +++ b/arch/arm/dts/stm32mp151.dtsi
> @@ -41,9 +41,10 @@
>  	reboot_mode_tamp: reboot-mode {
>  		compatible = "syscon-reboot-mode";
>  		offset = <0x150>; /* reg20 */
> -		mask = <0xff>;
> +		mask = <0xffff>;
>  		mode-normal = <0>;
>  		mode-loader = <0xBB>;
>  		mode-recovery = <0xBC>;
> +		barebox,mode-serial = <0xFF>;
>  	};
>  };
> -- 
> 2.30.2
> 
> 
> 

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