[PATCH 2/2] arm: dts: am571x-idk: Reserve EMIF memory used by PPA

[Kumar, Udit]

On 11/28/2025 12:13 PM, Beleswar Padhi wrote:
> The AM571x SoC has 1 GB DDR space. However on HS devices, the top
> 0x2500000 is used by PPA and is firewalled. We should reserve this
> memory in device-tree so that U-Boot doesn't use that memory for
> anything. Reserve the top 0x2600000 memory (aligned to 2MB as per page
> size for ARM32) for the same.
>
> Signed-off-by: Beleswar Padhi <b-padhi at ti.com>
> ---
>   arch/arm/dts/am571x-idk.dts | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
>
> diff --git a/arch/arm/dts/am571x-idk.dts b/arch/arm/dts/am571x-idk.dts
> index b3592b22a0c..0cbd8c8a685 100644
> --- a/arch/arm/dts/am571x-idk.dts
> +++ b/arch/arm/dts/am571x-idk.dts
> @@ -20,6 +20,18 @@
>   		reg = <0x0 0x80000000 0x0 0x40000000>;
>   	};
>   
> +	reserved-memory {
> +		#address-cells = <2>;
> +		#size-cells = <2>;
> +		ranges;
> +
> +		ppa_firewall_memory_region: ppa-firewall-memory at bda00000 {
> +			compatible = "shared-dma-pool";
> +			reg = <0x00 0xbda00000 0x00 0x2600000>;
> +			no-map;
> +		};
> +	};

You will lose this memory on GP device as well .

I suggest to have DT specific to HS device, or reserve this at run-time 
after detecting HS device.


> +
>   	leds {
>   		compatible = "gpio-leds";
>   		cpu0-led {