On 5/16/19 3:28 AM, Hsin-Yi Wang wrote:
> Introducing a chosen node, rng-seed, which is an entropy that can be
> passed to kernel called very early to increase initial device
> randomness. Bootloader should provide this entropy and the value is
> read from /chosen/rng-seed in DT.
>
> Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> ---
> change v2->v3:
> 1. use arch hook for fdt pgprot change
> 2. handle CONFIG_KEXEC
> ---
> Documentation/devicetree/bindings/chosen.txt | 14 +++++
> drivers/of/fdt.c | 55 ++++++++++++++++++++
> 2 files changed, 69 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt
> index 45e79172a646..fef5c82672dc 100644
> --- a/Documentation/devicetree/bindings/chosen.txt
> +++ b/Documentation/devicetree/bindings/chosen.txt
> @@ -28,6 +28,20 @@ mode) when EFI_RNG_PROTOCOL is supported, it will be overwritten by
> the Linux EFI stub (which will populate the property itself, using
> EFI_RNG_PROTOCOL).
>
> +rng-seed
> +-----------
> +
> +This property served as an entropy to add device randomness. It is parsed
serves
> +as a byte array, e.g.
> +
> +/ {
> + chosen {
> + rng-seed = <0x31 0x95 0x1b 0x3c 0xc9 0xfa 0xb3 ...>;
> + };
> +};
> +
> +This random value should be provided by bootloader.
> +
> stdout-path
> -----------
>
--
~Randy
