Re: [edk2-platforms PATCH] Platform/RaspberryPi: Check for Boot Discovery Policy change.

["Ard Biesheuvel" <ardb@kernel.org>]

On Wed, 18 Aug 2021 at 09:38, Grzegorz Bernacki <gjb@semihalf.com> wrote:
>
> This patch adds checks if Boot Discovery Policy has been
> changed. Only in that case EfiBootManagerRefreshAllBootOption()
> should be called.
>
> Signed-off-by: Grzegorz Bernacki <gjb@semihalf.com>

To be honest, I'm not a fan of this bodge. Can you explain why we need
two separate EFI variables to keep track of this state?


> ---
>  Platform/RaspberryPi/Library/PlatformBootManagerLib/PlatformBm.c | 24 +++++++++++++++++++-
>  1 file changed, 23 insertions(+), 1 deletion(-)
>
> diff --git a/Platform/RaspberryPi/Library/PlatformBootManagerLib/PlatformBm.c b/Platform/RaspberryPi/Library/PlatformBootManagerLib/PlatformBm.c
> index c8305ce4f5..378ba0ebf4 100644
> --- a/Platform/RaspberryPi/Library/PlatformBootManagerLib/PlatformBm.c
> +++ b/Platform/RaspberryPi/Library/PlatformBootManagerLib/PlatformBm.c
> @@ -617,6 +617,7 @@ BootDiscoveryPolicyHandler (
>  {
>    EFI_STATUS                       Status;
>    UINT32                           DiscoveryPolicy;
> +  UINT32                           DiscoveryPolicyOld;
>    UINTN                            Size;
>    EFI_BOOT_MANAGER_POLICY_PROTOCOL *BMPolicy;
>    EFI_GUID                         *Class;
> @@ -678,7 +679,28 @@ BootDiscoveryPolicyHandler (
>      return Status;
>    }
>
> -  EfiBootManagerRefreshAllBootOption();
> +  //
> +  // Refresh Boot Options if Boot Discovery Policy has been changed
> +  //
> +  Size = sizeof (DiscoveryPolicyOld);
> +  Status = gRT->GetVariable (
> +                  BOOT_DISCOVERY_POLICY_OLD_VAR,
> +                  &gBootDiscoveryPolicyMgrFormsetGuid,
> +                  NULL,
> +                  &Size,
> +                  &DiscoveryPolicyOld
> +                  );
> +  if ((Status == EFI_NOT_FOUND) || (DiscoveryPolicyOld != DiscoveryPolicy)) {
> +    EfiBootManagerRefreshAllBootOption();
> +
> +    Status = gRT->SetVariable (
> +                    BOOT_DISCOVERY_POLICY_OLD_VAR,
> +                    &gBootDiscoveryPolicyMgrFormsetGuid,
> +                    EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS,
> +                    sizeof (DiscoveryPolicyOld),
> +                    &DiscoveryPolicy
> +                    );
> +  }
>
>    return EFI_SUCCESS;
>  }
> --
> 2.25.1
>