Re: [PATCH edk2-platforms v2 3/3] Platform/ARM/SgiPkg: Enable MmCommunication module on the platform

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On Thu, 20 Dec 2018 at 06:48, Sughosh Ganu <sughosh.ganu@arm.com> wrote:
>
> The ArmMmCommunication module is used for communication between
> non-secure and secure world using Arm's Management Mode
> Specification. Enable this module on Sgi platforms. This would be used
> subsequently by the RAS and SecureBoot features, support for which
> is to be added on the platform.
>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Sughosh Ganu <sughosh.ganu@arm.com>
> ---
>  Platform/ARM/SgiPkg/SgiPlatform.dsc | 18 ++++++++++++++++++
>  Platform/ARM/SgiPkg/SgiPlatform.fdf |  5 +++++
>  2 files changed, 23 insertions(+)
>
> diff --git a/Platform/ARM/SgiPkg/SgiPlatform.dsc b/Platform/ARM/SgiPkg/SgiPlatform.dsc
> index 7995c7d132d6..948b75631a00 100644
> --- a/Platform/ARM/SgiPkg/SgiPlatform.dsc
> +++ b/Platform/ARM/SgiPkg/SgiPlatform.dsc
> @@ -197,6 +197,20 @@ [PcdsFixedAtBuild.common]
>    gArmSgiTokenSpaceGuid.PcdVirtioNetSize|0x10000
>    gArmSgiTokenSpaceGuid.PcdVirtioNetInterrupt|204
>
> +!if $(ARM_STANDALONE_MM_ENABLE) == TRUE

Why is this inclusion conditional (here and below)? I was under the
impression that the communicate driver fails gracefully if the secure
standalone MM is absent. If this is not the case, please propose how
to fix the core driver so that it does.

> +  #
> +  # Set the base address and size of the buffer used
> +  # for communication between the Normal world edk2
> +  # with StandaloneMm image at S-EL0 through MM_COMMUNICATE.
> +  # This buffer gets allocated in ATF and since we do not have
> +  # a mechanism currently to communicate the base address and
> +  # size of this buffer from ATF, hard-code it here
> +  #
> +  ## MM Communicate
> +  gArmTokenSpaceGuid.PcdMmBufferBase|0xFF600000
> +  gArmTokenSpaceGuid.PcdMmBufferSize|0x10000
> +!endif
> +
>  ################################################################################
>  #
>  # Components Section - list of all EDK II Modules needed by this Platform
> @@ -331,3 +345,7 @@ [Components.common]
>    # SATA Controller
>    #
>    MdeModulePkg/Bus/Pci/SataControllerDxe/SataControllerDxe.inf
> +
> +!if $(ARM_STANDALONE_MM_ENABLE) == TRUE
> +  ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
> +!endif
> diff --git a/Platform/ARM/SgiPkg/SgiPlatform.fdf b/Platform/ARM/SgiPkg/SgiPlatform.fdf
> index 80c3412fd4ad..01799de8a0c8 100644
> --- a/Platform/ARM/SgiPkg/SgiPlatform.fdf
> +++ b/Platform/ARM/SgiPkg/SgiPlatform.fdf
> @@ -169,6 +169,11 @@ [FV.FvMain]
>    #
>    INF  ShellPkg/Application/Shell/Shell.inf
>
> +!if $(ARM_STANDALONE_MM_ENABLE) == TRUE
> +  # MM Communicate
> +  INF ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf
> +!endif
> +
>    #
>    # Platform driver
>    #
> --
> 2.7.4
>