Re: [PATCH v1] Platform/ARM/VExpressPkg: Fix RSDT pointer in RSDP

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

On 6 March 2018 at 14:15, Sami Mujawar <sami.mujawar@arm.com> wrote:
> According to the SBBR Specification (ARM DEN 0044B), Section 4.2.1.1
>   "Within the RSDP, the RsdtAddress field must be null (zero)
>    and the XsdtAddresss MUST be a valid, non-null, 64-bit value."
>
> The PcdAcpiExposedTableVersions is used to indicate the ACPI versions
> that are supported. The default value for PcdAcpiExposedTableVersions
> is 0x3E which indicates that the ACPI versions 1.0B and above are
> supported.
>
> For ACPI 1.0B the RSDT pointer is set in the RSDP table. However for
> ACPI versions greater than ACPI 1.0B the AcpiTableDxe populates
> the RSDP with the RSDT address set to NULL.
>
> Therefore set the PcdAcpiExposedTableVersions to 0x20 indicating
> support for ACPI 5.0 and above.
>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
> Signed-off-by: Evan Lloyd <evan.lloyd@arm.com>

I am changing the subject into

Platform/ARM/VExpressPkg: Provide only 64-bit ACPI entrypoint

but the patch looks fine to me.

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Pushed as 9422cb8c75b3

Thanks


> ---
>
> The changes can be seen at
> https://github.com/samimujawar/edk2-platforms/tree/212_fvp_rsdt_fix_v1
>
> Notes:
>     v1:
>     - Setup PcdAcpiExposedTableVersions correctly so that the
>       AcpiTableDxe populates the RSDP with the RSDT address set
>       to NULL.                                                     [SAMI]
>
>  Platform/ARM/VExpressPkg/ArmVExpress-FVP-AArch64.dsc | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/Platform/ARM/VExpressPkg/ArmVExpress-FVP-AArch64.dsc b/Platform/ARM/VExpressPkg/ArmVExpress-FVP-AArch64.dsc
> index 295e9a126b0ebaa4653d7e25e2f7d8c396403764..cdf9e2d49784d542701dc84eb511f592e77ec106 100644
> --- a/Platform/ARM/VExpressPkg/ArmVExpress-FVP-AArch64.dsc
> +++ b/Platform/ARM/VExpressPkg/ArmVExpress-FVP-AArch64.dsc
> @@ -1,5 +1,5 @@
>  #
> -#  Copyright (c) 2011-2017, ARM Limited. All rights reserved.
> +#  Copyright (c) 2011-2018, ARM Limited. All rights reserved.
>  #
>  #  This program and the accompanying materials
>  #  are licensed and made available under the terms and conditions of the BSD License
> @@ -162,6 +162,11 @@ [PcdsFixedAtBuild.common]
>    # the entire FVP address space can be covered by 36 bit VAs
>    gEmbeddedTokenSpaceGuid.PcdPrePiCpuMemorySize|36
>
> +  #
> +  # ACPI Table Version
> +  #
> +  gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiExposedTableVersions|0x20
> +
>  ################################################################################
>  #
>  # Components Section - list of all EDK II Modules needed by this Platform
> --
> 'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'
>
>