Re: [edk2-devel] [PATCH v1 1/1] MdeModulePkg: PcdAcpiExposedTableVersions default for Arm64 platforms

["Laszlo Ersek" <lersek@redhat.com>]

On 03/22/20 17:08, Samer El-Haj-Mahmoud wrote:
> Set the default value of PcdAcpiExposedTableVersions for Aarch64
> platforms to 0x20. Previously, the default was set to 0x3E for all
> platforms. The new value removes ACPI 1.0b compatability, which forces
> the use of XSDT 64-bit pointer, as required by Arm SBBR specification.
> This also resolves an error reported by acpiview command, as seen on
> the RPi (see https://github.com/pftf/RPi4/issues/25).
> 
> Cc: Dandan Bi <dandan.bi@intel.com>
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Cc: Leif Lindholm <leif@nuviainc.com>
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> 
> Signed-off-by: Samer El-Haj-Mahmoud <samer@elhajmahmoud.com>
> ---
>  MdeModulePkg/MdeModulePkg.dec | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
> index 91a3c608231c..027f444903ef 100644
> --- a/MdeModulePkg/MdeModulePkg.dec
> +++ b/MdeModulePkg/MdeModulePkg.dec
> @@ -1549,6 +1549,9 @@ [PcdsPatchableInModule, PcdsDynamic, PcdsDynamicEx]
>    # @Prompt Console Output Row of Text Setup
>    gEfiMdeModulePkgTokenSpaceGuid.PcdSetupConOutRow|25|UINT32|0x4000000e
>  
> +[PcdsFixedAtBuild.AARCH64, PcdsPatchableInModule.AARCH64]
> +  gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiExposedTableVersions|0x20|UINT32|0x0001004c
> +
>  [PcdsFixedAtBuild, PcdsPatchableInModule, PcdsDynamic, PcdsDynamicEx]
>    ## UART clock frequency is for the baud rate configuration.
>    # @Prompt Serial Port Clock Rate.
> 

Please consider appending another patch to this series: once the new DEC
default is in place, the same PCD setting is no longer necessary in, and
should arguably be removed from, "ArmVirtPkg/ArmVirtQemu.dsc":

  # ACPI predates the AARCH64 architecture by 5 versions, so
  # we only target OSes that support ACPI v5.0 or later
  gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiExposedTableVersions|0x20

Basically: "git revert e0692789058e".

Thanks!
Laszlo