Re: [PATCH 1/1] ArmPkg: Add Pcd to disable EFI_MEMORY_ATTRIBUTE_PROTOCOL

["Gerd Hoffmann" <kraxel@redhat.com>]

On Mon, Jun 19, 2023 at 10:32:25PM +0200, Oliver Steffen wrote:
> Recent versions of shim (15.6 and 15.7) crash when the newly added
> EFI_MEMORY_ATTRIBUTE_PROTOCOL is provided by the firmware.  To allow
> existing installations to boot, provide a workaround in form of a Pcd
> that allows tuning it off at build time (defaults to 'enabled').

Background:  We have untested + broken code for
EFI_MEMORY_ATTRIBUTE_PROTOCOL support in the listed shim releases.

Now that firmware starts to actually provide that protocol the
time bomb explodes.

> --- a/ArmPkg/ArmPkg.dec
> +++ b/ArmPkg/ArmPkg.dec
> @@ -172,6 +172,9 @@ [PcdsFixedAtBuild.common]
>    gArmTokenSpaceGuid.PcdCpuVectorBaseAddress|0xffff0000|UINT64|0x00000004
>    gArmTokenSpaceGuid.PcdCpuResetAddress|0x00000000|UINT32|0x00000005
>  
> +  # Enable/Disable EFI_MEMORY_ATTRIBUTE_PROTOCOL
> +  gArmTokenSpaceGuid.PcdEnableEfiMemoryAttributeProtocol|TRUE|BOOLEAN|0x000000EE
> +
>    #
>    # ARM Secure Firmware PCDs
>    #

Given that I expect we will run into the very same problem on x64 as
soon as EFI_MEMORY_ATTRIBUTE_PROTOCOL gets enabled there we should
probably define the PCD in MdePkg not ArmPkg (which implies splitting
the patch into a mini series with one MdePkg and one ArmPkg patch).

take care,
  Gerd