Re: [PATCH edk2-platforms 2/2] Platform/DeveloperBox: disable variable runtime cache

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

On Thu, 28 Nov 2019 at 16:02, Leif Lindholm <leif.lindholm@linaro.org> wrote:
>
> On Thu, Nov 28, 2019 at 15:48:40 +0100, Ard Biesheuvel wrote:
> > The variable runtime cache for SMM enabled implementations of the
> > variable runtime DXE driver was introduced after the standalone
> > MM based implementation was merged for the DeveloperBox platform.
> >
> > This means the combined binary image of ARM Trusted Firmware and
> > the standalone MM runtime we carry in edk2-non-osi predates this
> > feature, so we need to disable it when building the non-secure side
> > when incorporating the prebuilt binary.
>
> Is this something that needs to be explicitly disabled in current
> upstream TF? (And if so, could we add a comment to edk2-non-osi
> README?) Or does this only affect the requests made from Non-secure
> side?
>

No, it has to be disabled on both sides. But this .dsc.inc gets
included by both sides when you build them from scratch.

> > Whether it makes sense to enable the runtime cache for this platform
> > is a different question, so let's keep it enabled entirely until
>
> enabled -> disabled?
>

Yep

>
> > someone identifies a need for it.
> >
> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> > ---
> >  Platform/Socionext/DeveloperBox/DeveloperBox.dsc.inc | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/Platform/Socionext/DeveloperBox/DeveloperBox.dsc.inc b/Platform/Socionext/DeveloperBox/DeveloperBox.dsc.inc
> > index a10e48ca07ea..084b4c994b97 100644
> > --- a/Platform/Socionext/DeveloperBox/DeveloperBox.dsc.inc
> > +++ b/Platform/Socionext/DeveloperBox/DeveloperBox.dsc.inc
> > @@ -130,6 +130,8 @@ [PcdsFeatureFlag]
> >    # needed for NFIT tables installed by RamDiskDxe
> >    gEfiMdeModulePkgTokenSpaceGuid.PcdInstallAcpiSdtProtocol|TRUE
> >
> > +  gEfiMdeModulePkgTokenSpaceGuid.PcdEnableVariableRuntimeCache|FALSE
> > +
> >  [PcdsFixedAtBuild.common]
> >  !ifdef $(FIRMWARE_VENDOR)
> >    gEfiMdeModulePkgTokenSpaceGuid.PcdFirmwareVendor|L"$(FIRMWARE_VENDOR)"
> > --
> > 2.20.1
> >