Re: [edk2-devel] [PATCH resend] MdeModulePkg/EsrtDxe: allocate ESRT table from RtServicesData memory

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

On Fri, 19 Apr 2019 at 20:38, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
>
> On Fri, 19 Apr 2019 at 20:23, Kinney, Michael D
> <michael.d.kinney@intel.com> wrote:
> >
> > Ard,
> >
> > Let's see if we can remove the ESRT access from those
> > paths.  That would be the better fix.
> >
>
> I am not that familiar with this code, but it seems that the only
> reason we access the ESRT at runtime is to check whether a capsule is
> a nested FMP capsule, where the outer GUID is cross referenced against
> the ESRT before checking whether the inner GUID is the FMP guid.
>
> Could we relax this check? FMP capsule can only be dispatched across a
> reboot anyway, and so the runtime capsule handling could accept any
> capsule that has an inner FMP guid.
>
> If not, it means we do need to read the ESRT at runtime, in which case
> my patch is the simplest solution. We would have to clarify the spec
> though.
>

Actually, I might be able to cache just the list of GUIDs at
ReadyToBoot, so we can do the comparisons at runtime.