Re: [edk2-devel] [PATCH] UefiCpuPkg: support single EFI_PEI_CORE_FV_LOCATION_PPI in PpiList

["Chiu, Chasel" <chasel.chiu@intel.com>]

> -----Original Message-----
> From: Ni, Ray
> Sent: Thursday, September 5, 2019 2:04 AM
> To: devel@edk2.groups.io; Chiu, Chasel <chasel.chiu@intel.com>
> Cc: Dong, Eric <eric.dong@intel.com>; Laszlo Ersek <lersek@redhat.com>
> Subject: RE: [edk2-devel] [PATCH] UefiCpuPkg: support single
> EFI_PEI_CORE_FV_LOCATION_PPI in PpiList
> 
> > -----Original Message-----
> > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Chiu,
> > Chasel
> > Sent: Wednesday, September 4, 2019 1:56 AM
> > To: devel@edk2.groups.io
> > Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>;
> > Laszlo Ersek <lersek@redhat.com>
> > Subject: [edk2-devel] [PATCH] UefiCpuPkg: support single
> > EFI_PEI_CORE_FV_LOCATION_PPI in PpiList
> >
> > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2153
> >
> > Current logic will skip searching EFI_PEI_CORE_FV_LOCATION_PPI when
> > the PPI in PpiList having EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST flag,
> > but platform may pass single PPI in PpiList that should be supported.
> >
> > Changed the logic to verify PpiList first before checking
> > EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST flag.
> >
> > Test: Verified single EFI_PEI_CORE_FV_LOCATION_PPI in PpiList and
> >       still can boot with the PeiCore specified by above PPI.
> >
> > Cc: Eric Dong <eric.dong@intel.com>
> > Cc: Ray Ni <ray.ni@intel.com>
> > Cc: Laszlo Ersek <lersek@redhat.com>
> > Signed-off-by: Chasel Chiu <chasel.chiu@intel.com>
> > ---
> >  UefiCpuPkg/SecCore/SecMain.c | 8 ++++----
> >  1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/UefiCpuPkg/SecCore/SecMain.c
> > b/UefiCpuPkg/SecCore/SecMain.c index 66c952b897..6beb025b4b 100644
> > --- a/UefiCpuPkg/SecCore/SecMain.c
> > +++ b/UefiCpuPkg/SecCore/SecMain.c
> > @@ -238,9 +238,8 @@ SecStartupPhase2(
> >    // is enabled.
> >    //
> >    if (PpiList != NULL) {
> > -    for (Index = 0;
> > -      (PpiList[Index].Flags &
> EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST) !=
> EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST;
> > -      Index++) {
> > +    Index = 0;
> > +    do {
> >        if (CompareGuid (PpiList[Index].Guid,
> &gEfiPeiCoreFvLocationPpiGuid) &&
> >            (((EFI_PEI_CORE_FV_LOCATION_PPI *)
> PpiList[Index].Ppi)->PeiCoreFvLocation != 0)
> >           ) {
> > @@ -261,7 +260,8 @@ SecStartupPhase2(
> >            CpuDeadLoop ();
> >          }
> >        }
> > -    }
> > +      Index++;
> > +    } while ((PpiList[Index].Flags &
> > + EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST) !=
> > + EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST);
> 
> Index is firstly increased, and comparison of the Flags is after that.
> What if there is only one PPI in the list, the comparison happens in the
> random data out of the PPI list.

Good catch! Let me update and re-test it again. Thanks!

> 
> Thanks,
> Ray