Re: MinPlatformPkg/PlatformInit: FV code

["Yao, Jiewen" <jiewen.yao@intel.com>]

Marvin
I have filed 2 bugzilla to record this.

https://bugzilla.tianocore.org/show_bug.cgi?id=872
https://bugzilla.tianocore.org/show_bug.cgi?id=871

Thank you
Yao Jiewen


> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Yao,
> Jiewen
> Sent: Saturday, February 3, 2018 9:54 AM
> To: Marvin H?user <Marvin.Haeuser@outlook.com>; edk2-devel@lists.01.org
> Subject: Re: [edk2] MinPlatformPkg/PlatformInit: FV code
> 
> Ah, good catch.
> 
> That is correct - it is irrelevant to PEI. To put to FV Hob is enough, I believe.
> 
> Appreciate your careful review, which helps us clean up the code. :-)
> 
> Thank you
> Yao Jiewen
> 
> 
> > -----Original Message-----
> > From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of
> > Marvin H?user
> > Sent: Saturday, February 3, 2018 2:30 AM
> > To: edk2-devel@lists.01.org; Yao, Jiewen <jiewen.yao@intel.com>
> > Subject: Re: [edk2] MinPlatformPkg/PlatformInit: FV code
> >
> > Good point with the DxeCore, I didn't consider that. Though OsBoot would be
> > irrelevant to the PEI phase, wouldn't it be?
> >
> > Thanks,
> > Marvin
> >
> > From: Yao, Jiewen [mailto:jiewen.yao@intel.com]
> > Sent: Friday, February 2, 2018 1:40 PM
> > To: Marvin H?user <Marvin.Haeuser@outlook.com>; edk2-devel@lists.01.org
> > Subject: RE: MinPlatformPkg/PlatformInit: FV code
> >
> > Excellent question.
> >
> > Comment inline.
> >
> > From: Marvin H?user [mailto:Marvin.Haeuser@outlook.com]
> > Sent: Wednesday, January 31, 2018 1:54 AM
> > To: edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>; Yao, Jiewen
> > <jiewen.yao@intel.com<mailto:jiewen.yao@intel.com>>
> > Subject: MinPlatformPkg/PlatformInit: FV code
> >
> > Dear developers, dear Jiewen,
> >
> > I have been investigating the devel-MinPlatform branch of edk2-platforms for
> > educational purposes and got two questions regarding the Firmware Volume
> > code in PlatformInitPreMem, if you do not mind. I assume the tree was tested,
> so
> > most likely I misunderstood some things.
> >
> >
> >   1.  Why is a Firmware Volume HOB built to cover the entire flash range
> >
> (https://github.com/tianocore/edk2-platforms/blob/devel-MinPlatform/Platfor
> >
> m/Intel/MinPlatformPkg/PlatformInit/PlatformInitPei/PlatformInitPreMem.c#L3
> > 79)? Am I correct that this implies a FV spanning through the entire flash
> MMIO
> > range, which would then imply all other FVs are contained within it? This would
> > make sense, however that's not what I saw in the KabylakeOpenBoardPkg
> Flash
> > Map, which has the NV Storage first
> >
> (https://github.com/tianocore/edk2-platforms/blob/devel-MinPlatform/Platfor
> > m/Intel/KabylakeOpenBoardPkg/Include/Fdf/FlashMapInclude.fdf#L25).
> >
> > [Jiewen] You are right. We should not use FD region for FV. Will fix it.
> >
> >
> >
> >   1.  Why are FV Info PPIs installed for the UefiBoot and the OsBoot FVs
> >
> (https://github.com/tianocore/edk2-platforms/blob/devel-MinPlatform/Platfor
> >
> m/Intel/MinPlatformPkg/PlatformInit/PlatformInitPei/PlatformInitPreMem.c#L3
> > 44)? If I checked correctly, installing this PPI type will trigger PeiCore to
> dispatch
> > PEIMs in the FVs, however there are only DXE drivers in these. Why are no FV
> > HOBs installed, which are gotten by DxeCore?
> >
> > [Jiewen] In DxeIpl, PeiServicesFfsFindNextVolume() is used to search DxeCore.
> > In PeiCore, PeiFfsFindNextVolume() calls FindNextCoreFvHandle() for DxeCore
> > one by one. If PcdFrameworkCompatibilitySupport is FALSE, it returns
> > &Private->Fv[Instance] directly.
> >
> > And Fv[Instance] is added in FirmwareVolmeInfoPpiNotifyCallback(), when
> > gEfiPeiFirmwareVolumeInfo2PpiGuid is installed.
> >
> > So if PcdFrameworkCompatibilitySupport is FALSE, install PPI is the only way to
> > let PEI core discover DxeCore.
> > Only if PcdFrameworkCompatibilitySupport is TRUE, install PPI is not required,
> > but the FindNextCoreFvHandle() will install the PPI for the HobFv. The result is
> > same.
> >
> >
> > Thank you
> > Yao Jiewen
> >
> >
> >
> >
> > Thanks in advance for your time!
> >
> > Best regards,
> > Marvin.
> > _______________________________________________
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> > edk2-devel@lists.01.org
> > https://lists.01.org/mailman/listinfo/edk2-devel
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