Re: [PATCH V2 3/4] UefiCpuPkg/ResetVector: Add Main32 entry point in Main.asm

["Min Xu" <min.m.xu@intel.com>]

I see. I will update it in the next version.

Thanks!

> -----Original Message-----
> From: Yao, Jiewen <jiewen.yao@intel.com>
> Sent: Sunday, July 25, 2021 3:44 PM
> To: Xu, Min M <min.m.xu@intel.com>; devel@edk2.groups.io
> Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>
> Subject: RE: [PATCH V2 3/4] UefiCpuPkg/ResetVector: Add Main32 entry point
> in Main.asm
> 
> Yes, if that can avoid the UefiCpuPkg change.
> 
> > -----Original Message-----
> > From: Xu, Min M <min.m.xu@intel.com>
> > Sent: Sunday, July 25, 2021 3:42 PM
> > To: Yao, Jiewen <jiewen.yao@intel.com>; devel@edk2.groups.io
> > Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>
> > Subject: RE: [PATCH V2 3/4] UefiCpuPkg/ResetVector: Add Main32 entry
> > point in Main.asm
> >
> > On July 25, 2021 2:08 PM, Yao, Jiewen wrote:
> > > Current OvmfPkg Reser vector is a mess (see my previous email).
> > > I also compared the ResetVector code in UefiCpuPkg and OvmfPkg.
> > > There are already duplication/override.
> > >
> > > I suggest we just drop UefiCpuPkg change, and focus on improving OvmfPkg.
> > > If we need add something in UefiCpuPkg, let's copy the file to
> > > OvmfPkg and update there.
> > >
> > Do you mean we create the Main.asm in OvmfPkg/ResetVector/ and update
> > the changes in this Main.asm?
> > >
> > > I really don't want to mess up UefiCpuPkg at this moment.
> > > We can make a better architecture to share reset vector in virtual
> > > BIOS and physical BIOS later. But at this moment, let's finish the
> > > virtual BIOS architecture at first.
> > >
> > > Thank you
> > > Yao Jiewen
> > >
> > > > -----Original Message-----
> > > > From: Xu, Min M <min.m.xu@intel.com>
> > > > Sent: Thursday, July 22, 2021 1:52 PM
> > > > To: devel@edk2.groups.io
> > > > Cc: Xu, Min M <min.m.xu@intel.com>; Dong, Eric
> > > > <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>; Yao, Jiewen
> > > > <jiewen.yao@intel.com>
> > > > Subject: [PATCH V2 3/4] UefiCpuPkg/ResetVector: Add Main32 entry
> > > > point in Main.asm
> > > >
> > > > RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429
> > > >
> > > > In Tdx all CPUs "reset" to run on 32-bit protected mode with flat
> > > > descriptor (paging disabled). Main32 entry point is added in
> > > > UefiCpuPkg/ResetVector/Vtf0/Main.asm so that Main.asm can support
> > > > the 32-bit protected mode.
> > > >
> > > > Init32.asm is the 32-bit initialization code. It is a null stub in
> > > > UefiCpuPkg. The actual initialization can be implemented in the
> > > > platform (OvmfPkg/ResetVector/Ia32/Init32.asm is the example.)
> > > >
> > > > Cc: Eric Dong <eric.dong@intel.com>
> > > > Cc: Ray Ni <ray.ni@intel.com>
> > > > Cc: Jiewen Yao <jiewen.yao@intel.com>
> > > > Signed-off-by: Min Xu <min.m.xu@intel.com>
> > > > ---
> > > >  UefiCpuPkg/ResetVector/Vtf0/Ia32/Init32.asm | 13 +++++++++++++
> > > >  UefiCpuPkg/ResetVector/Vtf0/Main.asm        | 14 ++++++++++++++
> > > >  UefiCpuPkg/ResetVector/Vtf0/Vtf0.nasmb      |  2 +-
> > > >  3 files changed, 28 insertions(+), 1 deletion(-)  create mode
> > > > 100644 UefiCpuPkg/ResetVector/Vtf0/Ia32/Init32.asm
> > > >
> > > > diff --git a/UefiCpuPkg/ResetVector/Vtf0/Ia32/Init32.asm
> > > > b/UefiCpuPkg/ResetVector/Vtf0/Ia32/Init32.asm
> > > > new file mode 100644
> > > > index 000000000000..0cdae4a4a84a
> > > > --- /dev/null
> > > > +++ b/UefiCpuPkg/ResetVector/Vtf0/Ia32/Init32.asm
> > > > @@ -0,0 +1,13 @@
> > > > +;----------------------------------------------------------------
> > > > +----
> > > > +----------
> > > > +; @file
> > > > +;   32-bit initialization code.
> > > > +; Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
> > > > +;
> > > > +SPDX-License-Identifier: BSD-2-Clause-Patent ;
> > > > +;----------------------------------------------------------------
> > > > +----
> > > > +----------
> > > > +
> > > > +BITS 32
> > > > +
> > > > +Init32:
> > > > +    nop
> > > > +    OneTimeCallRet Init32
> > > > diff --git a/UefiCpuPkg/ResetVector/Vtf0/Main.asm
> > > > b/UefiCpuPkg/ResetVector/Vtf0/Main.asm
> > > > index 19d08482f831..4920c6937e1b 100644
> > > > --- a/UefiCpuPkg/ResetVector/Vtf0/Main.asm
> > > > +++ b/UefiCpuPkg/ResetVector/Vtf0/Main.asm
> > > > @@ -36,6 +36,20 @@ Main16:
> > > >
> > > >  BITS    32
> > > >
> > > > +%ifdef ARCH_X64
> > > > +
> > > > +    jmp SearchBfv
> > > > +
> > > > +;
> > > > +; Entry point of Main32
> > > > +;
> > > > +Main32:
> > > > +
> > > > +    OneTimeCall Init32
> > > > +
> > > > +%endif
> > > > +
> > > > +SearchBfv:
> > > >      ;
> > > >      ; Search for the Boot Firmware Volume (BFV)
> > > >      ;
> > > > diff --git a/UefiCpuPkg/ResetVector/Vtf0/Vtf0.nasmb
> > > > b/UefiCpuPkg/ResetVector/Vtf0/Vtf0.nasmb
> > > > index 493738c79c1c..6493b9863c48 100644
> > > > --- a/UefiCpuPkg/ResetVector/Vtf0/Vtf0.nasmb
> > > > +++ b/UefiCpuPkg/ResetVector/Vtf0/Vtf0.nasmb
> > > > @@ -51,7 +51,7 @@
> > > >  %include "Ia32/SearchForSecEntry.asm"
> > > >
> > > >  %ifdef ARCH_X64
> > > > -%include "Ia32/Flat32ToFlat64.asm"
> > > > +%include "Ia32/Init32.asm"
> > > >  %include "Ia32/PageTables64.asm"
> > > >  %endif
> > > >
> > > > --
> > > > 2.29.2.windows.2