回复: [edk2-devel] [PATCH] MdeModulePkg: Disambiguate the meaning of PcdDxeIplSwitchToLongMode

["gaoliming" <gaoliming@byosoft.com.cn>]

It is good to me. Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>

> -----邮件原件-----
> 发件人: Liu, Zhiguang <zhiguang.liu@intel.com>
> 发送时间: 2023年2月1日 13:28
> 收件人: devel@edk2.groups.io; Liu, Zhiguang <zhiguang.liu@intel.com>; Gao,
> Liming <gaoliming@byosoft.com.cn>; Wang, Jian J <jian.j.wang@intel.com>
> 抄送: Ni, Ray <ray.ni@intel.com>
> 主题: RE: [edk2-devel] [PATCH] MdeModulePkg: Disambiguate the meaning
> of PcdDxeIplSwitchToLongMode
> 
> Hi Liming and Jian,
> 
> What do you think about this patch?
> 
> Thanks
> Zhiguang
> 
> > -----Original Message-----
> > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of
> > Zhiguang Liu
> > Sent: Monday, January 9, 2023 11:34 AM
> > To: devel@edk2.groups.io
> > Cc: Liu, Zhiguang <zhiguang.liu@intel.com>; Wang, Jian J
> > <jian.j.wang@intel.com>; Gao, Liming <gaoliming@byosoft.com.cn>; Ni, Ray
> > <ray.ni@intel.com>
> > Subject: [edk2-devel] [PATCH] MdeModulePkg: Disambiguate the meaning
> > of PcdDxeIplSwitchToLongMode
> >
> > Literally, the meaning of PcdDxeIplSwitchToLongMode is clear, indicating
> > whether need switch to long mode when loading DxeCore.
> > However, the comments in dec are confusing for the case where PEI core
> > and DXE core are both in 64-bit. This patch makes it clear.
> > PcdDxeIplSwitchToLongMode is true only when PEI core is 32-bit, and
switch
> > to long mode to load 64-bit DXE core. In other cases, this PCD is false.
> > This also aligns with current usage in OvmfPkg.
> >
> > Cc: Jian J Wang <jian.j.wang@intel.com>
> > Cc: Liming Gao <gaoliming@byosoft.com.cn>
> > Cc: Ray Ni <ray.ni@intel.com>
> > Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
> > ---
> >  MdeModulePkg/MdeModulePkg.dec | 4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/MdeModulePkg/MdeModulePkg.dec
> > b/MdeModulePkg/MdeModulePkg.dec index be5e829ca9..5e4535e353
> > 100644
> > --- a/MdeModulePkg/MdeModulePkg.dec
> > +++ b/MdeModulePkg/MdeModulePkg.dec
> > @@ -922,10 +922,8 @@
> >
> >  [PcdsFeatureFlag.IA32, PcdsFeatureFlag.X64]
> >    ## Indicates if DxeIpl should switch to long mode to enter DXE phase.
> > -  #  It is assumed that 64-bit DxeCore is built in firmware if it is
true;
> > otherwise 32-bit DxeCore
> > -  #  is built in firmware.<BR><BR>
> >    #   TRUE  - DxeIpl will load a 64-bit DxeCore and switch to long
> mode to hand
> > over to DxeCore.<BR>
> > -  #   FALSE - DxeIpl will load a 32-bit DxeCore and perform stack
switch
> to
> > hand over to DxeCore.<BR>
> > +  #   FALSE - DxeIpl will load a 32-bit or 64-bit DxeCore and perform
> stack
> > switch to hand over to DxeCore.<BR>
> >    # @Prompt DxeIpl switch to long mode.
> >
> > gEfiMdeModulePkgTokenSpaceGuid.PcdDxeIplSwitchToLongMode|TRUE|B
> > OOLEAN|0x0001003b
> >
> > --
> > 2.31.1.windows.1
> >
> >
> >
> > 
> >