Re: [edk2-devel] [Patch 1/3] EmulatorPkg: Fix VS20xx IA32 boot failure

["Wu, Hao A" <hao.a.wu@intel.com>]

> -----Original Message-----
> From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of
> Michael D Kinney
> Sent: Wednesday, August 07, 2019 12:20 PM
> To: devel@edk2.groups.io
> Cc: Justen, Jordan L; Andrew Fish; Ni, Ray
> Subject: [edk2-devel] [Patch 1/3] EmulatorPkg: Fix VS20xx IA32 boot failure
> 
> https://bugzilla.tianocore.org/show_bug.cgi?id=2056
> 
> The IA32 build of the EmulatorPkg for VS20xx does not boot
> because the default value of PCD PcdPeiServicesTablePage
> is set for X64 Windows Host environments.  If the
> EmulatorPkg is build for an IA32 Windows Host environment,
> then set this PCD to 0x13000000 that can be mapped into a
> 32-bit user process.


Hello Mike,

I have a question for this patch.

For the main() function within file EmulatorPkg/Win/Host/WinHost.c, I saw
the below codes:

  EmuMagicPage = (VOID *)(UINTN)(FixedPcdGet64 (PcdPeiServicesTablePage) & MAX_UINTN);
  if (EmuMagicPage != NULL) {
    UINT64  Size;
    Status = WinNtOpenFile (
              NULL,
              SIZE_4KB,
              0,
              &EmuMagicPage,
              &Size
              );
    if (EFI_ERROR (Status)) {
      SecPrint ("ERROR : Could not allocate PeiServicesTablePage @ %p\n", EmuMagicPage);
      return EFI_DEVICE_ERROR;
    }
  }

My understanding is that the WinNtOpenFile() function call is attempting
to map the address specified by 'EmuMagicPage'. For IA32 case, the value
in 'EmuMagicPage' here has already been truncated (0x03000000). If the
WinNtOpenFile() call returned successfully, the address should be mapped.

Is it the case that even if WinNtOpenFile() returns with no error, the
specified address (0x03000000) is not actually being mapped?

Best Regards,
Hao Wu


> 
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Andrew Fish <afish@apple.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
> ---
>  EmulatorPkg/EmulatorPkg.dsc | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/EmulatorPkg/EmulatorPkg.dsc b/EmulatorPkg/EmulatorPkg.dsc
> index ea8b6ce76e..c4ec10d1d8 100644
> --- a/EmulatorPkg/EmulatorPkg.dsc
> +++ b/EmulatorPkg/EmulatorPkg.dsc
> @@ -4,7 +4,7 @@
>  # The Emulation Platform can be used to debug individual modules, prior to
> creating
>  # a real platform. This also provides an example for how an DSC is created.
>  #
> -# Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
> +# Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
>  # Portions copyright (c) 2010 - 2011, Apple Inc. All rights reserved.<BR>
>  #
>  # SPDX-License-Identifier: BSD-2-Clause-Patent
> @@ -225,6 +225,10 @@ [PcdsFixedAtBuild]
>    #  0-PCANSI, 1-VT100, 2-VT00+, 3-UTF8, 4-TTYTERM
>    gEfiMdePkgTokenSpaceGuid.PcdDefaultTerminalType|1
> 
> +!if "IA32" in $(ARCH) && "MSFT" in $(FAMILY)
> +  gEmulatorPkgTokenSpaceGuid.PcdPeiServicesTablePage|0x13000000
> +!endif
> +
>  [PcdsDynamicDefault.common.DEFAULT]
>    gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase64|0
> 
> gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase64|
> 0
> --
> 2.21.0.windows.1
> 
> 
>