[PATCH 2/4] MdeModulePkg/DxeCore: invoke the emulator protocol for foreign images

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

When encountering PE/COFF images that cannot be supported natively,
attempt to locate an instance of the PE/COFF image emulator protocol,
and if it supports the image, proceed with loading it and register it
with the emulator.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 MdeModulePkg/Core/Dxe/DxeMain.h     |  3 ++
 MdeModulePkg/Core/Dxe/DxeMain.inf   |  1 +
 MdeModulePkg/Core/Dxe/Image/Image.c | 39 +++++++++++++++++---
 3 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/MdeModulePkg/Core/Dxe/DxeMain.h b/MdeModulePkg/Core/Dxe/DxeMain.h
index 7ec82388a3f9..57b3861d9813 100644
--- a/MdeModulePkg/Core/Dxe/DxeMain.h
+++ b/MdeModulePkg/Core/Dxe/DxeMain.h
@@ -53,6 +53,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include <Protocol/TcgService.h>
 #include <Protocol/HiiPackageList.h>
 #include <Protocol/SmmBase2.h>
+#include <Protocol/PeCoffImageEmulator.h>
 #include <Guid/MemoryTypeInformation.h>
 #include <Guid/FirmwareFileSystem2.h>
 #include <Guid/FirmwareFileSystem3.h>
@@ -229,6 +230,8 @@ typedef struct {
   UINT16                      Machine;
   /// EBC Protocol pointer
   EFI_EBC_PROTOCOL            *Ebc;
+  /// PE/COFF Image Emulator Protocol pointer
+  EDKII_PECOFF_IMAGE_EMULATOR_PROTOCOL  *Emu;
   /// Runtime image list
   EFI_RUNTIME_IMAGE_ENTRY     *RuntimeData;
   /// Pointer to Loaded Image Device Path Protocol
diff --git a/MdeModulePkg/Core/Dxe/DxeMain.inf b/MdeModulePkg/Core/Dxe/DxeMain.inf
index 68fa0a01d9bd..d7591aa0da6d 100644
--- a/MdeModulePkg/Core/Dxe/DxeMain.inf
+++ b/MdeModulePkg/Core/Dxe/DxeMain.inf
@@ -180,6 +180,7 @@
   gEfiVariableArchProtocolGuid                  ## CONSUMES
   gEfiCapsuleArchProtocolGuid                   ## CONSUMES
   gEfiWatchdogTimerArchProtocolGuid             ## CONSUMES
+  gEdkiiPeCoffImageEmulatorProtocolGuid         ## SOMETIMES_CONSUMES
 
 [FeaturePcd]
   gEfiMdeModulePkgTokenSpaceGuid.PcdFrameworkCompatibilitySupport     ## CONSUMES
diff --git a/MdeModulePkg/Core/Dxe/Image/Image.c b/MdeModulePkg/Core/Dxe/Image/Image.c
index eddca140ee1a..e2dd80790657 100644
--- a/MdeModulePkg/Core/Dxe/Image/Image.c
+++ b/MdeModulePkg/Core/Dxe/Image/Image.c
@@ -67,6 +67,7 @@ LOADED_IMAGE_PRIVATE_DATA mCorePrivateImage  = {
   NULL,                       // JumpContext
   0,                          // Machine
   NULL,                       // Ebc
+  NULL,                       // Emu
   NULL,                       // RuntimeData
   NULL                        // LoadedImageDevicePath
 };
@@ -476,12 +477,23 @@ CoreLoadPeImage (
   if (!EFI_IMAGE_MACHINE_TYPE_SUPPORTED (Image->ImageContext.Machine)) {
     if (!EFI_IMAGE_MACHINE_CROSS_TYPE_SUPPORTED (Image->ImageContext.Machine)) {
       //
-      // The PE/COFF loader can support loading image types that can be executed.
-      // If we loaded an image type that we can not execute return EFI_UNSUPORTED.
+      // Locate the emulator protocol to check whether it supports this
+      // image.
       //
-      DEBUG ((EFI_D_ERROR, "Image type %s can't be loaded ", GetMachineTypeName(Image->ImageContext.Machine)));
-      DEBUG ((EFI_D_ERROR, "on %s UEFI system.\n", GetMachineTypeName(mDxeCoreImageMachineType)));
-      return EFI_UNSUPPORTED;
+      Status = CoreLocateProtocol (&gEdkiiPeCoffImageEmulatorProtocolGuid,
+                 NULL, (VOID **)&Image->Emu);
+      if (EFI_ERROR (Status) ||
+          !Image->Emu->IsImageSupported (Image->Emu,
+                                         Image->ImageContext.Machine,
+                                         Image->ImageContext.ImageType)) {
+        //
+        // The PE/COFF loader can support loading image types that can be executed.
+        // If we loaded an image type that we can not execute return EFI_UNSUPORTED.
+        //
+        DEBUG ((EFI_D_ERROR, "Image type %s can't be loaded ", GetMachineTypeName(Image->ImageContext.Machine)));
+        DEBUG ((EFI_D_ERROR, "on %s UEFI system.\n", GetMachineTypeName(mDxeCoreImageMachineType)));
+        return EFI_UNSUPPORTED;
+      }
     }
   }
 
@@ -687,6 +699,14 @@ CoreLoadPeImage (
     if (EFI_ERROR(Status)) {
       goto Done;
     }
+  } else if (Image->Emu != NULL) {
+    Status = Image->Emu->RegisterImage (Image->Emu, Image->ImageBasePage,
+                           EFI_PAGES_TO_SIZE (Image->NumberOfPages));
+    if (EFI_ERROR (Status)) {
+      DEBUG ((DEBUG_LOAD | DEBUG_ERROR,
+        "CoreLoadPeImage: Failed to load register foreign image with emulator.\n"));
+      goto Done;
+    }
   }
 
   //
@@ -874,6 +894,13 @@ CoreUnloadAndCloseImage (
     Image->Ebc->UnloadImage (Image->Ebc, Image->Handle);
   }
 
+  if (Image->Emu != NULL) {
+    //
+    // If the PE/COFF Emulator protocol exists we must unregister the image.
+    //
+    Image->Emu->UnregisterImage (Image->Emu, Image->ImageBasePage);
+  }
+
   //
   // Unload image, free Image->ImageContext->ModHandle
   //
@@ -1599,7 +1626,7 @@ CoreStartImage (
   //
   // The image to be started must have the machine type supported by DxeCore.
   //
-  if (!EFI_IMAGE_MACHINE_TYPE_SUPPORTED (Image->Machine)) {
+  if (!EFI_IMAGE_MACHINE_TYPE_SUPPORTED (Image->Machine) && Image->Emu == NULL) {
     //
     // Do not ASSERT here, because image might be loaded via EFI_IMAGE_MACHINE_CROSS_TYPE_SUPPORTED
     // But it can not be started.
-- 
2.17.1