[PATCH v2 3/3] EmbeddedPkg/DtPlatformDxe: load platform DTB via new library

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

To give platforms some room to decide which DTB is suitable and where
to load it from, indirect loading of the DTB image via the new
DtPlatformDtbLoaderLib library class.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.c   | 26 ++++++++++----------
 EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.inf |  2 +-
 EmbeddedPkg/EmbeddedPkg.dsc                         |  2 ++
 3 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.c b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.c
index 5778633b4985..c75f088a34e5 100644
--- a/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.c
+++ b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.c
@@ -15,7 +15,7 @@
 #include <Library/BaseLib.h>
 #include <Library/DebugLib.h>
 #include <Library/DevicePathLib.h>
-#include <Library/DxeServicesLib.h>
+#include <Library/DtPlatformDtbLoaderLib.h>
 #include <Library/HiiLib.h>
 #include <Library/MemoryAllocationLib.h>
 #include <Library/UefiBootServicesTableLib.h>
@@ -114,14 +114,12 @@ DtPlatformDxeEntryPoint (
   UINTN                           BufferSize;
   VOID                            *Dtb;
   UINTN                           DtbSize;
-  VOID                            *DtbCopy;
 
   //
   // Check whether a DTB blob is included in the firmware image.
   //
   Dtb = NULL;
-  Status = GetSectionFromAnyFv (&gDtPlatformDefaultDtbFileGuid,
-             EFI_SECTION_RAW, 0, &Dtb, &DtbSize);
+  Status = DtPlatformLoadDtb (&Dtb, &DtbSize);
   if (EFI_ERROR (Status)) {
     DEBUG ((DEBUG_WARN, "%a: no DTB blob found, defaulting to ACPI\n",
       __FUNCTION__));
@@ -157,7 +155,7 @@ DtPlatformDxeEntryPoint (
                     EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS,
                     sizeof (DtAcpiPref), &DtAcpiPref);
     if (EFI_ERROR (Status)) {
-      return Status;
+      goto FreeDtb;
     }
   }
 
@@ -172,23 +170,18 @@ DtPlatformDxeEntryPoint (
       DEBUG ((DEBUG_ERROR,
         "%a: failed to install gEdkiiPlatformHasAcpiGuid as a protocol\n",
         __FUNCTION__));
-      return Status;
+      goto FreeDtb;
     }
   } else if (DtAcpiPref.Pref == DT_ACPI_SELECT_DT) {
     //
     // DT was selected: copy the blob into newly allocated memory and install
     // a reference to it as the FDT configuration table.
     //
-    DtbCopy = AllocateCopyPool (DtbSize, Dtb);
-    if (DtbCopy == NULL) {
-      return EFI_OUT_OF_RESOURCES;
-    }
-    Status = gBS->InstallConfigurationTable (&gFdtTableGuid, DtbCopy);
+    Status = gBS->InstallConfigurationTable (&gFdtTableGuid, Dtb);
     if (EFI_ERROR (Status)) {
       DEBUG ((DEBUG_ERROR, "%a: failed to install FDT configuration table\n",
         __FUNCTION__));
-      FreePool (DtbCopy);
-      return Status;
+      goto FreeDtb;
     }
   } else {
     ASSERT (FALSE);
@@ -210,4 +203,11 @@ DtPlatformDxeEntryPoint (
   // installed in that case.
   //
   return InstallHiiPages ();
+
+FreeDtb:
+  if (Dtb != NULL) {
+    FreePool (Dtb);
+  }
+
+  return Status;
 }
diff --git a/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.inf b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.inf
index b73877a6086b..45dfd9088bf0 100644
--- a/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.inf
+++ b/EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.inf
@@ -40,7 +40,7 @@ [Packages]
 [LibraryClasses]
   BaseLib
   DebugLib
-  DxeServicesLib
+  DtPlatformDtbLoaderLib
   HiiLib
   MemoryAllocationLib
   UefiBootServicesTableLib
diff --git a/EmbeddedPkg/EmbeddedPkg.dsc b/EmbeddedPkg/EmbeddedPkg.dsc
index 0d5db68631bb..b75678276e8d 100644
--- a/EmbeddedPkg/EmbeddedPkg.dsc
+++ b/EmbeddedPkg/EmbeddedPkg.dsc
@@ -294,5 +294,7 @@ [Components.common]
   EmbeddedPkg/Library/PrePiHobLib/PrePiHobLib.inf
   EmbeddedPkg/Library/PrePiMemoryAllocationLib/PrePiMemoryAllocationLib.inf
 
+  EmbeddedPkg/Drivers/DtPlatformDxe/DtPlatformDxe.inf
+
 [Components.IA32, Components.X64, Components.IPF, Components.ARM]
   EmbeddedPkg/GdbStub/GdbStub.inf
-- 
2.9.3