[PATCH v2 12/13] Platforms/Juno: add DtPlatformDtbLoaderLib implementation

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

In preparation of switching to DtPlatformDxe to supply the device
tree image to the OS, add an implementation of DtPlatformDtbLoaderLib
that loads the correct version from an FV.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 Platforms/ARM/Juno/Library/JunoDtPlatformDtbLoaderLib/JunoDtPlatformDtbLoaderLib.c   | 71 ++++++++++++++++++++
 Platforms/ARM/Juno/Library/JunoDtPlatformDtbLoaderLib/JunoDtPlatformDtbLoaderLib.inf | 38 +++++++++++
 2 files changed, 109 insertions(+)

diff --git a/Platforms/ARM/Juno/Library/JunoDtPlatformDtbLoaderLib/JunoDtPlatformDtbLoaderLib.c b/Platforms/ARM/Juno/Library/JunoDtPlatformDtbLoaderLib/JunoDtPlatformDtbLoaderLib.c
new file mode 100644
index 000000000000..8b4d1cbecffb
--- /dev/null
+++ b/Platforms/ARM/Juno/Library/JunoDtPlatformDtbLoaderLib/JunoDtPlatformDtbLoaderLib.c
@@ -0,0 +1,71 @@
+/** @file
+*
+*  Copyright (c) 2017, Linaro, Ltd. All rights reserved.
+*
+*  This program and the accompanying materials
+*  are licensed and made available under the terms and conditions of the BSD License
+*  which accompanies this distribution.  The full text of the license may be found at
+*  http://opensource.org/licenses/bsd-license.php
+*
+*  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+*  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+*
+**/
+
+#include <PiDxe.h>
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/DxeServicesLib.h>
+#include <Library/IoLib.h>
+#include <Library/MemoryAllocationLib.h>
+
+#include "ArmPlatform.h"
+
+/**
+  Return a pool allocated copy of the DTB image that is appropriate for
+  booting the current platform via DT.
+
+  @param[out]   Dtb                   Pointer to the DTB copy
+  @param[out]   DtbSize               Size of the DTB copy
+
+  @retval       EFI_SUCCESS           Operation completed successfully
+  @retval       EFI_NOT_FOUND         No suitable DTB image could be located
+  @retval       EFI_OUT_OF_RESOURCES  No pool memory available
+
+**/
+EFI_STATUS
+EFIAPI
+DtPlatformLoadDtb (
+  OUT   VOID        **Dtb,
+  OUT   UINTN       *DtbSize
+  )
+{
+  EFI_STATUS                Status;
+  VOID                      *OrigDtb;
+  VOID                      *CopyDtb;
+  UINTN                     OrigDtbSize;
+  UINT32                    JunoRevision;
+
+  GetJunoRevision(JunoRevision);
+  ASSERT (JunoRevision >= JUNO_REVISION_R0 && JunoRevision <= JUNO_REVISION_R2);
+  if (JunoRevision < JUNO_REVISION_R0 || JunoRevision > JUNO_REVISION_R2) {
+    return EFI_NOT_FOUND;
+  }
+  
+  Status = GetSectionFromAnyFv (&gDtPlatformDefaultDtbFileGuid,
+             EFI_SECTION_RAW, (UINTN)JunoRevision - 1, &OrigDtb, &OrigDtbSize);
+  if (EFI_ERROR (Status)) {
+    return EFI_NOT_FOUND;
+  }
+
+  CopyDtb = AllocateCopyPool (OrigDtbSize, OrigDtb);
+  if (CopyDtb == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  *Dtb = CopyDtb;
+  *DtbSize = OrigDtbSize;
+
+  return EFI_SUCCESS;
+}
diff --git a/Platforms/ARM/Juno/Library/JunoDtPlatformDtbLoaderLib/JunoDtPlatformDtbLoaderLib.inf b/Platforms/ARM/Juno/Library/JunoDtPlatformDtbLoaderLib/JunoDtPlatformDtbLoaderLib.inf
new file mode 100644
index 000000000000..8018278546fe
--- /dev/null
+++ b/Platforms/ARM/Juno/Library/JunoDtPlatformDtbLoaderLib/JunoDtPlatformDtbLoaderLib.inf
@@ -0,0 +1,38 @@
+/** @file
+*
+*  Copyright (c) 2017, Linaro, Ltd. All rights reserved.
+*
+*  This program and the accompanying materials
+*  are licensed and made available under the terms and conditions of the BSD License
+*  which accompanies this distribution.  The full text of the license may be found at
+*  http://opensource.org/licenses/bsd-license.php
+*
+*  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+*  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+*
+**/
+
+[Defines]
+  INF_VERSION                    = 0x00010019
+  BASE_NAME                      = JunoDtPlatformDtbLoaderLib
+  FILE_GUID                      = 050d6041-1508-4ae7-a69f-250155ccb567
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = DtPlatformDtbLoaderLib|DXE_DRIVER
+
+[Sources]
+  JunoDtPlatformDtbLoaderLib.c
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  MdePkg/MdePkg.dec
+  EmbeddedPkg/EmbeddedPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DxeServicesLib
+  IoLib
+  MemoryAllocationLib
+
+[Guids]
+  gDtPlatformDefaultDtbFileGuid
-- 
2.9.3