Re: [PATCH v1 5/5] DynamicTablesPkg: Add DynamicPlatRepo library


Sami Mujawar
 

Hi Pierre,

Please find my feedback inline marked [SAMI].

Regards,

Sami Mujawar

On 23/06/2021 02:36 PM, Pierre.Gondois@... wrote:
From: Pierre Gondois <Pierre.Gondois@...>

The DynamicPlatRepo library allows to handle dynamically created
CmObj. The dynamic platform repository can be in the following states:
1 - Non-initialised
2 - Transient:
    Possibility to add CmObj to the platform, but not to query them.
3 - Finalised:
    Possibility to query CmObj, but not to add new.

A token is allocated to each CmObj added to the dynamic platform
repository (except for reference tokens CmObj). This allows to retrieve
dynamic CmObjs among all CmObj (static CmObj for instance).

This patch add the inf file of the module and the main module
functionnalities and update the dsc file of the package.

Signed-off-by: Sami Mujawar <sami.mujawar@...>
Signed-off-by: Pierre Gondois <Pierre.Gondois@...>
---
 DynamicTablesPkg/DynamicTablesPkg.dsc         |   1 +
 .../Include/Library/DynamicPlatRepoLib.h      |   4 +-
 .../DynamicPlatRepoLib/DynamicPlatRepo.c      | 518 ++++++++++++++++++
 .../DynamicPlatRepoInternal.h                 |  78 +++
 .../DynamicPlatRepoLib/DynamicPlatRepoLib.inf |  33 ++
 5 files changed, 633 insertions(+), 1 deletion(-)
 create mode 100644 DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepo.c
 create mode 100644 DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepoInternal.h
 create mode 100644 DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepoLib.inf

diff --git a/DynamicTablesPkg/DynamicTablesPkg.dsc b/DynamicTablesPkg/DynamicTablesPkg.dsc
index fd7345891cf1..432c958cf8b2 100644
--- a/DynamicTablesPkg/DynamicTablesPkg.dsc
+++ b/DynamicTablesPkg/DynamicTablesPkg.dsc
@@ -43,6 +43,7 @@ [Components.common]
   DynamicTablesPkg/Library/Common/SsdtSerialPortFixupLib/SsdtSerialPortFixupLib.inf
   DynamicTablesPkg/Library/Common/TableHelperLib/TableHelperLib.inf
   DynamicTablesPkg/Library/FdtHwInfoParserLib/FdtHwInfoParserLib.inf
+  DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepoLib.inf
 
 [BuildOptions]
   *_*_*_CC_FLAGS = -D DISABLE_NEW_DEPRECATED_INTERFACES
diff --git a/DynamicTablesPkg/Include/Library/DynamicPlatRepoLib.h b/DynamicTablesPkg/Include/Library/DynamicPlatRepoLib.h
index 8e4665bf5c59..4a76b30399b4 100644
--- a/DynamicTablesPkg/Include/Library/DynamicPlatRepoLib.h
+++ b/DynamicTablesPkg/Include/Library/DynamicPlatRepoLib.h
@@ -13,6 +13,8 @@
 #ifndef DYNAMIC_PLAT_REPO_H_
 #define DYNAMIC_PLAT_REPO_H_
 
+#include <Protocol/ConfigurationManagerProtocol.h>
+
[SAMI] I think the changes in this file can be merged with patch 1/5.
 /** A structure describing the platform configuration
     manager repository information
 */
@@ -109,4 +111,4 @@ DynamicPlatRepoShutdown (
   IN  DYNAMIC_PLATFORM_REPOSITORY_INFO * DynPlatRepo
   );
 
-#endif DYNAMIC_PLAT_REPO_H_
+#endif // DYNAMIC_PLAT_REPO_H_
diff --git a/DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepo.c b/DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepo.c
new file mode 100644
index 000000000000..f26f8ad32bc8
--- /dev/null
+++ b/DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepo.c
@@ -0,0 +1,518 @@
+/** @file
+  Dynamic Platform Info Repository
+
+  Copyright (c) 2021, Arm Limited. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+  @par Glossary:
+    - Cm or CM   - Configuration Manager
+    - Obj or OBJ - Object
+**/
+
+#include <Protocol/ConfigurationManagerProtocol.h>
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemoryAllocationLib.h>
+
+#include "CmObjectTokenFixer.h"
+#include "DynamicPlatRepoInternal.h"
+#include "TokenGenerator.h"
+
+/** Allocate a CM_OBJ_NODE.
+
+  @param [in]  CmObjDesc  CmObj to wrap in a node.
+                          All the fields of the CmObj (Data field included),
+                          are copied.
+  @param [in]  Token      Token to assign to this CmObj/node.
+  @param [out] ObjNode    Allocated ObjNode.
+
+  @retval EFI_SUCCESS           Success.
+  @retval EFI_INVALID_PARAMETER A parameter is invalid.
+  @retval EFI_OUT_OF_RESOURCES  An allocation has failed.
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+AllocCmObjNode (
+  IN  CONST CM_OBJ_DESCRIPTOR   * CmObjDesc,
+  IN        CM_OBJECT_TOKEN       Token,
+  OUT       CM_OBJ_NODE        ** ObjNode
+  )
+{
+  CM_OBJ_NODE       *Node;
+  CM_OBJ_DESCRIPTOR *Desc;
+
+  if ((CmObjDesc == NULL) || (ObjNode == NULL)) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Node = AllocateZeroPool (sizeof (CM_OBJ_NODE));
+  if (Node == NULL) {
+    ASSERT (0);
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  // Initialise the list head.
+  InitializeListHead (&Node->Link);
+  Node->Token = Token;
+  Desc = &Node->CmObjDesc;
+  Desc->ObjectId = CmObjDesc->ObjectId;
+  Desc->Size = CmObjDesc->Size;
+  Desc->Count = CmObjDesc->Count;
+
+  // Allocate and copy the CmObject Data.
+  Desc->Data = AllocateCopyPool (CmObjDesc->Size, CmObjDesc->Data);
+  if (Desc->Data == NULL) {
+    FreePool (Node);
+    ASSERT (0);
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  *ObjNode = Node;
+  return EFI_SUCCESS;
+}
+
+/** Free a CM_OBJ_NODE.
+
+  @param [in]  ObjNode    ObjNode to free.
+
+  @retval EFI_SUCCESS           Success.
+  @retval EFI_INVALID_PARAMETER A parameter is invalid.
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+FreeCmObjNode (
+  IN  CM_OBJ_NODE   * ObjNode
+  )
+{
+  CM_OBJ_DESCRIPTOR   *Desc;
+
+  if (ObjNode == NULL) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Unlink Node
+  RemoveEntryList (&ObjNode->Link);
+
+  Desc = &ObjNode->CmObjDesc;
+  if (Desc->Data != NULL) {
+    FreePool (Desc->Data);
+  }
+
+  FreePool (ObjNode);
+  return EFI_SUCCESS;
+}
+
+/** Add an object to the dynamic platform repository.
+
+  @param [in]  This       This dynamic platform repository.
+  @param [in]  CmObjDesc  CmObj to add. The data is copied.
+  @param [out] Token      If not NULL, token allocated to this CmObj.
+
+  @retval EFI_SUCCESS           Success.
+  @retval EFI_INVALID_PARAMETER A parameter is invalid.
+  @retval EFI_OUT_OF_RESOURCES  An allocation has failed.
+**/
+EFI_STATUS
+EFIAPI
+DynPlatRepoAddObject (
+  IN        DYNAMIC_PLATFORM_REPOSITORY_INFO    * This,
+  IN  CONST CM_OBJ_DESCRIPTOR                   * CmObjDesc,
+  OUT       CM_OBJECT_TOKEN                     * Token OPTIONAL
+  )
+{
+  EFI_STATUS              Status;
+  CM_OBJ_NODE             *ObjNode;
+  CM_OBJECT_ID            ArmNamespaceObjId;
+  CM_OBJECT_TOKEN         NewToken;
+
+  // The dynamic repository must be able to receive objects.
+  if ((This == NULL)      ||
+      (CmObjDesc == NULL) ||
+      (This->RepoState != DynRepoTransient)) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Check the CmObjDesc:
+  //  - only Arm objects are supported for now.
+  //  - only EArmObjCmRef objects can be added as arrays.
+  ArmNamespaceObjId = GET_CM_OBJECT_ID (CmObjDesc->ObjectId);
+  if ((CmObjDesc->Size == 0)              ||
+      (CmObjDesc->Count == 0)             ||
+      (ArmNamespaceObjId >= EArmObjMax)   ||
+      ((CmObjDesc->Count > 1)  && (ArmNamespaceObjId != EArmObjCmRef))  ||
+      (GET_CM_NAMESPACE_ID (CmObjDesc->ObjectId) != EObjNameSpaceArm)) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Generate a token.
+  NewToken = GenerateToken ();
+
+  // Create an ObjNode.
+  Status = AllocCmObjNode (CmObjDesc, NewToken, &ObjNode);
+  if (EFI_ERROR (Status)) {
+    ASSERT (0);
+    return Status;
+  }
+
+  // Fixup self-token if necessary.
+  Status = FixupCmObjectSelfToken (&ObjNode->CmObjDesc, NewToken);
+  if (EFI_ERROR (Status)) {
+    FreeCmObjNode (ObjNode);
+    ASSERT (0);
+    return Status;
+  }
+
+  // Add to link list.
+  InsertTailList (&This->ArmCmObjList[ArmNamespaceObjId], &ObjNode->Link);
+  This->ObjectCount += 1;
+
+  if (Token != NULL) {
+    *Token = NewToken;
+  }
+  return EFI_SUCCESS;
+}
+
+/** Group lists of CmObjNode from the ArmNameSpace to one array.
+
+  @param [in]  This         This dynamic platform repository.
+  @param [in]  ArmObjIndex  Index in EARM_OBJECT_ID
+                            (must be < EArmObjMax).
+
+  @retval EFI_SUCCESS           Success.
+  @retval EFI_INVALID_PARAMETER A parameter is invalid.
+  @retval EFI_BUFFER_TOO_SMALL    Buffer too small.
+  @retval EFI_OUT_OF_RESOURCES  An allocation has failed.
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+GroupCmObjNodes (
+  IN  DYNAMIC_PLATFORM_REPOSITORY_INFO    * This,
+  IN  UINT32                                ArmObjIndex
+  )
+{
+  EFI_STATUS          Status;
+  UINTN               Count;
+  UINTN               Size;
+  UINT32              CmObjId;
+  UINT8               *GroupedData;
+  UINT8               *Data;
+  CM_OBJ_DESCRIPTOR   *CmObjDesc;
+  LIST_ENTRY          *ListHead;
+  LIST_ENTRY          *Link;
+
+  if ((This == NULL)  ||
+      (ArmObjIndex >= EArmObjMax)) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Count = 0;
+  Size = 0;
+  CmObjId = CREATE_CM_ARM_OBJECT_ID (ArmObjIndex);
+  ListHead = &This->ArmCmObjList[ArmObjIndex];
+  Link = GetFirstNode (ListHead);
+
+  // Compute the total count and size of the CmObj in the list.
+  while (Link != ListHead) {
+    CmObjDesc = &((CM_OBJ_NODE*)Link)->CmObjDesc;
+
+    if (CmObjDesc->ObjectId != CmObjId) {
+      ASSERT (0);
+      return EFI_INVALID_PARAMETER;
+    }
+
+    if ((CmObjDesc->Count != 1) && (ArmObjIndex != EArmObjCmRef)){
+      // We expect each descriptor to contain an individual object.
+      // EArmObjCmRef objects are counted as groups, so +1 as well.
+      ASSERT (0);
+      return EFI_INVALID_PARAMETER;
+    }
+
+    Count++;
+    Size += CmObjDesc->Size;
+
+    // Next Link
+    Link = GetNextNode (ListHead, Link);
+  } // while
+
+  if (Count == 0) {
+    // No objects found.
+    return EFI_SUCCESS;
+  }
+
+  GroupedData = AllocateZeroPool (Size);
+  if (GroupedData == NULL) {
+    ASSERT (0);
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  // Copy the Object Data and add to the TokenMapper.
+  Data = GroupedData;
+  Link = GetFirstNode (ListHead);
+  while (Link != ListHead) {
+    CmObjDesc = &((CM_OBJ_NODE*)Link)->CmObjDesc;
+    CopyMem (Data, CmObjDesc->Data, CmObjDesc->Size);
+
+    // Add the object to the Token Mapper.
+    // Note: The CmObject Data field of objects in the Token Mapper point
+    //       to the memory in the GroupedData array.
+    Status = TokenMapperAddObject (
+               &This->TokenMapper,
+               ((CM_OBJ_NODE*)Link)->Token,
+               CmObjDesc->ObjectId,
+               CmObjDesc->Size,
+               Data
+               );
+    if (EFI_ERROR (Status)) {
+      FreePool (GroupedData);
+      return Status;
+    }
+
+    Data += CmObjDesc->Size;
+    Link = GetNextNode (ListHead, Link);
+  } // while
+
+  CmObjDesc = &This->ArmCmObjArray[ArmObjIndex];
+  CmObjDesc->ObjectId = CmObjId;
+  CmObjDesc->Size = Size;
+  CmObjDesc->Count = Count;
+  CmObjDesc->Data = GroupedData;
+
+  return Status;
+}
+
+/** Finalise the dynamic repository.
+
+  Finalising means:
+   - Preventing any further objects from being added.
+   - Allowing to get objects from the dynamic repository
+     (not possible before a call to this function).
+
+  @param [in]  This       This dynamic platform repository.
+
+  @retval EFI_SUCCESS           Success.
+  @retval EFI_ALREADY_STARTED   Instance already initialised.
+  @retval EFI_INVALID_PARAMETER A parameter is invalid.
+  @retval EFI_BUFFER_TOO_SMALL  Buffer too small.
+  @retval EFI_OUT_OF_RESOURCES  An allocation has failed.
+**/
+EFI_STATUS
+EFIAPI
+DynamicPlatRepoFinalise (
+  IN  DYNAMIC_PLATFORM_REPOSITORY_INFO      * This
+  )
+{
+  EFI_STATUS    Status;
+  UINTN         ArmObjIndex;
+
+  if ((This == NULL)  ||
+      (This->RepoState != DynRepoTransient)) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Prevent any further objects from being added.
+  This->RepoState = DynRepoFinalized;
+
+  // Initialise the token mapper.
+  Status = TokenMapperInitialise (&This->TokenMapper, This->ObjectCount);
+  if (EFI_ERROR (Status)) {
+    ASSERT (0);
+    return Status;
+  }
+
+  // For each CM_OBJECT_ID:
+  //  - Convert the list of nodes to an array
+  //    (the array is wrapped in a CmObjDesc).
+  //  - Add the Token/CmObj binding to the token mapper.
+  for (ArmObjIndex = 0; ArmObjIndex < EArmObjMax; ArmObjIndex++) {
+      Status = GroupCmObjNodes (This, ArmObjIndex);
+      if (EFI_ERROR (Status)) {
+        ASSERT (0);
+        // Free the TokenMapper.
+        // Ignore the returned Status since we already failed.
+        TokenMapperShutdown (&This->TokenMapper);
+        return Status;
+      }
+  } // for
+
+  return EFI_SUCCESS;
+}
+
+/** Get a CmObj from the dynamic repository.
+
+  @param [in]      This        Pointer to the Dynamic Platform Repository.
+  @param [in]      CmObjectId  The Configuration Manager Object ID.
+  @param [in]      Token       An optional token identifying the object. If
+                               unused this must be CM_NULL_TOKEN.
+  @param [in, out] CmObjDesc   Pointer to the Configuration Manager Object
+                               descriptor describing the requested Object.
+
+  @retval EFI_SUCCESS           Success.
+  @retval EFI_INVALID_PARAMETER A parameter is invalid.
+  @retval EFI_NOT_FOUND         The required object information is not found.
+**/
+EFI_STATUS
+EFIAPI
+DynamicPlatRepoGetObject (
+  IN      DYNAMIC_PLATFORM_REPOSITORY_INFO    * This,
+  IN      CM_OBJECT_ID                          CmObjectId,
+  IN      CM_OBJECT_TOKEN                       Token OPTIONAL,
+  IN  OUT CM_OBJ_DESCRIPTOR                   * CmObjDesc
+  )
+{
+  EFI_STATUS          Status;
+  CM_OBJ_DESCRIPTOR   *Desc;
+  CM_OBJECT_ID        ArmNamespaceObjId;
+
+  if ((This == NULL)      ||
+      (CmObjDesc == NULL) ||
+      (This->RepoState != DynRepoFinalized)) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  ArmNamespaceObjId = GET_CM_OBJECT_ID (CmObjectId);
+  if (ArmNamespaceObjId >= EArmObjMax) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if (Token != CM_NULL_TOKEN) {
+    // Search in the Token Mapper and return the object.
+    Status = TokenMapperGetObject (
+               &This->TokenMapper,
+               Token,
+               CmObjectId,
+               CmObjDesc
+               );
+    ASSERT_EFI_ERROR (Status);
+    return Status;
+  }
+
+  if (ArmNamespaceObjId == EArmObjCmRef) {
+    // EArmObjCmRef object must be requested using a valid token.
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Desc = &This->ArmCmObjArray[ArmNamespaceObjId];
+
+  // Nothing here.
+  if (Desc->Count == 0) {
+    return EFI_NOT_FOUND;
+  } else {
+    // Return the full array.
+    CmObjDesc->ObjectId = Desc->ObjectId;
+    CmObjDesc->Size = Desc->Size;
+    CmObjDesc->Data = Desc->Data;
+    CmObjDesc->Count = Desc->Count;
+  }
+
+  return EFI_SUCCESS;
+}
+
+/** Initialize the dynamic platform repository.
+
+  @param [out]  DynPlatRepo   If success, contains the initialised dynamic
+                              platform repository.
+
+  @retval EFI_SUCCESS           Success.
+  @retval EFI_INVALID_PARAMETER A parameter is invalid.
+  @retval EFI_OUT_OF_RESOURCES  An allocation has failed.
+**/
+EFI_STATUS
+EFIAPI
+DynamicPlatRepoInit (
+  OUT DYNAMIC_PLATFORM_REPOSITORY_INFO   ** DynPlatRepo
+  )
+{
+  UINTN                              Index;
+  DYNAMIC_PLATFORM_REPOSITORY_INFO * Repo;
+
+  if (DynPlatRepo == NULL) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Repo = AllocateZeroPool (sizeof (DYNAMIC_PLATFORM_REPOSITORY_INFO));
+  if (Repo == NULL) {
+    ASSERT (0);
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  // Initialise the CmObject List.
+  for (Index = 0; Index < EArmObjMax; Index++) {
+    InitializeListHead (&Repo->ArmCmObjList[Index]);
+  }
+
+  Repo->ObjectCount = 0;
+  Repo->RepoState = DynRepoTransient;
+
+  *DynPlatRepo = Repo;
+
+  return EFI_SUCCESS;
+}
+
+/** Shutdown the dynamic platform repository.
+
+  Free all the memory allocated for the dynamic platform repository.
+
+  @param [in]  DynPlatRepo    The dynamic platform repository.
+
+  @retval EFI_INVALID_PARAMETER A parameter is invalid.
+  @retval EFI_SUCCESS           Success.
+**/
+EFI_STATUS
+EFIAPI
+DynamicPlatRepoShutdown (
+  IN  DYNAMIC_PLATFORM_REPOSITORY_INFO * DynPlatRepo
+  )
+{
+  EFI_STATUS            Status;
+  UINT32                Index;
+  LIST_ENTRY          * ListHead;
+  CM_OBJ_DESCRIPTOR   * CmObjDesc;
+  VOID                * Data;
+
+  if (DynPlatRepo == NULL) {
+    ASSERT (0);
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Free the list of objects.
+  for (Index = 0; Index < EArmObjMax; Index++) {
+    // Free all the nodes with this object Id.
+    ListHead = &DynPlatRepo->ArmCmObjList[Index];
+    while (!IsListEmpty (ListHead)) {
+      FreeCmObjNode ((CM_OBJ_NODE*)GetFirstNode (ListHead));
+    } // while
+  } // for
+
+  // Free the arrays.
+  CmObjDesc = DynPlatRepo->ArmCmObjArray;
+  for (Index = 0; Index < EArmObjMax; Index++) {
+    Data = CmObjDesc[Index].Data;
+    if (Data != NULL) {
+      FreePool (Data);
+    }
+  } // for
+
+  // Free the TokenMapper
+  Status = TokenMapperShutdown (&DynPlatRepo->TokenMapper);
+  if (EFI_ERROR (Status)) {
+    ASSERT (0);
[SAMI] In DynamicPlatRepoFinalise() if an error occurs the Token Mapper would have been shutdown freeing all the memory.  So I think in TokenMapperShutdown(), the TokenDescArray should be set to NULL after freeing, and MaxTokenDescCount should  be set to 0.
Can you check, please?
[/SAMI]
+  }
+
+  FreePool (DynPlatRepo);
+  return Status;
+}
diff --git a/DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepoInternal.h b/DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepoInternal.h
new file mode 100644
index 000000000000..d03fa2b7dcec
--- /dev/null
+++ b/DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepoInternal.h
@@ -0,0 +1,78 @@
+/** @file
+  Dynamic Platform Info Repository Internal
+
+  Copyright (c) 2021, Arm Limited. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+  @par Glossary:
+    - Cm or CM   - Configuration Manager
+    - Obj or OBJ - Object
+**/
+
+#ifndef DYNAMIC_PLAT_REPO_INTERNAL_H_
+#define DYNAMIC_PLAT_REPO_INTERNAL_H_
+
+#include "TokenMapper.h"
+
+#pragma pack(1)
+
+/** CmObj node.
+
+  This is a node wrapper around the CM_OBJ_DESCRIPTOR structure.
+  It also allows to bind a token to the CM_OBJ_DESCRIPTOR.
+*/
+typedef struct CmObjectNode {
+  /// This must be the first field in this structure.
+  LIST_ENTRY          Link;
+
+  /// Token associated with the CmObjDesc.
+  CM_OBJECT_TOKEN     Token;
+
+  /// CmObjDesc wrapped.
+  /// Note: the CM_OBJ_DESCRIPTOR.Data field is allocated and copied.
+  CM_OBJ_DESCRIPTOR   CmObjDesc;
+} CM_OBJ_NODE;
+
+/** Dynamic repository states.
+
+  The states must progress as:
+  UnInitialised -> Transient -> Finalized
+*/
+typedef enum DynRepoState {
+  DynRepoUnInitialised, ///< Un-Initialised state
+  DynRepoTransient,     ///< Transient state - CmObjects can be added.
+  DynRepoFinalized,     ///< Repo Locked - No further CmObjects can be added.
+                        ///< Getting objects is now possible.
+  DynRepoMax            ///< Max value.
+} EDYNAMIC_REPO_STATE;
+
+/** A structure describing the platform configuration
+    manager repository information
+*/
+typedef struct DynamicPlatformRepositoryInfo {
+  /// Repo state machine.
+  EDYNAMIC_REPO_STATE   RepoState;
+
+  /// Count of all the objects added to the Dynamic Platform Repo
+  /// during the Transient state.
+  UINTN                 ObjectCount;
+
+  /// Link lists of CmObj from the ArmNameSpace
+  /// that are added in the Transient state.
+  LIST_ENTRY            ArmCmObjList[EArmObjMax];
+
+  /// Structure Members used in Finalized state.
+  /// An array of CmObj Descriptors from the ArmNameSpace
+  /// This array is populated when the Repo is finalized.
+  CM_OBJ_DESCRIPTOR     ArmCmObjArray[EArmObjMax];
+
+  /// A token mapper for the objects in the ArmNamespaceObjectArray
+  /// The Token mapper is populated when the Repo is finalized in
+  /// a call to DynamicPlatRepoFinalise ().
+  TOKEN_MAPPER          TokenMapper;
+} DYNAMIC_PLATFORM_REPOSITORY_INFO;
+
+#pragma pack()
+
+#endif // DYNAMIC_PLAT_REPO_INTERNAL_H_
diff --git a/DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepoLib.inf b/DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepoLib.inf
new file mode 100644
index 000000000000..9a3cc87fd91d
--- /dev/null
+++ b/DynamicTablesPkg/Library/Common/DynamicPlatRepoLib/DynamicPlatRepoLib.inf
@@ -0,0 +1,33 @@
+## @file
+#  Dynamic Platform Repository
+#
+#  Copyright (c) 2021, Arm Limited. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+  INF_VERSION    = 0x0001001B
+  BASE_NAME      = DynamicPlatRepoLib
+  FILE_GUID      = 836D253D-3144-4A89-9BEE-BC55AFDC814E
+  VERSION_STRING = 1.0
+  MODULE_TYPE    = DXE_DRIVER
+  LIBRARY_CLASS  = DynamicPlatRepoLib
+
+[Sources]
+  CmObjectTokenFixer.c
+  CmObjectTokenFixer.h
+  DynamicPlatRepo.c
+  DynamicPlatRepoInternal.h
+  TokenGenerator.c
+  TokenGenerator.h
+  TokenMapper.c
+  TokenMapper.h
+
+[Packages]
+  MdePkg/MdePkg.dec
+  DynamicTablesPkg/DynamicTablesPkg.dec
+
+[LibraryClasses]
+  AcpiHelperLib
+  BaseLib

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