ArmPkg/BaseMemoryLibStm: implement new IsZeroGuid() API function

[mirror_edk2.git] / ArmPkg / Library / BaseMemoryLibStm / MemLibGuid.c

diff --git a/ArmPkg/Library/BaseMemoryLibStm/MemLibGuid.c b/ArmPkg/Library/BaseMemoryLibStm/MemLibGuid.c
index 2b4ed57755816c9e10313b3a22626efb7e4e6db4..36d42d71d79a5486aaafca3e1623274884509945 100644 (file)
--- a/ArmPkg/Library/BaseMemoryLibStm/MemLibGuid.c
+++ b/ArmPkg/Library/BaseMemoryLibStm/MemLibGuid.c
@@ -130,3 +130,32 @@ ScanGuid (
   }\r
   return NULL;\r
 }\r
+\r
+/**\r
+  Checks if the given GUID is a zero GUID.\r
+\r
+  This function checks whether the given GUID is a zero GUID. If the GUID is\r
+  identical to a zero GUID then TRUE is returned. Otherwise, FALSE is returned.\r
+\r
+  If Guid is NULL, then ASSERT().\r
+\r
+  @param  Guid        The pointer to a 128 bit GUID.\r
+\r
+  @retval TRUE        Guid is a zero GUID.\r
+  @retval FALSE       Guid is not a zero GUID.\r
+\r
+**/\r
+BOOLEAN\r
+EFIAPI\r
+IsZeroGuid (\r
+  IN CONST GUID  *Guid\r
+  )\r
+{\r
+  UINT64  LowPartOfGuid;\r
+  UINT64  HighPartOfGuid;\r
+\r
+  LowPartOfGuid  = ReadUnaligned64 ((CONST UINT64*) Guid);\r
+  HighPartOfGuid = ReadUnaligned64 ((CONST UINT64*) Guid + 1);\r
+\r
+  return (BOOLEAN) (LowPartOfGuid == 0 && HighPartOfGuid == 0);\r
+}\r