1 files changed, 18 insertions, 1 deletions
diff --git a/MdeModulePkg/Include/Ppi/BaseMemoryTest.h b/MdeModulePkg/Include/Ppi/BaseMemoryTest.h
index e769a9929f..5e069a6802 100644
--- a/MdeModulePkg/Include/Ppi/BaseMemoryTest.h
+++ b/MdeModulePkg/Include/Ppi/BaseMemoryTest.h
@@ -1,5 +1,5 @@
 /** @file
-  Pei memory test PPI used to Perform memory test in PEI phase.
+  This file defines Pei memory test PPI used to Perform memory test in PEI phase.
 
 Copyright (c) 2006 - 2008, Intel Corporation. <BR>
 All rights reserved. This program and the accompanying materials
@@ -20,6 +20,10 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
 typedef struct _PEI_BASE_MEMORY_TEST_PPI  PEI_BASE_MEMORY_TEST_PPI;
 
+//
+// 4 different test operations
+// Ignore op not test memory, Quick and Sparse op test memory quickly, Extensive op test memory detailedly.
+//
 typedef enum {
   Ignore,
   Quick,
@@ -27,6 +31,19 @@ typedef enum {
   Extensive
 } PEI_MEMORY_TEST_OP;
 
+/**
+  Test a range memory space is ready to read and write.
+
+  @param PeiServices      An indirect pointer to the PEI Services Table published by the PEI Foundation.
+  @param This             Pointer to Pei memory test PPI instance.
+  @param BeginAddress     Beginning of the memory address to be checked.
+  @param MemoryLength     Bytes of memory range to be checked.
+  @param Operation        Type of memory check operation to be performed.
+  @param ErrorAddress     Address which has error when checked.
+
+  @retval EFI_SUCCESS         Memory range pass basic read and write test.
+  @retval EFI_DEVICE_ERROR    Memory is not ready to access.
+**/
 typedef
 EFI_STATUS
 (EFIAPI *PEI_BASE_MEMORY_TEST) (