X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=MdePkg%2FLibrary%2FUefiMemoryLib%2FMemLibGeneric.c;h=73ef0d92d1ca12426b4d694950c5ed1b26b56b53;hb=9344f0921518309295da89c221d10cbead8531aa;hp=e9e0f171ba0e9188ee2aee2069939c8a20716fe9;hpb=1fef058f4b8fefc455bb171e4908c3e835b1b492;p=mirror_edk2.git

diff --git a/MdePkg/Library/UefiMemoryLib/MemLibGeneric.c b/MdePkg/Library/UefiMemoryLib/MemLibGeneric.c
index e9e0f171ba..73ef0d92d1 100644
--- a/MdePkg/Library/UefiMemoryLib/MemLibGeneric.c
+++ b/MdePkg/Library/UefiMemoryLib/MemLibGeneric.c
@@ -6,14 +6,8 @@
     PeiMemoryLib
     UefiMemoryLib
 
-  Copyright (c) 2006 - 2009, Intel Corporation<BR>
-  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.
+  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
 
@@ -22,9 +16,9 @@
 /**
   Fills a target buffer with a 16-bit value, and returns the target buffer.
 
-  @param  Buffer  Pointer to the target buffer to fill.
-  @param  Length  Count of 16-bit value to fill.
-  @param  Value   Value with which to fill Length bytes of Buffer.
+  @param  Buffer  The pointer to the target buffer to fill.
+  @param  Length  The count of 16-bit value to fill.
+  @param  Value   The value with which to fill Length bytes of Buffer.
 
   @return Buffer
 
@@ -37,18 +31,18 @@ InternalMemSetMem16 (
   IN      UINT16                    Value
   )
 {
-  do {
-    ((UINT16*)Buffer)[--Length] = Value;
-  } while (Length != 0);
+  for (; Length != 0; Length--) {
+    ((UINT16*)Buffer)[Length - 1] = Value;
+  }
   return Buffer;
 }
 
 /**
   Fills a target buffer with a 32-bit value, and returns the target buffer.
 
-  @param  Buffer  Pointer to the target buffer to fill.
-  @param  Length  Count of 32-bit value to fill.
-  @param  Value   Value with which to fill Length bytes of Buffer.
+  @param  Buffer  The pointer to the target buffer to fill.
+  @param  Length  The count of 32-bit value to fill.
+  @param  Value   The value with which to fill Length bytes of Buffer.
 
   @return Buffer
 
@@ -61,18 +55,18 @@ InternalMemSetMem32 (
   IN      UINT32                    Value
   )
 {
-  do {
-    ((UINT32*)Buffer)[--Length] = Value;
-  } while (Length != 0);
+  for (; Length != 0; Length--) {
+    ((UINT32*)Buffer)[Length - 1] = Value;
+  }
   return Buffer;
 }
 
 /**
   Fills a target buffer with a 64-bit value, and returns the target buffer.
 
-  @param  Buffer  Pointer to the target buffer to fill.
-  @param  Length  Count of 64-bit value to fill.
-  @param  Value   Value with which to fill Length bytes of Buffer.
+  @param  Buffer  The pointer to the target buffer to fill.
+  @param  Length  The count of 64-bit value to fill.
+  @param  Value   The value with which to fill Length bytes of Buffer.
 
   @return Buffer
 
@@ -85,9 +79,9 @@ InternalMemSetMem64 (
   IN      UINT64                    Value
   )
 {
-  do {
-    ((UINT64*)Buffer)[--Length] = Value;
-  } while (Length != 0);
+  for (; Length != 0; Length--) {
+    ((UINT64*)Buffer)[Length - 1] = Value;
+  }
   return Buffer;
 }
 
@@ -95,7 +89,7 @@ InternalMemSetMem64 (
   Set Buffer to 0 for Size bytes.
 
   @param  Buffer Memory to set.
-  @param  Length Number of bytes to set
+  @param  Length The number of bytes to set
 
   @return Buffer
 
@@ -113,9 +107,9 @@ InternalMemZeroMem (
 /**
   Compares two memory buffers of a given length.
 
-  @param  DestinationBuffer First memory buffer
-  @param  SourceBuffer      Second memory buffer
-  @param  Length            Length of DestinationBuffer and SourceBuffer memory
+  @param  DestinationBuffer The first memory buffer
+  @param  SourceBuffer      The second memory buffer
+  @param  Length            The length of DestinationBuffer and SourceBuffer memory
                             regions to compare. Must be non-zero.
 
   @return 0                 All Length bytes of the two buffers are identical.
@@ -143,11 +137,11 @@ InternalMemCompareMem (
   Scans a target buffer for an 8-bit value, and returns a pointer to the
   matching 8-bit value in the target buffer.
 
-  @param  Buffer  Pointer to the target buffer to scan.
-  @param  Length  Count of 8-bit value to scan. Must be non-zero.
-  @param  Value   Value to search for in the target buffer.
+  @param  Buffer  The pointer to the target buffer to scan.
+  @param  Length  The count of 8-bit value to scan. Must be non-zero.
+  @param  Value   The value to search for in the target buffer.
 
-  @return Pointer to the first occurrence or NULL if not found.
+  @return The pointer to the first occurrence or NULL if not found.
 
 **/
 CONST VOID *
@@ -163,7 +157,7 @@ InternalMemScanMem8 (
   Pointer = (CONST UINT8*)Buffer;
   do {
     if (*(Pointer++) == Value) {
-      return Pointer;
+      return --Pointer;
     }
   } while (--Length != 0);
   return NULL;
@@ -173,11 +167,11 @@ InternalMemScanMem8 (
   Scans a target buffer for a 16-bit value, and returns a pointer to the
   matching 16-bit value in the target buffer.
 
-  @param  Buffer  Pointer to the target buffer to scan.
-  @param  Length  Count of 16-bit value to scan. Must be non-zero.
-  @param  Value   Value to search for in the target buffer.
+  @param  Buffer  The pointer to the target buffer to scan.
+  @param  Length  The count of 16-bit value to scan. Must be non-zero.
+  @param  Value   The value to search for in the target buffer.
 
-  @return Pointer to the first occurrence or NULL if not found.
+  @return The pointer to the first occurrence or NULL if not found.
 
 **/
 CONST VOID *
@@ -193,7 +187,7 @@ InternalMemScanMem16 (
   Pointer = (CONST UINT16*)Buffer;
   do {
     if (*(Pointer++) == Value) {
-      return Pointer;
+      return --Pointer;
     }
   } while (--Length != 0);
   return NULL;
@@ -203,11 +197,11 @@ InternalMemScanMem16 (
   Scans a target buffer for a 32-bit value, and returns a pointer to the
   matching 32-bit value in the target buffer.
 
-  @param  Buffer  Pointer to the target buffer to scan.
-  @param  Length  Count of 32-bit value to scan. Must be non-zero.
-  @param  Value   Value to search for in the target buffer.
+  @param  Buffer  The pointer to the target buffer to scan.
+  @param  Length  The count of 32-bit value to scan. Must be non-zero.
+  @param  Value   The value to search for in the target buffer.
 
-  @return Pointer to the first occurrence or NULL if not found.
+  @return The pointer to the first occurrence or NULL if not found.
 
 **/
 CONST VOID *
@@ -223,7 +217,7 @@ InternalMemScanMem32 (
   Pointer = (CONST UINT32*)Buffer;
   do {
     if (*(Pointer++) == Value) {
-      return Pointer;
+      return --Pointer;
     }
   } while (--Length != 0);
   return NULL;
@@ -233,11 +227,11 @@ InternalMemScanMem32 (
   Scans a target buffer for a 64-bit value, and returns a pointer to the
   matching 64-bit value in the target buffer.
 
-  @param  Buffer  Pointer to the target buffer to scan.
-  @param  Length  Count of 64-bit value to scan. Must be non-zero.
-  @param  Value   Value to search for in the target buffer.
+  @param  Buffer  The pointer to the target buffer to scan.
+  @param  Length  The count of 64-bit value to scan. Must be non-zero.
+  @param  Value   The value to search for in the target buffer.
 
-  @return Pointer to the first occurrence or NULL if not found.
+  @return The pointer to the first occurrence or NULL if not found.
 
 **/
 CONST VOID *
@@ -253,8 +247,37 @@ InternalMemScanMem64 (
   Pointer = (CONST UINT64*)Buffer;
   do {
     if (*(Pointer++) == Value) {
-      return Pointer;
+      return --Pointer;
     }
   } while (--Length != 0);
   return NULL;
 }
+
+/**
+  Checks whether the contents of a buffer are all zeros.
+
+  @param  Buffer  The pointer to the buffer to be checked.
+  @param  Length  The size of the buffer (in bytes) to be checked.
+
+  @retval TRUE    Contents of the buffer are all zeros.
+  @retval FALSE   Contents of the buffer are not all zeros.
+
+**/
+BOOLEAN
+EFIAPI
+InternalMemIsZeroBuffer (
+  IN CONST VOID  *Buffer,
+  IN UINTN       Length
+  )
+{
+  CONST UINT8 *BufferData;
+  UINTN       Index;
+
+  BufferData = Buffer;
+  for (Index = 0; Index < Length; Index++) {
+    if (BufferData[Index] != 0) {
+      return FALSE;
+    }
+  }
+  return TRUE;
+}