X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=MdePkg%2FLibrary%2FUefiMemoryLib%2FMemLibGeneric.c;h=f1efdbb413d1dc10971b039e5488f952c586c1bc;hb=41bfaffd13094d9042110091e6c37adf20c4032c;hp=ef9f358a7950b5eef35877b349b822d3dd5355bf;hpb=878ddf1fc3540a715f63594ed22b6929e881afb4;p=mirror_edk2.git

diff --git a/MdePkg/Library/UefiMemoryLib/MemLibGeneric.c b/MdePkg/Library/UefiMemoryLib/MemLibGeneric.c
index ef9f358a79..f1efdbb413 100644
--- a/MdePkg/Library/UefiMemoryLib/MemLibGeneric.c
+++ b/MdePkg/Library/UefiMemoryLib/MemLibGeneric.c
@@ -1,49 +1,30 @@
 /** @file
   Architecture Independent Base Memory Library Implementation.
 
-  Copyright (c) 2006, Intel Corporation<BR>
-  All rights reserved. This program and the accompanying materials
+  The following BaseMemoryLib instances contain the same copy of this file:
+    BaseMemoryLib
+    PeiMemoryLib
+    UefiMemoryLib
+
+  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
+  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
+  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.
 
-  Module Name:  MemLibGeneric.c
-
-  The following BaseMemoryLib instances share the same version of this file:
-
-    BaseMemoryLib
-    PeiMemoryLib
-    UefiMemoryLib
-
 **/
 
-/**
-  Set Buffer to Value for Size bytes.
-
-  @param  Buffer Memory to set.
-  @param  Size Number of bytes to set
-  @param  Value Value of the set operation.
-
-  @return Buffer
-
-**/
-VOID *
-EFIAPI
-InternalMemSetMem (
-  OUT     VOID                      *Buffer,
-  IN      UINTN                     Length,
-  IN      UINT8                     Value
-  );
+#include "MemLibInternals.h"
 
 /**
   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  Number of bytes in Buffer 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
 
@@ -56,18 +37,18 @@ 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  Number of bytes in Buffer 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
 
@@ -80,18 +61,18 @@ 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  Number of bytes in Buffer 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
 
@@ -104,9 +85,9 @@ InternalMemSetMem64 (
   IN      UINT64                    Value
   )
 {
-  do {
-    ((UINT64*)Buffer)[--Length] = Value;
-  } while (Length != 0);
+  for (; Length != 0; Length--) {
+    ((UINT64*)Buffer)[Length - 1] = Value;
+  }
   return Buffer;
 }
 
@@ -114,7 +95,7 @@ InternalMemSetMem64 (
   Set Buffer to 0 for Size bytes.
 
   @param  Buffer Memory to set.
-  @param  Size Number of bytes to set
+  @param  Length The number of bytes to set
 
   @return Buffer
 
@@ -132,12 +113,14 @@ 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.
 
-  @retval 0     if MemOne == MemTwo
+  @return 0                 All Length bytes of the two buffers are identical.
+  @retval Non-zero          The first mismatched byte in SourceBuffer subtracted from the first
+                            mismatched byte in DestinationBuffer.
 
 **/
 INTN
@@ -148,7 +131,6 @@ InternalMemCompareMem (
   IN      UINTN                     Length
   )
 {
-  ASSERT (Length > 0);
   while ((--Length != 0) &&
          (*(INT8*)DestinationBuffer == *(INT8*)SourceBuffer)) {
     DestinationBuffer = (INT8*)DestinationBuffer + 1;
@@ -161,11 +143,11 @@ 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  Number of bytes in Buffer 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 *
@@ -178,11 +160,10 @@ InternalMemScanMem8 (
 {
   CONST UINT8                       *Pointer;
 
-  ASSERT (Length > 0);
   Pointer = (CONST UINT8*)Buffer;
   do {
     if (*(Pointer++) == Value) {
-      return Pointer;
+      return --Pointer;
     }
   } while (--Length != 0);
   return NULL;
@@ -192,11 +173,11 @@ 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  Number of bytes in Buffer 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 *
@@ -209,11 +190,10 @@ InternalMemScanMem16 (
 {
   CONST UINT16                      *Pointer;
 
-  ASSERT (Length > 0);
   Pointer = (CONST UINT16*)Buffer;
   do {
     if (*(Pointer++) == Value) {
-      return Pointer;
+      return --Pointer;
     }
   } while (--Length != 0);
   return NULL;
@@ -223,11 +203,11 @@ 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  Number of bytes in Buffer 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 *
@@ -240,11 +220,10 @@ InternalMemScanMem32 (
 {
   CONST UINT32                      *Pointer;
 
-  ASSERT (Length > 0);
   Pointer = (CONST UINT32*)Buffer;
   do {
     if (*(Pointer++) == Value) {
-      return Pointer;
+      return --Pointer;
     }
   } while (--Length != 0);
   return NULL;
@@ -254,11 +233,11 @@ 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  Number of bytes in Buffer 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 *
@@ -271,12 +250,40 @@ InternalMemScanMem64 (
 {
   CONST UINT64                      *Pointer;
 
-  ASSERT (Length > 0);
   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;
+}