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[mirror_edk2.git] / MdeModulePkg / Library / DxeCrc32GuidedSectionExtractLib / DxeCrc32GuidedSectionExtractLib.c

diff --git a/MdeModulePkg/Library/DxeCrc32GuidedSectionExtractLib/DxeCrc32GuidedSectionExtractLib.c b/MdeModulePkg/Library/DxeCrc32GuidedSectionExtractLib/DxeCrc32GuidedSectionExtractLib.c
index 99f728510853c82dbc46d650a69cb7be7da16c3d..398adfcac16f56ad759d08f207e9e33057e14b43 100644 (file)
--- a/MdeModulePkg/Library/DxeCrc32GuidedSectionExtractLib/DxeCrc32GuidedSectionExtractLib.c
+++ b/MdeModulePkg/Library/DxeCrc32GuidedSectionExtractLib/DxeCrc32GuidedSectionExtractLib.c
@@ -1,7 +1,8 @@
 /** @file\r
 \r
-  Implements CRC32 guided section handler to parse CRC32 encapsulation section, \r
-  extract data and authenticate 32 bit CRC value.\r
+  This library registers CRC32 guided section handler \r
+  to parse CRC32 encapsulation section and extract raw data.\r
+  It uses UEFI boot service CalculateCrc32 to authenticate 32 bit CRC value.\r
 \r
 Copyright (c) 2007 - 2008, Intel Corporation                                                         \r
 All rights reserved. This program and the accompanying materials                          \r
@@ -15,22 +16,28 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 **/\r
 \r
 #include <PiDxe.h>\r
-#include <Protocol/Crc32GuidedSectionExtraction.h>\r
+#include <Guid/Crc32GuidedSectionExtraction.h>\r
 #include <Protocol/SecurityPolicy.h>\r
 #include <Library/ExtractGuidedSectionLib.h>\r
 #include <Library/DebugLib.h>\r
 #include <Library/BaseMemoryLib.h>\r
 #include <Library/UefiBootServicesTableLib.h>\r
 \r
+#define EFI_SECITON_SIZE_MASK 0x00ffffff\r
+\r
+///\r
+/// CRC32 Guided Section header\r
+///\r
 typedef struct {\r
-  EFI_GUID_DEFINED_SECTION  GuidedSectionHeader;\r
-  UINT32                    CRC32Checksum;\r
+  EFI_GUID_DEFINED_SECTION  GuidedSectionHeader; ///< EFI guided section header\r
+  UINT32                    CRC32Checksum;       ///< 32bit CRC check sum\r
 } CRC32_SECTION_HEADER;\r
 \r
 /**\r
 \r
-  The implementation of Crc32 guided section GetInfo() to get \r
-  size and attribute of the guided section.\r
+  GetInfo gets raw data size and attribute of the input guided section.\r
+  It first checks whether the input guid section is supported. \r
+  If not, EFI_INVALID_PARAMETER will return.\r
 \r
   @param InputSection       Buffer containing the input GUIDed section to be processed.\r
   @param OutputBufferSize   The size of OutputBuffer.\r
@@ -55,7 +62,7 @@ Crc32GuidedSectionGetInfo (
   // Check whether the input guid section is recognized.\r
   //\r
   if (!CompareGuid (\r
-        &gEfiCrc32GuidedSectionExtractionProtocolGuid, \r
+        &gEfiCrc32GuidedSectionExtractionGuid, \r
         &(((EFI_GUID_DEFINED_SECTION *) InputSection)->SectionDefinitionGuid))) {\r
     return EFI_INVALID_PARAMETER;\r
   }\r
@@ -64,7 +71,7 @@ Crc32GuidedSectionGetInfo (
   //\r
   *SectionAttribute  = ((EFI_GUID_DEFINED_SECTION *) InputSection)->Attributes;\r
   *ScratchBufferSize = 0;\r
-  *OutputBufferSize  = *(UINT32 *) (((EFI_COMMON_SECTION_HEADER *) InputSection)->Size) & 0x00ffffff;\r
+  *OutputBufferSize  = *(UINT32 *) (((EFI_COMMON_SECTION_HEADER *) InputSection)->Size) & EFI_SECITON_SIZE_MASK;\r
   *OutputBufferSize  -= ((EFI_GUID_DEFINED_SECTION *) InputSection)->DataOffset;\r
 \r
   return EFI_SUCCESS;\r
@@ -72,13 +79,16 @@ Crc32GuidedSectionGetInfo (
 \r
 /**\r
 \r
-  The implementation of Crc32 Guided section extraction to get the section data.\r
+  Extraction handler tries to extract raw data from the input guided section.\r
+  It also does authentication check for 32bit CRC value in the input guided section.\r
+  It first checks whether the input guid section is supported. \r
+  If not, EFI_INVALID_PARAMETER will return.\r
 \r
   @param InputSection    Buffer containing the input GUIDed section to be processed.\r
-  @param OutputBuffer    to contain the output data, which is allocated by the caller.\r
+  @param OutputBuffer    Buffer to contain the output raw data allocated by the caller.\r
   @param ScratchBuffer   A pointer to a caller-allocated buffer for function internal use.\r
   @param AuthenticationStatus A pointer to a caller-allocated UINT32 that indicates the\r
-                         authentication status of the output buffer.\r
+                              authentication status of the output buffer.\r
 \r
   @retval EFI_SUCCESS            Section Data and Auth Status is extracted successfully.\r
   @retval EFI_INVALID_PARAMETER  The GUID in InputSection does not match this instance guid.\r
@@ -103,7 +113,7 @@ Crc32GuidedSectionHandler (
   // Check whether the input guid section is recognized.\r
   //\r
   if (!CompareGuid (\r
-        &gEfiCrc32GuidedSectionExtractionProtocolGuid, \r
+        &gEfiCrc32GuidedSectionExtractionGuid, \r
         &(((EFI_GUID_DEFINED_SECTION *) InputSection)->SectionDefinitionGuid))) {\r
     return EFI_INVALID_PARAMETER;\r
   }\r
@@ -117,7 +127,7 @@ Crc32GuidedSectionHandler (
   //\r
   Crc32SectionHeader = (CRC32_SECTION_HEADER *) InputSection;\r
   *OutputBuffer      = (UINT8 *) InputSection + Crc32SectionHeader->GuidedSectionHeader.DataOffset;\r
-  OutputBufferSize   = *(UINT32 *) (((EFI_COMMON_SECTION_HEADER *) InputSection)->Size) & 0x00ffffff; \r
+  OutputBufferSize   = *(UINT32 *) (((EFI_COMMON_SECTION_HEADER *) InputSection)->Size) & EFI_SECITON_SIZE_MASK; \r
   OutputBufferSize   -= Crc32SectionHeader->GuidedSectionHeader.DataOffset;\r
 \r
   //\r
@@ -159,18 +169,23 @@ Crc32GuidedSectionHandler (
 }\r
 \r
 /**\r
-  Register Crc32 section handler.\r
+  Register the handler to extract CRC32 guided section.\r
+\r
+  @param  ImageHandle  ImageHandle of the loaded driver.\r
+  @param  SystemTable  Pointer to the EFI System Table.\r
 \r
-  @retval  RETURN_SUCCESS            Register successfully.\r
-  @retval  RETURN_OUT_OF_RESOURCES   No enough memory to register this handler.\r
+  @retval  EFI_SUCCESS            Register successfully.\r
+  @retval  EFI_OUT_OF_RESOURCES   No enough memory to register this handler.\r
 **/\r
 EFI_STATUS\r
 EFIAPI\r
 DxeCrc32GuidedSectionExtractLibConstructor (\r
+  IN EFI_HANDLE        ImageHandle,\r
+  IN EFI_SYSTEM_TABLE  *SystemTable\r
   )\r
 {\r
   return ExtractGuidedSectionRegisterHandlers (\r
-          &gEfiCrc32GuidedSectionExtractionProtocolGuid,\r
+          &gEfiCrc32GuidedSectionExtractionGuid,\r
           Crc32GuidedSectionGetInfo,\r
           Crc32GuidedSectionHandler\r
           );\r