audk/MdePkg/ChangeLog.txt

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!!!!!!!!!!!!!!!!!               Notes for this ChangeLog.txt             !!!!!!!!!!!!!!!!!

This log file is used to record two kinds of important information:
 a) "Non-Compatible Changes": all non-compatible changes should be recorded. These info
    will help the package user to merge this package; and some non-compatible changes
    can also be added into release notes as news features when we release this package.
    Normally Non-Compatible Changes contains the following types:
      1) Package's external services were changed/updated
      2) Package's common .h file is renamed, deleted, or the file path is changed.
      3) The definition of package's common data structure is changed
      ...

 b) "Important Compatible Changes": some important compatible changes can aslo be recorded
    in this file, and we can add these updating into release notes when we release this
    package.

Non-Compatible and Compatible example format:
==========================================================================================
EDK_0010: Non-Compatible: owner

	  Class_HFile: PPI A of MdePkg has been removed.

		Code Change :
		1) Removed the .h file: MdePkg\Include\Ppi\A.h

		Possible Impacts:
		1) All modules that used this PPI A should be updated.

==========================================================================================
EDK_0000: Compatible: owner

	  Class_BuildTool: with the EDK_0000 build.exe, the build performance is enhanced great.

		Code Change :
		1) BaseTools\Bin\Win32\build.exe

!!!!!!!!!!!!!!!!!!                     End of Notes                     !!!!!!!!!!!!!!!!!!
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==========================================================================================
EDK_3983: Non-Compatible: lgao4
	
	Class_Library: Remove CustomDecompressLib library class.
	
	Code Change:
	1) Remove the definition MdePkg\Include\Library\CustomDecompressLib.h and 
	   library instance MdePkg\Library\BaseCustomDecompressLibNull for CustomDecompressLib.
	
	Possible Impacts:
	1) Drivers don't use this library class any longer. But they can use new ExtractGuidedSectionLib
	   library class to extract the compressed guided section data.
	2) The instance of CustomDecompressLib should be changed to register the decode function 
	   into ExtractGuidedSectionHandler list, and not to produce CustomDecompressLib class.
	3) Platform.dsc file doesn't use this library instance any longer.

==========================================================================================
EDK_3980: Non-Compatible: lgao4
	
	Class_Library: Add ExtractGuidedSectionLib library class to replace CustomDecompressLib.
	
	Code Change:
	1) Add the definition MdePkg\Include\Library\ExtractGuidedSectionLib.h and 
	   library instance MdePkg\Library\PeiDxeExtractGuidedSectionLib for new ExtractGuidedSectionLib.
	2) Add gEfiMdePkgTokenSpaceGuid.PcdMaximumGuidedExtractHandler in MdePkg, which is used by 
	   PeiDxeExtractGuidedSectionLib library instance.
	3) Update DxeIpl and DxeMain modules of MdeModulePkg to use new ExtractGuidedSectionLib library class.
	4) Update BaseUefiTianoCustomDecompressLib of IntelFrameworkModulePkg not to produce CustomDecompressLib,
	   and to register TianoDecomress handler into ExtractGuidedSectionHandler list.
	
	Possible Impacts:
	1) Platform.dsc file should update library instance and PCD if it contains DxeIpl and DxeMain modules.
	   It should use MdePkg\Library\PeiDxeExtractGuidedSectionLib library instance and 
	   set gEfiMdePkgTokenSpaceGuid.PcdMaximumGuidedExtractHandler PCD value.

==========================================================================================
EDK_3871: Non-Compatible: klu2
	
	Class_PIEnable[1]: Use new entry point for PeiCore defined in PI specification.
	
	Code Change:
	1) Remove the definition and library instance for OldPeiCoreEntryPoinLib
	
	Possible Impacts:
	1) Platform should select MdePkg/Library/PeiCoreEntryPoint/PeiCoreEntryPoint.inf for 
	   PeiMain module.
	2) The SecCore module should provide parameters for new entry point defined in 
	   MdePkg\Include\Library\PeiCoreEntryPoint.h


EDK_3922:  Non-Compatible: qwang12, klu2
  Class_PIEnable[0]:  Update PeiServicesLib based on new features defined in PI spec.

      Code Change :
      1) Add the following services:PeiServicesRegisterForShadow, PeiServicesFfsGetFileInfo, PeiServicesFfsFindFileByName and PeiServicesFfsGetVolumeInfo
      2) The paramter list of these functiuon has also been updated to replace EFI_FIRMWARE_VOLUME_HEADER to EFI_PEI_FV_HANDLE and EFI_FFS_FILE_HEADER
         to EFI_PEI_FILE_HANDLE.
      3) Add CONST to parameter of PeiServices EFI_PEI_SERVICES.EFI_PEI_RESET_SYSTEM

      Possible Impacts:

      1) Platform code should be updated to make use of these new PI features. The functions in MdePkg/Include/Library/PeiServicesLib.h are 
         recommended as PeiServices is saved for every PEI Services API invokation.
      2) Now PEIM entry point is upadted to pass in PeiServices in type of (CONST EFI_PEI_SERVICS **). Platform code should be updated to 
         add (EFI_PEI_SERVICS **) cast to PeiServices before passing it to the previously defined PPI interface which needs a (EFI_PEI_SERVICS **)
         type for PeiServices parameter.
      3) The newly defined PPI should not inlcude PeiSevices in the paramter list as PI spec has standard way to retrive PeiServices (check VOL 1
         Section 4.4 PEI Sevices Table Retrieval) for details. Beside, GetPeiServicesTablePointer() in MdePkg\Include\Library\PeiServicesTablePointerLib.h
         also provide convinient way to retrieve the pointer to Pei Service Table.
         

EDK_4067:  Non-Compatible: qwang12
  Class_PIEnable[1]:  Add PeiPiLib library class and replace PiLib with DxePiLib library class.

      Code Change :
      1) Change MdePkg/Include/Library/PiLib.h to MdePkg/Include/Library/DxePiLib.h. DxePiLib is mainly used
         for modules in DXE phase. Add a DxePiLib.h library instance at MdePkg/Library/DxePiLib/DxePiLib.inf.
      2) Add MdePkg/Include/Library/PeiPiLib.h. PeiPiLib is mainly used by modules in PEI phase. 
         Add a DxePiLib.h library instance at MdePkg/Library/PeiPiLib/PeiPiLib.inf.
      3) Rename API in PeiPiLib.h from PeiPiLibBuildPiFvInfoPpi to PiLibInstallFvInfoPpi.
      4) Rename APIs originally in PiLib.h with new names defined in DxePiLib.h:
          4.1) GetSectionFrom*Fv functions are changed to PiLibGetSectionFrom*Fv to reduce possibility of name collision.
          4.2) Remove API named ImageHandleToFvHandle and GetSectionFromFvFile 


      Possible Impacts:

      1) Platform modules that reference PeiPiLibBuildPiFvInfoPpi and GetSectionFrom*Fv should reference the new
         names defined.
      2) Platform DSC file that specifying library instance for PiLib should be updated to add one line (a example 
         is given below):
          [LibraryClasses.common.DXE_DRIVER]
              ...
              DxePiLib|MdePkg/Library/DxePiLib/DxePiLib.inf
              ...
      3) Platform DSC file including modules that make use of API from PeiPiLib.h should add the following line (a example 
         is given below):
          [LibraryClasses.common.PEIM]
              ...
              PeiPiLib|MdePkg/Library/PeiPiLib/PeiPiLib.inf
              ...
          

EDK_5835:  Non-Compatible: qwang12
  Class General Definitions: NULL_HANDLE definition is removed from UefiBaseType.h. If any modules referencs NULL_HANDLE, they should be updated to use NULL. 
  
EDK_5869:  Non-Compatible: qhuang8
  Class General Definitions: Update the macro ALIGN_VARIALBE to drop the second parameter.
  
		Code Change:
			The macro ALIGN_VARIABLE in base.h is changed to keep the first paramter

		Possible Impacts:
			Modules using this macro, it needs to adapt to new interface.
			
EDK_5939:  Non-Compatible: qwang12
  Library API moved frrom HiiLib to UefiLib.
  
		Code Change:
			Change HiiLibGetCurrentLanguage to GetCurrentLanguage and moved it from HiiLib to UefiLib.

		Possible Impacts:
			All module that reference HiiLibGetCurrentLanguage should be updated in the following step:
			  0) Change HiiLibGetCurrentLanguage to GetCurrentLanguage.
				1) Add UefiLib to [LibraryClass] in INF if it is not included before.
				2) Remove HiiLib from [LibraryClass] if HiiLibGetCurrentLanguage is the only API from original HiiLib referenced by this module.
				3) Add UefiLib to [LibraryClasses.common.Module Type] for the affected module if UefiLib is not in the list.
				
EDK_5989:  Non-Compatible: qwang12
  Library API name changed:
   In IfrSupportLib,
	 Rename BufToHexString to BufInReverseOrderToHexString 
   Rename HexStringToBuf to HexStringToBufInReverseOrder

Possible Impacts:
			All module that reference BufToHexString or HexStringToBuf should be updated in the following step:
			  0) Change HiiLibGetCurrentLanguage to GetCurrentLanguage.
				1) Change BufToHexString to BufInReverseOrderToHexString 
			  2) Change HexStringToBuf to HexStringToBufInReverseOrder

EDK_6111:  Non-Compatible: qwang12
  Module type Include file is not included on default.
   In Protocol/PPI/GUID/Libary header file, the "#include" of the module type header file such as <Base.h>, <PiPei.h>, <PiDxe.h> and 
   <Uefi.h> are removed. The module (DXE driver, UEFI Driver, PEIM) should include these files if required.

Possible Impacts:
			Customer's module (DXE driver, UEFI Driver, PEIM) may failed to build as module type header file such as <Base.h>, <PiPei.h>, <PiDxe.h>
			<Uefi.h> is removed from the Protocol/PPI/GUID/Libary header file. If the module can build before the update but failed after the update
			because of some undefined basic data type such as "EFI_GUID", module developer should include the module type header file accordingly.
				
EDK_6131:  Non-Compatible: qwang12

Base on PI spec, GetPeiServicesTablePointer in PeiServicesTablePointer library is updated to return CONST EFI_PEI_SERVICES**. This is a incompatible changes. All file that reference this must be updated.

Possible Impacts:
			Customer's module that reference GetPeiServicesTablePointer in PeiServicesTablePointer library may need to updated. Otherwise
			a build break (mismatch of data type) may occur.
			
EDK_6307:  Non-Compatible: qwang12

Remove SafeFreePool from MemoryAllocationLib as this API's name is misleading. Its implementation only check if a pointer is NULL. If a garbage pointer is passed in, the gBS->FreePool will still ASSERT in debug build and return error code. 

It is recommended that module writer should keep track how a pointer is allocated and free it after use.

Possible Impacts:
			Customer's module that reference SafeFreePool need to updated. Otherwise
			a build break may occur.
			
EDK_6496-6519:  Non-Compatible: qhuang8

	A bundle of library class/instance renames, moves and merges:
	1.  Rename library class UsbLib to UefiUsbLib
	2.  Rename library class ScsiLib to UefiScsiLib
	3.  Rename library class PalCallLib to PalLib
	4.  Rename library class DxePiLib to DxeSerivcesLib and drop the prefix "PiLib" to all its APIs.
	5.  Merge library class PiPeiLib to PeiServicesLib and rename the PiLibInstallFvInfoPpi() to PeiServicesInstallFvInfoPpi()
	6.  Move library class HiiLib to MdeModulePkg
	7.  Move library class IfrSupportLib to MdeModulePkg
	8.  Move library class FvbServiceLib to MdeModulePkg
	9.  Rename library instance of BasePalCallLibNull to BasePalLibNull
	10. Move library instance UefiHiiLib to MdeModulePkg
	11. Move library instance UefiIfrSupportLib to MdeModulePkg

Possible Impacts:
	 Every change listed above is non-backward compatible for MdePkg and other packages. It is required to update module
	 sources (*.c;*.h), module meta data files (*.inf) and update the platform DSC files to fix the build break.
	 However, it is less likely to bring about functional issue for these updates.


EDK_6565:  Non-Compatible: qhuang8
	
	Remove some macro in UefiScsiLib:
	EFI_SCSI_STALL_1_MICROSECOND, EFI_SCSI_STALL_1_MILLISECOND, EFI_SCSI_STALL_1_SECOND & EFI_SCSI_STALL_SECONDS(a)  
	
Possible Impacts:
	Modules depending on UefiScsiLib for these macros should update the source to use new UefiLib macros
	EFI_TIMER_PERIOD_MICROSECONDS(X), EFI_TIMER_PERIOD_MILLISECONDS(X) and EFI_TIMER_PERIOD_SECONDS(X) for managing Timer Events.
	Especailly, EFI_SCSI_STALL_SECONDS(a) is simply replaced by EFI_TIMER_PERIOD_SECONDS(a)