https://bugzilla.tianocore.org/show_bug.cgi?id=1373 Replace BSD 2-Clause License with BSD+Patent License. This change is based on the following emails: https://lists.01.org/pipermail/edk2-devel/2019-February/036260.html https://lists.01.org/pipermail/edk2-devel/2018-October/030385.html RFCs with detailed process for the license change: V3: https://lists.01.org/pipermail/edk2-devel/2019-March/038116.html V2: https://lists.01.org/pipermail/edk2-devel/2019-March/037669.html V1: https://lists.01.org/pipermail/edk2-devel/2019-March/037500.html Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
		
			
				
	
	
		
			126 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			126 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /** @file
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| 
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|   Utility functions for serializing (persistently storing) and deserializing
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|   OVMF's platform configuration.
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| 
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|   Copyright (C) 2014, Red Hat, Inc.
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| 
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|   SPDX-License-Identifier: BSD-2-Clause-Patent
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| 
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| **/
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| 
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| #include <Library/BaseMemoryLib.h>
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| #include <Library/DebugLib.h>
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| #include <Library/MemoryAllocationLib.h>
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| #include <Library/UefiLib.h>
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| #include <Library/UefiRuntimeServicesTableLib.h>
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| #include <Guid/OvmfPlatformConfig.h>
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| 
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| #include "PlatformConfig.h"
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| 
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| //
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| // Name of the UEFI variable that we use for persistent storage.
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| //
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| STATIC CHAR16 mVariableName[] = L"PlatformConfig";
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| 
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| 
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| /**
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|   Serialize and persistently save platform configuration.
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| 
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|   @param[in] PlatformConfig  The platform configuration to serialize and save.
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| 
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|   @return  Status codes returned by gRT->SetVariable().
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| **/
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| EFI_STATUS
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| EFIAPI
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| PlatformConfigSave (
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|   IN PLATFORM_CONFIG *PlatformConfig
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|   )
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| {
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|   EFI_STATUS Status;
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| 
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|   //
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|   // We could implement any kind of translation here, as part of serialization.
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|   // For example, we could expose the platform configuration in separate
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|   // variables with human-readable contents, allowing other tools to access
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|   // them more easily. For now, just save a binary dump.
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|   //
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|   Status = gRT->SetVariable (mVariableName, &gOvmfPlatformConfigGuid,
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|                   EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS |
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|                     EFI_VARIABLE_RUNTIME_ACCESS,
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|                   sizeof *PlatformConfig, PlatformConfig);
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|   return Status;
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| }
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| 
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| 
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| /**
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|   Load and deserialize platform configuration.
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| 
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|   When the function fails, output parameters are indeterminate.
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| 
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|   @param[out] PlatformConfig    The platform configuration to receive the
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|                                 loaded data.
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| 
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|   @param[out] OptionalElements  This bitmap describes the presence of optional
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|                                 configuration elements that have been loaded.
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|                                 PLATFORM_CONFIG_F_DOWNGRADE means that some
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|                                 unknown elements, present in the wire format,
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|                                 have been ignored.
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| 
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|   @retval  EFI_SUCCESS         Loading & deserialization successful.
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|   @return                      Error codes returned by GetVariable2().
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| **/
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| EFI_STATUS
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| EFIAPI
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| PlatformConfigLoad (
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|   OUT PLATFORM_CONFIG *PlatformConfig,
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|   OUT UINT64          *OptionalElements
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|   )
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| {
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|   VOID       *Data;
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|   UINTN      DataSize;
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|   EFI_STATUS Status;
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| 
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|   //
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|   // Any translation done in PlatformConfigSave() would have to be mirrored
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|   // here. For now, just load the binary dump.
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|   //
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|   // Versioning of the binary wire format is implemented based on size
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|   // (only incremental changes, ie. new fields), and on GUID.
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|   // (Incompatible changes require a GUID change.)
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|   //
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|   Status = GetVariable2 (mVariableName, &gOvmfPlatformConfigGuid, &Data,
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|              &DataSize);
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|   if (EFI_ERROR (Status)) {
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|     return Status;
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|   }
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| 
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|   *OptionalElements = 0;
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|   if (DataSize > sizeof *PlatformConfig) {
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|     //
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|     // Handle firmware downgrade -- keep only leading part.
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|     //
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|     CopyMem (PlatformConfig, Data, sizeof *PlatformConfig);
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|     *OptionalElements |= PLATFORM_CONFIG_F_DOWNGRADE;
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|   } else {
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|     CopyMem (PlatformConfig, Data, DataSize);
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| 
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|     //
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|     // Handle firmware upgrade -- zero out missing fields.
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|     //
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|     ZeroMem ((UINT8 *)PlatformConfig + DataSize,
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|       sizeof *PlatformConfig - DataSize);
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|   }
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| 
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|   //
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|   // Based on DataSize, report the optional features that we recognize.
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|   //
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|   if (DataSize >= (OFFSET_OF (PLATFORM_CONFIG, VerticalResolution) +
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|                    sizeof PlatformConfig->VerticalResolution)) {
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|     *OptionalElements |= PLATFORM_CONFIG_F_GRAPHICS_RESOLUTION;
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|   }
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| 
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|   FreePool (Data);
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|   return EFI_SUCCESS;
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| }
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