UEFI 各階段資料的傳遞方式

  將bios 選單變數(ex: SetupData.my_var)傳遞到PEI及DXE的方法

  //
  // PEI 接收資料
  //
  Status = (*PeiServices)->LocatePpi (
                          PeiServices,
                          &gEfiPeiReadOnlyVariablePpiGuid,
                          0,
                          NULL,
                          &ReadOnlyVariable
                          );
                          
  ASSERT_PEI_ERROR (PeiServices, Status);
  VariableSize = sizeof (SETUP_DATA);
  
  Status = ReadOnlyVariable->GetVariable (
                            PeiServices,
                            L"Setup",
                            &gEfiSetupGuid,
                            NULL,
                            &VariableSize,
                            &SetupData
                            );
                            
  if (EFI_ERROR (Status)) 
      return;

// DXE 接收資料
 //
 Status = gRT->GetVariable(
                  L"Setup", 
                  &gSetupGuid, 
                  NULL,
                  &VariableSize, 
                  &SetupData
                );

 if (EFI_ERROR (Status)) 
       return;

設定變數方法

 // 先建好資料結構，並給予GUID

#define VSENSOR_GUID \
    { 0xAEA3956D, 0x738, 0x4087, { 0xB4, 0x96, 0xB1, 0x1E, 0x85, 0xE2, 0x85, 0x96 }
EFI_GUID VSensor_Guid = VSENSOR_GUID; 
  
  typedef struct {
              UINT8    data;
  } VSENSOR_INFO;
 
  VSENSOR_INFO VSensor;
  
  VSensor.data = 0; // 要存的資料
  // 設定變數GUID
  Status = pRS->SetVariable (
                             L"VSENSOR_INFO",
                             &VSensor_Guid,
                             EFI_VARIABLE_NON_VOLATILE | 
                             EFI_VARIABLE_BOOTSERVICE_ACCESS | 
                             EFI_VARIABLE_RUNTIME_ACCESS,
                             sizeof(VSENSOR_INFO),
                             &VSensor
                          );