VariableDxe.c

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#include "Variable.h"
 
#include <Protocol/VariablePolicy.h>
#include <Library/VariablePolicyLib.h>
 
EFI_STATUS
EFIAPI
ProtocolIsVariablePolicyEnabled (
  OUT BOOLEAN  *State
  );
 
EFI_HANDLE                      mHandle                      = NULL;
EFI_EVENT                       mVirtualAddressChangeEvent   = NULL;
VOID                            *mFtwRegistration            = NULL;
VOID                            ***mVarCheckAddressPointer   = NULL;
UINTN                           mVarCheckAddressPointerCount = 0;
EDKII_VARIABLE_LOCK_PROTOCOL    mVariableLock                = { VariableLockRequestToLock };
EDKII_VARIABLE_POLICY_PROTOCOL  mVariablePolicyProtocol      = {
  EDKII_VARIABLE_POLICY_PROTOCOL_REVISION,
  DisableVariablePolicy,
  ProtocolIsVariablePolicyEnabled,
  RegisterVariablePolicy,
  DumpVariablePolicy,
  LockVariablePolicy
};
EDKII_VAR_CHECK_PROTOCOL        mVarCheck = {
  VarCheckRegisterSetVariableCheckHandler,
  VarCheckVariablePropertySet,
  VarCheckVariablePropertyGet
};
 
STATIC EFI_GUID  mAcpiGlobalVariableGuid = {
  0xAF9FFD67, 0xEC10, 0x488A, { 0x9D, 0xFC, 0x6C, 0xBF, 0x5E, 0xE2, 0x2C, 0x2E }
};
 
STATIC
VOID *
  mAcpiGlobalVariable = NULL;
 
STATIC
UINT32
  mAcpiGlobalVariableAttributes;
 
VOID
EFIAPI
RecordSecureBootPolicyVarData (
  VOID
  );
 
BOOLEAN
AtRuntime (
  VOID
  )
{
  return EfiAtRuntime ();
}
 
EFI_LOCK *
InitializeLock (
  IN OUT EFI_LOCK  *Lock,
  IN     EFI_TPL   Priority
  )
{
  return EfiInitializeLock (Lock, Priority);
}
 
VOID
AcquireLockOnlyAtBootTime (
  IN EFI_LOCK  *Lock
  )
{
  if (!AtRuntime ()) {
    EfiAcquireLock (Lock);
  }
}
 
VOID
ReleaseLockOnlyAtBootTime (
  IN EFI_LOCK  *Lock
  )
{
  if (!AtRuntime ()) {
    EfiReleaseLock (Lock);
  }
}
 
EFI_STATUS
GetFtwProtocol (
  OUT VOID  **FtwProtocol
  )
{
  EFI_STATUS  Status;
 
  //
  // Locate Fault Tolerent Write protocol
  //
  Status = gBS->LocateProtocol (
                  &gEfiFaultTolerantWriteProtocolGuid,
                  NULL,
                  FtwProtocol
                  );
  return Status;
}
 
EFI_STATUS
GetFvbByHandle (
  IN  EFI_HANDLE                          FvBlockHandle,
  OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  **FvBlock
  )
{
  //
  // To get the FVB protocol interface on the handle
  //
  return gBS->HandleProtocol (
                FvBlockHandle,
                &gEfiFirmwareVolumeBlockProtocolGuid,
                (VOID **)FvBlock
                );
}
 
EFI_STATUS
GetFvbCountAndBuffer (
  OUT UINTN       *NumberHandles,
  OUT EFI_HANDLE  **Buffer
  )
{
  EFI_STATUS  Status;
 
  //
  // Locate all handles of Fvb protocol
  //
  Status = gBS->LocateHandleBuffer (
                  ByProtocol,
                  &gEfiFirmwareVolumeBlockProtocolGuid,
                  NULL,
                  NumberHandles,
                  Buffer
                  );
  return Status;
}
 
VOID
EFIAPI
VariableClassAddressChangeEvent (
  IN EFI_EVENT  Event,
  IN VOID       *Context
  )
{
  UINTN  Index;
 
  if (mVariableModuleGlobal->FvbInstance != NULL) {
    EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->FvbInstance->GetBlockSize);
    EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->FvbInstance->GetPhysicalAddress);
    EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->FvbInstance->GetAttributes);
    EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->FvbInstance->SetAttributes);
    EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->FvbInstance->Read);
    EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->FvbInstance->Write);
    EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->FvbInstance->EraseBlocks);
    EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->FvbInstance);
  }
 
  EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->PlatformLangCodes);
  EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->LangCodes);
  EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->PlatformLang);
  EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->VariableGlobal.NonVolatileVariableBase);
  EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->VariableGlobal.VolatileVariableBase);
  EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal->VariableGlobal.HobVariableBase);
  EfiConvertPointer (0x0, (VOID **)&mVariableModuleGlobal);
  EfiConvertPointer (0x0, (VOID **)&mNvVariableCache);
  EfiConvertPointer (0x0, (VOID **)&mNvFvHeaderCache);
 
  if (mAuthContextOut.AddressPointer != NULL) {
    for (Index = 0; Index < mAuthContextOut.AddressPointerCount; Index++) {
      EfiConvertPointer (0x0, (VOID **)mAuthContextOut.AddressPointer[Index]);
    }
  }
 
  if (mVarCheckAddressPointer != NULL) {
    for (Index = 0; Index < mVarCheckAddressPointerCount; Index++) {
      EfiConvertPointer (0x0, (VOID **)mVarCheckAddressPointer[Index]);
    }
  }
}
 
VOID
EFIAPI
OnReadyToBoot (
  EFI_EVENT  Event,
  VOID       *Context
  )
{
  EFI_STATUS  Status;
 
  if (!mEndOfDxe) {
    MorLockInitAtEndOfDxe ();
 
    Status = LockVariablePolicy ();
    ASSERT_EFI_ERROR (Status);
    //
    // Set the End Of DXE bit in case the EFI_END_OF_DXE_EVENT_GROUP_GUID event is not signaled.
    //
    mEndOfDxe               = TRUE;
    mVarCheckAddressPointer = VarCheckLibInitializeAtEndOfDxe (&mVarCheckAddressPointerCount);
    //
    // The initialization for variable quota.
    //
    InitializeVariableQuota ();
  }
 
  ReclaimForOS ();
  if (FeaturePcdGet (PcdVariableCollectStatistics)) {
    if (mVariableModuleGlobal->VariableGlobal.AuthFormat) {
      gBS->InstallConfigurationTable (&gEfiAuthenticatedVariableGuid, gVariableInfo);
    } else {
      gBS->InstallConfigurationTable (&gEfiVariableGuid, gVariableInfo);
    }
  }
 
  gBS->CloseEvent (Event);
}
 
VOID
EFIAPI
OnEndOfDxe (
  EFI_EVENT  Event,
  VOID       *Context
  )
{
  EFI_STATUS  Status;
 
  DEBUG ((DEBUG_INFO, "[Variable]END_OF_DXE is signaled\n"));
  MorLockInitAtEndOfDxe ();
  Status = LockVariablePolicy ();
  ASSERT_EFI_ERROR (Status);
  mEndOfDxe               = TRUE;
  mVarCheckAddressPointer = VarCheckLibInitializeAtEndOfDxe (&mVarCheckAddressPointerCount);
  //
  // The initialization for variable quota.
  //
  InitializeVariableQuota ();
  if (PcdGetBool (PcdReclaimVariableSpaceAtEndOfDxe)) {
    ReclaimForOS ();
  }
 
  gBS->CloseEvent (Event);
}
 
VOID
VariableWriteServiceInitializeDxe (
  VOID
  )
{
  EFI_STATUS  Status;
 
  Status = VariableWriteServiceInitialize ();
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Variable write service initialization failed. Status = %r\n", Status));
  }
 
  //
  // Some Secure Boot Policy Var (SecureBoot, etc) updates following other
  // Secure Boot Policy Variable change. Record their initial value.
  //
  RecordSecureBootPolicyVarData ();
 
  //
  // Install the Variable Write Architectural protocol.
  //
  Status = gBS->InstallProtocolInterface (
                  &mHandle,
                  &gEfiVariableWriteArchProtocolGuid,
                  EFI_NATIVE_INTERFACE,
                  NULL
                  );
  ASSERT_EFI_ERROR (Status);
}
 
VOID
EFIAPI
FtwNotificationEvent (
  IN  EFI_EVENT  Event,
  IN  VOID       *Context
  )
{
  EFI_STATUS                          Status;
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *FvbProtocol;
  EFI_FAULT_TOLERANT_WRITE_PROTOCOL   *FtwProtocol;
  EFI_PHYSICAL_ADDRESS                NvStorageVariableBase;
  EFI_GCD_MEMORY_SPACE_DESCRIPTOR     GcdDescriptor;
  EFI_PHYSICAL_ADDRESS                BaseAddress;
  UINT64                              Length;
  EFI_PHYSICAL_ADDRESS                VariableStoreBase;
  UINT64                              VariableStoreLength;
  UINTN                               FtwMaxBlockSize;
 
  //
  // Ensure FTW protocol is installed.
  //
  Status = GetFtwProtocol ((VOID **)&FtwProtocol);
  if (EFI_ERROR (Status)) {
    return;
  }
 
  Status = FtwProtocol->GetMaxBlockSize (FtwProtocol, &FtwMaxBlockSize);
  if (!EFI_ERROR (Status)) {
    ASSERT (PcdGet32 (PcdFlashNvStorageVariableSize) <= FtwMaxBlockSize);
  }
 
  NvStorageVariableBase = NV_STORAGE_VARIABLE_BASE;
  VariableStoreBase     = NvStorageVariableBase + mNvFvHeaderCache->HeaderLength;
 
  //
  // Let NonVolatileVariableBase point to flash variable store base directly after FTW ready.
  //
  mVariableModuleGlobal->VariableGlobal.NonVolatileVariableBase = VariableStoreBase;
 
  //
  // Find the proper FVB protocol for variable.
  //
  Status = GetFvbInfoByAddress (NvStorageVariableBase, NULL, &FvbProtocol);
  if (EFI_ERROR (Status)) {
    return;
  }
 
  mVariableModuleGlobal->FvbInstance = FvbProtocol;
 
  //
  // Mark the variable storage region of the FLASH as RUNTIME.
  //
  VariableStoreLength = mNvVariableCache->Size;
  BaseAddress         = VariableStoreBase & (~EFI_PAGE_MASK);
  Length              = VariableStoreLength + (VariableStoreBase - BaseAddress);
  Length              = (Length + EFI_PAGE_SIZE - 1) & (~EFI_PAGE_MASK);
 
  Status = gDS->GetMemorySpaceDescriptor (BaseAddress, &GcdDescriptor);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_WARN, "Variable driver failed to get flash memory attribute.\n"));
  } else {
    if ((GcdDescriptor.Attributes & EFI_MEMORY_RUNTIME) == 0) {
      Status = gDS->SetMemorySpaceAttributes (
                      BaseAddress,
                      Length,
                      GcdDescriptor.Attributes | EFI_MEMORY_RUNTIME
                      );
      if (EFI_ERROR (Status)) {
        DEBUG ((DEBUG_WARN, "Variable driver failed to add EFI_MEMORY_RUNTIME attribute to Flash.\n"));
      }
    }
  }
 
  //
  // Initializes variable write service after FTW was ready.
  //
  VariableWriteServiceInitializeDxe ();
 
  //
  // Close the notify event to avoid install gEfiVariableWriteArchProtocolGuid again.
  //
  gBS->CloseEvent (Event);
}
 
EFI_STATUS
EFIAPI
ProtocolIsVariablePolicyEnabled (
  OUT BOOLEAN  *State
  )
{
  *State = IsVariablePolicyEnabled ();
  return EFI_SUCCESS;
}
 
STATIC
EFI_STATUS
EFIAPI
MapCreateEventEx (
  IN       UINT32            Type,
  IN       EFI_TPL           NotifyTpl,
  IN       EFI_EVENT_NOTIFY  NotifyFunction OPTIONAL,
  IN CONST VOID              *NotifyContext OPTIONAL,
  IN CONST EFI_GUID          *EventGroup    OPTIONAL,
  OUT      EFI_EVENT         *Event
  )
{
  EFI_STATUS  Status;
 
  Status = EFI_UNSUPPORTED;
 
  if (Type == EVT_NOTIFY_SIGNAL) {
    if (CompareGuid (EventGroup, &gEfiEventVirtualAddressChangeGuid)) {
      Type   = EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE;
      Status = EFI_SUCCESS;
    }
  }
 
  if (EFI_ERROR (Status)) {
    return Status;
  }
 
  return gBS->CreateEvent (
                Type,
                NotifyTpl,
                NotifyFunction,
                (VOID *)NotifyContext,
                Event
                );
}
 
STATIC
VOID
SaveAcpiGlobalVariable (
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS  Status;
  UINTN       DataSize;
  VOID        *Interface;
 
  Status = gBS->LocateProtocol (&gEfiVariableArchProtocolGuid, NULL, &Interface);
 
  if (!EFI_ERROR (Status)) {
    //
    // If present, we must transfer this into emulated NVRAM in order for wake from S3 sleep to work.
    //
    DataSize = sizeof (mAcpiGlobalVariable);
    Status   = SystemTable->RuntimeServices->GetVariable (
                                               L"AcpiGlobalVariable",
                                               &mAcpiGlobalVariableGuid,
                                               &mAcpiGlobalVariableAttributes,
                                               &DataSize,
                                               &mAcpiGlobalVariable
                                               );
 
    if (EFI_ERROR (Status)) {
      mAcpiGlobalVariable = NULL;
    }
 
    DEBUG ((
      EFI_ERROR (Status) && Status != EFI_NOT_FOUND ? DEBUG_WARN : DEBUG_INFO,
      "Existing AcpiGlobalVariable %p 0x%x - %r\n",
      mAcpiGlobalVariable,
      mAcpiGlobalVariableAttributes,
      Status
      ));
  }
}
 
STATIC
VOID
RestoreAcpiGlobalVariable (
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS  Status;
 
  if (mAcpiGlobalVariable != NULL) {
    Status = SystemTable->RuntimeServices->SetVariable (
                                             L"AcpiGlobalVariable",
                                             &mAcpiGlobalVariableGuid,
                                             mAcpiGlobalVariableAttributes,
                                             sizeof (mAcpiGlobalVariable),
                                             &mAcpiGlobalVariable
                                             );
 
    DEBUG ((
      EFI_ERROR (Status) ? DEBUG_WARN : DEBUG_INFO,
      "Transfer AcpiGlobalVariable to emulated NVRAM - %r\n",
      Status
      ));
  }
}
 
EFI_STATUS
EFIAPI
VariableServiceInitialize (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS           Status;
  EFI_EVENT            ReadyToBootEvent;
  EFI_EVENT            EndOfDxeEvent;
  EFI_CREATE_EVENT_EX  OriginalCreateEventEx;
 
  SaveAcpiGlobalVariable (SystemTable);
 
  //
  // Probably worth noting that attempting to remove any pre-existing protocols here
  // before installing them below seems to cause problems rather than solving them.
  //
 
  Status = VariableCommonInitialize ();
  ASSERT_EFI_ERROR (Status);
 
  Status = gBS->InstallMultipleProtocolInterfaces (
                  &mHandle,
                  &gEdkiiVariableLockProtocolGuid,
                  &mVariableLock,
                  NULL
                  );
  ASSERT_EFI_ERROR (Status);
 
  Status = gBS->InstallMultipleProtocolInterfaces (
                  &mHandle,
                  &gEdkiiVarCheckProtocolGuid,
                  &mVarCheck,
                  NULL
                  );
  ASSERT_EFI_ERROR (Status);
 
  SystemTable->RuntimeServices->GetVariable         = VariableServiceGetVariable;
  SystemTable->RuntimeServices->GetNextVariableName = VariableServiceGetNextVariableName;
  SystemTable->RuntimeServices->SetVariable         = VariableServiceSetVariable;
  //
  // Avoid setting UEFI 2.x interface member on EFI 1.x.
  //
  // Note 1: It is always desirable to overwrite the value here if it already exists:
  //         we need a consistent runtime variable implementation.
  //
  // Note 2: We ignore the theoretical situation where some other spoofer has modified
  //         the gRT header revision but not allocated sufficient space for this method,
  //         since this is a highly theoretical 'problem', and providing a solution for
  //         it over-complicates the code, instead of just over-complicating this comment.
  //
  if (SystemTable->RuntimeServices->Hdr.Revision >= EFI_2_00_SYSTEM_TABLE_REVISION) {
    SystemTable->RuntimeServices->QueryVariableInfo = VariableServiceQueryVariableInfo;
  }
 
  //
  // Now install the Variable Runtime Architectural protocol on a new handle.
  // When we reinstall this on newer Apple firmware then the three runtime services functions
  // above get preserved, but wrapped by additional Apple security, which is believed to have
  // desirable functionality, e.g. possibility of writing variables to different stores,
  // allowing them to have intended effect.
  //
  Status = gBS->InstallProtocolInterface (
                  &mHandle,
                  &gEfiVariableArchProtocolGuid,
                  EFI_NATIVE_INTERFACE,
                  NULL
                  );
 
  ASSERT_EFI_ERROR (Status);
 
  if (!PcdGetBool (PcdEmuVariableNvModeEnable)) {
    //
    // Register FtwNotificationEvent () notify function.
    //
    EfiCreateProtocolNotifyEvent (
      &gEfiFaultTolerantWriteProtocolGuid,
      TPL_CALLBACK,
      FtwNotificationEvent,
      (VOID *)SystemTable,
      &mFtwRegistration
      );
  } else {
    //
    // Emulated non-volatile variable mode does not depend on FVB and FTW.
    //
    VariableWriteServiceInitializeDxe ();
 
    RestoreAcpiGlobalVariable (SystemTable);
  }
 
  OriginalCreateEventEx = gBS->CreateEventEx;
  gBS->CreateEventEx    = MapCreateEventEx;
 
  Status = gBS->CreateEventEx (
                  EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  VariableClassAddressChangeEvent,
                  NULL,
                  &gEfiEventVirtualAddressChangeGuid,
                  &mVirtualAddressChangeEvent
                  );
  ASSERT_EFI_ERROR (Status);
 
  //
  // Register the event handling function to reclaim variable for OS usage.
  //
  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  OnReadyToBoot,
                  NULL,
                  &ReadyToBootEvent
                  );
  ASSERT_EFI_ERROR (Status);
 
  //
  // Register the event handling function to set the End Of DXE flag.
  //
  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL,
                  TPL_CALLBACK,
                  OnEndOfDxe,
                  NULL,
                  &EndOfDxeEvent
                  );
  ASSERT_EFI_ERROR (Status);
 
  // Register and initialize the VariablePolicy engine.
  Status = InitVariablePolicyLib (VariableServiceGetVariable);
  ASSERT_EFI_ERROR (Status);
  Status = VarCheckRegisterSetVariableCheckHandler (ValidateSetVariable);
  ASSERT_EFI_ERROR (Status);
  Status = gBS->InstallMultipleProtocolInterfaces (
                  &mHandle,
                  &gEdkiiVariablePolicyProtocolGuid,
                  &mVariablePolicyProtocol,
                  NULL
                  );
  ASSERT_EFI_ERROR (Status);
 
  gBS->CreateEventEx = OriginalCreateEventEx;
 
  // Signal events immediately. These events occur in this order and before
  // OpenCore is loaded when the equivalent driver is part of OpenDuet.
  gBS->SignalEvent (EndOfDxeEvent);
  gBS->SignalEvent (ReadyToBootEvent);
 
  return EFI_SUCCESS;
}