AppleHibernate.c

Go to the documentation of this file.

 
#include <Guid/AppleVariable.h>
 
#include <IndustryStandard/AppleHibernate.h>
 
#include <Library/MemoryAllocationLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DevicePathLib.h>
#include <Library/OcBootManagementLib.h>
#include <Library/OcCryptoLib.h>
#include <Library/OcDevicePathLib.h>
#include <Library/OcDebugLogLib.h>
#include <Library/OcRtcLib.h>
#include <Library/UefiLib.h>
#include <Library/UefiRuntimeServicesTableLib.h>
 
EFI_STATUS
OcActivateHibernateWake (
  IN UINT32  HibernateMask
  )
{
  EFI_STATUS                Status;
  UINTN                     Size;
  UINT32                    Attributes;
  VOID                      *Value;
  AppleRTCHibernateVars     RtcVars;
  BOOLEAN                   HasHibernateInfo;
  BOOLEAN                   HasHibernateInfoInRTC;
  UINT8                     Index;
  UINT8                     *RtcRawVars;
  EFI_DEVICE_PATH_PROTOCOL  *BootImagePath;
  EFI_DEVICE_PATH_PROTOCOL  *RemainingPath;
  INTN                      NumPatchedNodes;
 
  if (HibernateMask == HIBERNATE_MODE_NONE) {
    return EFI_INVALID_PARAMETER;
  }
 
  HasHibernateInfo      = FALSE;
  HasHibernateInfoInRTC = FALSE;
 
  //
  // If legacy boot-switch-vars exists (NVRAM working), then use it.
  //
  Status = GetVariable2 (L"boot-switch-vars", &gAppleBootVariableGuid, &Value, &Size);
  if (!EFI_ERROR (Status)) {
    //
    // Leave it as is.
    //
    SecureZeroMem (Value, Size);
    FreePool (Value);
    DEBUG ((DEBUG_INFO, "OCB: Found legacy boot-switch-vars\n"));
    return EFI_SUCCESS;
  }
 
  Status = GetVariable3 (
             L"boot-image",
             &gAppleBootVariableGuid,
             (VOID **)&BootImagePath,
             &Size,
             &Attributes
             );
  if (!EFI_ERROR (Status)) {
    if (IsDevicePathValid (BootImagePath, Size)) {
      DebugPrintDevicePath (
        DEBUG_INFO,
        "OCB: boot-image pre-fix",
        BootImagePath
        );
 
      //
      // WARN: BootImagePath must be allocated from pool as it may be reallocated.
      //
      NumPatchedNodes = OcFixAppleBootDevicePath (
                          &BootImagePath,
                          &RemainingPath
                          );
      if (NumPatchedNodes > 0) {
        DebugPrintDevicePath (
          DEBUG_INFO,
          "OCB: boot-image post-fix",
          BootImagePath
          );
 
        //
        // Updated DevicePath may have different size.
        //
        Size = GetDevicePathSize (BootImagePath);
 
        Status = gRT->SetVariable (
                        L"boot-image",
                        &gAppleBootVariableGuid,
                        Attributes,
                        Size,
                        BootImagePath
                        );
      }
 
      if (NumPatchedNodes >= 0) {
        DebugPrintDevicePath (
          DEBUG_INFO,
          "OCB: boot-image post-fix remainder",
          RemainingPath
          );
      }
    } else {
      DEBUG ((DEBUG_INFO, "OCB: Invalid boot-image variable\n"));
    }
 
    SecureZeroMem (BootImagePath, Size);
    FreePool (BootImagePath);
  }
 
  DEBUG ((DEBUG_INFO, "OCB: boot-image is %u bytes - %r\n", (UINT32)Size, Status));
 
  RtcRawVars = (UINT8 *)&RtcVars;
 
  //
  // Work with RTC memory if allowed.
  //
  if (HibernateMask & HIBERNATE_MODE_RTC) {
    for (Index = 0; Index < sizeof (AppleRTCHibernateVars); Index++) {
      RtcRawVars[Index] = OcRtcRead (Index + 128);
    }
 
    HasHibernateInfoInRTC = RtcVars.signature[0] == 'A'
                            && RtcVars.signature[1] == 'A'
                            && RtcVars.signature[2] == 'P'
                            && RtcVars.signature[3] == 'L';
    HasHibernateInfo = HasHibernateInfoInRTC;
 
    DEBUG ((DEBUG_INFO, "OCB: RTC hibernation is %d\n", HasHibernateInfoInRTC));
  }
 
  if (HibernateMask & HIBERNATE_MODE_NVRAM) {
    //
    // If RTC variables is still written to NVRAM (and RTC is broken).
    // Prior to 10.13.6.
    //
    Status = GetVariable2 (L"IOHibernateRTCVariables", &gAppleBootVariableGuid, &Value, &Size);
    if (!HasHibernateInfo && !EFI_ERROR (Status) && (Size == sizeof (RtcVars))) {
      CopyMem (RtcRawVars, Value, sizeof (RtcVars));
      HasHibernateInfo = RtcVars.signature[0] == 'A'
                         && RtcVars.signature[1] == 'A'
                         && RtcVars.signature[2] == 'P'
                         && RtcVars.signature[3] == 'L';
    }
 
    DEBUG ((
      DEBUG_INFO,
      "OCB: NVRAM hibernation is %d / %r / %u\n",
      HasHibernateInfo,
      Status,
      (UINT32)Size
      ));
 
    //
    // Erase RTC variables in NVRAM.
    //
    if (!EFI_ERROR (Status)) {
      Status = gRT->SetVariable (
                      L"IOHibernateRTCVariables",
                      &gAppleBootVariableGuid,
                      EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
                      0,
                      NULL
                      );
      SecureZeroMem (Value, Size);
      FreePool (Value);
    }
  }
 
  //
  // Convert RTC data to boot-key and boot-signature
  //
  if (HasHibernateInfo) {
    gRT->SetVariable (
           L"boot-image-key",
           &gAppleBootVariableGuid,
           EFI_VARIABLE_BOOTSERVICE_ACCESS,
           sizeof (RtcVars.wiredCryptKey),
           RtcVars.wiredCryptKey
           );
    gRT->SetVariable (
           L"boot-signature",
           &gAppleBootVariableGuid,
           EFI_VARIABLE_BOOTSERVICE_ACCESS,
           sizeof (RtcVars.booterSignature),
           RtcVars.booterSignature
           );
  }
 
  //
  // Erase RTC memory similarly to AppleBds.
  //
  if (HasHibernateInfoInRTC) {
    SecureZeroMem (RtcRawVars, sizeof (AppleRTCHibernateVars));
    RtcVars.signature[0] = 'D';
    RtcVars.signature[1] = 'E';
    RtcVars.signature[2] = 'A';
    RtcVars.signature[3] = 'D';
 
    for (Index = 0; Index < sizeof (AppleRTCHibernateVars); Index++) {
      OcRtcWrite (Index + 128, RtcRawVars[Index]);
    }
  }
 
  //
  // We have everything we need now.
  //
  if (HasHibernateInfo) {
    return EFI_SUCCESS;
  }
 
  return EFI_NOT_FOUND;
}
 
BOOLEAN
OcIsAppleHibernateWake (
  VOID
  )
{
  EFI_STATUS  Status;
  UINTN       ValueSize;
 
  //
  // This is reverse engineered from boot.efi.
  // To cancel hibernate wake it is enough to delete the variables.
  // Starting with 10.13.6 boot-switch-vars is no longer supported.
  //
  ValueSize = 0;
  Status    = gRT->GetVariable (
                     L"boot-signature",
                     &gAppleBootVariableGuid,
                     NULL,
                     &ValueSize,
                     NULL
                     );
 
  if (Status == EFI_BUFFER_TOO_SMALL) {
    ValueSize = 0;
    Status    = gRT->GetVariable (
                       L"boot-image-key",
                       &gAppleBootVariableGuid,
                       NULL,
                       &ValueSize,
                       NULL
                       );
 
    if (Status == EFI_BUFFER_TOO_SMALL) {
      return TRUE;
    }
  } else {
    ValueSize = 0;
    Status    = gRT->GetVariable (
                       L"boot-switch-vars",
                       &gAppleBootVariableGuid,
                       NULL,
                       &ValueSize,
                       NULL
                       );
 
    if (Status == EFI_BUFFER_TOO_SMALL) {
      return TRUE;
    }
  }
 
  return FALSE;
}