system76-edk2/MdeModulePkg/Core/RuntimeDxe/Runtime.c

/** @file
  This file implements Runtime Architectural Protocol as defined in the
  Platform Initialization specification 1.0 VOLUME 2 DXE Core Interface.

  This code is used to produce the EFI runtime virtual switch over

  THIS IS VERY DANGEROUS CODE BE VERY CAREFUL IF YOU CHANGE IT

  The transition for calling EFI Runtime functions in physical mode to calling
  them in virtual mode is very very complex. Every pointer in needs to be
  converted from physical mode to virtual mode. Be very careful walking linked
  lists! Then to make it really hard the code it's self needs be relocated into
  the new virtual address space.

  So here is the concept. The code in this module will never ever be called in
  virtual mode. This is the code that collects the information needed to convert
  to virtual mode (DXE core registers runtime stuff with this code). Since this
  code is used to fix up all runtime images, it CAN NOT fix it's self up. So some
  code has to stay behind and that is us.

  Also you need to be careful about when you allocate memory, as once we are in
  runtime (including our EVT_SIGNAL_EXIT_BOOT_SERVICES event) you can no longer
  allocate memory.

  Any runtime driver that gets loaded before us will not be callable in virtual
  mode. This is due to the fact that the DXE core can not register the info
  needed with us. This is good, since it keeps the code in this file from
  getting registered.


Revision History:

  - Move the CalculateCrc32 function from Runtime Arch Protocol to Boot Service.
  Runtime Arch Protocol definition no longer contains CalculateCrc32. Boot Service
  Table now contains an item named CalculateCrc32.


Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "Runtime.h"

//
// Global Variables
//
EFI_MEMORY_DESCRIPTOR  *mVirtualMap = NULL;
UINTN                  mVirtualMapDescriptorSize;
UINTN                  mVirtualMapMaxIndex;
VOID                   *mMyImageBase;

//
// The handle onto which the Runtime Architectural Protocol instance is installed
//
EFI_HANDLE  mRuntimeHandle = NULL;

//
// The Runtime Architectural Protocol instance produced by this driver
//
EFI_RUNTIME_ARCH_PROTOCOL  mRuntime = {
  INITIALIZE_LIST_HEAD_VARIABLE (mRuntime.ImageHead),
  INITIALIZE_LIST_HEAD_VARIABLE (mRuntime.EventHead),

  //
  // Make sure Size != sizeof (EFI_MEMORY_DESCRIPTOR). This will
  // prevent people from having pointer math bugs in their code.
  // now you have to use *DescriptorSize to make things work.
  //
  sizeof (EFI_MEMORY_DESCRIPTOR) + sizeof (UINT64) - (sizeof (EFI_MEMORY_DESCRIPTOR) % sizeof (UINT64)),
  EFI_MEMORY_DESCRIPTOR_VERSION,
  0,
  NULL,
  NULL,
  FALSE,
  FALSE
};

//
// Worker Functions
//

/**

  Calculate the 32-bit CRC in a EFI table using the Runtime Drivers
  internal function.  The EFI Boot Services Table can not be used because
  the EFI Boot Services Table was destroyed at ExitBootServices().
  This is a internal function.


  @param Hdr             Pointer to an EFI standard header

**/
VOID
RuntimeDriverCalculateEfiHdrCrc (
  IN OUT EFI_TABLE_HEADER  *Hdr
  )
{
  UINT32  Crc;

  Hdr->CRC32 = 0;

  Crc = 0;
  RuntimeDriverCalculateCrc32 ((UINT8 *)Hdr, Hdr->HeaderSize, &Crc);
  Hdr->CRC32 = Crc;
}

/**

  Determines the new virtual address that is to be used on subsequent memory accesses.


  @param DebugDisposition Supplies type information for the pointer being converted.
  @param ConvertAddress  A pointer to a pointer that is to be fixed to be the value needed
                         for the new virtual address mappings being applied.

  @retval  EFI_SUCCESS              The pointer pointed to by Address was modified.
  @retval  EFI_NOT_FOUND            The pointer pointed to by Address was not found to be part
                                    of the current memory map. This is normally fatal.
  @retval  EFI_INVALID_PARAMETER    1) Address is NULL.
                                    2) *Address is NULL and DebugDisposition does
                                    not have the EFI_OPTIONAL_PTR bit set.
  @retval  EFI_UNSUPPORTED          This call is not supported by this platform at the time the call is made.
                                    The platform should describe this runtime service as unsupported at runtime
                                    via an EFI_RT_PROPERTIES_TABLE configuration table.

**/
EFI_STATUS
EFIAPI
RuntimeDriverConvertPointer (
  IN     UINTN  DebugDisposition,
  IN OUT VOID   **ConvertAddress
  )
{
  UINTN                  Address;
  UINT64                 VirtEndOfRange;
  EFI_MEMORY_DESCRIPTOR  *VirtEntry;
  UINTN                  Index;

  //
  // Make sure ConvertAddress is a valid pointer
  //
  if (ConvertAddress == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Get the address to convert
  //
  Address = (UINTN)*ConvertAddress;

  //
  // If this is a null pointer, return if it's allowed
  //
  if (Address == 0) {
    if ((DebugDisposition & EFI_OPTIONAL_PTR) != 0) {
      return EFI_SUCCESS;
    }

    return EFI_INVALID_PARAMETER;
  }

  VirtEntry = mVirtualMap;
  for (Index = 0; Index < mVirtualMapMaxIndex; Index++) {
    //
    //  To prevent the inclusion of 64-bit math functions a UINTN was placed in
    //  front of VirtEntry->NumberOfPages to cast it to a 32-bit thing on IA-32
    //  platforms. If you get this ASSERT remove the UINTN and do a 64-bit
    //  multiply.
    //
    ASSERT (((UINTN)VirtEntry->NumberOfPages < 0xffffffff) || (sizeof (UINTN) > 4));

    if ((VirtEntry->Attribute & EFI_MEMORY_RUNTIME) == EFI_MEMORY_RUNTIME) {
      if (Address >= VirtEntry->PhysicalStart) {
        VirtEndOfRange = VirtEntry->PhysicalStart + (((UINTN)VirtEntry->NumberOfPages) * EFI_PAGE_SIZE);
        if (Address < VirtEndOfRange) {
          //
          // Compute new address
          //
          *ConvertAddress = (VOID *)(Address - (UINTN)VirtEntry->PhysicalStart + (UINTN)VirtEntry->VirtualStart);
          return EFI_SUCCESS;
        }
      }
    }

    VirtEntry = NEXT_MEMORY_DESCRIPTOR (VirtEntry, mVirtualMapDescriptorSize);
  }

  return EFI_NOT_FOUND;
}

/**

  Determines the new virtual address that is to be used on subsequent memory accesses
  for internal pointers.
  This is a internal function.


  @param ConvertAddress  A pointer to a pointer that is to be fixed to be the value needed
                         for the new virtual address mappings being applied.

  @retval  EFI_SUCCESS              The pointer pointed to by Address was modified.
  @retval  EFI_NOT_FOUND            The pointer pointed to by Address was not found to be part
                                    of the current memory map. This is normally fatal.
  @retval  EFI_INVALID_PARAMETER    One of the parameters has an invalid value.

**/
EFI_STATUS
RuntimeDriverConvertInternalPointer (
  IN OUT VOID  **ConvertAddress
  )
{
  return RuntimeDriverConvertPointer (0x0, ConvertAddress);
}

/**

  Changes the runtime addressing mode of EFI firmware from physical to virtual.


  @param MemoryMapSize   The size in bytes of VirtualMap.
  @param DescriptorSize  The size in bytes of an entry in the VirtualMap.
  @param DescriptorVersion The version of the structure entries in VirtualMap.
  @param VirtualMap      An array of memory descriptors which contain new virtual
                         address mapping information for all runtime ranges.

  @retval  EFI_SUCCESS            The virtual address map has been applied.
  @retval  EFI_UNSUPPORTED        EFI firmware is not at runtime, or the EFI firmware is already in
                                  virtual address mapped mode.
  @retval  EFI_INVALID_PARAMETER  DescriptorSize or DescriptorVersion is invalid.
  @retval  EFI_NO_MAPPING         A virtual address was not supplied for a range in the memory
                                  map that requires a mapping.
  @retval  EFI_NOT_FOUND          A virtual address was supplied for an address that is not found
                                  in the memory map.
  @retval  EFI_UNSUPPORTED        This call is not supported by this platform at the time the call is made.
                                  The platform should describe this runtime service as unsupported at runtime
                                  via an EFI_RT_PROPERTIES_TABLE configuration table.

**/
EFI_STATUS
EFIAPI
RuntimeDriverSetVirtualAddressMap (
  IN UINTN                  MemoryMapSize,
  IN UINTN                  DescriptorSize,
  IN UINT32                 DescriptorVersion,
  IN EFI_MEMORY_DESCRIPTOR  *VirtualMap
  )
{
  EFI_STATUS               Status;
  EFI_RUNTIME_EVENT_ENTRY  *RuntimeEvent;
  EFI_RUNTIME_IMAGE_ENTRY  *RuntimeImage;
  LIST_ENTRY               *Link;
  EFI_PHYSICAL_ADDRESS     VirtImageBase;

  //
  // Can only switch to virtual addresses once the memory map is locked down,
  // and can only set it once
  //
  if (!mRuntime.AtRuntime || mRuntime.VirtualMode) {
    return EFI_UNSUPPORTED;
  }

  //
  // Only understand the original descriptor format
  //
  if ((DescriptorVersion != EFI_MEMORY_DESCRIPTOR_VERSION) || (DescriptorSize < sizeof (EFI_MEMORY_DESCRIPTOR))) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // We are now committed to go to virtual mode, so lets get to it!
  //
  mRuntime.VirtualMode = TRUE;

  //
  // ConvertPointer() needs this mVirtualMap to do the conversion. So set up
  // globals we need to parse the virtual address map.
  //
  mVirtualMapDescriptorSize = DescriptorSize;
  mVirtualMapMaxIndex       = MemoryMapSize / DescriptorSize;
  mVirtualMap               = VirtualMap;

  //
  // ReporstStatusCodeLib will check and make sure this service can be called in runtime mode.
  //
  REPORT_STATUS_CODE (EFI_PROGRESS_CODE, (EFI_SOFTWARE_EFI_RUNTIME_SERVICE | EFI_SW_RS_PC_SET_VIRTUAL_ADDRESS_MAP));

  //
  // Report Status Code here since EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE event will be signalled.
  //
  REPORT_STATUS_CODE (EFI_PROGRESS_CODE, (EFI_SOFTWARE_DXE_BS_DRIVER | EFI_SW_DXE_BS_PC_VIRTUAL_ADDRESS_CHANGE_EVENT));

  //
  // Signal all the EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE events.
  // All runtime events are stored in a list in Runtime AP.
  //
  for (Link = mRuntime.EventHead.ForwardLink; Link != &mRuntime.EventHead; Link = Link->ForwardLink) {
    RuntimeEvent = BASE_CR (Link, EFI_RUNTIME_EVENT_ENTRY, Link);
    if ((RuntimeEvent->Type & EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE) == EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE) {
      //
      // Work around the bug in the Platform Init specification (v1.7),
      // reported as Mantis#2017: "EFI_RUNTIME_EVENT_ENTRY.Event" should have
      // type EFI_EVENT, not (EFI_EVENT*). The PI spec documents the field
      // correctly as "The EFI_EVENT returned by CreateEvent()", but the type
      // of the field doesn't match the natural language description. Therefore
      // we need an explicit cast here.
      //
      RuntimeEvent->NotifyFunction (
                      (EFI_EVENT)RuntimeEvent->Event,
                      RuntimeEvent->NotifyContext
                      );
    }
  }

  //
  // Relocate runtime images. All runtime images are stored in a list in Runtime AP.
  //
  for (Link = mRuntime.ImageHead.ForwardLink; Link != &mRuntime.ImageHead; Link = Link->ForwardLink) {
    RuntimeImage = BASE_CR (Link, EFI_RUNTIME_IMAGE_ENTRY, Link);
    //
    // We don't want to relocate our selves, as we only run in physical mode.
    //
    if (mMyImageBase != RuntimeImage->ImageBase) {
      VirtImageBase = (EFI_PHYSICAL_ADDRESS)(UINTN)RuntimeImage->ImageBase;
      Status        = RuntimeDriverConvertPointer (0, (VOID **)&VirtImageBase);
      ASSERT_EFI_ERROR (Status);

      PeCoffLoaderRelocateImageForRuntime (
        (EFI_PHYSICAL_ADDRESS)(UINTN)RuntimeImage->ImageBase,
        VirtImageBase,
        (UINTN)RuntimeImage->ImageSize,
        RuntimeImage->RelocationData
        );

      InvalidateInstructionCacheRange (RuntimeImage->ImageBase, (UINTN)RuntimeImage->ImageSize);
    }
  }

  //
  // Convert all the Runtime Services except ConvertPointer() and SetVirtualAddressMap()
  // and recompute the CRC-32
  //
  RuntimeDriverConvertInternalPointer ((VOID **)&gRT->GetTime);
  RuntimeDriverConvertInternalPointer ((VOID **)&gRT->SetTime);
  RuntimeDriverConvertInternalPointer ((VOID **)&gRT->GetWakeupTime);
  RuntimeDriverConvertInternalPointer ((VOID **)&gRT->SetWakeupTime);
  RuntimeDriverConvertInternalPointer ((VOID **)&gRT->ResetSystem);
  RuntimeDriverConvertInternalPointer ((VOID **)&gRT->GetNextHighMonotonicCount);
  RuntimeDriverConvertInternalPointer ((VOID **)&gRT->GetVariable);
  RuntimeDriverConvertInternalPointer ((VOID **)&gRT->SetVariable);
  RuntimeDriverConvertInternalPointer ((VOID **)&gRT->GetNextVariableName);
  RuntimeDriverConvertInternalPointer ((VOID **)&gRT->QueryVariableInfo);
  RuntimeDriverConvertInternalPointer ((VOID **)&gRT->UpdateCapsule);
  RuntimeDriverConvertInternalPointer ((VOID **)&gRT->QueryCapsuleCapabilities);
  RuntimeDriverCalculateEfiHdrCrc (&gRT->Hdr);

  //
  // UEFI don't require System Configuration Tables Conversion.
  //

  //
  // Convert the runtime fields of the EFI System Table and recompute the CRC-32
  //
  RuntimeDriverConvertInternalPointer ((VOID **)&gST->FirmwareVendor);
  RuntimeDriverConvertInternalPointer ((VOID **)&gST->ConfigurationTable);
  RuntimeDriverConvertInternalPointer ((VOID **)&gST->RuntimeServices);
  RuntimeDriverCalculateEfiHdrCrc (&gST->Hdr);

  //
  // At this point, gRT and gST are physical pointers, but the contents of these tables
  // have been converted to runtime.
  //
  //
  // mVirtualMap is only valid during SetVirtualAddressMap() call
  //
  mVirtualMap         = NULL;
  mVirtualMapMaxIndex = 0;

  return EFI_SUCCESS;
}

/**
  Entry Point for Runtime driver.

  This function installs Runtime Architectural Protocol and registers CalculateCrc32 boot services table,
  SetVirtualAddressMap & ConvertPointer runtime services table.

  @param ImageHandle     Image handle of this driver.
  @param SystemTable     a Pointer to the EFI System Table.

  @retval  EFI_SUCEESS  Runtime Driver Architectural Protocol is successfully installed
  @return  Others       Some error occurs when installing Runtime Driver Architectural Protocol.

**/
EFI_STATUS
EFIAPI
RuntimeDriverInitialize (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS                 Status;
  EFI_LOADED_IMAGE_PROTOCOL  *MyLoadedImage;

  //
  // This image needs to be excluded from relocation for virtual mode, so cache
  // a copy of the Loaded Image protocol to test later.
  //
  Status = gBS->HandleProtocol (
                  ImageHandle,
                  &gEfiLoadedImageProtocolGuid,
                  (VOID **)&MyLoadedImage
                  );
  ASSERT_EFI_ERROR (Status);
  mMyImageBase = MyLoadedImage->ImageBase;

  //
  // Fill in the entries of the EFI Boot Services and EFI Runtime Services Tables
  //
  gBS->CalculateCrc32       = RuntimeDriverCalculateCrc32;
  gRT->SetVirtualAddressMap = RuntimeDriverSetVirtualAddressMap;
  gRT->ConvertPointer       = RuntimeDriverConvertPointer;

  //
  // Install the Runtime Architectural Protocol onto a new handle
  //
  Status = gBS->InstallMultipleProtocolInterfaces (
                  &mRuntimeHandle,
                  &gEfiRuntimeArchProtocolGuid,
                  &mRuntime,
                  NULL
                  );
  ASSERT_EFI_ERROR (Status);

  return Status;
}