/** @file

  Copyright (c) 2024, Mikhail Krichanov. All rights reserved.
  SPDX-License-Identifier: BSD-3-Clause

**/

#include "DxeMain.h"
#include "SupportedProtocols.h"

EFI_DISK_IO_PROTOCOL  *mCoreDiskIoProtocol;
EFI_BLOCK_IO_PROTOCOL *mCoreBlockIoProtocol;
UINTN                 mRing3InterfacePointer = 0;

EFI_STATUS
EFIAPI
CallInstallMultipleProtocolInterfaces (
  IN EFI_HANDLE  *Handle,
  IN VOID        **ArgList,
  IN UINT32      ArgListSize,
  IN VOID        *Function
  );

STATIC
EFI_STATUS
EFIAPI
FindGuid (
  IN  EFI_GUID  *Ring3,
  OUT EFI_GUID  **Core,
  OUT UINT32    *CoreSize
  )
{
  ASSERT (Core != NULL);
  ASSERT (CoreSize != NULL);

  if (CompareGuid (Ring3, &gEfiDevicePathUtilitiesProtocolGuid)) {

    *Core     = &gEfiDevicePathUtilitiesProtocolGuid;
    *CoreSize = sizeof (EFI_DEVICE_PATH_UTILITIES_PROTOCOL);

  } else if (CompareGuid (Ring3, &gEfiLoadedImageProtocolGuid)) {

    *Core     = &gEfiLoadedImageProtocolGuid;
    *CoreSize = sizeof (EFI_LOADED_IMAGE_PROTOCOL);

  } else if (CompareGuid (Ring3, &gEfiBlockIoProtocolGuid)) {

    *Core     = &gEfiBlockIoProtocolGuid;
    *CoreSize = sizeof (EFI_BLOCK_IO_PROTOCOL);

  } else if (CompareGuid (Ring3, &gEfiDiskIoProtocolGuid)) {

    *Core     = &gEfiDiskIoProtocolGuid;
    *CoreSize = sizeof (EFI_DISK_IO_PROTOCOL);

  } else if (CompareGuid (Ring3, &gEfiDriverBindingProtocolGuid)) {

    *Core     = &gEfiDriverBindingProtocolGuid;
    *CoreSize = sizeof (EFI_DRIVER_BINDING_PROTOCOL);

  } else if (CompareGuid (Ring3, &gEfiComponentNameProtocolGuid)) {

    *Core     = &gEfiComponentNameProtocolGuid;
    *CoreSize = sizeof (EFI_COMPONENT_NAME_PROTOCOL);

  } else if (CompareGuid (Ring3, &gEfiDevicePathProtocolGuid)) {

    *Core     = &gEfiDevicePathProtocolGuid;
    *CoreSize = sizeof (EFI_DEVICE_PATH_PROTOCOL);

  } else if (CompareGuid (Ring3, &gEfiSimpleFileSystemProtocolGuid)) {

    *Core     = &gEfiSimpleFileSystemProtocolGuid;
    *CoreSize = sizeof (EFI_SIMPLE_FILE_SYSTEM_PROTOCOL);

  } else {
    DEBUG ((DEBUG_ERROR, "Ring0: Unknown protocol.\n"));
    return EFI_NOT_FOUND;
  }

  return EFI_SUCCESS;
}

STATIC
VOID *
EFIAPI
PrepareRing3Interface (
  IN EFI_GUID  *Guid,
  IN VOID      *CoreInterface,
  IN UINT32    CoreSize
  )
{
  UINTN                  Ring3Limit;
  VOID                   *Ring3Interface;
  EFI_BLOCK_IO_PROTOCOL  *BlockIo;

  ASSERT (Guid != NULL);
  ASSERT (CoreInterface != NULL);

  if (mRing3InterfacePointer == 0) {
    mRing3InterfacePointer = (UINTN)gRing3Interfaces;
  }

  Ring3Limit = (UINTN)gRing3Interfaces + EFI_PAGES_TO_SIZE (RING3_INTERFACES_PAGES);

  ASSERT ((mRing3InterfacePointer + CoreSize) <= Ring3Limit);

  Ring3Interface = (VOID *)mRing3InterfacePointer;

  CopyMem ((VOID *)mRing3InterfacePointer, CoreInterface, CoreSize);
  mRing3InterfacePointer += CoreSize;

  if (CompareGuid (Guid, &gEfiDiskIoProtocolGuid)) {

    mCoreDiskIoProtocol = (EFI_DISK_IO_PROTOCOL *)CoreInterface;

  } else if (CompareGuid (Guid, &gEfiBlockIoProtocolGuid)) {
    ASSERT ((mRing3InterfacePointer + sizeof (EFI_BLOCK_IO_MEDIA)) <= Ring3Limit);

    mCoreBlockIoProtocol = (EFI_BLOCK_IO_PROTOCOL *)CoreInterface;
    BlockIo              = (EFI_BLOCK_IO_PROTOCOL *)Ring3Interface;

    CopyMem ((VOID *)mRing3InterfacePointer, (VOID *)BlockIo->Media, sizeof (EFI_BLOCK_IO_MEDIA));

    BlockIo->Media = (EFI_BLOCK_IO_MEDIA *)mRing3InterfacePointer;

    mRing3InterfacePointer += sizeof (EFI_BLOCK_IO_MEDIA);
  }

  return Ring3Interface;
}

typedef struct {
  UINTN  Argument1;
  UINTN  Argument2;
  UINTN  Argument3;
} CORE_STACK;

typedef struct {
  UINTN  Rip;
  UINTN  Arguments[];
} RING3_STACK;
//
// Stack:
//  rsp - User Rsp
//  rbp - User Rbp
//  rcx - Rip for SYSCALL
//  r11 - User data segment selector
//  r9  - Argument 3
//  r8  - Argument 2
//  rdx - Argument 1 <- CoreRbp
//
EFI_STATUS
EFIAPI
CallBootService (
  IN UINT8       Type,
  IN CORE_STACK  *CoreRbp,
  IN RING3_STACK *UserRsp
  )
{
  EFI_STATUS Status;
  UINT64     Attributes;
  VOID       *Interface;
  EFI_GUID   *CoreProtocol;
  UINT32     MemoryCoreSize;
  UINTN      Argument4;
  UINTN      Argument5;
  UINTN      Argument6;
  UINT32     Index;
  VOID       **UserArgList;
  VOID       *CoreArgList[MAX_LIST];
  EFI_HANDLE CoreHandle;

  EFI_DRIVER_BINDING_PROTOCOL      *CoreDriverBinding;
  EFI_SIMPLE_FILE_SYSTEM_PROTOCOL  *CoreSimpleFileSystem;
  //
  // TODO: Check User variables.
  //
  gCpu->GetMemoryAttributes (gCpu, (EFI_PHYSICAL_ADDRESS)UserRsp, &Attributes);
  ASSERT ((Attributes & EFI_MEMORY_USER) != 0);

  switch (Type) {
    case SysCallLocateProtocol:
      //
      // Argument 1: EFI_GUID  *Protocol
      // Argument 2: VOID      *CoreRegistration
      // Argument 3: VOID      **Interface
      //
      DisableSMAP ();
      Status = FindGuid ((EFI_GUID *)CoreRbp->Argument1, &CoreProtocol, &MemoryCoreSize);
      EnableSMAP ();
      if (EFI_ERROR (Status)) {
        return Status;
      }

      Status = gBS->LocateProtocol (
                      CoreProtocol,
                      (VOID *)CoreRbp->Argument2,
                      &Interface
                      );

      DisableSMAP ();
      if (Interface != NULL) {
        Interface = PrepareRing3Interface (CoreProtocol, Interface, MemoryCoreSize);
      }

      *(VOID **)CoreRbp->Argument3 = Interface;
      EnableSMAP ();

      return Status;

    case SysCallOpenProtocol:
      //
      // Argument 1: EFI_HANDLE  CoreUserHandle
      // Argument 2: EFI_GUID    *Protocol
      // Argument 3: VOID        **Interface
      // Argument 4: EFI_HANDLE  CoreImageHandle
      // Argument 5: EFI_HANDLE  CoreControllerHandle
      // Argument 6: UINT32      Attributes
      //
      DisableSMAP ();
      Status = FindGuid ((EFI_GUID *)CoreRbp->Argument2, &CoreProtocol, &MemoryCoreSize);
      if (EFI_ERROR (Status)) {
        EnableSMAP ();
        return Status;
      }

      Argument4 = UserRsp->Arguments[4];
      Argument5 = UserRsp->Arguments[5];
      Argument6 = UserRsp->Arguments[6];
      EnableSMAP ();

      Status = gBS->OpenProtocol (
                      (EFI_HANDLE)CoreRbp->Argument1,
                      CoreProtocol,
                      &Interface,
                      (EFI_HANDLE)Argument4,
                      (EFI_HANDLE)Argument5,
                      (UINT32)Argument6
                      );

      DisableSMAP ();
      if (Interface != NULL) {
        Interface = PrepareRing3Interface (CoreProtocol, Interface, MemoryCoreSize);
      }

      *(VOID **)CoreRbp->Argument3 = Interface;
      EnableSMAP ();

      return Status;

    case SysCallInstallMultipleProtocolInterfaces:
      //
      // Argument 1: EFI_HANDLE  *Handle
      // ...
      //
      DisableSMAP ();
      CoreHandle  = *(EFI_HANDLE *)CoreRbp->Argument1;
      UserArgList = (VOID **)CoreRbp->Argument2;

      for (Index = 0; UserArgList[Index] != NULL; Index += 2) {
        Status = FindGuid ((EFI_GUID *)UserArgList[Index], (EFI_GUID **)&CoreArgList[Index], &MemoryCoreSize);
        if (EFI_ERROR (Status)) {
          EnableSMAP ();

          while (Index > 0) {
            FreePool (CoreArgList[Index - 1]);
            Index -= 2;
          }

          return Status;
        }

        CoreArgList[Index + 1] = AllocateCopyPool (MemoryCoreSize, (VOID *)UserArgList[Index + 1]);
      }
      EnableSMAP ();

      ASSERT (Index < MAX_LIST);
      CoreArgList[Index] = NULL;

      for (Index = 0; CoreArgList[Index] != NULL; Index += 2) {
        if (CompareGuid ((EFI_GUID *)CoreArgList[Index], &gEfiDriverBindingProtocolGuid)) {
          CoreDriverBinding = (EFI_DRIVER_BINDING_PROTOCOL *)CoreArgList[Index + 1];

          mRing3DriverBindingProtocol.Supported = CoreDriverBinding->Supported;
          mRing3DriverBindingProtocol.Start     = CoreDriverBinding->Start;
          mRing3DriverBindingProtocol.Stop      = CoreDriverBinding->Stop;

          CoreDriverBinding->Supported = CoreDriverBindingSupported;
          CoreDriverBinding->Start     = CoreDriverBindingStart;
          CoreDriverBinding->Stop      = CoreDriverBindingStop;
        } else if (CompareGuid ((EFI_GUID *)CoreArgList[Index], &gEfiSimpleFileSystemProtocolGuid)) {
          CoreSimpleFileSystem = (EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *)CoreArgList[Index + 1];

          mRing3SimpleFileSystemProtocol.OpenVolume = CoreSimpleFileSystem->OpenVolume;

          CoreSimpleFileSystem->OpenVolume = CoreOpenVolume;

          DisableSMAP ();
          mRing3SimpleFileSystemPointer = (EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *)UserArgList[Index + 1];
          EnableSMAP ();
        }
      }

      Status = CallInstallMultipleProtocolInterfaces (
                 &CoreHandle,
                 CoreArgList,
                 Index + 1,
                 (VOID *)gBS->InstallMultipleProtocolInterfaces
                 );

      return Status;

    case SysCallCloseProtocol:
      //
      // Argument 1: EFI_HANDLE  CoreUserHandle
      // Argument 2: EFI_GUID    *Protocol
      // Argument 3: EFI_HANDLE  CoreAgentHandle
      // Argument 4: EFI_HANDLE  CoreControllerHandle
      //
      DisableSMAP ();
      Status = FindGuid ((EFI_GUID *)CoreRbp->Argument2, &CoreProtocol, &MemoryCoreSize);
      if (EFI_ERROR (Status)) {
        EnableSMAP ();
        return Status;
      }

      Argument4 = UserRsp->Arguments[4];
      EnableSMAP ();

      Status = gBS->CloseProtocol (
                      (EFI_HANDLE)CoreRbp->Argument1,
                      CoreProtocol,
                      (EFI_HANDLE)CoreRbp->Argument3,
                      (EFI_HANDLE)Argument4
                      );

      return Status;

    case SysCallHandleProtocol:
      //
      // Argument 1: EFI_HANDLE  CoreUserHandle
      // Argument 2: EFI_GUID    *Protocol
      // Argument 3: VOID        **Interface
      //
      DisableSMAP ();
      Status = FindGuid ((EFI_GUID *)CoreRbp->Argument2, &CoreProtocol, &MemoryCoreSize);
      EnableSMAP ();
      if (EFI_ERROR (Status)) {
        return Status;
      }

      Status = gBS->HandleProtocol (
                      (EFI_HANDLE)CoreRbp->Argument1,
                      CoreProtocol,
                      &Interface
                      );

      DisableSMAP ();
      if (Interface != NULL) {
        Interface = PrepareRing3Interface (CoreProtocol, Interface, MemoryCoreSize);
      }

      *(VOID **)CoreRbp->Argument3 = Interface;
      EnableSMAP ();

      return Status;

    case SysCallAllocatePages:
      //
      // Argument 1: EFI_ALLOCATE_TYPE     Type
      // Argument 2: EFI_MEMORY_TYPE       MemoryType
      // Argument 3: UINTN                 NumberOfPages
      // Argument 4: EFI_PHYSICAL_ADDRESS  *Memory
      //
      Status = gBS->AllocatePages (
                      (EFI_ALLOCATE_TYPE)CoreRbp->Argument1,
                      (EFI_MEMORY_TYPE)CoreRbp->Argument2,
                      CoreRbp->Argument3,
                      (EFI_PHYSICAL_ADDRESS *)&Argument4
                      );

      DisableSMAP ();
      *(EFI_PHYSICAL_ADDRESS *)UserRsp->Arguments[4] = (EFI_PHYSICAL_ADDRESS)Argument4;
      EnableSMAP ();

      return Status;

    case SysCallFreePages:
      //
      // Argument 1: EFI_PHYSICAL_ADDRESS  Memory
      // Argument 2: UINTN                 NumberOfPages
      //
      return gBS->FreePages (
                    (EFI_PHYSICAL_ADDRESS)CoreRbp->Argument1,
                    CoreRbp->Argument2
                    );

    case SysCallRaiseTpl:
      //
      // Argument 1: EFI_TPL  NewTpl
      //
      return (EFI_STATUS)gBS->RaiseTPL (
                                (EFI_TPL)CoreRbp->Argument1
                                );

    case SysCallRestoreTpl:
      //
      // Argument 1: EFI_TPL  NewTpl
      //
      gBS->RestoreTPL ((EFI_TPL)CoreRbp->Argument1);

      return EFI_SUCCESS;

    case SysCallBlockIoReset:
      //
      // Argument 1: EFI_BLOCK_IO_PROTOCOL  *This
      // Argument 2: BOOLEAN                ExtendedVerification
      //
      return mCoreBlockIoProtocol->Reset (
                                     mCoreBlockIoProtocol,
                                     (BOOLEAN)CoreRbp->Argument2
                                     );

    case SysCallBlockIoRead:
      //
      // Argument 1: EFI_BLOCK_IO_PROTOCOL *This
      // Argument 2: UINT32                MediaId
      // Argument 3: EFI_LBA               Lba
      // Argument 4: UINTN                 BufferSize
      // Argument 5: VOID                 *Buffer
      //
      DisableSMAP ();
      Argument4 = UserRsp->Arguments[4];
      EnableSMAP ();

      Argument5 = (UINTN)AllocatePool (Argument4);
      if ((VOID *)Argument5 == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }

      Status = mCoreBlockIoProtocol->ReadBlocks (
                                       mCoreBlockIoProtocol,
                                       (UINT32)CoreRbp->Argument2,
                                       (EFI_LBA)CoreRbp->Argument3,
                                       Argument4,
                                       (VOID *)Argument5
                                       );
      DisableSMAP ();
      CopyMem ((VOID *)UserRsp->Arguments[5], (VOID *)Argument5, Argument4);
      EnableSMAP ();

      FreePool ((VOID *)Argument5);

      return Status;

    case SysCallBlockIoWrite:
      //
      // Argument 1: EFI_BLOCK_IO_PROTOCOL *This
      // Argument 2: UINT32                MediaId
      // Argument 3: EFI_LBA               Lba
      // Argument 4: UINTN                 BufferSize
      // Argument 5: VOID                 *Buffer
      //
      DisableSMAP ();
      Argument4 = UserRsp->Arguments[4];
      EnableSMAP ();

      Argument5 = (UINTN)AllocatePool (Argument4);
      if ((VOID *)Argument5 == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }

      DisableSMAP ();
      CopyMem ((VOID *)Argument5,(VOID *)UserRsp->Arguments[5], Argument4);
      EnableSMAP ();

      Status = mCoreBlockIoProtocol->WriteBlocks (
                                       mCoreBlockIoProtocol,
                                       (UINT32)CoreRbp->Argument2,
                                       (EFI_LBA)CoreRbp->Argument3,
                                       Argument4,
                                       (VOID *)Argument5
                                       );

      FreePool ((VOID *)Argument5);

      return Status;

    case SysCallBlockIoFlush:
      //
      // Argument 1: EFI_BLOCK_IO_PROTOCOL  *This
      //
      return mCoreBlockIoProtocol->FlushBlocks (
                                     mCoreBlockIoProtocol
                                     );

    case SysCallDiskIoRead:
      //
      // Argument 1: EFI_DISK_IO_PROTOCOL  *This
      // Argument 2: UINT32                MediaId
      // Argument 3: UINT64                Offset
      // Argument 4: UINTN                 BufferSize
      // Argument 5: VOID                 *Buffer
      //
      DisableSMAP ();
      Argument4 = UserRsp->Arguments[4];
      EnableSMAP ();

      Argument5 = (UINTN)AllocatePool (Argument4);
      if ((VOID *)Argument5 == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }

      Status = mCoreDiskIoProtocol->ReadDisk (
                                      mCoreDiskIoProtocol,
                                      (UINT32)CoreRbp->Argument2,
                                      (UINT64)CoreRbp->Argument3,
                                      Argument4,
                                      (VOID *)Argument5
                                      );
      DisableSMAP ();
      CopyMem ((VOID *)UserRsp->Arguments[5], (VOID *)Argument5, Argument4);
      EnableSMAP ();

      FreePool ((VOID *)Argument5);

      return Status;

    case SysCallDiskIoWrite:
      //
      // Argument 1: EFI_DISK_IO_PROTOCOL  *This
      // Argument 2: UINT32                MediaId
      // Argument 3: UINT64                Offset
      // Argument 4: UINTN                 BufferSize
      // Argument 5: VOID                 *Buffer
      //
      DisableSMAP ();
      Argument4 = UserRsp->Arguments[4];
      EnableSMAP ();

      Argument5 = (UINTN)AllocatePool (Argument4);
      if ((VOID *)Argument5 == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }

      DisableSMAP ();
      CopyMem ((VOID *)Argument5, (VOID *)UserRsp->Arguments[5], Argument4);
      EnableSMAP ();

      Status = mCoreDiskIoProtocol->WriteDisk (
                                      mCoreDiskIoProtocol,
                                      (UINT32)CoreRbp->Argument2,
                                      (UINT64)CoreRbp->Argument3,
                                      Argument4,
                                      (VOID *)Argument5
                                      );

      FreePool ((VOID *)Argument5);

      return Status;
    default:
      DEBUG ((DEBUG_ERROR, "Ring0: Unknown syscall type.\n"));
      break;
  }

  return EFI_UNSUPPORTED;
}