OvmfPkg: Change complex DEBUG_CODE() to DEBUG_CODE_BEGIN/END()

[mirror_edk2.git] / OvmfPkg / Csm / LegacyBiosDxe / Thunk.c

/** @file\r
  Call into 16-bit BIOS code, Use AsmThunk16 function of BaseLib.\r
\r
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "LegacyBiosInterface.h"\r
\r
THUNK_CONTEXT      mThunkContext;\r
\r
/**\r
  Sets the counter value for Timer #0 in a legacy 8254 timer.\r
\r
  @param  Count - The 16-bit counter value to program into Timer #0 of the legacy 8254 timer.\r
\r
**/\r
VOID\r
SetPitCount (\r
  IN UINT16  Count\r
  )\r
{\r
  IoWrite8 (TIMER_CONTROL_PORT, TIMER0_CONTROL_WORD);\r
  IoWrite8 (TIMER0_COUNT_PORT, (UINT8) (Count & 0xFF));\r
  IoWrite8 (TIMER0_COUNT_PORT, (UINT8) ((Count>>8) & 0xFF));\r
}\r
\r
/**\r
  Thunk to 16-bit real mode and execute a software interrupt with a vector\r
  of BiosInt. Regs will contain the 16-bit register context on entry and\r
  exit.\r
\r
  @param  This    Protocol instance pointer.\r
  @param  BiosInt Processor interrupt vector to invoke\r
  @param  Regs    Register contexted passed into (and returned) from thunk to\r
                  16-bit mode\r
\r
  @retval FALSE   Thunk completed, and there were no BIOS errors in the target code.\r
                  See Regs for status.\r
  @retval TRUE    There was a BIOS erro in the target code.\r
\r
**/\r
BOOLEAN\r
EFIAPI\r
LegacyBiosInt86 (\r
  IN  EFI_LEGACY_BIOS_PROTOCOL      *This,\r
  IN  UINT8                         BiosInt,\r
  IN  EFI_IA32_REGISTER_SET         *Regs\r
  )\r
{\r
  UINT16                Segment;\r
  UINT16                Offset;\r
\r
  Regs->X.Flags.Reserved1 = 1;\r
  Regs->X.Flags.Reserved2 = 0;\r
  Regs->X.Flags.Reserved3 = 0;\r
  Regs->X.Flags.Reserved4 = 0;\r
  Regs->X.Flags.IOPL      = 3;\r
  Regs->X.Flags.NT        = 0;\r
  Regs->X.Flags.IF        = 0;\r
  Regs->X.Flags.TF        = 0;\r
  Regs->X.Flags.CF        = 0;\r
  //\r
  // The base address of legacy interrupt vector table is 0.\r
  // We use this base address to get the legacy interrupt handler.\r
  //\r
  ACCESS_PAGE0_CODE (\r
    Segment               = (UINT16)(((UINT32 *)0)[BiosInt] >> 16);\r
    Offset                = (UINT16)((UINT32 *)0)[BiosInt];\r
  );\r
\r
  return InternalLegacyBiosFarCall (\r
           This,\r
           Segment,\r
           Offset,\r
           Regs,\r
           &Regs->X.Flags,\r
           sizeof (Regs->X.Flags)\r
           );\r
}\r
\r
/**\r
  Thunk to 16-bit real mode and call Segment:Offset. Regs will contain the\r
  16-bit register context on entry and exit. Arguments can be passed on\r
  the Stack argument\r
\r
  @param  This                   Protocol instance pointer.\r
  @param  Segment                Segemnt of 16-bit mode call\r
  @param  Offset                 Offset of 16-bit mdoe call\r
  @param  Regs                   Register contexted passed into (and returned) from\r
                                 thunk to  16-bit mode\r
  @param  Stack                  Caller allocated stack used to pass arguments\r
  @param  StackSize              Size of Stack in bytes\r
\r
  @retval FALSE                  Thunk completed, and there were no BIOS errors in\r
                                 the target code. See Regs for status.\r
  @retval TRUE                   There was a BIOS erro in the target code.\r
\r
**/\r
BOOLEAN\r
EFIAPI\r
LegacyBiosFarCall86 (\r
  IN  EFI_LEGACY_BIOS_PROTOCOL        *This,\r
  IN  UINT16                          Segment,\r
  IN  UINT16                          Offset,\r
  IN  EFI_IA32_REGISTER_SET           *Regs,\r
  IN  VOID                            *Stack,\r
  IN  UINTN                           StackSize\r
  )\r
{\r
  Regs->X.Flags.Reserved1 = 1;\r
  Regs->X.Flags.Reserved2 = 0;\r
  Regs->X.Flags.Reserved3 = 0;\r
  Regs->X.Flags.Reserved4 = 0;\r
  Regs->X.Flags.IOPL      = 3;\r
  Regs->X.Flags.NT        = 0;\r
  Regs->X.Flags.IF        = 1;\r
  Regs->X.Flags.TF        = 0;\r
  Regs->X.Flags.CF        = 0;\r
\r
  return InternalLegacyBiosFarCall (This, Segment, Offset, Regs, Stack, StackSize);\r
}\r
\r
/**\r
  Provide NULL interrupt handler which is used to check\r
  if there is more than one HW interrupt registers with the CPU AP.\r
\r
  @param  InterruptType - The type of interrupt that occurred\r
  @param  SystemContext - A pointer to the system context when the interrupt occurred\r
\r
**/\r
VOID\r
EFIAPI\r
LegacyBiosNullInterruptHandler (\r
  IN EFI_EXCEPTION_TYPE   InterruptType,\r
  IN EFI_SYSTEM_CONTEXT   SystemContext\r
  )\r
{\r
}\r
\r
/**\r
  Thunk to 16-bit real mode and call Segment:Offset. Regs will contain the\r
  16-bit register context on entry and exit. Arguments can be passed on\r
  the Stack argument\r
\r
  @param  This       Protocol instance pointer.\r
  @param  Segment    Segemnt of 16-bit mode call\r
  @param  Offset     Offset of 16-bit mdoe call\r
  @param  Regs       Register contexted passed into (and returned) from thunk to\r
                     16-bit mode\r
  @param  Stack      Caller allocated stack used to pass arguments\r
  @param  StackSize  Size of Stack in bytes\r
\r
  @retval FALSE      Thunk completed, and there were no BIOS errors in the target code.\r
                     See Regs for status.\r
  @retval TRUE       There was a BIOS erro in the target code.\r
\r
**/\r
BOOLEAN\r
EFIAPI\r
InternalLegacyBiosFarCall (\r
  IN  EFI_LEGACY_BIOS_PROTOCOL        *This,\r
  IN  UINT16                          Segment,\r
  IN  UINT16                          Offset,\r
  IN  EFI_IA32_REGISTER_SET           *Regs,\r
  IN  VOID                            *Stack,\r
  IN  UINTN                           StackSize\r
  )\r
{\r
  UINTN                 Status;\r
  LEGACY_BIOS_INSTANCE  *Private;\r
  UINT16                *Stack16;\r
  EFI_TPL               OriginalTpl;\r
  IA32_REGISTER_SET     ThunkRegSet;\r
  BOOLEAN               InterruptState;\r
  UINT64                TimerPeriod;\r
\r
  Private = LEGACY_BIOS_INSTANCE_FROM_THIS (This);\r
\r
  ZeroMem (&ThunkRegSet, sizeof (ThunkRegSet));\r
  ThunkRegSet.X.DI   = Regs->X.DI;\r
  ThunkRegSet.X.SI   = Regs->X.SI;\r
  ThunkRegSet.X.BP   = Regs->X.BP;\r
  ThunkRegSet.X.BX   = Regs->X.BX;\r
  ThunkRegSet.X.DX   = Regs->X.DX;\r
  //\r
  // Sometimes, ECX is used to pass in 32 bit data. For example, INT 1Ah, AX = B10Dh is\r
  // "PCI BIOS v2.0c + Write Configuration DWORD" and ECX has the dword to write.\r
  //\r
  ThunkRegSet.E.ECX   = Regs->E.ECX;\r
  ThunkRegSet.X.AX   = Regs->X.AX;\r
  ThunkRegSet.E.DS   = Regs->X.DS;\r
  ThunkRegSet.E.ES   = Regs->X.ES;\r
\r
  CopyMem (&(ThunkRegSet.E.EFLAGS.UintN), &(Regs->X.Flags), sizeof (Regs->X.Flags));\r
\r
  //\r
  // Clear the error flag; thunk code may set it. Stack16 should be the high address\r
  // Make Statk16 address the low 16 bit must be not zero.\r
  //\r
  Stack16 = (UINT16 *)((UINT8 *) mThunkContext.RealModeBuffer + mThunkContext.RealModeBufferSize - sizeof (UINT16));\r
\r
  //\r
  // Save current rate of DXE Timer\r
  //\r
  Private->Timer->GetTimerPeriod (Private->Timer, &TimerPeriod);\r
\r
  //\r
  // Disable DXE Timer while executing in real mode\r
  //\r
  Private->Timer->SetTimerPeriod (Private->Timer, 0);\r
\r
  //\r
  // Save and disable interrupt of debug timer\r
  //\r
  InterruptState = SaveAndSetDebugTimerInterrupt (FALSE);\r
\r
  //\r
  // The call to Legacy16 is a critical section to EFI\r
  //\r
  OriginalTpl = gBS->RaiseTPL (TPL_HIGH_LEVEL);\r
\r
  //\r
  // Check to see if there is more than one HW interrupt registers with the CPU AP.\r
  // If there is, then ASSERT() since that is not compatible with the CSM because\r
  // interupts other than the Timer interrupt that was disabled above can not be\r
  // handled properly from real mode.\r
  //\r
  DEBUG_CODE_BEGIN ();\r
    UINTN  Vector;\r
    UINTN  Count;\r
\r
    for (Vector = 0x20, Count = 0; Vector < 0x100; Vector++) {\r
      Status = Private->Cpu->RegisterInterruptHandler (Private->Cpu, Vector, LegacyBiosNullInterruptHandler);\r
      if (Status == EFI_ALREADY_STARTED) {\r
        Count++;\r
      }\r
      if (Status == EFI_SUCCESS) {\r
        Private->Cpu->RegisterInterruptHandler (Private->Cpu, Vector, NULL);\r
      }\r
    }\r
    if (Count >= 2) {\r
      DEBUG ((DEBUG_ERROR, "ERROR: More than one HW interrupt active with CSM enabled\n"));\r
    }\r
    ASSERT (Count < 2);\r
  DEBUG_CODE_END ();\r
\r
  //\r
  // If the Timer AP has enabled the 8254 timer IRQ and the current 8254 timer\r
  // period is less than the CSM required rate of 54.9254, then force the 8254\r
  // PIT counter to 0, which is the CSM required rate of 54.9254 ms\r
  //\r
  if (Private->TimerUses8254 && TimerPeriod < 549254) {\r
    SetPitCount (0);\r
  }\r
\r
  if (Stack != NULL && StackSize != 0) {\r
    //\r
    // Copy Stack to low memory stack\r
    //\r
    Stack16 -= StackSize / sizeof (UINT16);\r
    CopyMem (Stack16, Stack, StackSize);\r
  }\r
\r
  ThunkRegSet.E.SS   = (UINT16) (((UINTN) Stack16 >> 16) << 12);\r
  ThunkRegSet.E.ESP  = (UINT16) (UINTN) Stack16;\r
  ThunkRegSet.E.CS   = Segment;\r
  ThunkRegSet.E.Eip  = Offset;\r
\r
  mThunkContext.RealModeState      = &ThunkRegSet;\r
\r
  //\r
  // Set Legacy16 state. 0x08, 0x70 is legacy 8259 vector bases.\r
  //\r
  Status = Private->Legacy8259->SetMode (Private->Legacy8259, Efi8259LegacyMode, NULL, NULL);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  AsmThunk16 (&mThunkContext);\r
\r
  if (Stack != NULL && StackSize != 0) {\r
    //\r
    // Copy low memory stack to Stack\r
    //\r
    CopyMem (Stack, Stack16, StackSize);\r
  }\r
\r
  //\r
  // Restore protected mode interrupt state\r
  //\r
  Status = Private->Legacy8259->SetMode (Private->Legacy8259, Efi8259ProtectedMode, NULL, NULL);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  mThunkContext.RealModeState = NULL;\r
\r
  //\r
  // Enable and restore rate of DXE Timer\r
  //\r
  Private->Timer->SetTimerPeriod (Private->Timer, TimerPeriod);\r
\r
  //\r
  // End critical section\r
  //\r
  gBS->RestoreTPL (OriginalTpl);\r
\r
  //\r
  // OPROM may allocate EBDA range by itself and change EBDA base and EBDA size.\r
  // Get the current EBDA base address, and compared with pre-allocate minimum\r
  // EBDA base address, if the current EBDA base address is smaller, it indicates\r
  // PcdEbdaReservedMemorySize should be adjusted to larger for more OPROMs.\r
  //\r
  DEBUG_CODE_BEGIN ();\r
    {\r
      UINTN                 EbdaBaseAddress;\r
      UINTN                 ReservedEbdaBaseAddress;\r
\r
      ACCESS_PAGE0_CODE (\r
        EbdaBaseAddress = (*(UINT16 *) (UINTN) 0x40E) << 4;\r
        ReservedEbdaBaseAddress = CONVENTIONAL_MEMORY_TOP\r
                                  - PcdGet32 (PcdEbdaReservedMemorySize);\r
        ASSERT (ReservedEbdaBaseAddress <= EbdaBaseAddress);\r
      );\r
    }\r
  DEBUG_CODE_END ();\r
\r
  //\r
  // Restore interrupt of debug timer\r
  //\r
  SaveAndSetDebugTimerInterrupt (InterruptState);\r
\r
  Regs->E.EDI      = ThunkRegSet.E.EDI;\r
  Regs->E.ESI      = ThunkRegSet.E.ESI;\r
  Regs->E.EBP      = ThunkRegSet.E.EBP;\r
  Regs->E.EBX      = ThunkRegSet.E.EBX;\r
  Regs->E.EDX      = ThunkRegSet.E.EDX;\r
  Regs->E.ECX      = ThunkRegSet.E.ECX;\r
  Regs->E.EAX      = ThunkRegSet.E.EAX;\r
  Regs->X.SS       = ThunkRegSet.E.SS;\r
  Regs->X.CS       = ThunkRegSet.E.CS;\r
  Regs->X.DS       = ThunkRegSet.E.DS;\r
  Regs->X.ES       = ThunkRegSet.E.ES;\r
\r
  CopyMem (&(Regs->X.Flags), &(ThunkRegSet.E.EFLAGS.UintN), sizeof (Regs->X.Flags));\r
\r
  return (BOOLEAN) (Regs->X.Flags.CF == 1);\r
}\r
\r
/**\r
  Allocate memory < 1 MB and copy the thunker code into low memory. Se up\r
  all the descriptors.\r
\r
  @param  Private                Private context for Legacy BIOS\r
\r
  @retval EFI_SUCCESS            Should only pass.\r
\r
**/\r
EFI_STATUS\r
LegacyBiosInitializeThunk (\r
  IN  LEGACY_BIOS_INSTANCE    *Private\r
  )\r
{\r
  EFI_STATUS              Status;\r
  EFI_PHYSICAL_ADDRESS    MemoryAddress;\r
  UINT8                   TimerVector;\r
\r
  MemoryAddress   = (EFI_PHYSICAL_ADDRESS) (UINTN) Private->IntThunk;\r
\r
  mThunkContext.RealModeBuffer     = (VOID *) (UINTN) (MemoryAddress + ((sizeof (LOW_MEMORY_THUNK) / EFI_PAGE_SIZE) + 1) * EFI_PAGE_SIZE);\r
  mThunkContext.RealModeBufferSize = EFI_PAGE_SIZE;\r
  mThunkContext.ThunkAttributes    = THUNK_ATTRIBUTE_BIG_REAL_MODE | THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15;\r
\r
  AsmPrepareThunk16 (&mThunkContext);\r
\r
  //\r
  // Get the interrupt vector number corresponding to IRQ0 from the 8259 driver\r
  //\r
  TimerVector = 0;\r
  Status = Private->Legacy8259->GetVector (Private->Legacy8259, Efi8259Irq0, &TimerVector);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Check to see if the Timer AP has hooked the IRQ0 from the 8254 PIT\r
  //\r
  Status = Private->Cpu->RegisterInterruptHandler (\r
                           Private->Cpu,\r
                           TimerVector,\r
                           LegacyBiosNullInterruptHandler\r
                           );\r
  if (Status == EFI_SUCCESS) {\r
    //\r
    // If the Timer AP has not enabled the 8254 timer IRQ, then force the 8254 PIT\r
    // counter to 0, which is the CSM required rate of 54.9254 ms\r
    //\r
    Private->Cpu->RegisterInterruptHandler (\r
                    Private->Cpu,\r
                    TimerVector,\r
                    NULL\r
                    );\r
    SetPitCount (0);\r
\r
    //\r
    // Save status that the Timer AP is not using the 8254 PIT\r
    //\r
    Private->TimerUses8254 = FALSE;\r
  } else if (Status == EFI_ALREADY_STARTED) {\r
    //\r
    // Save status that the Timer AP is using the 8254 PIT\r
    //\r
    Private->TimerUses8254 = TRUE;\r
  } else {\r
    //\r
    // Unexpected status from CPU AP RegisterInterruptHandler()\r
    //\r
    ASSERT (FALSE);\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r