/** @file | |
Execute 64-bit code in Long Mode. | |
Provide a thunk function to transition from long mode to compatibility mode to execute 32-bit code and then transit | |
back to long mode. | |
Copyright (c) 2014 - 2022, Intel Corporation. All rights reserved.<BR> | |
SPDX-License-Identifier: BSD-2-Clause-Patent | |
**/ | |
#include <Uefi.h> | |
#include <Library/BaseLib.h> | |
#include <FspEas.h> | |
/** | |
FSP API functions. | |
@param[in] Param1 The first parameter to pass to 64bit code. | |
@param[in] Param2 The second parameter to pass to 64bit code. | |
@return EFI_STATUS. | |
**/ | |
typedef | |
EFI_STATUS | |
(EFIAPI *FSP_FUNCTION)( | |
IN VOID *Param1, | |
IN VOID *Param2 | |
); | |
#pragma pack(1) | |
typedef union { | |
struct { | |
UINT32 LimitLow : 16; | |
UINT32 BaseLow : 16; | |
UINT32 BaseMid : 8; | |
UINT32 Type : 4; | |
UINT32 System : 1; | |
UINT32 Dpl : 2; | |
UINT32 Present : 1; | |
UINT32 LimitHigh : 4; | |
UINT32 Software : 1; | |
UINT32 Reserved : 1; | |
UINT32 DefaultSize : 1; | |
UINT32 Granularity : 1; | |
UINT32 BaseHigh : 8; | |
} Bits; | |
UINT64 Uint64; | |
} IA32_GDT; | |
#pragma pack() | |
GLOBAL_REMOVE_IF_UNREFERENCED IA32_GDT mGdtEntries[] = { | |
{ | |
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } | |
}, /* 0x0: reserve */ | |
{ | |
{ 0xFFFF, 0, 0, 0xB, 1, 0, 1, 0xF, 0, 0, 1, 1, 0 } | |
}, /* 0x8: compatibility mode */ | |
{ | |
{ 0xFFFF, 0, 0, 0xB, 1, 0, 1, 0xF, 0, 1, 0, 1, 0 } | |
}, /* 0x10: for long mode */ | |
{ | |
{ 0xFFFF, 0, 0, 0x3, 1, 0, 1, 0xF, 0, 0, 1, 1, 0 } | |
}, /* 0x18: data */ | |
{ | |
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } | |
}, /* 0x20: reserve */ | |
}; | |
// | |
// IA32 Gdt register | |
// | |
GLOBAL_REMOVE_IF_UNREFERENCED IA32_DESCRIPTOR mGdt = { | |
sizeof (mGdtEntries) - 1, | |
(UINTN)mGdtEntries | |
}; | |
/** | |
Assembly function to transition from long mode to compatibility mode to execute 32-bit code and then transit back to | |
long mode. | |
@param[in] Function The 32bit code entry to be executed. | |
@param[in] Param1 The first parameter to pass to 32bit code | |
@param[in] Param2 The second parameter to pass to 32bit code | |
@param[in] InternalGdtr The GDT and GDT descriptor used by this library | |
@return status. | |
**/ | |
UINT32 | |
EFIAPI | |
AsmExecute32BitCode ( | |
IN UINT64 Function, | |
IN UINT64 Param1, | |
IN UINT64 Param2, | |
IN IA32_DESCRIPTOR *InternalGdtr | |
); | |
/** | |
Wrapper for a thunk to transition from long mode to compatibility mode to execute 32-bit code and then transit back to | |
long mode. | |
@param[in] Function The 32bit code entry to be executed. | |
@param[in] Param1 The first parameter to pass to 32bit code. | |
@param[in] Param2 The second parameter to pass to 32bit code. | |
@return EFI_STATUS. | |
**/ | |
EFI_STATUS | |
Execute32BitCode ( | |
IN UINT64 Function, | |
IN UINT64 Param1, | |
IN UINT64 Param2 | |
) | |
{ | |
EFI_STATUS Status; | |
IA32_DESCRIPTOR Idtr; | |
// | |
// Idtr might be changed inside of FSP. 32bit FSP only knows the <4G address. | |
// If IDTR.Base is >4G, FSP can not handle. So we need save/restore IDTR here for X64 only. | |
// Interrupt is already disabled here, so it is safety to update IDTR. | |
// | |
AsmReadIdtr (&Idtr); | |
Status = AsmExecute32BitCode (Function, Param1, Param2, &mGdt); | |
// | |
// Convert FSP Status code from 32bit to 64bit to match caller expectation. | |
// | |
Status = (Status & ~(BIT31 + BIT30)) | LShiftU64 (Status & (BIT31 + BIT30), 32); | |
AsmWriteIdtr (&Idtr); | |
return Status; | |
} | |
/** | |
Wrapper to execute 64-bit code directly from long mode. | |
@param[in] Function The 64bit code entry to be executed. | |
@param[in] Param1 The first parameter to pass to 64bit code. | |
@param[in] Param2 The second parameter to pass to 64bit code. | |
@return EFI_STATUS. | |
**/ | |
EFI_STATUS | |
Execute64BitCode ( | |
IN UINT64 Function, | |
IN UINT64 Param1, | |
IN UINT64 Param2 | |
) | |
{ | |
FSP_FUNCTION EntryFunc; | |
EFI_STATUS Status; | |
EntryFunc = (FSP_FUNCTION)(UINTN)(Function); | |
Status = EntryFunc ((VOID *)(UINTN)Param1, (VOID *)(UINTN)Param2); | |
return Status; | |
} |