/** @file | |
PEI Services Table Pointer Library for IA-32 and x64. | |
According to PI specification, the peiservice pointer is stored prior at IDT | |
table in IA32 and x64 architecture. | |
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR> | |
SPDX-License-Identifier: BSD-2-Clause-Patent | |
**/ | |
#include <PiPei.h> | |
#include <Library/BaseLib.h> | |
#include <Library/PeiServicesTablePointerLib.h> | |
#include <Library/DebugLib.h> | |
#include <Library/BaseMemoryLib.h> | |
/** | |
Retrieves the cached value of the PEI Services Table pointer. | |
Returns the cached value of the PEI Services Table pointer in a CPU specific manner | |
as specified in the CPU binding section of the Platform Initialization Pre-EFI | |
Initialization Core Interface Specification. | |
If the cached PEI Services Table pointer is NULL, then ASSERT(). | |
@return The pointer to PeiServices. | |
**/ | |
CONST EFI_PEI_SERVICES ** | |
EFIAPI | |
GetPeiServicesTablePointer ( | |
VOID | |
) | |
{ | |
CONST EFI_PEI_SERVICES **PeiServices; | |
IA32_DESCRIPTOR Idtr; | |
AsmReadIdtr (&Idtr); | |
PeiServices = (CONST EFI_PEI_SERVICES **)(*(UINTN *)(Idtr.Base - sizeof (UINTN))); | |
ASSERT (PeiServices != NULL); | |
return PeiServices; | |
} | |
/** | |
Caches a pointer PEI Services Table. | |
Caches the pointer to the PEI Services Table specified by PeiServicesTablePointer | |
in a CPU specific manner as specified in the CPU binding section of the Platform Initialization | |
Pre-EFI Initialization Core Interface Specification. | |
The function set the pointer of PEI services immediately preceding the IDT table | |
according to PI specification. | |
If PeiServicesTablePointer is NULL, then ASSERT(). | |
@param PeiServicesTablePointer The address of PeiServices pointer. | |
**/ | |
VOID | |
EFIAPI | |
SetPeiServicesTablePointer ( | |
IN CONST EFI_PEI_SERVICES **PeiServicesTablePointer | |
) | |
{ | |
IA32_DESCRIPTOR Idtr; | |
ASSERT (PeiServicesTablePointer != NULL); | |
AsmReadIdtr (&Idtr); | |
(*(UINTN *)(Idtr.Base - sizeof (UINTN))) = (UINTN)PeiServicesTablePointer; | |
} | |
/** | |
Perform CPU specific actions required to migrate the PEI Services Table | |
pointer from temporary RAM to permanent RAM. | |
For IA32 CPUs, the PEI Services Table pointer is stored in the 4 bytes | |
immediately preceding the Interrupt Descriptor Table (IDT) in memory. | |
For X64 CPUs, the PEI Services Table pointer is stored in the 8 bytes | |
immediately preceding the Interrupt Descriptor Table (IDT) in memory. | |
For Itanium and ARM CPUs, a the PEI Services Table Pointer is stored in | |
a dedicated CPU register. This means that there is no memory storage | |
associated with storing the PEI Services Table pointer, so no additional | |
migration actions are required for Itanium or ARM CPUs. | |
If The cached PEI Services Table pointer is NULL, then ASSERT(). | |
If the permanent memory is allocated failed, then ASSERT(). | |
**/ | |
VOID | |
EFIAPI | |
MigratePeiServicesTablePointer ( | |
VOID | |
) | |
{ | |
EFI_STATUS Status; | |
IA32_DESCRIPTOR Idtr; | |
EFI_PHYSICAL_ADDRESS IdtBase; | |
CONST EFI_PEI_SERVICES **PeiServices; | |
// | |
// Get PEI Services Table pointer | |
// | |
AsmReadIdtr (&Idtr); | |
PeiServices = (CONST EFI_PEI_SERVICES **)(*(UINTN *)(Idtr.Base - sizeof (UINTN))); | |
ASSERT (PeiServices != NULL); | |
// | |
// Allocate the permanent memory. | |
// | |
Status = (*PeiServices)->AllocatePages ( | |
PeiServices, | |
EfiBootServicesCode, | |
EFI_SIZE_TO_PAGES (Idtr.Limit + 1 + sizeof (UINTN)), | |
&IdtBase | |
); | |
ASSERT_EFI_ERROR (Status); | |
// | |
// Idt table needs to be migrated into memory. | |
// | |
CopyMem ((VOID *)(UINTN)IdtBase, (VOID *)(Idtr.Base - sizeof (UINTN)), Idtr.Limit + 1 + sizeof (UINTN)); | |
Idtr.Base = (UINTN)IdtBase + sizeof (UINTN); | |
AsmWriteIdtr (&Idtr); | |
return; | |
} |