MdePkg: Replace BSD License with BSD+Patent License

[mirror_edk2.git] / MdePkg / Library / PeiServicesTablePointerLibIdt / PeiServicesTablePointer.c

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