IntelFspWrapperPkg/Library/SecPeiFspPlatformSecLibSample/SecTempRamSupport.c

   1 /** @file
   2   Sample to provide SecTemporaryRamSupport function.
   3
   4   Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include <PiPei.h>
  10
  11 #include <Ppi/TemporaryRamSupport.h>
  12
  13 #include <Library/BaseMemoryLib.h>
  14 #include <Library/DebugLib.h>
  15 #include <Library/PcdLib.h>
  16 #include <Library/DebugAgentLib.h>
  17
  18 /**
  19   Switch the stack in the temporary memory to the one in the permanent memory.
  20
  21   This function must be invoked after the memory migration immediately. The relative
  22   position of the stack in the temporary and permanent memory is same.
  23
  24   @param[in] TemporaryMemoryBase  Base address of the temporary memory.
  25   @param[in] PermenentMemoryBase  Base address of the permanent memory.
  26 **/
  27 VOID
  28 EFIAPI
  29 SecSwitchStack (
  30   IN UINT32   TemporaryMemoryBase,
  31   IN UINT32   PermenentMemoryBase
  32   );
  33
  34 /**
  35   This service of the TEMPORARY_RAM_SUPPORT_PPI that migrates temporary RAM into
  36   permanent memory.
  37
  38   @param[in] PeiServices            Pointer to the PEI Services Table.
  39   @param[in] TemporaryMemoryBase    Source Address in temporary memory from which the SEC or PEIM will copy the
  40                                     Temporary RAM contents.
  41   @param[in] PermanentMemoryBase    Destination Address in permanent memory into which the SEC or PEIM will copy the
  42                                     Temporary RAM contents.
  43   @param[in] CopySize               Amount of memory to migrate from temporary to permanent memory.
  44
  45   @retval EFI_SUCCESS           The data was successfully returned.
  46   @retval EFI_INVALID_PARAMETER PermanentMemoryBase + CopySize > TemporaryMemoryBase when
  47                                 TemporaryMemoryBase > PermanentMemoryBase.
  48
  49 **/
  50 EFI_STATUS
  51 EFIAPI
  52 SecTemporaryRamSupport (
  53   IN CONST EFI_PEI_SERVICES   **PeiServices,
  54   IN EFI_PHYSICAL_ADDRESS     TemporaryMemoryBase,
  55   IN EFI_PHYSICAL_ADDRESS     PermanentMemoryBase,
  56   IN UINTN                    CopySize
  57   )
  58 {
  59   IA32_DESCRIPTOR   IdtDescriptor;
  60   VOID*             OldHeap;
  61   VOID*             NewHeap;
  62   VOID*             OldStack;
  63   VOID*             NewStack;
  64   DEBUG_AGENT_CONTEXT_POSTMEM_SEC  DebugAgentContext;
  65   BOOLEAN           OldStatus;
  66   UINTN             PeiStackSize;
  67
  68   PeiStackSize = (UINTN)PcdGet32 (PcdPeiTemporaryRamStackSize);
  69   if (PeiStackSize == 0) {
  70     PeiStackSize = (CopySize >> 1);
  71   }
  72
  73   ASSERT (PeiStackSize < CopySize);
  74
  75   //
  76   // |-------------------|---->
  77   // |      Stack        |    PeiStackSize
  78   // |-------------------|---->
  79   // |      Heap         |    PeiTemporayRamSize
  80   // |-------------------|---->  TempRamBase
  81   //
  82   // |-------------------|---->
  83   // |      Heap         |    PeiTemporayRamSize
  84   // |-------------------|---->
  85   // |      Stack        |    PeiStackSize
  86   // |-------------------|---->  PermanentMemoryBase
  87   //
  88
  89   OldHeap = (VOID*)(UINTN)TemporaryMemoryBase;
  90   NewHeap = (VOID*)((UINTN)PermanentMemoryBase + PeiStackSize);
  91
  92   OldStack = (VOID*)((UINTN)TemporaryMemoryBase + CopySize - PeiStackSize);
  93   NewStack = (VOID*)(UINTN)PermanentMemoryBase;
  94
  95   DebugAgentContext.HeapMigrateOffset = (UINTN)NewHeap - (UINTN)OldHeap;
  96   DebugAgentContext.StackMigrateOffset = (UINTN)NewStack - (UINTN)OldStack;
  97
  98   OldStatus = SaveAndSetDebugTimerInterrupt (FALSE);
  99   //
 100   // Initialize Debug Agent to support source level debug in PEI phase after memory ready.
 101   // It will build HOB and fix up the pointer in IDT table.
 102   //
 103   InitializeDebugAgent (DEBUG_AGENT_INIT_POSTMEM_SEC, (VOID *) &DebugAgentContext, NULL);
 104
 105   //
 106   // Migrate Heap
 107   //
 108   CopyMem (NewHeap, OldHeap, CopySize - PeiStackSize);
 109
 110   //
 111   // Migrate Stack
 112   //
 113   CopyMem (NewStack, OldStack, PeiStackSize);
 114
 115
 116   //
 117   // We need *not* fix the return address because currently,
 118   // The PeiCore is executed in flash.
 119   //
 120
 121   //
 122   // Rebase IDT table in permanent memory
 123   //
 124   AsmReadIdtr (&IdtDescriptor);
 125   IdtDescriptor.Base = IdtDescriptor.Base - (UINTN)OldStack + (UINTN)NewStack;
 126
 127   AsmWriteIdtr (&IdtDescriptor);
 128
 129
 130   //
 131   // Program MTRR
 132   //
 133
 134   //
 135   // SecSwitchStack function must be invoked after the memory migration
 136   // immediately, also we need fixup the stack change caused by new call into
 137   // permanent memory.
 138   //
 139   SecSwitchStack (
 140     (UINT32) (UINTN) OldStack,
 141     (UINT32) (UINTN) NewStack
 142     );
 143
 144   SaveAndSetDebugTimerInterrupt (OldStatus);
 145
 146   return EFI_SUCCESS;
 147 }
 148