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   This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php.
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include <PiPei.h>
  16
  17 #include <Ppi/TemporaryRamSupport.h>
  18
  19 #include <Library/BaseMemoryLib.h>
  20 #include <Library/DebugLib.h>
  21 #include <Library/PcdLib.h>
  22 #include <Library/DebugAgentLib.h>
  23
  24 /**
  25   Switch the stack in the temporary memory to the one in the permanent memory.
  26
  27   This function must be invoked after the memory migration immediately. The relative
  28   position of the stack in the temporary and permanent memory is same.
  29
  30   @param[in] TemporaryMemoryBase  Base address of the temporary memory.
  31   @param[in] PermenentMemoryBase  Base address of the permanent memory.
  32 **/
  33 VOID
  34 EFIAPI
  35 SecSwitchStack (
  36   IN UINT32   TemporaryMemoryBase,
  37   IN UINT32   PermenentMemoryBase
  38   );
  39
  40 /**
  41   This service of the TEMPORARY_RAM_SUPPORT_PPI that migrates temporary RAM into
  42   permanent memory.
  43
  44   @param[in] PeiServices            Pointer to the PEI Services Table.
  45   @param[in] TemporaryMemoryBase    Source Address in temporary memory from which the SEC or PEIM will copy the
  46                                     Temporary RAM contents.
  47   @param[in] PermanentMemoryBase    Destination Address in permanent memory into which the SEC or PEIM will copy the
  48                                     Temporary RAM contents.
  49   @param[in] CopySize               Amount of memory to migrate from temporary to permanent memory.
  50
  51   @retval EFI_SUCCESS           The data was successfully returned.
  52   @retval EFI_INVALID_PARAMETER PermanentMemoryBase + CopySize > TemporaryMemoryBase when
  53                                 TemporaryMemoryBase > PermanentMemoryBase.
  54
  55 **/
  56 EFI_STATUS
  57 EFIAPI
  58 SecTemporaryRamSupport (
  59   IN CONST EFI_PEI_SERVICES   **PeiServices,
  60   IN EFI_PHYSICAL_ADDRESS     TemporaryMemoryBase,
  61   IN EFI_PHYSICAL_ADDRESS     PermanentMemoryBase,
  62   IN UINTN                    CopySize
  63   )
  64 {
  65   IA32_DESCRIPTOR   IdtDescriptor;
  66   VOID*             OldHeap;
  67   VOID*             NewHeap;
  68   VOID*             OldStack;
  69   VOID*             NewStack;
  70   DEBUG_AGENT_CONTEXT_POSTMEM_SEC  DebugAgentContext;
  71   BOOLEAN           OldStatus;
  72   UINTN             PeiStackSize;
  73
  74   PeiStackSize = (UINTN)PcdGet32 (PcdPeiTemporaryRamStackSize);
  75   if (PeiStackSize == 0) {
  76     PeiStackSize = (CopySize >> 1);
  77   }
  78
  79   ASSERT (PeiStackSize < CopySize);
  80
  81   //
  82   // |-------------------|---->
  83   // |      Stack        |    PeiStackSize
  84   // |-------------------|---->
  85   // |      Heap         |    PeiTemporayRamSize
  86   // |-------------------|---->  TempRamBase
  87   //
  88   // |-------------------|---->
  89   // |      Heap         |    PeiTemporayRamSize
  90   // |-------------------|---->
  91   // |      Stack        |    PeiStackSize
  92   // |-------------------|---->  PermanentMemoryBase
  93   //
  94
  95   OldHeap = (VOID*)(UINTN)TemporaryMemoryBase;
  96   NewHeap = (VOID*)((UINTN)PermanentMemoryBase + PeiStackSize);
  97
  98   OldStack = (VOID*)((UINTN)TemporaryMemoryBase + CopySize - PeiStackSize);
  99   NewStack = (VOID*)(UINTN)PermanentMemoryBase;
 100
 101   DebugAgentContext.HeapMigrateOffset = (UINTN)NewHeap - (UINTN)OldHeap;
 102   DebugAgentContext.StackMigrateOffset = (UINTN)NewStack - (UINTN)OldStack;
 103
 104   OldStatus = SaveAndSetDebugTimerInterrupt (FALSE);
 105   //
 106   // Initialize Debug Agent to support source level debug in PEI phase after memory ready.
 107   // It will build HOB and fix up the pointer in IDT table.
 108   //
 109   InitializeDebugAgent (DEBUG_AGENT_INIT_POSTMEM_SEC, (VOID *) &DebugAgentContext, NULL);
 110
 111   //
 112   // Migrate Heap
 113   //
 114   CopyMem (NewHeap, OldHeap, CopySize - PeiStackSize);
 115
 116   //
 117   // Migrate Stack
 118   //
 119   CopyMem (NewStack, OldStack, PeiStackSize);
 120
 121
 122   //
 123   // We need *not* fix the return address because currently,
 124   // The PeiCore is executed in flash.
 125   //
 126
 127   //
 128   // Rebase IDT table in permanent memory
 129   //
 130   AsmReadIdtr (&IdtDescriptor);
 131   IdtDescriptor.Base = IdtDescriptor.Base - (UINTN)OldStack + (UINTN)NewStack;
 132
 133   AsmWriteIdtr (&IdtDescriptor);
 134
 135
 136   //
 137   // Program MTRR
 138   //
 139
 140   //
 141   // SecSwitchStack function must be invoked after the memory migration
 142   // immediatly, also we need fixup the stack change caused by new call into
 143   // permenent memory.
 144   //
 145   SecSwitchStack (
 146     (UINT32) (UINTN) OldStack,
 147     (UINT32) (UINTN) NewStack
 148     );
 149
 150   SaveAndSetDebugTimerInterrupt (OldStatus);
 151
 152   return EFI_SUCCESS;
 153 }
 154