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
SecTemporaryRamSupport(IN CONST EFI_PEI_SERVICES ** PeiServices,IN EFI_PHYSICAL_ADDRESS TemporaryMemoryBase,IN EFI_PHYSICAL_ADDRESS PermanentMemoryBase,IN UINTN CopySize)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 
155