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f3b33289 1/** @file\r
2 x64 Virtual Memory Management Services in the form of an IA-32 driver. \r
3 Used to establish a 1:1 Virtual to Physical Mapping that is required to\r
4 enter Long Mode (x64 64-bit mode).\r
5\r
6 While we make a 1:1 mapping (identity mapping) for all physical pages \r
7 we still need to use the MTRR's to ensure that the cachability attirbutes\r
8 for all memory regions is correct.\r
9\r
10 The basic idea is to use 2MB page table entries where ever possible. If\r
11 more granularity of cachability is required then 4K page tables are used.\r
12\r
13 References:\r
14 1) IA-32 Intel(R) Atchitecture Software Developer's Manual Volume 1:Basic Architecture, Intel\r
15 2) IA-32 Intel(R) Atchitecture Software Developer's Manual Volume 2:Instruction Set Reference, Intel\r
16 3) IA-32 Intel(R) Atchitecture Software Developer's Manual Volume 3:System Programmer's Guide, Intel\r
17\r
18Copyright (c) 2006 - 2008, Intel Corporation. <BR>\r
19All rights reserved. This program and the accompanying materials\r
20are licensed and made available under the terms and conditions of the BSD License\r
21which accompanies this distribution. The full text of the license may be found at\r
22http://opensource.org/licenses/bsd-license.php\r
23\r
24THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
25WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
26\r
27**/ \r
28\r
29#include "DxeIpl.h"\r
30#include "VirtualMemory.h"\r
31\r
f3b33289 32/**\r
33 Allocates and fills in the Page Directory and Page Table Entries to\r
34 establish a 1:1 Virtual to Physical mapping.\r
35\r
36 @param NumberOfProcessorPhysicalAddressBits Number of processor address bits \r
37 to use. Limits the number of page \r
38 table entries to the physical \r
39 address space. \r
40\r
48557c65 41 @return The address of 4 level page map.\r
f3b33289 42\r
43**/\r
44UINTN\r
45CreateIdentityMappingPageTables (\r
46 VOID\r
47 )\r
48{ \r
49 UINT8 PhysicalAddressBits;\r
50 EFI_PHYSICAL_ADDRESS PageAddress;\r
51 UINTN IndexOfPml4Entries;\r
52 UINTN IndexOfPdpEntries;\r
53 UINTN IndexOfPageDirectoryEntries;\r
54 UINTN NumberOfPml4EntriesNeeded;\r
55 UINTN NumberOfPdpEntriesNeeded;\r
56 PAGE_MAP_AND_DIRECTORY_POINTER *PageMapLevel4Entry;\r
57 PAGE_MAP_AND_DIRECTORY_POINTER *PageMap;\r
58 PAGE_MAP_AND_DIRECTORY_POINTER *PageDirectoryPointerEntry;\r
59 PAGE_TABLE_ENTRY *PageDirectoryEntry;\r
60 UINTN TotalPagesNum;\r
61 UINTN BigPageAddress;\r
62 VOID *Hob;\r
63\r
64 //\r
65 // Get physical address bits supported from CPU HOB.\r
66 //\r
67 PhysicalAddressBits = 36;\r
68 \r
69 Hob = GetFirstHob (EFI_HOB_TYPE_CPU);\r
70 if (Hob != NULL) {\r
48557c65 71 PhysicalAddressBits = ((EFI_HOB_CPU *) Hob)->SizeOfMemorySpace;\r
f3b33289 72 }\r
73\r
74 //\r
75 // Calculate the table entries needed.\r
76 //\r
77 if (PhysicalAddressBits <= 39 ) {\r
78 NumberOfPml4EntriesNeeded = 1;\r
79 NumberOfPdpEntriesNeeded = LShiftU64 (1, (PhysicalAddressBits - 30));\r
80 } else {\r
81 NumberOfPml4EntriesNeeded = LShiftU64 (1, (PhysicalAddressBits - 39));\r
82 NumberOfPdpEntriesNeeded = 512;\r
83 }\r
84\r
85 //\r
86 // Pre-allocate big pages to avoid later allocations. \r
87 //\r
88 TotalPagesNum = (NumberOfPdpEntriesNeeded + 1) * NumberOfPml4EntriesNeeded + 1;\r
89 BigPageAddress = (UINTN) AllocatePages (TotalPagesNum);\r
90 ASSERT (BigPageAddress != 0);\r
91\r
92 //\r
93 // By architecture only one PageMapLevel4 exists - so lets allocate storage for it.\r
94 //\r
95 PageMap = (VOID *) BigPageAddress;\r
96 BigPageAddress += EFI_PAGE_SIZE;\r
97\r
98 PageMapLevel4Entry = PageMap;\r
99 PageAddress = 0;\r
100 for (IndexOfPml4Entries = 0; IndexOfPml4Entries < NumberOfPml4EntriesNeeded; IndexOfPml4Entries++, PageMapLevel4Entry++) {\r
101 //\r
102 // Each PML4 entry points to a page of Page Directory Pointer entires.\r
103 // So lets allocate space for them and fill them in in the IndexOfPdpEntries loop.\r
104 //\r
105 PageDirectoryPointerEntry = (VOID *) BigPageAddress;\r
106 BigPageAddress += EFI_PAGE_SIZE;\r
107\r
108 //\r
109 // Make a PML4 Entry\r
110 //\r
111 PageMapLevel4Entry->Uint64 = (UINT64)(UINTN)PageDirectoryPointerEntry;\r
112 PageMapLevel4Entry->Bits.ReadWrite = 1;\r
113 PageMapLevel4Entry->Bits.Present = 1;\r
114\r
115 for (IndexOfPdpEntries = 0; IndexOfPdpEntries < NumberOfPdpEntriesNeeded; IndexOfPdpEntries++, PageDirectoryPointerEntry++) {\r
116 //\r
117 // Each Directory Pointer entries points to a page of Page Directory entires.\r
118 // So allocate space for them and fill them in in the IndexOfPageDirectoryEntries loop.\r
119 // \r
120 PageDirectoryEntry = (VOID *) BigPageAddress;\r
121 BigPageAddress += EFI_PAGE_SIZE;\r
122\r
123 //\r
124 // Fill in a Page Directory Pointer Entries\r
125 //\r
126 PageDirectoryPointerEntry->Uint64 = (UINT64)(UINTN)PageDirectoryEntry;\r
127 PageDirectoryPointerEntry->Bits.ReadWrite = 1;\r
128 PageDirectoryPointerEntry->Bits.Present = 1;\r
129\r
130 for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PageAddress += 0x200000) {\r
131 //\r
132 // Fill in the Page Directory entries\r
133 //\r
134 PageDirectoryEntry->Uint64 = (UINT64)PageAddress;\r
135 PageDirectoryEntry->Bits.ReadWrite = 1;\r
136 PageDirectoryEntry->Bits.Present = 1;\r
137 PageDirectoryEntry->Bits.MustBe1 = 1;\r
138\r
139 }\r
140 }\r
141 }\r
142\r
143 //\r
144 // For the PML4 entries we are not using fill in a null entry.\r
145 // For now we just copy the first entry.\r
146 //\r
147 for (; IndexOfPml4Entries < 512; IndexOfPml4Entries++, PageMapLevel4Entry++) {\r
148 CopyMem (\r
149 PageMapLevel4Entry,\r
150 PageMap,\r
151 sizeof (PAGE_MAP_AND_DIRECTORY_POINTER)\r
152 );\r
153 }\r
154\r
155 return (UINTN)PageMap;\r
156}\r
157\r