--- /dev/null
+/*++\r
+\r
+Copyright (c) 2006 - 2007, Intel Corporation \r
+All rights reserved. This program and the accompanying materials \r
+are licensed and made available under the terms and conditions of the BSD License \r
+which accompanies this distribution. The full text of the license may be found at \r
+http://opensource.org/licenses/bsd-license.php \r
+ \r
+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r
+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r
+\r
+Module Name:\r
+ Paging.c\r
+\r
+Abstract:\r
+\r
+Revision History:\r
+\r
+--*/\r
+\r
+#include "HobGeneration.h"\r
+#include "VirtualMemory.h"\r
+\r
+//\r
+// Create 2M-page table\r
+// PML4 (47:39)\r
+// PDPTE (38:30)\r
+// PDE (29:21)\r
+//\r
+\r
+#define EFI_2M_PAGE_BITS_NUM 21\r
+#define EFI_MAX_ENTRY_BITS_NUM 9\r
+\r
+#define EFI_PAGE_SIZE_4K 0x1000\r
+#define EFI_PAGE_SIZE_2M (1 << EFI_2M_PAGE_BITS_NUM)\r
+\r
+#ifndef MIN\r
+ #define MIN(a, b) ((a) < (b) ? (a) : (b))\r
+#endif\r
+#define ENTRY_NUM(x) ((UINTN)1 << (x))\r
+\r
+UINT8 gPML4BitsNum;\r
+UINT8 gPDPTEBitsNum;\r
+UINT8 gPDEBitsNum;\r
+\r
+UINTN gPageNum2M;\r
+UINTN gPageNum4K;\r
+\r
+VOID\r
+EnableNullPointerProtection (\r
+ UINT8 *PageTable\r
+ )\r
+{\r
+ X64_PAGE_TABLE_ENTRY_4K *PageTableEntry4KB;\r
+\r
+ PageTableEntry4KB = (X64_PAGE_TABLE_ENTRY_4K *) (PageTable + gPageNum2M * EFI_PAGE_SIZE_4K);\r
+ //\r
+ // Fill in the Page Table entries\r
+ // Mark 0~4K as not present\r
+ //\r
+ PageTableEntry4KB->Bits.Present = 0;\r
+\r
+ return ;\r
+}\r
+\r
+VOID\r
+X64Create4KPageTables (\r
+ UINT8 *PageTable\r
+ )\r
+/*++\r
+Routine Description:\r
+ Create 4K-Page-Table for the low 2M memory.\r
+ This will change the previously created 2M-Page-Table-Entry.\r
+--*/\r
+{\r
+ UINT64 PageAddress;\r
+ UINTN PTEIndex;\r
+ X64_PAGE_DIRECTORY_ENTRY_4K *PageDirectoryEntry4KB;\r
+ X64_PAGE_TABLE_ENTRY_4K *PageTableEntry4KB;\r
+\r
+ //\r
+ // Page Table structure 4 level 4K.\r
+ //\r
+ // PageMapLevel4Entry : bits 47-39\r
+ // PageDirectoryPointerEntry : bits 38-30\r
+ // Page Table 4K : PageDirectoryEntry4K : bits 29-21\r
+ // PageTableEntry : bits 20-12\r
+ //\r
+\r
+ PageTableEntry4KB = (X64_PAGE_TABLE_ENTRY_4K *)(PageTable + gPageNum2M * EFI_PAGE_SIZE_4K);\r
+\r
+ PageDirectoryEntry4KB = (X64_PAGE_DIRECTORY_ENTRY_4K *) (PageTable + 2 * EFI_PAGE_SIZE_4K);\r
+ PageDirectoryEntry4KB->Uint64 = (UINT64)(UINTN)PageTableEntry4KB;\r
+ PageDirectoryEntry4KB->Bits.ReadWrite = 1;\r
+ PageDirectoryEntry4KB->Bits.Present = 1;\r
+ PageDirectoryEntry4KB->Bits.MustBeZero = 0;\r
+\r
+ for (PTEIndex = 0, PageAddress = 0; \r
+ PTEIndex < ENTRY_NUM (EFI_MAX_ENTRY_BITS_NUM); \r
+ PTEIndex++, PageTableEntry4KB++, PageAddress += EFI_PAGE_SIZE_4K\r
+ ) {\r
+ //\r
+ // Fill in the Page Table entries\r
+ //\r
+ PageTableEntry4KB->Uint64 = (UINT64)PageAddress;\r
+ PageTableEntry4KB->Bits.ReadWrite = 1;\r
+ PageTableEntry4KB->Bits.Present = 1;\r
+ }\r
+\r
+ return ;\r
+}\r
+\r
+VOID\r
+X64Create2MPageTables (\r
+ UINT8 *PageTable\r
+ )\r
+{\r
+ UINT64 PageAddress;\r
+ UINT8 *TempPageTable;\r
+ UINTN PML4Index;\r
+ UINTN PDPTEIndex;\r
+ UINTN PDEIndex;\r
+ X64_PAGE_MAP_AND_DIRECTORY_POINTER_2MB_4K *PageMapLevel4Entry;\r
+ X64_PAGE_MAP_AND_DIRECTORY_POINTER_2MB_4K *PageDirectoryPointerEntry;\r
+ X64_PAGE_TABLE_ENTRY_2M *PageDirectoryEntry2MB;\r
+\r
+ TempPageTable = PageTable;\r
+ PageAddress = 0;\r
+\r
+ //\r
+ // Page Table structure 3 level 2MB.\r
+ //\r
+ // PageMapLevel4Entry : bits 47-39\r
+ // PageDirectoryPointerEntry : bits 38-30\r
+ // Page Table 2MB : PageDirectoryEntry2M : bits 29-21\r
+ //\r
+\r
+ PageMapLevel4Entry = (X64_PAGE_MAP_AND_DIRECTORY_POINTER_2MB_4K *)TempPageTable;\r
+\r
+ for (PML4Index = 0; PML4Index < ENTRY_NUM (gPML4BitsNum); PML4Index++, PageMapLevel4Entry++) {\r
+ //\r
+ // Each PML4 entry points to a page of Page Directory Pointer entires.\r
+ // \r
+ TempPageTable += EFI_PAGE_SIZE_4K;\r
+ PageDirectoryPointerEntry = (X64_PAGE_MAP_AND_DIRECTORY_POINTER_2MB_4K *)TempPageTable;\r
+\r
+ //\r
+ // Make a PML4 Entry\r
+ //\r
+ PageMapLevel4Entry->Uint64 = (UINT64)(UINTN)(TempPageTable);\r
+ PageMapLevel4Entry->Bits.ReadWrite = 1;\r
+ PageMapLevel4Entry->Bits.Present = 1;\r
+\r
+ for (PDPTEIndex = 0; PDPTEIndex < ENTRY_NUM (gPDPTEBitsNum); PDPTEIndex++, PageDirectoryPointerEntry++) {\r
+ //\r
+ // Each Directory Pointer entries points to a page of Page Directory entires.\r
+ // \r
+ TempPageTable += EFI_PAGE_SIZE_4K;\r
+ PageDirectoryEntry2MB = (X64_PAGE_TABLE_ENTRY_2M *)TempPageTable;\r
+\r
+ //\r
+ // Fill in a Page Directory Pointer Entries\r
+ //\r
+ PageDirectoryPointerEntry->Uint64 = (UINT64)(UINTN)(TempPageTable);\r
+ PageDirectoryPointerEntry->Bits.ReadWrite = 1;\r
+ PageDirectoryPointerEntry->Bits.Present = 1;\r
+\r
+ for (PDEIndex = 0; PDEIndex < ENTRY_NUM (gPDEBitsNum); PDEIndex++, PageDirectoryEntry2MB++) {\r
+ //\r
+ // Fill in the Page Directory entries\r
+ //\r
+ PageDirectoryEntry2MB->Uint64 = (UINT64)PageAddress;\r
+ PageDirectoryEntry2MB->Bits.ReadWrite = 1;\r
+ PageDirectoryEntry2MB->Bits.Present = 1;\r
+ PageDirectoryEntry2MB->Bits.MustBe1 = 1;\r
+\r
+ PageAddress += EFI_PAGE_SIZE_2M;\r
+ }\r
+ }\r
+ }\r
+\r
+ return ;\r
+}\r
+\r
+VOID *\r
+PreparePageTable (\r
+ VOID *PageNumberTop,\r
+ UINT8 SizeOfMemorySpace\r
+ )\r
+/*++\r
+Description:\r
+ Generate pagetable below PageNumberTop, \r
+ and return the bottom address of pagetable for putting other things later.\r
+--*/\r
+{\r
+ VOID *PageNumberBase;\r
+\r
+ SizeOfMemorySpace -= EFI_2M_PAGE_BITS_NUM;\r
+ gPDEBitsNum = MIN (SizeOfMemorySpace, EFI_MAX_ENTRY_BITS_NUM);\r
+ SizeOfMemorySpace = SizeOfMemorySpace - gPDEBitsNum;\r
+ gPDPTEBitsNum = MIN (SizeOfMemorySpace, EFI_MAX_ENTRY_BITS_NUM);\r
+ SizeOfMemorySpace = SizeOfMemorySpace - gPDPTEBitsNum;\r
+ gPML4BitsNum = SizeOfMemorySpace;\r
+ if (gPML4BitsNum > EFI_MAX_ENTRY_BITS_NUM) {\r
+ return NULL;\r
+ }\r
+\r
+ //\r
+ // Suppose we have:\r
+ // 2MPage:\r
+ // Entry: PML4 -> PDPTE -> PDE -> Page\r
+ // EntryNum: a b c\r
+ // then\r
+ // Occupy4KPage: 1 a a*b\r
+ // \r
+ // 2M 4KPage:\r
+ // Entry: PTE -> Page\r
+ // EntryNum: 512\r
+ // then\r
+ // Occupy4KPage: 1\r
+ // \r
+\r
+ gPageNum2M = 1 + ENTRY_NUM (gPML4BitsNum) + ENTRY_NUM (gPML4BitsNum + gPDPTEBitsNum);\r
+ gPageNum4K = 1;\r
+\r
+\r
+ PageNumberBase = (VOID *)((UINTN)PageNumberTop - (gPageNum2M + gPageNum4K) * EFI_PAGE_SIZE_4K);\r
+ ZeroMem (PageNumberBase, (gPageNum2M + gPageNum4K) * EFI_PAGE_SIZE_4K);\r
+\r
+ X64Create2MPageTables (PageNumberBase);\r
+ X64Create4KPageTables (PageNumberBase);\r
+ //\r
+ // Not enable NULL Pointer Protection if using INTx call\r
+ //\r
+// EnableNullPointerProtection (PageNumberBase);\r
+\r
+ return PageNumberBase;\r
+}\r
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