diff options
Diffstat (limited to 'OvmfPkg/Sec/SecMain.c')
| -rw-r--r-- | OvmfPkg/Sec/SecMain.c | 144 |
1 files changed, 142 insertions, 2 deletions
diff --git a/OvmfPkg/Sec/SecMain.c b/OvmfPkg/Sec/SecMain.c index 3882dadd63..56081c9b44 100644 --- a/OvmfPkg/Sec/SecMain.c +++ b/OvmfPkg/Sec/SecMain.c @@ -1,7 +1,7 @@ /** @file Main SEC phase code. Transitions to PEI. - Copyright (c) 2008 - 2011, Intel Corporation. All rights reserved.<BR> + Copyright (c) 2008 - 2013, Intel Corporation. All rights reserved.<BR> This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License @@ -31,6 +31,8 @@ #include <Ppi/TemporaryRamSupport.h> +#include <IndustryStandard/X64Paging.h> + #define SEC_IDT_ENTRY_COUNT 34 typedef struct _SEC_IDT_TABLE { @@ -523,6 +525,137 @@ FindImageBase ( } } +#if defined (MDE_CPU_X64) +/** + Allocates and fills in the Page Directory and Page Table Entries to + establish a 1:1 Virtual to Physical mapping. + + @param Location Memory to build the page tables in + +**/ +VOID +Create4GbIdentityMappingPageTables ( + VOID *Location + ) +{ + UINT32 RegEax; + UINT32 RegEdx; + EFI_PHYSICAL_ADDRESS PageAddress; + UINTN IndexOfPml4Entries; + UINTN IndexOfPdpEntries; + UINTN IndexOfPageDirectoryEntries; + UINT32 NumberOfPml4EntriesNeeded; + UINT32 NumberOfPdpEntriesNeeded; + X64_PAGE_MAP_AND_DIRECTORY_POINTER *PageMapLevel4Entry; + X64_PAGE_MAP_AND_DIRECTORY_POINTER *PageMap; + X64_PAGE_MAP_AND_DIRECTORY_POINTER *PageDirectoryPointerEntry; + X64_PAGE_TABLE_ENTRY *PageDirectoryEntry; + UINTN NextAllocAddress; + BOOLEAN Page1GSupport; + X64_PAGE_TABLE_1G_ENTRY *PageDirectory1GEntry; + + Page1GSupport = FALSE; + AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL); + if (RegEax >= 0x80000001) { + AsmCpuid (0x80000001, NULL, NULL, NULL, &RegEdx); + if ((RegEdx & BIT26) != 0) { + Page1GSupport = TRUE; + } + } + + // + // Only build entries for the first 4GB at this stage. + // + NumberOfPml4EntriesNeeded = 1; + NumberOfPdpEntriesNeeded = 4; + + NextAllocAddress = (UINTN) Location; + + // + // By architecture only one PageMapLevel4 exists - so lets allocate storage for it. + // + PageMap = (VOID *) NextAllocAddress; + NextAllocAddress += SIZE_4KB; + + PageMapLevel4Entry = PageMap; + PageAddress = 0; + for (IndexOfPml4Entries = 0; IndexOfPml4Entries < NumberOfPml4EntriesNeeded; IndexOfPml4Entries++, PageMapLevel4Entry++) { + // + // Each PML4 entry points to a page of Page Directory Pointer entires. + // So lets allocate space for them and fill them in in the IndexOfPdpEntries loop. + // + PageDirectoryPointerEntry = (VOID *) NextAllocAddress; + NextAllocAddress += SIZE_4KB; + + // + // Make a PML4 Entry + // + PageMapLevel4Entry->Uint64 = (UINT64)(UINTN)PageDirectoryPointerEntry; + PageMapLevel4Entry->Bits.ReadWrite = 1; + PageMapLevel4Entry->Bits.Present = 1; + + if (Page1GSupport) { + PageDirectory1GEntry = (VOID *) PageDirectoryPointerEntry; + + for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectory1GEntry++, PageAddress += SIZE_1GB) { + // + // Fill in the Page Directory entries + // + PageDirectory1GEntry->Uint64 = (UINT64)PageAddress; + PageDirectory1GEntry->Bits.ReadWrite = 1; + PageDirectory1GEntry->Bits.Present = 1; + PageDirectory1GEntry->Bits.MustBe1 = 1; + } + } else { + for (IndexOfPdpEntries = 0; IndexOfPdpEntries < NumberOfPdpEntriesNeeded; IndexOfPdpEntries++, PageDirectoryPointerEntry++) { + // + // Each Directory Pointer entries points to a page of Page Directory entires. + // So allocate space for them and fill them in in the IndexOfPageDirectoryEntries loop. + // + PageDirectoryEntry = (VOID *) NextAllocAddress; + NextAllocAddress += SIZE_4KB; + + // + // Fill in a Page Directory Pointer Entries + // + PageDirectoryPointerEntry->Uint64 = (UINT64)(UINTN)PageDirectoryEntry; + PageDirectoryPointerEntry->Bits.ReadWrite = 1; + PageDirectoryPointerEntry->Bits.Present = 1; + + for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PageAddress += SIZE_2MB) { + // + // Fill in the Page Directory entries + // + PageDirectoryEntry->Uint64 = (UINT64)PageAddress; + PageDirectoryEntry->Bits.ReadWrite = 1; + PageDirectoryEntry->Bits.Present = 1; + PageDirectoryEntry->Bits.MustBe1 = 1; + } + } + + for (; IndexOfPdpEntries < 512; IndexOfPdpEntries++, PageDirectoryPointerEntry++) { + ZeroMem ( + PageDirectoryPointerEntry, + sizeof(X64_PAGE_MAP_AND_DIRECTORY_POINTER) + ); + } + } + } + + // + // For the PML4 entries we are not using fill in a null entry. + // + for (; IndexOfPml4Entries < 512; IndexOfPml4Entries++, PageMapLevel4Entry++) { + ZeroMem ( + PageMapLevel4Entry, + sizeof (X64_PAGE_MAP_AND_DIRECTORY_POINTER) + ); + } + + AsmWriteCr3 ((UINTN) PageMap); +} +#endif + /* Find and return Pei Core entry point. @@ -645,7 +778,14 @@ SecCoreStartupWithStack ( // IoWrite8 (0x21, 0xff); IoWrite8 (0xA1, 0xff); - + +#if defined (MDE_CPU_X64) + // + // Create Identity Mapped Pages in RAM + // + Create4GbIdentityMappingPageTables (TopOfCurrentStack); +#endif + // // Initialize Debug Agent to support source level debug in SEC/PEI phases before memory ready. // |