/**
Split 1G page to 2M.
@param[in] PhysicalAddress Start physical address the 1G page covered.
@param[in, out] PageEntry1G Pointer to 1G page entry.
@param[in] StackBase Stack base address.
@param[in] StackSize Stack size.
**/
VOID
Split1GPageTo2M (
IN EFI_PHYSICAL_ADDRESS PhysicalAddress,
IN OUT UINT64 *PageEntry1G,
IN EFI_PHYSICAL_ADDRESS StackBase,
IN UINTN StackSize
)
{
EFI_PHYSICAL_ADDRESS PhysicalAddress2M;
UINTN IndexOfPageDirectoryEntries;
PAGE_TABLE_ENTRY *PageDirectoryEntry;
PageDirectoryEntry = AllocatePages (1);
//
// Fill in 1G page entry.
//
*PageEntry1G = (UINT64) (UINTN) PageDirectoryEntry | IA32_PG_P | IA32_PG_RW;
PhysicalAddress2M = PhysicalAddress;
for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PhysicalAddress2M += SIZE_2MB) {
if ((PhysicalAddress2M < StackBase + StackSize) && ((PhysicalAddress2M + SIZE_2MB) > StackBase)) {
//
// Need to split this 2M page that covers stack range.
//
Split2MPageTo4K (PhysicalAddress2M, (UINT64 *) PageDirectoryEntry, StackBase, StackSize);
} else {
//
// Fill in the Page Directory entries
//
PageDirectoryEntry->Uint64 = (UINT64) PhysicalAddress2M;
PageDirectoryEntry->Bits.ReadWrite = 1;
PageDirectoryEntry->Bits.Present = 1;
PageDirectoryEntry->Bits.MustBe1 = 1;
}
}
}
/**
Allocates and fills in the Page Directory and Page Table Entries to
establish a 1:1 Virtual to Physical mapping.
@param[in] StackBase Stack base address.
@param[in] StackSize Stack size.
@return The address of 4 level page map.
**/
UINTN
CreateIdentityMappingPageTables (
IN EFI_PHYSICAL_ADDRESS StackBase,
IN UINTN StackSize
)
{
UINT32 RegEax;
UINT32 RegEdx;
UINT8 PhysicalAddressBits;
EFI_PHYSICAL_ADDRESS PageAddress;
UINTN IndexOfPml4Entries;
UINTN IndexOfPdpEntries;
UINTN IndexOfPageDirectoryEntries;
UINT32 NumberOfPml4EntriesNeeded;
UINT32 NumberOfPdpEntriesNeeded;
PAGE_MAP_AND_DIRECTORY_POINTER *PageMapLevel4Entry;
PAGE_MAP_AND_DIRECTORY_POINTER *PageMap;
PAGE_MAP_AND_DIRECTORY_POINTER *PageDirectoryPointerEntry;
PAGE_TABLE_ENTRY *PageDirectoryEntry;
UINTN TotalPagesNum;
UINTN BigPageAddress;
VOID *Hob;
BOOLEAN Page1GSupport;
PAGE_TABLE_1G_ENTRY *PageDirectory1GEntry;
Page1GSupport = FALSE;
if (PcdGetBool(PcdUse1GPageTable)) {
AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);
if (RegEax >= 0x80000001) {
AsmCpuid (0x80000001, NULL, NULL, NULL, &RegEdx);
if ((RegEdx & BIT26) != 0) {
Page1GSupport = TRUE;
}
}
}
//
// Get physical address bits supported.
//
Hob = GetFirstHob (EFI_HOB_TYPE_CPU);
if (Hob != NULL) {
PhysicalAddressBits = ((EFI_HOB_CPU *) Hob)->SizeOfMemorySpace;
} else {
AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);
if (RegEax >= 0x80000008) {
AsmCpuid (0x80000008, &RegEax, NULL, NULL, NULL);
PhysicalAddressBits = (UINT8) RegEax;
} else {
PhysicalAddressBits = 36;
}
}
//
// IA-32e paging translates 48-bit linear addresses to 52-bit physical addresses.
//
ASSERT (PhysicalAddressBits <= 52);
if (PhysicalAddressBits > 48) {
PhysicalAddressBits = 48;
}
//
// Calculate the table entries needed.
//
if (PhysicalAddressBits <= 39 ) {
NumberOfPml4EntriesNeeded = 1;
NumberOfPdpEntriesNeeded = (UINT32)LShiftU64 (1, (PhysicalAddressBits - 30));
} else {
NumberOfPml4EntriesNeeded = (UINT32)LShiftU64 (1, (PhysicalAddressBits - 39));
NumberOfPdpEntriesNeeded = 512;
}
//
// Pre-allocate big pages to avoid later allocations.
//
if (!Page1GSupport) {
TotalPagesNum = (NumberOfPdpEntriesNeeded + 1) * NumberOfPml4EntriesNeeded + 1;
} else {
TotalPagesNum = NumberOfPml4EntriesNeeded + 1;
}
BigPageAddress = (UINTN) AllocatePages (TotalPagesNum);
ASSERT (BigPageAddress != 0);
//
// By architecture only one PageMapLevel4 exists - so lets allocate storage for it.
//
PageMap = (VOID *) BigPageAddress;
BigPageAddress += 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 *) BigPageAddress;
BigPageAddress += 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) {
if (PcdGetBool (PcdSetNxForStack) && (PageAddress < StackBase + StackSize) && ((PageAddress + SIZE_1GB) > StackBase)) {
Split1GPageTo2M (PageAddress, (UINT64 *) PageDirectory1GEntry, StackBase, StackSize);
} else {
//
// 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 *) BigPageAddress;
BigPageAddress += 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) {
if (PcdGetBool (PcdSetNxForStack) && (PageAddress < StackBase + StackSize) && ((PageAddress + SIZE_2MB) > StackBase)) {
//
// Need to split this 2M page that covers stack range.
//
Split2MPageTo4K (PageAddress, (UINT64 *) PageDirectoryEntry, StackBase, StackSize);
} else {
//
// 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(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 (PAGE_MAP_AND_DIRECTORY_POINTER)
);
}
if (PcdGetBool (PcdSetNxForStack)) {
EnableExecuteDisableBit ();
}
return (UINTN)PageMap;
}
/**
Allocates and fills in the Page Directory and Page Table Entries to
establish a 4G page table.
@param[in] StackBase Stack base address.
@param[in] StackSize Stack size.
@return The address of page table.
**/
UINTN
Create4GPageTablesIa32Pae (
IN EFI_PHYSICAL_ADDRESS StackBase,
IN UINTN StackSize
)
{
UINT8 PhysicalAddressBits;
EFI_PHYSICAL_ADDRESS PhysicalAddress;
UINTN IndexOfPdpEntries;
UINTN IndexOfPageDirectoryEntries;
UINT32 NumberOfPdpEntriesNeeded;
PAGE_MAP_AND_DIRECTORY_POINTER *PageMap;
PAGE_MAP_AND_DIRECTORY_POINTER *PageDirectoryPointerEntry;
PAGE_TABLE_ENTRY *PageDirectoryEntry;
UINTN TotalPagesNum;
UINTN PageAddress;
UINT64 AddressEncMask;
//
// Make sure AddressEncMask is contained to smallest supported address field
//
AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64;
PhysicalAddressBits = 32;
//
// Calculate the table entries needed.
//
NumberOfPdpEntriesNeeded = (UINT32) LShiftU64 (1, (PhysicalAddressBits - 30));
TotalPagesNum = NumberOfPdpEntriesNeeded + 1;
PageAddress = (UINTN) AllocatePageTableMemory (TotalPagesNum);
ASSERT (PageAddress != 0);
PageMap = (VOID *) PageAddress;
PageAddress += SIZE_4KB;
PageDirectoryPointerEntry = PageMap;
PhysicalAddress = 0;
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 *) PageAddress;
PageAddress += SIZE_4KB;
//
// Fill in a Page Directory Pointer Entries
//
PageDirectoryPointerEntry->Uint64 = (UINT64) (UINTN) PageDirectoryEntry | AddressEncMask;
PageDirectoryPointerEntry->Bits.Present = 1;
for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PhysicalAddress += SIZE_2MB) {
if ((IsNullDetectionEnabled () && PhysicalAddress == 0)
|| ((PhysicalAddress < StackBase + StackSize)
&& ((PhysicalAddress + SIZE_2MB) > StackBase))) {
//
// Need to split this 2M page that covers stack range.
//
Split2MPageTo4K (PhysicalAddress, (UINT64 *) PageDirectoryEntry, StackBase, StackSize);
} else {
//
// Fill in the Page Directory entries
//
PageDirectoryEntry->Uint64 = (UINT64) PhysicalAddress | AddressEncMask;
PageDirectoryEntry->Bits.ReadWrite = 1;
PageDirectoryEntry->Bits.Present = 1;
PageDirectoryEntry->Bits.MustBe1 = 1;
}
}
}
for (; IndexOfPdpEntries < 512; IndexOfPdpEntries++, PageDirectoryPointerEntry++) {
ZeroMem (
PageDirectoryPointerEntry,
sizeof (PAGE_MAP_AND_DIRECTORY_POINTER)
);
}
//
// Protect the page table by marking the memory used for page table to be
// read-only.
//
EnablePageTableProtection ((UINTN)PageMap, FALSE);
return (UINTN) PageMap;
}