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/** @file
Create the variable to save the base address of page table and stack
for transferring into long mode in IA32 capsule PEI.
Copyright (c) 2011 - 2018, 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
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include <Uefi.h>
#include <Protocol/Capsule.h>
#include <Protocol/DxeSmmReadyToLock.h>
#include <Protocol/VariableLock.h>
#include <Guid/CapsuleVendor.h>
#include <Guid/AcpiS3Context.h>
#include <Library/DebugLib.h>
#include <Library/PcdLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiRuntimeServicesTableLib.h>
#include <Library/UefiRuntimeLib.h>
#include <Library/BaseLib.h>
#include <Library/UefiLib.h>
#include <Library/BaseMemoryLib.h>
//
// 8 extra pages for PF handler.
//
#define EXTRA_PAGE_TABLE_PAGES 8
/**
Allocate EfiReservedMemoryType below 4G memory address.
This function allocates EfiReservedMemoryType below 4G memory address.
@param Size Size of memory to allocate.
@return Allocated Address for output.
**/
VOID*
AllocateReservedMemoryBelow4G (
IN UINTN Size
)
{
UINTN Pages;
EFI_PHYSICAL_ADDRESS Address;
EFI_STATUS Status;
VOID* Buffer;
Pages = EFI_SIZE_TO_PAGES (Size);
Address = 0xffffffff;
Status = gBS->AllocatePages (
AllocateMaxAddress,
EfiReservedMemoryType,
Pages,
&Address
);
ASSERT_EFI_ERROR (Status);
Buffer = (VOID *) (UINTN) Address;
ZeroMem (Buffer, Size);
return Buffer;
}
/**
Register callback function upon VariableLockProtocol
to lock EFI_CAPSULE_LONG_MODE_BUFFER_NAME variable to avoid malicious code to update it.
@param[in] Event Event whose notification function is being invoked.
@param[in] Context Pointer to the notification function's context.
**/
VOID
EFIAPI
VariableLockCapsuleLongModeBufferVariable (
IN EFI_EVENT Event,
IN VOID *Context
)
{
EFI_STATUS Status;
EDKII_VARIABLE_LOCK_PROTOCOL *VariableLock;
//
// Mark EFI_CAPSULE_LONG_MODE_BUFFER_NAME variable to read-only if the Variable Lock protocol exists
//
Status = gBS->LocateProtocol (&gEdkiiVariableLockProtocolGuid, NULL, (VOID **) &VariableLock);
if (!EFI_ERROR (Status)) {
Status = VariableLock->RequestToLock (VariableLock, EFI_CAPSULE_LONG_MODE_BUFFER_NAME, &gEfiCapsuleVendorGuid);
ASSERT_EFI_ERROR (Status);
}
}
/**
1. Allocate Reserved memory for capsule PEIM to establish a 1:1 Virtual to Physical mapping.
2. Allocate Reserved memroy as a stack for capsule PEIM to transfer from 32-bit mdoe to 64-bit mode.
**/
VOID
EFIAPI
PrepareContextForCapsulePei (
VOID
)
{
UINTN ExtraPageTablePages;
UINT32 RegEax;
UINT32 RegEdx;
UINTN TotalPagesNum;
UINT8 PhysicalAddressBits;
UINT32 NumberOfPml4EntriesNeeded;
UINT32 NumberOfPdpEntriesNeeded;
BOOLEAN Page1GSupport;
EFI_CAPSULE_LONG_MODE_BUFFER LongModeBuffer;
EFI_STATUS Status;
VOID *Registration;
//
// Calculate the size of page table, allocate the memory.
//
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;
}
}
}
//
// Create 4G page table by default,
// and let PF handler to handle > 4G request.
//
PhysicalAddressBits = 32;
ExtraPageTablePages = EXTRA_PAGE_TABLE_PAGES;
//
// 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;
}
if (!Page1GSupport) {
TotalPagesNum = (NumberOfPdpEntriesNeeded + 1) * NumberOfPml4EntriesNeeded + 1;
} else {
TotalPagesNum = NumberOfPml4EntriesNeeded + 1;
}
TotalPagesNum += ExtraPageTablePages;
DEBUG ((DEBUG_INFO, "CapsuleRuntimeDxe X64 TotalPagesNum - 0x%x pages\n", TotalPagesNum));
LongModeBuffer.PageTableAddress = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocateReservedMemoryBelow4G (EFI_PAGES_TO_SIZE (TotalPagesNum));
ASSERT (LongModeBuffer.PageTableAddress != 0);
//
// Allocate stack
//
LongModeBuffer.StackSize = PcdGet32 (PcdCapsulePeiLongModeStackSize);
LongModeBuffer.StackBaseAddress = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocateReservedMemoryBelow4G (PcdGet32 (PcdCapsulePeiLongModeStackSize));
ASSERT (LongModeBuffer.StackBaseAddress != 0);
Status = gRT->SetVariable (
EFI_CAPSULE_LONG_MODE_BUFFER_NAME,
&gEfiCapsuleVendorGuid,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS,
sizeof (EFI_CAPSULE_LONG_MODE_BUFFER),
&LongModeBuffer
);
if (!EFI_ERROR (Status)) {
//
// Register callback function upon VariableLockProtocol
// to lock EFI_CAPSULE_LONG_MODE_BUFFER_NAME variable to avoid malicious code to update it.
//
EfiCreateProtocolNotifyEvent (
&gEdkiiVariableLockProtocolGuid,
TPL_CALLBACK,
VariableLockCapsuleLongModeBufferVariable,
NULL,
&Registration
);
} else {
DEBUG ((EFI_D_ERROR, "FATAL ERROR: CapsuleLongModeBuffer cannot be saved: %r. Capsule in PEI may fail!\n", Status));
gBS->FreePages (LongModeBuffer.StackBaseAddress, EFI_SIZE_TO_PAGES (LongModeBuffer.StackSize));
}
}
/**
Create the variable to save the base address of page table and stack
for transferring into long mode in IA32 capsule PEI.
**/
VOID
SaveLongModeContext (
VOID
)
{
if ((FeaturePcdGet(PcdSupportUpdateCapsuleReset)) && (FeaturePcdGet (PcdDxeIplSwitchToLongMode))) {
//
// Allocate memory for Capsule IA32 PEIM, it will create page table to transfer to long mode to access capsule above 4GB.
//
PrepareContextForCapsulePei ();
}
}
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