CSM code has to access memory below 4096 (BDA, int vector, etc.). If NULL
pointer detection is enabled, the page 0 must be enabled temporarily before
accessing it and disabled again afterwards. Otherwise page fault will be
triggered.
Cc: Jiewen Yao <jiewen....@intel.com>
Cc: Eric Dong <eric.d...@intel.com>
Cc: Star Zeng <star.z...@intel.com>
Cc: Laszlo Ersek <ler...@redhat.com>
Cc: Justen, Jordan L <jordan.l.jus...@intel.com>
Cc: Kinney, Michael D <michael.d.kin...@intel.com>
Cc: Wolman, Ayellet <ayellet.wol...@intel.com>
Suggested-by: Wolman, Ayellet <ayellet.wol...@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Wang, Jian J <jian.j.w...@intel.com>
---
.../Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c | 10 +++-
.../Csm/BiosThunk/KeyboardDxe/BiosKeyboard.h | 18 +++++++
.../Csm/BiosThunk/KeyboardDxe/KeyboardDxe.inf | 2 +
.../Csm/LegacyBiosDxe/LegacyBda.c | 4 ++
.../Csm/LegacyBiosDxe/LegacyBios.c | 55 ++++++++++++++++++----
.../Csm/LegacyBiosDxe/LegacyBiosDxe.inf | 2 +
.../Csm/LegacyBiosDxe/LegacyBiosInterface.h | 23 +++++++++
.../Csm/LegacyBiosDxe/LegacyBootSupport.c | 33 ++++++++++---
.../Csm/LegacyBiosDxe/LegacyPci.c | 17 ++++++-
IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c | 41 ++++++++++------
10 files changed, 173 insertions(+), 32 deletions(-)
diff --git a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c
b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c
index 7308523ad8..96148ae367 100644
--- a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c
+++ b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.c
@@ -248,7 +248,7 @@ BiosKeyboardDriverBindingStart (
//
// Allocate the private device structure
//
- BiosKeyboardPrivate = (BIOS_KEYBOARD_DEV *) AllocateZeroPool (sizeof
(BIOS_KEYBOARD_DEV));
+ BiosKeyboardPrivate = (BIOS_KEYBOARD_DEV *) AllocateZeroPool (sizeof
(BIOS_KEYBOARD_DEV));
if (NULL == BiosKeyboardPrivate) {
Status = EFI_OUT_OF_RESOURCES;
goto Done;
@@ -281,6 +281,9 @@ BiosKeyboardDriverBindingStart (
BiosKeyboardPrivate->SimpleTextInputEx.UnregisterKeyNotify =
BiosKeyboardUnregisterKeyNotify;
InitializeListHead (&BiosKeyboardPrivate->NotifyList);
+ Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **)
&BiosKeyboardPrivate->Cpu);
+ ASSERT_EFI_ERROR(Status);
+
//
// Report that the keyboard is being enabled
//
@@ -1842,7 +1845,9 @@ BiosKeyboardTimerHandler (
//
// Clear the CTRL and ALT BDA flag
//
- KbFlag1 = *((UINT8 *) (UINTN) 0x417); // read the STATUS FLAGS 1
+ DISABLE_NULL_DETECTION(BiosKeyboardPrivate);
+
+ KbFlag1 = *((UINT8 *) (UINTN) 0x417); // read the STATUS FLAGS 1
KbFlag2 = *((UINT8 *) (UINTN) 0x418); // read STATUS FLAGS 2
DEBUG_CODE (
@@ -1916,6 +1921,7 @@ BiosKeyboardTimerHandler (
KbFlag1 &= ~0x0C;
*((UINT8 *) (UINTN) 0x417) = KbFlag1;
+ ENABLE_NULL_DETECTION(BiosKeyboardPrivate);
//
// Output EFI input key and shift/toggle state
diff --git a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.h
b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.h
index 0bf28ea140..b717ef676b 100644
--- a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.h
+++ b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.h
@@ -26,6 +26,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
EXPRESS OR IMPLIED.
#include <Protocol/IsaIo.h>
#include <Protocol/DevicePath.h>
#include <Protocol/Ps2Policy.h>
+#include <Protocol/Cpu.h>
#include <Library/DebugLib.h>
#include <Library/UefiLib.h>
@@ -212,6 +213,7 @@ typedef struct {
EFI_HANDLE Handle;
EFI_LEGACY_BIOS_PROTOCOL *LegacyBios;
EFI_ISA_IO_PROTOCOL *IsaIo;
+ EFI_CPU_ARCH_PROTOCOL *Cpu;
EFI_SIMPLE_TEXT_INPUT_PROTOCOL SimpleTextIn;
EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL SimpleTextInputEx;
UINT16 DataRegisterAddress;
@@ -242,6 +244,22 @@ typedef struct {
BIOS_KEYBOARD_DEV_SIGNATURE \
)
+//
+// CSM needs to access memory between 0-4095, which will cause page fault
exception
+// if NULL pointer detection mechanism is enabled. Following macros can be used
+// to disable/enable NULL pointer detection before/after accessing those
memory.
+//
+#define NULL_POINTER_DETECTION_ENABLED
((PcdGet8(PcdNullPointerDetectionPropertyMask) & BIT0) != 0)
+#define DISABLE_NULL_DETECTION(Instance)
\
+ if (NULL_POINTER_DETECTION_ENABLED && (Instance)->Cpu != NULL) {
\
+ (Instance)->Cpu->SetMemoryAttributes((Instance)->Cpu, 0, EFI_PAGE_SIZE,
0); \
+ }
+
+#define ENABLE_NULL_DETECTION(Instance)
\
+ if (NULL_POINTER_DETECTION_ENABLED && (Instance)->Cpu != NULL) {
\
+ (Instance)->Cpu->SetMemoryAttributes((Instance)->Cpu, 0, EFI_PAGE_SIZE,
EFI_MEMORY_RP); \
+ }
+
//
// Global Variables
//
diff --git a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/KeyboardDxe.inf
b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/KeyboardDxe.inf
index 4d4536466c..4291a10123 100644
--- a/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/KeyboardDxe.inf
+++ b/IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/KeyboardDxe.inf
@@ -67,12 +67,14 @@
gEfiSimpleTextInputExProtocolGuid ## BY_START
gEfiLegacyBiosProtocolGuid ## CONSUMES
gEfiPs2PolicyProtocolGuid ## SOMETIMES_CONSUMES
+ gEfiCpuArchProtocolGuid ## SOMETIMES_CONSUMES
[FeaturePcd]
gEfiMdeModulePkgTokenSpaceGuid.PcdPs2KbdExtendedVerification|FALSE ##
CONSUMES
[Pcd]
gEfiMdeModulePkgTokenSpaceGuid.PcdFastPS2Detection ##
SOMETIMES_CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask ##
CONSUMES
[UserExtensions.TianoCore."ExtraFiles"]
KeyboardDxeExtra.uni
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBda.c
b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBda.c
index c45d5d4c3e..e7cee4b8a3 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBda.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBda.c
@@ -34,6 +34,8 @@ LegacyBiosInitBda (
BDA_STRUC *Bda;
UINT8 *Ebda;
+ DISABLE_NULL_DETECTION(Private);
+
Bda = (BDA_STRUC *) ((UINTN) 0x400);
Ebda = (UINT8 *) ((UINTN) 0x9fc00);
@@ -62,5 +64,7 @@ LegacyBiosInitBda (
*Ebda = 0x01;
+ ENABLE_NULL_DETECTION(Private);
+
return EFI_SUCCESS;
}
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBios.c
b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBios.c
index 3ead2d9828..c3ef542ea3 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBios.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBios.c
@@ -40,6 +40,7 @@ VOID *mRuntimeSmbiosEntryPoint = NULL;
EFI_PHYSICAL_ADDRESS mReserveSmbiosEntryPoint = 0;
EFI_PHYSICAL_ADDRESS mStructureTableAddress = 0;
UINTN mStructureTablePages = 0;
+BOOLEAN mEndOfDxe = FALSE;
/**
Do an AllocatePages () of type AllocateMaxAddress for EfiBootServicesCode
@@ -765,6 +766,26 @@ InstallSmbiosEventCallback (
}
}
+/**
+ Callback function to toggle EndOfDxe status. NULL pointer detection needs
this
+ status to decide if it's necessary to change attributes of page 0.
+
+ @param Event Event whose notification function is being
invoked.
+ @param Context The pointer to the notification function's
context,
+ which is implementation-dependent.
+
+**/
+VOID
+EFIAPI
+ToggleEndOfDxeStatus (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ )
+{
+ mEndOfDxe = TRUE;
+ return;
+}
+
/**
Install Driver to produce Legacy BIOS protocol.
@@ -802,6 +823,7 @@ LegacyBiosInstall (
UINT64 Length;
UINT8 *SecureBoot;
EFI_EVENT InstallSmbiosEvent;
+ EFI_EVENT EndOfDxeEvent;
//
// Load this driver's image to memory
@@ -964,8 +986,10 @@ LegacyBiosInstall (
// Initialize region from 0x0000 to 4k. This initializes interrupt vector
// range.
//
- gBS->SetMem ((VOID *) ClearPtr, 0x400, INITIAL_VALUE_BELOW_1K);
- ZeroMem ((VOID *) ((UINTN)ClearPtr + 0x400), 0xC00);
+ DISABLE_NULL_DETECTION(Private);
+ gBS->SetMem ((VOID *) ClearPtr, 0x400, INITIAL_VALUE_BELOW_1K);
+ ZeroMem ((VOID *) ((UINTN)ClearPtr + 0x400), 0xC00);
+ ENABLE_NULL_DETECTION(Private);
//
// Allocate pages for OPROM usage
@@ -1104,12 +1128,14 @@ LegacyBiosInstall (
//
// Save Unexpected interrupt vector so can restore it just prior to boot
//
- BaseVectorMaster = (UINT32 *) (sizeof (UINT32) *
PROTECTED_MODE_BASE_VECTOR_MASTER);
- Private->BiosUnexpectedInt = BaseVectorMaster[0];
- IntRedirCode = (UINT32) (UINTN) Private->IntThunk->InterruptRedirectionCode;
- for (Index = 0; Index < 8; Index++) {
- BaseVectorMaster[Index] = (EFI_SEGMENT (IntRedirCode + Index * 4) << 16) |
EFI_OFFSET (IntRedirCode + Index * 4);
- }
+ DISABLE_NULL_DETECTION(Private);
+ BaseVectorMaster = (UINT32 *) (sizeof (UINT32) *
PROTECTED_MODE_BASE_VECTOR_MASTER);
+ Private->BiosUnexpectedInt = BaseVectorMaster[0];
+ IntRedirCode = (UINT32) (UINTN)
Private->IntThunk->InterruptRedirectionCode;
+ for (Index = 0; Index < 8; Index++) {
+ BaseVectorMaster[Index] = (EFI_SEGMENT (IntRedirCode + Index * 4) << 16)
| EFI_OFFSET (IntRedirCode + Index * 4);
+ }
+ ENABLE_NULL_DETECTION(Private);
//
// Save EFI value
//
@@ -1133,6 +1159,19 @@ LegacyBiosInstall (
);
ASSERT_EFI_ERROR (Status);
+ //
+ // Create callback to update status of EndOfDxe, which is needed by NULL
pointer detection
+ //
+ Status = gBS->CreateEventEx (
+ EVT_NOTIFY_SIGNAL,
+ TPL_NOTIFY,
+ ToggleEndOfDxeStatus,
+ NULL,
+ &gEfiEndOfDxeEventGroupGuid,
+ &EndOfDxeEvent
+ );
+ ASSERT_EFI_ERROR (Status);
+
//
// Make a new handle and install the protocol
//
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosDxe.inf
b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosDxe.inf
index 48473a0713..10dc392800 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosDxe.inf
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosDxe.inf
@@ -108,6 +108,7 @@
gEfiDiskInfoIdeInterfaceGuid ## SOMETIMES_CONSUMES ##GUID
#Used in LegacyBiosBuildIdeData() to assure device is a disk
gEfiSmbiosTableGuid ## SOMETIMES_CONSUMES
##SystemTable
gEfiLegacyBiosGuid ## SOMETIMES_CONSUMES ##GUID
#Used in LegacyBiosInstallVgaRom() to locate handle buffer
+ gEfiEndOfDxeEventGroupGuid
[Guids.IA32]
gEfiAcpi20TableGuid ## SOMETIMES_CONSUMES
##SystemTable
@@ -147,6 +148,7 @@
gEfiIntelFrameworkModulePkgTokenSpaceGuid.PcdHighPmmMemorySize ##
CONSUMES
gEfiIntelFrameworkModulePkgTokenSpaceGuid.PcdOpromReservedMemoryBase ##
CONSUMES
gEfiIntelFrameworkModulePkgTokenSpaceGuid.PcdOpromReservedMemorySize ##
CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask ##
CONSUMES
[Depex]
gEfiLegacyRegion2ProtocolGuid AND gEfiLegacyInterruptProtocolGuid AND
gEfiLegacyBiosPlatformProtocolGuid AND gEfiLegacy8259ProtocolGuid AND
gEfiGenericMemTestProtocolGuid AND gEfiCpuArchProtocolGuid AND
gEfiTimerArchProtocolGuid AND gEfiVariableWriteArchProtocolGuid
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosInterface.h
b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosInterface.h
index fe9dd7463a..9d479309a4 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosInterface.h
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBiosInterface.h
@@ -108,6 +108,27 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
EXPRESS OR IMPLIED.
#define NORMALIZE_EFI_SEGMENT(_Adr) (UINT16) (((UINTN) (_Adr)) >> 4)
#define NORMALIZE_EFI_OFFSET(_Adr) (UINT16) (((UINT16) ((UINTN) (_Adr)))
& 0xf)
+//
+// CSM needs to access memory between 0-4095, which will cause page fault
exception
+// if NULL pointer detection mechanism is enabled. Following macros can be used
+// to disable/enable NULL pointer detection before/after accessing those
memory.
+//
+#define NULL_DETECTION_ENABLED
\
+ ( ((mEndOfDxe == FALSE) && ((PcdGet8(PcdNullPointerDetectionPropertyMask) &
BIT0) == BIT0)) \
+ || ((mEndOfDxe == TRUE) && ((PcdGet8(PcdNullPointerDetectionPropertyMask) &
(BIT0|BIT7)) == BIT0)) \
+ )
+#define DISABLE_NULL_DETECTION(Instance)
\
+ if (NULL_DETECTION_ENABLED) {
\
+ DEBUG((DEBUG_INFO, "%a(): disable NULL detection\r\n", __func__));
\
+ (Instance)->Cpu->SetMemoryAttributes((Instance)->Cpu, 0, EFI_PAGE_SIZE,
0); \
+ }
+
+#define ENABLE_NULL_DETECTION(Instance)
\
+ if (NULL_DETECTION_ENABLED) {
\
+ (Instance)->Cpu->SetMemoryAttributes((Instance)->Cpu, 0, EFI_PAGE_SIZE,
EFI_MEMORY_RP); \
+ DEBUG((DEBUG_INFO, "%a(): enable NULL detection\r\n", __func__));
\
+ }
+
//
// Trace defines
//
@@ -509,6 +530,8 @@ extern BBS_TABLE *mBbsTable;
extern EFI_GENERIC_MEMORY_TEST_PROTOCOL *gGenMemoryTest;
+extern BOOLEAN mEndOfDxe;
+
#define PORT_70 0x70
#define PORT_71 0x71
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
index 1e098b3726..d381c2f735 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyBootSupport.c
@@ -1073,8 +1073,10 @@ GenericLegacyBoot (
// Use 182/10 to avoid floating point math.
//
LocalTime = (LocalTime * 182) / 10;
- BdaPtr = (UINT32 *) (UINTN)0x46C;
- *BdaPtr = LocalTime;
+ DISABLE_NULL_DETECTION(Private);
+ BdaPtr = (UINT32 *) (UINTN)0x46C;
+ *BdaPtr = LocalTime;
+ ENABLE_NULL_DETECTION(Private);
//
// Shadow PCI ROMs. We must do this near the end since this will kick
@@ -1320,6 +1322,7 @@ GenericLegacyBoot (
// set of TIANO vectors) or takes it over.
//
//
+ DISABLE_NULL_DETECTION(Private);
BaseVectorMaster = (UINT32 *) (sizeof (UINT32) *
PROTECTED_MODE_BASE_VECTOR_MASTER);
for (Index = 0; Index < 8; Index++) {
Private->ThunkSavedInt[Index] = BaseVectorMaster[Index];
@@ -1327,6 +1330,7 @@ GenericLegacyBoot (
BaseVectorMaster[Index] = (UINT32) (Private->BiosUnexpectedInt);
}
}
+ ENABLE_NULL_DETECTION(Private);
ZeroMem (&Regs, sizeof (EFI_IA32_REGISTER_SET));
Regs.X.AX = Legacy16Boot;
@@ -1340,10 +1344,12 @@ GenericLegacyBoot (
0
);
+ DISABLE_NULL_DETECTION(Private);
BaseVectorMaster = (UINT32 *) (sizeof (UINT32) *
PROTECTED_MODE_BASE_VECTOR_MASTER);
for (Index = 0; Index < 8; Index++) {
BaseVectorMaster[Index] = Private->ThunkSavedInt[Index];
}
+ ENABLE_NULL_DETECTION(Private);
}
Private->LegacyBootEntered = TRUE;
if ((mBootMode == BOOT_LEGACY_OS) || (mBootMode ==
BOOT_UNCONVENTIONAL_DEVICE)) {
@@ -1731,9 +1737,11 @@ LegacyBiosBuildE820 (
//
// First entry is 0 to (640k - EBDA)
//
- E820Table[0].BaseAddr = 0;
- E820Table[0].Length = (UINT64) ((*(UINT16 *) (UINTN)0x40E) << 4);
- E820Table[0].Type = EfiAcpiAddressRangeMemory;
+ DISABLE_NULL_DETECTION(Private);
+ E820Table[0].BaseAddr = 0;
+ E820Table[0].Length = (UINT64) ((*(UINT16 *) (UINTN)0x40E) << 4);
+ E820Table[0].Type = EfiAcpiAddressRangeMemory;
+ ENABLE_NULL_DETECTION(Private);
//
// Second entry is (640k - EBDA) to 640k
@@ -1967,6 +1975,8 @@ LegacyBiosCompleteBdaBeforeBoot (
UINT16 MachineConfig;
DEVICE_PRODUCER_DATA_HEADER *SioPtr;
+ DISABLE_NULL_DETECTION(Private);
+
Bda = (BDA_STRUC *) ((UINTN) 0x400);
MachineConfig = 0;
@@ -2025,6 +2035,8 @@ LegacyBiosCompleteBdaBeforeBoot (
MachineConfig = (UINT16) (MachineConfig + 0x00 + 0x02 +
(SioPtr->MousePresent * 0x04));
Bda->MachineConfig = MachineConfig;
+ ENABLE_NULL_DETECTION(Private);
+
return EFI_SUCCESS;
}
@@ -2049,15 +2061,20 @@ LegacyBiosUpdateKeyboardLedStatus (
UINT8 LocalLeds;
EFI_IA32_REGISTER_SET Regs;
- Bda = (BDA_STRUC *) ((UINTN) 0x400);
-
Private = LEGACY_BIOS_INSTANCE_FROM_THIS (This);
+
+ DISABLE_NULL_DETECTION(Private);
+
+ Bda = (BDA_STRUC *) ((UINTN) 0x400);
LocalLeds = Leds;
Bda->LedStatus = (UINT8) ((Bda->LedStatus &~0x07) | LocalLeds);
LocalLeds = (UINT8) (LocalLeds << 4);
Bda->ShiftStatus = (UINT8) ((Bda->ShiftStatus &~0x70) | LocalLeds);
LocalLeds = (UINT8) (Leds & 0x20);
Bda->KeyboardStatus = (UINT8) ((Bda->KeyboardStatus &~0x20) | LocalLeds);
+
+ ENABLE_NULL_DETECTION(Private);
+
//
// Call into Legacy16 code to allow it to do any processing
//
@@ -2102,7 +2119,9 @@ LegacyBiosCompleteStandardCmosBeforeBoot (
// to large capacity drives
// CMOS 14 = BDA 40:10 plus bit 3(display enabled)
//
+ DISABLE_NULL_DETECTION(Private);
Bda = (UINT8)(*((UINT8 *)((UINTN)0x410)) | BIT3);
+ ENABLE_NULL_DETECTION(Private);
//
// Force display enabled
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
index 8ffdf0c1ff..2ca5dddf00 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/LegacyPci.c
@@ -2279,6 +2279,7 @@ LegacyBiosInstallRom (
UINTN Function;
EFI_IA32_REGISTER_SET Regs;
UINT8 VideoMode;
+ UINT8 OldVideoMode;
EFI_TIME BootTime;
UINT32 *BdaPtr;
UINT32 LocalTime;
@@ -2299,6 +2300,7 @@ LegacyBiosInstallRom (
Device = 0;
Function = 0;
VideoMode = 0;
+ OldVideoMode = 0;
PhysicalAddress = 0;
MaxRomAddr = PcdGet32 (PcdEndOpromShadowAddress);
@@ -2401,6 +2403,8 @@ LegacyBiosInstallRom (
// 2. BBS compliants drives will not change 40:75 until boot time.
// 3. Onboard IDE controllers will change 40:75
//
+ DISABLE_NULL_DETECTION(Private);
+
LocalDiskStart = (UINT8) ((*(UINT8 *) ((UINTN) 0x475)) + 0x80);
if ((Private->Disk4075 + 0x80) < LocalDiskStart) {
//
@@ -2426,6 +2430,9 @@ LegacyBiosInstallRom (
//
VideoMode = *(UINT8 *) ((UINTN) (0x400 + BDA_VIDEO_MODE));
}
+
+ ENABLE_NULL_DETECTION(Private);
+
//
// Notify the platform that we are about to scan the ROM
//
@@ -2466,9 +2473,11 @@ LegacyBiosInstallRom (
// Multiply result by 18.2 for number of ticks since midnight.
// Use 182/10 to avoid floating point math.
//
+ DISABLE_NULL_DETECTION(Private);
LocalTime = (LocalTime * 182) / 10;
BdaPtr = (UINT32 *) ((UINTN) 0x46C);
*BdaPtr = LocalTime;
+ ENABLE_NULL_DETECTION(Private);
//
// Pass in handoff data
@@ -2564,7 +2573,11 @@ LegacyBiosInstallRom (
//
// Set mode settings since PrepareToScanRom may change mode
//
- if (VideoMode != *(UINT8 *) ((UINTN) (0x400 + BDA_VIDEO_MODE))) {
+ DISABLE_NULL_DETECTION(Private);
+ OldVideoMode = *(UINT8 *) ((UINTN) (0x400 + BDA_VIDEO_MODE));
+ ENABLE_NULL_DETECTION(Private);
+
+ if (VideoMode != OldVideoMode) {
//
// The active video mode is changed, restore it to original mode.
//
@@ -2604,7 +2617,9 @@ LegacyBiosInstallRom (
}
}
+ DISABLE_NULL_DETECTION(Private);
LocalDiskEnd = (UINT8) ((*(UINT8 *) ((UINTN) 0x475)) + 0x80);
+ ENABLE_NULL_DETECTION(Private);
//
// Allow platform to perform any required actions after the
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c
b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c
index 3d9a8b9649..50f6247a99 100644
--- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c
+++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c
@@ -57,7 +57,11 @@ LegacyBiosInt86 (
IN EFI_IA32_REGISTER_SET *Regs
)
{
- UINT32 *VectorBase;
+ UINT16 Segment;
+ UINT16 Offset;
+ LEGACY_BIOS_INSTANCE *Private;
+
+ Private = LEGACY_BIOS_INSTANCE_FROM_THIS (This);
Regs->X.Flags.Reserved1 = 1;
Regs->X.Flags.Reserved2 = 0;
@@ -72,12 +76,15 @@ LegacyBiosInt86 (
// The base address of legacy interrupt vector table is 0.
// We use this base address to get the legacy interrupt handler.
//
- VectorBase = 0;
+ DISABLE_NULL_DETECTION(Private);
+ Segment = (UINT16)(((UINT32 *)0)[BiosInt] >> 16);
+ Offset = (UINT16)((UINT32 *)0)[BiosInt];
+ ENABLE_NULL_DETECTION(Private);
return InternalLegacyBiosFarCall (
This,
- (UINT16) ((VectorBase)[BiosInt] >> 16),
- (UINT16) (VectorBase)[BiosInt],
+ Segment,
+ Offset,
Regs,
&Regs->X.Flags,
sizeof (Regs->X.Flags)
@@ -288,16 +295,22 @@ InternalLegacyBiosFarCall (
// EBDA base address, if the current EBDA base address is smaller, it
indicates
// PcdEbdaReservedMemorySize should be adjusted to larger for more OPROMs.
//
- DEBUG_CODE (
- {
- UINTN EbdaBaseAddress;
- UINTN ReservedEbdaBaseAddress;
-
- EbdaBaseAddress = (*(UINT16 *) (UINTN) 0x40E) << 4;
- ReservedEbdaBaseAddress = CONVENTIONAL_MEMORY_TOP - PcdGet32
(PcdEbdaReservedMemorySize);
- ASSERT (ReservedEbdaBaseAddress <= EbdaBaseAddress);
- }
- );
+ if (!NULL_DETECTION_ENABLED) {
+ //
+ // Only do following if NULL pointer detection is not enabled, because it
cannot
+ // be disabled at this time due to current TPL(=TPL_HIGH_LEVEL).
+ //
+ DEBUG_CODE (
+ {
+ UINTN EbdaBaseAddress;
+ UINTN ReservedEbdaBaseAddress;
+
+ EbdaBaseAddress = (*(UINT16 *) (UINTN) 0x40E) << 4;
+ ReservedEbdaBaseAddress = CONVENTIONAL_MEMORY_TOP - PcdGet32
(PcdEbdaReservedMemorySize);
+ ASSERT (ReservedEbdaBaseAddress <= EbdaBaseAddress);
+ }
+ );
+ }
if (Stack != NULL && StackSize != 0) {
//
--
2.14.1.windows.1
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