diff options
Diffstat (limited to 'IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c')
| -rw-r--r-- | IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c index 3d9a8b9649..f42c13cd89 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;
+ DisableNullDetection ();
+ Segment = (UINT16)(((UINT32 *)0)[BiosInt] >> 16);
+ Offset = (UINT16)((UINT32 *)0)[BiosInt];
+ EnableNullDetection ();
return InternalLegacyBiosFarCall (
This,
- (UINT16) ((VectorBase)[BiosInt] >> 16),
- (UINT16) (VectorBase)[BiosInt],
+ Segment,
+ Offset,
Regs,
&Regs->X.Flags,
sizeof (Regs->X.Flags)
@@ -293,9 +300,15 @@ InternalLegacyBiosFarCall ( UINTN EbdaBaseAddress;
UINTN ReservedEbdaBaseAddress;
- EbdaBaseAddress = (*(UINT16 *) (UINTN) 0x40E) << 4;
- ReservedEbdaBaseAddress = CONVENTIONAL_MEMORY_TOP - PcdGet32 (PcdEbdaReservedMemorySize);
- ASSERT (ReservedEbdaBaseAddress <= EbdaBaseAddress);
+ //
+ // Skip this part of debug code if NULL pointer detection is enabled
+ //
+ if ((PcdGet8 (PcdNullPointerDetectionPropertyMask) & BIT0) == 0) {
+ EbdaBaseAddress = (*(UINT16 *) (UINTN) 0x40E) << 4;
+ ReservedEbdaBaseAddress = CONVENTIONAL_MEMORY_TOP
+ - PcdGet32 (PcdEbdaReservedMemorySize);
+ ASSERT (ReservedEbdaBaseAddress <= EbdaBaseAddress);
+ }
}
);
|