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Diffstat (limited to 'DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c')
-rw-r--r--DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c27
1 files changed, 12 insertions, 15 deletions
diff --git a/DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c b/DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c
index b8603426c6..08ed35c1f4 100644
--- a/DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c
+++ b/DuetPkg/BiosVideoThunkDxe/LegacyBiosThunk.c
@@ -146,17 +146,17 @@ LegacyBiosInt86 (
BOOLEAN Ret;
UINT16 *Stack16;
- Regs->X.Flags.Reserved1 = 1;
- Regs->X.Flags.Reserved2 = 0;
- Regs->X.Flags.Reserved3 = 0;
- Regs->X.Flags.Reserved4 = 0;
- Regs->X.Flags.IOPL = 3;
- Regs->X.Flags.NT = 0;
- Regs->X.Flags.IF = 1;
- Regs->X.Flags.TF = 0;
- Regs->X.Flags.CF = 0;
-
ZeroMem (&ThunkRegSet, sizeof (ThunkRegSet));
+ ThunkRegSet.E.EFLAGS.Bits.Reserved_0 = 1;
+ ThunkRegSet.E.EFLAGS.Bits.Reserved_1 = 0;
+ ThunkRegSet.E.EFLAGS.Bits.Reserved_2 = 0;
+ ThunkRegSet.E.EFLAGS.Bits.Reserved_3 = 0;
+ ThunkRegSet.E.EFLAGS.Bits.IOPL = 3;
+ ThunkRegSet.E.EFLAGS.Bits.NT = 0;
+ ThunkRegSet.E.EFLAGS.Bits.IF = 1;
+ ThunkRegSet.E.EFLAGS.Bits.TF = 0;
+ ThunkRegSet.E.EFLAGS.Bits.CF = 0;
+
ThunkRegSet.E.EDI = Regs->E.EDI;
ThunkRegSet.E.ESI = Regs->E.ESI;
ThunkRegSet.E.EBP = Regs->E.EBP;
@@ -167,8 +167,6 @@ LegacyBiosInt86 (
ThunkRegSet.E.DS = Regs->E.DS;
ThunkRegSet.E.ES = Regs->E.ES;
- CopyMem (&(ThunkRegSet.E.EFLAGS), &(Regs->E.EFlags), sizeof (UINT32));
-
//
// The call to Legacy16 is a critical section to EFI
//
@@ -184,16 +182,15 @@ LegacyBiosInt86 (
ASSERT_EFI_ERROR (Status);
Stack16 = (UINT16 *)((UINT8 *) BiosDev->ThunkContext->RealModeBuffer + BiosDev->ThunkContext->RealModeBufferSize - sizeof (UINT16));
- Stack16 -= sizeof (ThunkRegSet.E.EFLAGS) / sizeof (UINT16);
- CopyMem (Stack16, &ThunkRegSet.E.EFLAGS, sizeof (ThunkRegSet.E.EFLAGS));
ThunkRegSet.E.SS = (UINT16) (((UINTN) Stack16 >> 16) << 12);
ThunkRegSet.E.ESP = (UINT16) (UINTN) Stack16;
+
ThunkRegSet.E.Eip = (UINT16)((UINT32 *)NULL)[BiosInt];
ThunkRegSet.E.CS = (UINT16)(((UINT32 *)NULL)[BiosInt] >> 16);
BiosDev->ThunkContext->RealModeState = &ThunkRegSet;
AsmThunk16 (BiosDev->ThunkContext);
-
+
//
// Restore protected mode interrupt state
//