BOOLEAN
FASTCALL
KiVdmOpcodePOPF(IN PKTRAP_FRAME TrapFrame,
IN ULONG Flags)
{
ULONG Esp, V86EFlags, EFlags, TrapEFlags;
/* Build flat ESP */
Esp = (TrapFrame->HardwareSegSs << 4) + (USHORT)TrapFrame->HardwareEsp;
/* Check for OPER32 */
if (KiVdmGetPrefixFlags(Flags) & PFX_FLAG_OPER32)
{
/* Read EFlags */
EFlags = *(PULONG)Esp;
Esp += 4;
}
else
{
/* Read EFlags */
EFlags = *(PUSHORT)Esp;
Esp += 2;
}
/* Set new ESP */
TrapFrame->HardwareEsp = Esp - (TrapFrame->HardwareSegSs << 4);
/* Mask out IOPL from the flags */
EFlags &= ~EFLAGS_IOPL;
/* Save the V86 flags, but mask out the nested task flag */
V86EFlags = EFlags & ~EFLAGS_NESTED_TASK;
/* Now leave only alignment, nested task and interrupt flag */
EFlags &= (EFLAGS_ALIGN_CHECK | EFLAGS_NESTED_TASK | EFLAGS_INTERRUPT_MASK);
/* Get trap EFlags */
TrapEFlags = TrapFrame->EFlags;
/* Check for VME support */
if(KeI386VirtualIntExtensions)
{
/* Copy the IF flag into the VIF one */
V86EFlags &= ~EFLAGS_VIF;
if(V86EFlags & EFLAGS_INTERRUPT_MASK)
{
V86EFlags |= EFLAGS_VIF;
/* Don't set the interrupt flag */
V86EFlags &= ~EFLAGS_INTERRUPT_MASK;
}
}
/* Add V86 flag */
V86EFlags |= EFLAGS_V86_MASK;
/* Update EFlags in trap frame */
TrapFrame->EFlags |= V86EFlags;
/* Check if ESP0 needs to be fixed up */
if (TrapEFlags & EFLAGS_V86_MASK) Ki386AdjustEsp0(TrapFrame);
/* Update the V8086 EFlags state */
KiVdmClearVdmEFlags(EFLAGS_ALIGN_CHECK | EFLAGS_NESTED_TASK | EFLAGS_INTERRUPT_MASK);
KiVdmSetVdmEFlags(EFlags);
/* FIXME: Check for VDM interrupts */
/* Update EIP */
TrapFrame->Eip += KiVdmGetInstructionSize(Flags);
/* We're done */
return TRUE;
}
BOOLEAN
FASTCALL
KiVdmOpcodeIRET(IN PKTRAP_FRAME TrapFrame,
IN ULONG Flags)
{
ULONG Esp, V86EFlags, EFlags, TrapEFlags, Eip;
/* Build flat ESP */
Esp = (TrapFrame->HardwareSegSs << 4) + TrapFrame->HardwareEsp;
/* Check for OPER32 */
if (KiVdmGetPrefixFlags(Flags) & PFX_FLAG_OPER32)
{
/* Build segmented EIP */
TrapFrame->Eip = *(PULONG)Esp;
TrapFrame->SegCs = *(PUSHORT)(Esp + 4);
/* Set new ESP */
TrapFrame->HardwareEsp += 12;
/* Get EFLAGS */
EFlags = *(PULONG)(Esp + 8);
}
else
{
/* Build segmented EIP */
TrapFrame->Eip = *(PUSHORT)Esp;
TrapFrame->SegCs = *(PUSHORT)(Esp + 2);
/* Set new ESP */
TrapFrame->HardwareEsp += 6;
/* Get EFLAGS */
EFlags = *(PUSHORT)(Esp + 4);
}
/* Mask out EFlags */
EFlags &= ~(EFLAGS_IOPL + EFLAGS_VIF + EFLAGS_NESTED_TASK + EFLAGS_VIP);
V86EFlags = EFlags;
/* Check for VME support */
ASSERT(KeI386VirtualIntExtensions == FALSE);
/* Add V86 and Interrupt flag */
EFlags |= EFLAGS_V86_MASK | EFLAGS_INTERRUPT_MASK;
/* Update EFlags in trap frame */
TrapEFlags = TrapFrame->EFlags;
TrapFrame->EFlags = (TrapFrame->EFlags & EFLAGS_VIP) | EFlags;
/* Check if ESP0 needs to be fixed up */
if (!(TrapEFlags & EFLAGS_V86_MASK)) Ki386AdjustEsp0(TrapFrame);
/* Update the V8086 EFlags state */
KiVdmClearVdmEFlags(EFLAGS_INTERRUPT_MASK);
KiVdmSetVdmEFlags(V86EFlags);
/* Build flat EIP and check if this is the BOP instruction */
Eip = (TrapFrame->SegCs << 4) + TrapFrame->Eip;
if (*(PUSHORT)Eip == 0xC4C4)
{
/* Dispatch the BOP */
VdmDispatchBop(TrapFrame);
}
else
{
/* FIXME: Check for VDM interrupts */
DPRINT("FIXME: Check for VDM interrupts\n");
}
/* We're done */
return TRUE;
}
VOID
NTAPI
VdmSwapContext(IN PKTRAP_FRAME TrapFrame,
IN PCONTEXT OutContext,
IN PCONTEXT InContext)
{
ULONG EFlags, OldEFlags;
/* Make sure that we're at APC_LEVEL and that this is a valid frame */
ASSERT(KeGetCurrentIrql() == APC_LEVEL);
//ASSERT(TrapFrame->DbgArgMark == 0xBADB0D00);
/* Check if this is a V86 frame */
if (TrapFrame->EFlags & EFLAGS_V86_MASK)
{
/* Copy segment registers */
OutContext->SegGs = TrapFrame->V86Gs;
OutContext->SegFs = TrapFrame->V86Fs;
OutContext->SegEs = TrapFrame->V86Es;
OutContext->SegDs = TrapFrame->V86Ds;
}
else if (TrapFrame->SegCs != (KGDT_R3_CODE | RPL_MASK))
{
/* This was kernel mode, copy segment registers */
OutContext->SegGs = TrapFrame->SegGs;
OutContext->SegFs = TrapFrame->SegFs;
OutContext->SegEs = TrapFrame->SegEs;
OutContext->SegDs = TrapFrame->SegDs;
}
/* Copy CS and SS */
OutContext->SegCs = TrapFrame->SegCs;
OutContext->SegSs = TrapFrame->HardwareSegSs;
/* Copy general purpose registers */
OutContext->Eax = TrapFrame->Eax;
OutContext->Ebx = TrapFrame->Ebx;
OutContext->Ecx = TrapFrame->Ecx;
OutContext->Edx = TrapFrame->Edx;
OutContext->Esi = TrapFrame->Esi;
OutContext->Edi = TrapFrame->Edi;
/* Copy stack and counter */
OutContext->Ebp = TrapFrame->Ebp;
OutContext->Esp = TrapFrame->HardwareEsp;
OutContext->Eip = TrapFrame->Eip;
/* Finally the flags */
OutContext->EFlags = TrapFrame->EFlags;
/* Now copy from the in frame to the trap frame */
TrapFrame->SegCs = InContext->SegCs;
TrapFrame->HardwareSegSs = InContext->SegSs;
/* Copy the general purpose registers */
TrapFrame->Eax = InContext->Eax;
TrapFrame->Ebx = InContext->Ebx;
TrapFrame->Ecx = InContext->Ecx;
TrapFrame->Edx = InContext->Edx;
TrapFrame->Esi = InContext->Esi;
TrapFrame->Edi = InContext->Edi;
/* Copy the stack and counter */
TrapFrame->Ebp = InContext->Ebp;
TrapFrame->HardwareEsp = InContext->Esp;
TrapFrame->Eip = InContext->Eip;
/* Check if the context is from V86 */
EFlags = InContext->EFlags;
if (EFlags & EFLAGS_V86_MASK)
{
/* Sanitize the flags for V86 */
EFlags &= KeI386EFlagsAndMaskV86;
EFlags |= KeI386EFlagsOrMaskV86;
}
else
{
/* Add RPL_MASK to segments */
TrapFrame->SegCs |= RPL_MASK;
TrapFrame->HardwareSegSs |= RPL_MASK;
/* Check for bogus CS */
if (TrapFrame->SegCs < KGDT_R0_CODE)
{
/* Set user-mode */
TrapFrame->SegCs = KGDT_R3_CODE | RPL_MASK;
}
/* Sanitize flags and add interrupt mask */
EFlags &= EFLAGS_USER_SANITIZE;
EFlags |=EFLAGS_INTERRUPT_MASK;
}
/* Save the new eflags */
OldEFlags = TrapFrame->EFlags;
TrapFrame->EFlags = EFlags;
/* Check if we need to fixup ESP0 */
if ((OldEFlags ^ EFlags) & EFLAGS_V86_MASK)
{
/* Fix it up */
Ki386AdjustEsp0(TrapFrame);
}
/* Check if this is a V86 context */
if (InContext->EFlags & EFLAGS_V86_MASK)
{
/* Copy VDM segments */
TrapFrame->V86Gs = InContext->SegGs;
TrapFrame->V86Fs = InContext->SegFs;
TrapFrame->V86Es = InContext->SegEs;
TrapFrame->V86Ds = InContext->SegDs;
}
else
{
/* Copy monitor segments */
TrapFrame->SegGs = InContext->SegGs;
TrapFrame->SegFs = InContext->SegFs;
TrapFrame->SegEs = InContext->SegEs;
TrapFrame->SegDs = InContext->SegDs;
}
/* Clear the exception list and return */
TrapFrame->ExceptionList = EXCEPTION_CHAIN_END;
}