Source code of Windows XP (NT5)
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

1299 lines
24 KiB

/*++
Copyright (c) 1999-2001 Microsoft Corporation. All Rights Reserved.
Module Name:
rtexcept.c
Abstract:
This module contains the realtime executive exception handlers. It also
has the code for setting up the 2 realtime executive IDTs: one for the
realtime executive thread switcher, and one for the realtime threads
themselves.
Author:
Joseph Ballantyne
Environment:
Kernel Mode
Revision History:
--*/
// This file contains the real time executive exception handlers.
// These exception handlers are used to build a separate real time IDT that is
// loaded whenever we switch into the real time executive. This real time IDT is
// kept loaded while any real time thread is running. We switch back to the Windows
// IDT when the real time executive transfers control back to Windows.
// It is very important that we do NOT allow the standard Windows exception handlers
// to fire while we are running real time threads. It makes Windows get very confused
// and the system will eventually crash.
// The first thing we do in all of these execption handlers is to disable the
// interrupt that drives the real time scheduler.
// Then we break into the debugger - since currently it is an error to cause any
// exception to fire while running in a real time thread.
// After we get control back from the debugger, we kill the real time thread that
// caused the exception.
// Since I switch the IDT AFTER I load in a valid DS, I should be able to turn off
// the scheduler interrupt in 1 instruction. I assume that DS is valid.
// In order to be able to turn off the scheduler in 1 instruction, I will need to
// map the APIC to memory where the real time executive is loaded. This will
// allow me to get around the x86 instruction set limits - which do not support
// indirect memory addressing.
// Currently that is not being done, so it takes 3 instructions to get the interrupt
// disabled instead of 1.
// Note that since loading the processor IDT register is a READ from memory, if
// I do not have to save the IDT first, then I can make it the VERY first thing
// that happens in the real time executive SwitchRealTimeThreads interrupt handler.
// That would be cool.
// It would be nice if the processor automatically pushed the old IDT settings into
// an internal register, and there was an instruction for poping it back out - as well
// as a flag that you could read if 2 pushes occur without a pop - and blow away
// one of the stored IDTs.
// One very cool thing is that I figured out that we can switch the IDT as the
// FIRST instruction of our real time interrupt handler - and we can restore it
// as the LAST instruction of our real time interrupt handler. This is possible
// as long as other people are NOT switching the IDT - so that the IDT that we
// reload for Windows is correct. If other people are switching the Windows IDT,
// then that will NOT work, since we will have to save the current IDT first before
// we load the new one and that would involve getting a valid segment register loaded
// that we can write into memory with.
// However, I now have the realtime executive saving eax on the stack in
// order to get working space rather than sticking it in DR0 or CR2.
// That is much faster and safer, and it seems to work just fine - as
// it should.
// Since I CAN use the stack to save state, I may be able to save the
// IDT directly on the stack at the start of the real time executive
// interrupt, and then load the new one as the second instruction.
// This means we will have to burn 16 cycles on every thread switch
// saving and loading the IDT (assuming that we also have a separate
// IDT for the real time executive itself). Which I think is probably
// a good idea. 4 cycles to save the initial IDT, 6 cycles to load
// the rt exec IDT, and 6 cycles to load the final IDT for the thread
// being switched to.
#include "common.h"
#include "rtp.h"
#include "x86.h"
#include "rtexcept.h"
#include "apic.h"
#include "irq.h"
#define MAX_DEFAULT_HANDLERS 20
#pragma LOCKED_CODE
#pragma LOCKED_DATA
#ifdef MASKABLEINTERRUPT
extern ULONG InjectWindowsInterrupt;
extern SPTR HandleWindowsInterrupt;
#endif
#ifdef DEBUG
ULONG HitInt3InRtThread=0;
#endif
#ifdef RAISE_DEBUGGER_IRQL
ULONG DebuggerSavedIrql=0;
#endif
// This is a collection of the entry point addresses of the handlers.
// It makes the IDT initialization simpler.
VOID (* RtExceptionHandlers[MAX_DEFAULT_HANDLERS])(VOID)={
DivideByZero, // 0x0
DebugExceptions,
RtExecPerfCounterNMI,
RtExecBreakPoint,
Overflow,
BoundsCheck,
InvalidOpcode,
DeviceNotAvailable,
DoubleFault,
IntelReserved,
InvalidTSS,
SegmentNotPresent,
StackException,
GeneralProtection,
PageFault,
IntelReserved,
FloatingPointError, // 0x10
AlignmentCheck,
MachineCheck,
IntelReserved
};
// This is the real time executive IDT itself. Note that Intel suggests that it is
// a good idea to make sure that the IDT does NOT cross a page boundary.
// TODO: Ensure RtThreadID and RtExecID do NOT cross a page boundary.
ID RtThreadID[RTTHREADLARGEIDTSIZE];
ID RtExecID[RTEXECIDTSIZE];
TSS RtTss={0};
ULONG TssStack[512];
// These hold the processor IDT register data for the rt exec and Windows. These
// are used to switch the IDTs.
IDT WindowsIDT;
IDT RtExecIDT;
IDT RtThreadIDT;
IDT DebugIDT; // This is the IDT that will be restored by RT exception handlers.
IDT NextIDT;
// These are for debug purposes - to see if either the Windows or RT exec IDT
// addresses change over time. The RT exec IDT should NEVER change. I expect
// the Windows NT IDT to never change. The Win9x IDT may change since who knows
// what the 3rd party VxD code does.
// Note that for Windows NT if the IDT never changes we could optimize out the
// saving of the current IDT and simply load the RT idt. That would allow us to
// do that as the very first thing in the interrupt handler.
// Doing that would also allow us to detect if SoftICE is trapping debug register
// accesses. I expect that it is.
#ifdef DEBUG
IDT LastWindowsIDT;
IDT LastRtThreadIDT;
#endif
VOID
RtpSetupTss (
VOID
)
{
RtTss.link=0;
RtTss.esp0=(ULONG)(TssStack+sizeof(TssStack)/sizeof(ULONG)-1);
RtTss.ss0=RealTimeSS;
RtTss.cr3=ReadCR3();
RtTss.eip=(ULONG)DoubleFault;
RtTss.eflags=0;
RtTss.esp=(ULONG)(TssStack+sizeof(TssStack)/sizeof(ULONG)-1);
RtTss.es=RealTimeDS;
RtTss.cs=RtExecCS;
RtTss.ss=RealTimeSS;
RtTss.ds=RealTimeDS;
RtTss.ldt=0;
RtTss.t=0;
RtTss.iomap=0x80; // Past end of TSS segment. All I/O causes exceptions.
}
VOID
RtpBuildIdt (
ID *Id,
ULONG Size
)
{
ULONG i,j;
// Now build our IDT.
j=0;
for (i=0; i<Size; i++) {
#ifdef GUARD_PAGE
if (i!=DOUBLEFAULTIDTINDEX) {
#endif
Id[i].lowoffset=(WORD)RtExceptionHandlers[j];
Id[i].selector=RtExecCS;
Id[i].flags=0x8e00;
Id[i].highoffset=(WORD)((DWORD)RtExceptionHandlers[j]>>16);
#ifdef GUARD_PAGE
}
else {
Id[i].lowoffset=0;
Id[i].selector=RtExecTSS;
Id[i].flags=0x8500;
Id[i].highoffset=0;
}
#endif
if (j<MAX_DEFAULT_HANDLERS-1) {
j++;
}
}
}
VOID
RtpReplaceDefaultIdtHandler (
ID *Id,
ULONG Size,
VOID (* ExceptionHandler)(VOID),
ULONG Location
)
{
ASSERT (Location < Size);
ASSERT (Location != DOUBLEFAULTIDTINDEX);
Id[Location].lowoffset=(WORD)ExceptionHandler;
Id[Location].selector=RtExecCS;
Id[Location].flags=0x8e00;
Id[Location].highoffset=(WORD)((DWORD)ExceptionHandler>>16);
}
VOID
RtpSetupIdtSwitch (
ULONG TimerVector,
ULONG PerfVector,
ULONG ErrorVector,
ULONG SpuriousVector
)
{
ULONG RtThreadIdtSize=RTTHREADSMALLIDTSIZE;
if (TimerVector!=MASKABLEIDTINDEX ||
PerfVector!=RTINTERRUPT ||
ErrorVector!=APICERRORIDTINDEX ||
SpuriousVector!=APICSPURIOUSIDTINDEX) {
// We are not using the default vector locations for the local APIC interrupt
// sources. This is because the HAL supports the local APIC and has already
// set it up, so use a full IDT rather than a small one. That way we will
// be able to use the same perf and timer vector locations as the ones the
// HAL has set up.
RtThreadIdtSize=RTTHREADLARGEIDTSIZE;
}
SaveIDT(WindowsIDT);
RtpSetupTss();
// We build the rt executive IDT without the SwitchRealTimeThreads vector
// in it. That way we can catch whenever we get an interrupt that would
// reenter SwitchRealTimeThreads.
RtpBuildIdt(RtExecID, RTEXECIDTSIZE);
#ifdef NONMI
RtpReplaceDefaultIdtHandler(RtExecID, RTEXECIDTSIZE, JumpToWindowsNmiHandler, NMIIDTINDEX);
#endif
#ifdef DEBUG
//RtpReplaceDefaultIdtHandler(RtExecID, RTEXECIDTSIZE, RtThreadBreakPoint, BREAKPOINTIDTINDEX);
#endif
// Now build the realtime thread IDT. This is the IDT that is loaded while
// any realtime thread is running.
RtpBuildIdt(RtThreadID, RtThreadIdtSize);
// Replace default vectors with those we need to enable the realtime threads to
// be switched properly.
#ifndef NONMI
RtpReplaceDefaultIdtHandler(RtThreadID, RtThreadIdtSize, RtThreadPerfCounterNMI, NMIIDTINDEX);
#endif
RtpReplaceDefaultIdtHandler(RtThreadID, RtThreadIdtSize, RtThreadBreakPoint, BREAKPOINTIDTINDEX);
#ifdef MASKABLEINTERRUPT
RtpReplaceDefaultIdtHandler(RtThreadID, RtThreadIdtSize, SwitchRealTimeThreads, PerfVector);
#endif
RtpReplaceDefaultIdtHandler(RtThreadID, RtThreadIdtSize, SwitchRealTimeThreads, TimerVector);
RtpReplaceDefaultIdtHandler(RtThreadID, RtThreadIdtSize, RtpLocalApicErrorHandler, ErrorVector);
RtpReplaceDefaultIdtHandler(RtThreadID, RtThreadIdtSize, RtpLocalApicSpuriousHandler, SpuriousVector);
RtThreadIDT.base=(DWORD)RtThreadID;
RtThreadIDT.limit=(WORD)(8*RtThreadIdtSize-1);
RtExecIDT.base=(DWORD)RtExecID;
RtExecIDT.limit=8*RTEXECIDTSIZE-1;
DebugIDT=RtExecIDT;
#ifdef DEBUG
//RtExecIDT=WindowsIDT;
LastWindowsIDT=WindowsIDT;
LastRtThreadIDT=RtThreadIDT;
#endif
}
// For now we force the debug code in the exception handlers to execute and
// we force the breakpoint to hit.
#ifndef DEBUG
#define DEBUG 1
#else
#define OLDDEBUG DEBUG
#endif
// Here are the exception handlers.
#ifdef NONMI
VOID __declspec(naked) JumpToWindowsNmiHandler(VOID)
{
// For now I do not mask the ApicIntrInterrupt - since it should ALWAYS be
// masked when we hit this anyway. Since we will only hit these after
// switching IDTs.
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
LoadIDT(WindowsIDT);
// Now we jump to the NMI handler in the Windows IDT.
__asm {
// Save space for address of windows NMI (int 2) handler.
sub esp,8
// Get working space in registers
push eax
push ecx
mov ecx, WindowsIDT.base
// ecx now has base address of the windows idt
mov eax, [ecx+NMIIDTINDEX*8]
shr eax, 16
mov dword ptr[esp+12], eax
// Now the selector for the windows NMI handler is on the stack
mov eax, [ecx+NMIIDTINDEX*8+4]
mov ax, [ecx+NMIIDTINDEX*8]
// eax now has offset of windows NMI handler
mov dword ptr[esp+8], eax
// stack now setup for far return to the windows NMI handler
// restore our registers
pop ecx
pop eax
retf
}
}
#endif
VOID __declspec(naked) DoWindowsNmi(VOID)
{
__asm push eax;
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
LoadIDT(WindowsIDT);
// Now we jump to the NMI handler in the Windows IDT.
__asm {
// Save space for address of windows NMI (int 2) handler.
sub esp,8
// Get working space in registers
push eax
push ecx
mov ecx, WindowsIDT.base
// ecx now has base address of the windows idt
mov eax, [ecx+NMIIDTINDEX*8]
shr eax, 16
mov dword ptr[esp+12], eax
// Now the selector for the windows NMI handler is on the stack
mov eax, [ecx+NMIIDTINDEX*8+4]
mov ax, [ecx+NMIIDTINDEX*8]
// eax now has offset of windows NMI handler
mov dword ptr[esp+8], eax
// stack now setup for far return to the windows NMI handler
// restore our registers
pop ecx
pop eax
retf
}
}
#pragma warning(disable: 4414)
VOID __declspec(naked) RtThreadPerfCounterNMI(VOID)
{
__asm {
// First check if we have masked the performance counter interrupt.
// If not, then jump to switchrealtimethreads.
test cs:PerformanceInterruptState, MASKPERF0INT
jz SwitchRealTimeThreads
// Otherwise, the performance counter interrupt is masked. Eat it.
}
Return();
}
VOID __declspec(naked) RtExecPerfCounterNMI(VOID)
{
__asm {
// First check if we have masked the performance counter interrupt.
// If not, then jump to switchrealtimethreads.
test cs:PerformanceInterruptState, MASKPERF0INT
jz IntelReserved
// Otherwise, the performance counter interrupt is masked. Eat it.
}
Return();
}
#pragma warning(default: 4414)
VOID __declspec(naked) DivideByZero(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}
// When this hits, we switch IDT's back to the WindowsIDT and then break
// into the debugger. Note this should catch if Winice is trapping my
// use of the debug register to hold EAX. (It is NOT.)
VOID __declspec(naked) DebugExceptions(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
LoadIDT(WindowsIDT);
Break();
Return();
}
VOID __declspec(naked) RtExecBreakPoint(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
#ifdef RAISE_DEBUGGER_IRQL
// Now save current IRQL setting, and set IRQL to HIGH_LEVEL.
// This is so we will work with the NT debugger - which pays attention to
// IRQL levels. If we don't do this, then we reboot on NT when we try to
// go after hitting a breakpoint inside the realtime executive.
__asm push ecx
__asm mov eax,pCurrentIrql
__asm mov cl, 0x1f
__asm xchg cl, byte ptr[eax]
__asm mov byte ptr[DebuggerSavedIrql],cl
__asm pop ecx
#endif
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
#ifdef RAISE_DEBUGGER_IRQL
// Restore IRQL BEFORE we load our IDT. This is so we can never
// overwrite the DebuggerSavedIrql before we have restored it.
__asm push eax
__asm push ecx
__asm mov eax,pCurrentIrql
__asm mov cl, byte ptr[DebuggerSavedIrql]
__asm mov DebuggerSavedIrql, 0
__asm mov byte ptr[eax], cl
__asm pop ecx
__asm pop eax
#endif
// Restore the appropriate IDT.
LoadIDT(DebugIDT);
#endif
Return();
}
// When this hits, we switch IDT's back to the WindowsIDT and then break
// into the debugger.
// Note that this will obviate the need for an RtTrap instruction. Since it will
// make normal breakpoints work properly automatically. Well it will make them
// work like RtTrap currently does - as long as we do NOT switch back the IDT
// before returning to the thread. As long as we handle the case when the
// real time thread yields control to the rt executive and the IDT is NOT the
// real time IDT and we don't break because of that we will be OK.
// At the end of this routine, we switch back to the current IDT.
// WARNING: We may need to change the limit on windows flat CS selector so that
// we do NOT get gp faults in it when we are stepping through the
// realtime code. Especially since we will be back in the windows IDT.
VOID __declspec(naked) RtThreadBreakPoint(VOID)
{
// For now I do not mask the ApicIntrInterrupt - since it should ALWAYS be
// masked when we hit this anyway. Since we will only hit these after
// switching IDTs.
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
LoadIDT(WindowsIDT);
// Now we jump to the int3 handler in the debugger.
__asm {
// But first we clear the IF flag on our stack - so that interrupts are
// disabled. This means the only way we will switch out of the
// realtime thread - if we break into it, is to RtYield. If the thread
// never RtYields, or blocks on a spinlock, or releases a spinlock
// blocking another thread, then we will be stuck in that thread forever.
and dword ptr[esp+8], ~(IF)
#ifdef OLDDEBUG
// Keep debug check for interrupts enabled from hitting since we just
// turned them off ourselves intentionally.
inc HitInt3InRtThread
#endif
// Save space for address of windows int3 handler.
sub esp,8
// Get working space in registers
push eax
push ecx
mov ecx, WindowsIDT.base
// ecx now has base address of the windows idt
mov eax, [ecx+3*8]
shr eax, 16
mov dword ptr[esp+12], eax
// Now the selector for the windows int 3 handler is on the stack
mov eax, [ecx+3*8+4]
mov ax, [ecx+3*8]
// eax now has offset of windows int 3 handler
mov dword ptr[esp+8], eax
// stack now setup for far return to the windows int 3 handler
// restore our registers
pop ecx
pop eax
retf
}
}
VOID __declspec(naked) Overflow(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}
VOID __declspec(naked) BoundsCheck(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}
VOID __declspec(naked) InvalidOpcode(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}
VOID __declspec(naked) DeviceNotAvailable(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}
VOID __declspec(naked) DoubleFault(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}
VOID __declspec(naked) IntelReserved(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}
VOID __declspec(naked) InvalidTSS(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}
VOID __declspec(naked) SegmentNotPresent(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}
VOID __declspec(naked) StackException(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}
VOID __declspec(naked) GeneralProtection(VOID)
{
#ifdef MASKABLEINTERRUPT
// Unfortunately when we are using a maskable interrupt to take control from
// windows, we can get PIC interrupts queued up in the cpu between the time
// that we enter our switchrealtimethreads handler, and the time that we
// mask the interrupt at the local apic itself.
__asm {
test dword ptr[esp],1
jz catchthis
test dword ptr[esp],2
jz catchthis
// If we get here, then this is an interrupt that got logged into the
// processor from the pic, between the time that interrupts were disabled
// by entering switchrealtimethreads, and the time that we masked
// external interrupts at the local apic.
// We need to save the error code - since it has the vector information
// of the interrupt that we need to call when we return back to
// windows. We also need to make sure that there isn't already an error
// code logged. If there is, that is a fatal error, since we don't
// currently support logging of multiple interrupts that we call when
// we finally get back to windows. We only support saving 1.
// Trap if there is already an interrupt logged.
test InjectWindowsInterrupt, 0xffffffff
jnz catchthis // Taking this route is a FATAL ERROR.
// Now, build the address of the windows interrupt handler for the
// interrupt that we just got. Jam it into InjectWindowsInterrupt.
push eax
push ecx
push edx
// we now have registers we can use
mov edx,[esp+12]
and edx, 0xfffffff8
// edx now has the selector index into the windows idt
mov ecx, WindowsIDT.base
// ecx now has base address of the windows idt
mov eax, [ecx+edx]
shr eax, 16
mov HandleWindowsInterrupt.selector, ax
// Now the selector is correct for the windows interrupt handler.
mov eax, [ecx+edx+4]
mov ax, [ecx+edx]
// eax now has address of interrupt handler we need to call when we
// eventually return to windows
mov InjectWindowsInterrupt, eax
pop edx
pop ecx
pop eax
// we have handled this nasty problem and are ready to rock
// exit this handler without stopping
jmp exit
catchthis:
}
#endif
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
#ifdef MASKABLEINTERRUPT
exit:
#endif
// Clean the error code off of the stack before returning.
__asm add esp,4
Return();
}
VOID __declspec(naked) PageFault(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
// Now clean the error code off of the stack before returning.
__asm add esp,4
Return();
}
VOID __declspec(naked) FloatingPointError(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}
VOID __declspec(naked) AlignmentCheck(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}
VOID __declspec(naked) MachineCheck(VOID)
{
__asm push eax;
DisablePerformanceCounterInterrupt();
__asm mov eax, ApicTimerInterrupt
__asm or dword ptr[eax], MASKED
__asm mov eax, cr0
__asm and eax, ~(FPUEMULATION)
__asm mov cr0, eax
__asm pop eax;
#ifdef DEBUG
LoadIDT(WindowsIDT);
Break();
LoadIDT(DebugIDT);
#endif
Return();
}