src/arch/x86/faults.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2007 The Hewlett-Packard Development Company
  * All rights reserved.
  *
  * The license below extends only to copyright in the software and shall
  * not be construed as granting a license to any other intellectual
  * property including but not limited to intellectual property relating
  * to a hardware implementation of the functionality of the software
  * licensed hereunder.  You may use the software subject to the license
  * terms below provided that you ensure that this notice is replicated
  * unmodified and in its entirety in all distributions of the software,
  * modified or unmodified, in source code or in binary form.
  *
  * Copyright (c) 2003-2007 The Regents of The University of Michigan
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met: redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer;
  * redistributions in binary form must reproduce the above copyright
  * notice, this list of conditions and the following disclaimer in the
  * documentation and/or other materials provided with the distribution;
  * neither the name of the copyright holders nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "arch/x86/faults.hh"

 #include "arch/x86/generated/decoder.hh"
 #include "arch/x86/insts/static_inst.hh"
 #include "arch/x86/mmu.hh"
 #include "base/loader/symtab.hh"
 #include "base/trace.hh"
 #include "cpu/thread_context.hh"
 #include "debug/Faults.hh"
 #include "sim/full_system.hh"
 #include "sim/process.hh"

 namespace gem5
 {

 namespace X86ISA
 {

 void
 X86FaultBase::invoke(ThreadContext *tc, const StaticInstPtr &inst)
 {
     if (!FullSystem) {
         FaultBase::invoke(tc, inst);
         return;
     }

     PCState pcState = tc->pcState();
     Addr pc = pcState.pc();
     DPRINTF(Faults, "RIP %#x: vector %d: %s\n", pc, vector, describe());
     using namespace X86ISAInst::rom_labels;
     HandyM5Reg m5reg = tc->readMiscRegNoEffect(MISCREG_M5_REG);
     MicroPC entry;
     if (m5reg.mode == LongMode) {
         entry = isSoft() ? extern_label_longModeSoftInterrupt :
                            extern_label_longModeInterrupt;
     } else {
         entry = extern_label_legacyModeInterrupt;
     }
     tc->setIntReg(INTREG_MICRO(1), vector);
     tc->setIntReg(INTREG_MICRO(7), pc);
     if (errorCode != (uint64_t)(-1)) {
         if (m5reg.mode == LongMode) {
             entry = extern_label_longModeInterruptWithError;
         } else {
             panic("Legacy mode interrupts with error codes "
                     "aren't implemented.");
         }
         // Software interrupts shouldn't have error codes. If one
         // does, there would need to be microcode to set it up.
         assert(!isSoft());
         tc->setIntReg(INTREG_MICRO(15), errorCode);
     }
     pcState.upc(romMicroPC(entry));
     pcState.nupc(romMicroPC(entry) + 1);
     tc->pcState(pcState);
 }

 std::string
 X86FaultBase::describe() const
 {
     std::stringstream ss;
     ccprintf(ss, "%s", mnemonic());
     if (errorCode != (uint64_t)(-1))
         ccprintf(ss, "(%#x)", errorCode);

     return ss.str();
 }

 void
 X86Trap::invoke(ThreadContext *tc, const StaticInstPtr &inst)
 {
     X86FaultBase::invoke(tc);
     if (!FullSystem)
         return;

     // This is the same as a fault, but it happens -after- the
     // instruction.
     PCState pc = tc->pcState();
     pc.uEnd();
 }

 void
 X86Abort::invoke(ThreadContext *tc, const StaticInstPtr &inst)
 {
     panic("Abort exception!");
 }

 void
 InvalidOpcode::invoke(ThreadContext *tc, const StaticInstPtr &inst)
 {
     if (FullSystem) {
         X86Fault::invoke(tc, inst);
     } else {
         auto *xsi = static_cast<X86StaticInst *>(inst.get());
         panic("Unrecognized/invalid instruction executed:\n %s",
                 xsi->machInst);
     }
 }

 void
 PageFault::invoke(ThreadContext *tc, const StaticInstPtr &inst)
 {
     if (FullSystem) {
         // Invalidate any matching TLB entries before handling the page fault.
         tc->getMMUPtr()->demapPage(addr, 0);
         HandyM5Reg m5reg = tc->readMiscRegNoEffect(MISCREG_M5_REG);
         X86FaultBase::invoke(tc);
         // If something bad happens while trying to enter the page fault
         // handler, I'm pretty sure that's a double fault and then all
         // bets are off. That means it should be safe to update this
         // state now.
         if (m5reg.mode == LongMode)
             tc->setMiscReg(MISCREG_CR2, addr);
         else
             tc->setMiscReg(MISCREG_CR2, (uint32_t)addr);
     } else if (!tc->getProcessPtr()->fixupFault(addr)) {
         PageFaultErrorCode code = errorCode;
         const char *modeStr = "";
         if (code.fetch)
             modeStr = "execute";
         else if (code.write)
             modeStr = "write";
         else
             modeStr = "read";

         // print information about what we are panic'ing on
         if (!inst) {
             panic("Tried to %s unmapped address %#x.", modeStr, addr);
         } else {
             panic("Tried to %s unmapped address %#x.\nPC: %#x, Instr: %s",
                   modeStr, addr, tc->pcState().pc(),
                   inst->disassemble(tc->pcState().pc(),
                       &loader::debugSymbolTable));
         }
     }
 }

 std::string
 PageFault::describe() const
 {
     std::stringstream ss;
     ccprintf(ss, "%s at %#x", X86FaultBase::describe(), addr);
     return ss.str();
 }

 void
 InitInterrupt::invoke(ThreadContext *tc, const StaticInstPtr &inst)
 {
     DPRINTF(Faults, "Init interrupt.\n");
     // The otherwise unmodified integer registers should be set to 0.
     for (int index = 0; index < NUM_ARCH_INTREGS; index++) {
         tc->setIntReg(index, 0);
     }

     CR0 cr0 = tc->readMiscReg(MISCREG_CR0);
     CR0 newCR0 = 1 << 4;
     newCR0.cd = cr0.cd;
     newCR0.nw = cr0.nw;
     tc->setMiscReg(MISCREG_CR0, newCR0);
     tc->setMiscReg(MISCREG_CR2, 0);
     tc->setMiscReg(MISCREG_CR3, 0);
     tc->setMiscReg(MISCREG_CR4, 0);

     tc->setMiscReg(MISCREG_RFLAGS, 0x0000000000000002ULL);

     tc->setMiscReg(MISCREG_EFER, 0);

     SegAttr dataAttr = 0;
     dataAttr.dpl = 0;
     dataAttr.unusable = 0;
     dataAttr.defaultSize = 0;
     dataAttr.longMode = 0;
     dataAttr.avl = 0;
     dataAttr.granularity = 0;
     dataAttr.present = 1;
     dataAttr.type = 3;
     dataAttr.writable = 1;
     dataAttr.readable = 1;
     dataAttr.expandDown = 0;
     dataAttr.system = 1;

     for (int seg = 0; seg != NUM_SEGMENTREGS; seg++) {
         tc->setMiscReg(MISCREG_SEG_SEL(seg), 0);
         tc->setMiscReg(MISCREG_SEG_BASE(seg), 0);
         tc->setMiscReg(MISCREG_SEG_EFF_BASE(seg), 0);
         tc->setMiscReg(MISCREG_SEG_LIMIT(seg), 0xffff);
         tc->setMiscReg(MISCREG_SEG_ATTR(seg), dataAttr);
     }

     SegAttr codeAttr = 0;
     codeAttr.dpl = 0;
     codeAttr.unusable = 0;
     codeAttr.defaultSize = 0;
     codeAttr.longMode = 0;
     codeAttr.avl = 0;
     codeAttr.granularity = 0;
     codeAttr.present = 1;
     codeAttr.type = 10;
     codeAttr.writable = 0;
     codeAttr.readable = 1;
     codeAttr.expandDown = 0;
     codeAttr.system = 1;

     tc->setMiscReg(MISCREG_CS, 0xf000);
     tc->setMiscReg(MISCREG_CS_BASE,
             0x00000000ffff0000ULL);
     tc->setMiscReg(MISCREG_CS_EFF_BASE,
             0x00000000ffff0000ULL);
     // This has the base value pre-added.
     tc->setMiscReg(MISCREG_CS_LIMIT, 0xffffffff);
     tc->setMiscReg(MISCREG_CS_ATTR, codeAttr);

     PCState pc(0x000000000000fff0ULL + tc->readMiscReg(MISCREG_CS_BASE));
     tc->pcState(pc);

     tc->setMiscReg(MISCREG_TSG_BASE, 0);
     tc->setMiscReg(MISCREG_TSG_LIMIT, 0xffff);

     tc->setMiscReg(MISCREG_IDTR_BASE, 0);
     tc->setMiscReg(MISCREG_IDTR_LIMIT, 0xffff);

     SegAttr tslAttr = 0;
     tslAttr.present = 1;
     tslAttr.type = 2; // LDT
     tc->setMiscReg(MISCREG_TSL, 0);
     tc->setMiscReg(MISCREG_TSL_BASE, 0);
     tc->setMiscReg(MISCREG_TSL_LIMIT, 0xffff);
     tc->setMiscReg(MISCREG_TSL_ATTR, tslAttr);

     SegAttr trAttr = 0;
     trAttr.present = 1;
     trAttr.type = 3; // Busy 16-bit TSS
     tc->setMiscReg(MISCREG_TR, 0);
     tc->setMiscReg(MISCREG_TR_BASE, 0);
     tc->setMiscReg(MISCREG_TR_LIMIT, 0xffff);
     tc->setMiscReg(MISCREG_TR_ATTR, trAttr);

     // This value should be the family/model/stepping of the processor.
     // (page 418). It should be consistent with the value from CPUID, but
     // the actual value probably doesn't matter much.
     tc->setIntReg(INTREG_RDX, 0);

     tc->setMiscReg(MISCREG_DR0, 0);
     tc->setMiscReg(MISCREG_DR1, 0);
     tc->setMiscReg(MISCREG_DR2, 0);
     tc->setMiscReg(MISCREG_DR3, 0);

     tc->setMiscReg(MISCREG_DR6, 0x00000000ffff0ff0ULL);
     tc->setMiscReg(MISCREG_DR7, 0x0000000000000400ULL);

     tc->setMiscReg(MISCREG_MXCSR, 0x1f80);

     // Flag all elements on the x87 stack as empty.
     tc->setMiscReg(MISCREG_FTW, 0xFFFF);

     // Update the handy M5 Reg.
     tc->setMiscReg(MISCREG_M5_REG, 0);
     MicroPC entry = X86ISAInst::rom_labels::extern_label_initIntHalt;
     pc.upc(romMicroPC(entry));
     pc.nupc(romMicroPC(entry) + 1);
     tc->pcState(pc);
 }

 void
 StartupInterrupt::invoke(ThreadContext *tc, const StaticInstPtr &inst)
 {
     DPRINTF(Faults, "Startup interrupt with vector %#x.\n", vector);
     HandyM5Reg m5Reg = tc->readMiscReg(MISCREG_M5_REG);
     if (m5Reg.mode != LegacyMode || m5Reg.submode != RealMode) {
         panic("Startup IPI recived outside of real mode. "
                 "Don't know what to do. %d, %d", m5Reg.mode, m5Reg.submode);
     }

     tc->setMiscReg(MISCREG_CS, vector << 8);
     tc->setMiscReg(MISCREG_CS_BASE, vector << 12);
     tc->setMiscReg(MISCREG_CS_EFF_BASE, vector << 12);
     // This has the base value pre-added.
     tc->setMiscReg(MISCREG_CS_LIMIT, 0xffff);

     tc->pcState(tc->readMiscReg(MISCREG_CS_BASE));
 }

 } // namespace X86ISA
 } // namespace gem5
	/*
	* Copyright (c) 2007 The Hewlett-Packard Development Company
	* All rights reserved.
	*
	* The license below extends only to copyright in the software and shall
	* not be construed as granting a license to any other intellectual
	* property including but not limited to intellectual property relating
	* to a hardware implementation of the functionality of the software
	* licensed hereunder. You may use the software subject to the license
	* terms below provided that you ensure that this notice is replicated
	* unmodified and in its entirety in all distributions of the software,
	* modified or unmodified, in source code or in binary form.
	*
	* Copyright (c) 2003-2007 The Regents of The University of Michigan
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met: redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer;
	* redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution;
	* neither the name of the copyright holders nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "arch/x86/faults.hh"

	#include "arch/x86/generated/decoder.hh"
	#include "arch/x86/insts/static_inst.hh"
	#include "arch/x86/mmu.hh"
	#include "base/loader/symtab.hh"
	#include "base/trace.hh"
	#include "cpu/thread_context.hh"
	#include "debug/Faults.hh"
	#include "sim/full_system.hh"
	#include "sim/process.hh"

	namespace gem5
	{

	namespace X86ISA
	{

	void
	X86FaultBase::invoke(ThreadContext *tc, const StaticInstPtr &inst)
	{
	if (!FullSystem) {
	FaultBase::invoke(tc, inst);
	return;
	}

	PCState pcState = tc->pcState();
	Addr pc = pcState.pc();
	DPRINTF(Faults, "RIP %#x: vector %d: %s\n", pc, vector, describe());
	using namespace X86ISAInst::rom_labels;
	HandyM5Reg m5reg = tc->readMiscRegNoEffect(MISCREG_M5_REG);
	MicroPC entry;
	if (m5reg.mode == LongMode) {
	entry = isSoft() ? extern_label_longModeSoftInterrupt :
	extern_label_longModeInterrupt;
	} else {
	entry = extern_label_legacyModeInterrupt;
	}
	tc->setIntReg(INTREG_MICRO(1), vector);
	tc->setIntReg(INTREG_MICRO(7), pc);
	if (errorCode != (uint64_t)(-1)) {
	if (m5reg.mode == LongMode) {
	entry = extern_label_longModeInterruptWithError;
	} else {
	panic("Legacy mode interrupts with error codes "
	"aren't implemented.");
	}
	// Software interrupts shouldn't have error codes. If one
	// does, there would need to be microcode to set it up.
	assert(!isSoft());
	tc->setIntReg(INTREG_MICRO(15), errorCode);
	}
	pcState.upc(romMicroPC(entry));
	pcState.nupc(romMicroPC(entry) + 1);
	tc->pcState(pcState);
	}

	std::string
	X86FaultBase::describe() const
	{
	std::stringstream ss;
	ccprintf(ss, "%s", mnemonic());
	if (errorCode != (uint64_t)(-1))
	ccprintf(ss, "(%#x)", errorCode);

	return ss.str();
	}

	void
	X86Trap::invoke(ThreadContext *tc, const StaticInstPtr &inst)
	{
	X86FaultBase::invoke(tc);
	if (!FullSystem)
	return;

	// This is the same as a fault, but it happens -after- the
	// instruction.
	PCState pc = tc->pcState();
	pc.uEnd();
	}

	void
	X86Abort::invoke(ThreadContext *tc, const StaticInstPtr &inst)
	{
	panic("Abort exception!");
	}

	void
	InvalidOpcode::invoke(ThreadContext *tc, const StaticInstPtr &inst)
	{
	if (FullSystem) {
	X86Fault::invoke(tc, inst);
	} else {
	auto xsi = static_cast<X86StaticInst >(inst.get());
	panic("Unrecognized/invalid instruction executed:\n %s",
	xsi->machInst);
	}
	}

	void
	PageFault::invoke(ThreadContext *tc, const StaticInstPtr &inst)
	{
	if (FullSystem) {
	// Invalidate any matching TLB entries before handling the page fault.
	tc->getMMUPtr()->demapPage(addr, 0);
	HandyM5Reg m5reg = tc->readMiscRegNoEffect(MISCREG_M5_REG);
	X86FaultBase::invoke(tc);
	// If something bad happens while trying to enter the page fault
	// handler, I'm pretty sure that's a double fault and then all
	// bets are off. That means it should be safe to update this
	// state now.
	if (m5reg.mode == LongMode)
	tc->setMiscReg(MISCREG_CR2, addr);
	else
	tc->setMiscReg(MISCREG_CR2, (uint32_t)addr);
	} else if (!tc->getProcessPtr()->fixupFault(addr)) {
	PageFaultErrorCode code = errorCode;
	const char *modeStr = "";
	if (code.fetch)
	modeStr = "execute";
	else if (code.write)
	modeStr = "write";
	else
	modeStr = "read";

	// print information about what we are panic'ing on
	if (!inst) {
	panic("Tried to %s unmapped address %#x.", modeStr, addr);
	} else {
	panic("Tried to %s unmapped address %#x.\nPC: %#x, Instr: %s",
	modeStr, addr, tc->pcState().pc(),
	inst->disassemble(tc->pcState().pc(),
	&loader::debugSymbolTable));
	}
	}
	}

	std::string
	PageFault::describe() const
	{
	std::stringstream ss;
	ccprintf(ss, "%s at %#x", X86FaultBase::describe(), addr);
	return ss.str();
	}

	void
	InitInterrupt::invoke(ThreadContext *tc, const StaticInstPtr &inst)
	{
	DPRINTF(Faults, "Init interrupt.\n");
	// The otherwise unmodified integer registers should be set to 0.
	for (int index = 0; index < NUM_ARCH_INTREGS; index++) {
	tc->setIntReg(index, 0);
	}

	CR0 cr0 = tc->readMiscReg(MISCREG_CR0);
	CR0 newCR0 = 1 << 4;
	newCR0.cd = cr0.cd;
	newCR0.nw = cr0.nw;
	tc->setMiscReg(MISCREG_CR0, newCR0);
	tc->setMiscReg(MISCREG_CR2, 0);
	tc->setMiscReg(MISCREG_CR3, 0);
	tc->setMiscReg(MISCREG_CR4, 0);

	tc->setMiscReg(MISCREG_RFLAGS, 0x0000000000000002ULL);

	tc->setMiscReg(MISCREG_EFER, 0);

	SegAttr dataAttr = 0;
	dataAttr.dpl = 0;
	dataAttr.unusable = 0;
	dataAttr.defaultSize = 0;
	dataAttr.longMode = 0;
	dataAttr.avl = 0;
	dataAttr.granularity = 0;
	dataAttr.present = 1;
	dataAttr.type = 3;
	dataAttr.writable = 1;
	dataAttr.readable = 1;
	dataAttr.expandDown = 0;
	dataAttr.system = 1;

	for (int seg = 0; seg != NUM_SEGMENTREGS; seg++) {
	tc->setMiscReg(MISCREG_SEG_SEL(seg), 0);
	tc->setMiscReg(MISCREG_SEG_BASE(seg), 0);
	tc->setMiscReg(MISCREG_SEG_EFF_BASE(seg), 0);
	tc->setMiscReg(MISCREG_SEG_LIMIT(seg), 0xffff);
	tc->setMiscReg(MISCREG_SEG_ATTR(seg), dataAttr);
	}

	SegAttr codeAttr = 0;
	codeAttr.dpl = 0;
	codeAttr.unusable = 0;
	codeAttr.defaultSize = 0;
	codeAttr.longMode = 0;
	codeAttr.avl = 0;
	codeAttr.granularity = 0;
	codeAttr.present = 1;
	codeAttr.type = 10;
	codeAttr.writable = 0;
	codeAttr.readable = 1;
	codeAttr.expandDown = 0;
	codeAttr.system = 1;

	tc->setMiscReg(MISCREG_CS, 0xf000);
	tc->setMiscReg(MISCREG_CS_BASE,
	0x00000000ffff0000ULL);
	tc->setMiscReg(MISCREG_CS_EFF_BASE,
	0x00000000ffff0000ULL);
	// This has the base value pre-added.
	tc->setMiscReg(MISCREG_CS_LIMIT, 0xffffffff);
	tc->setMiscReg(MISCREG_CS_ATTR, codeAttr);

	PCState pc(0x000000000000fff0ULL + tc->readMiscReg(MISCREG_CS_BASE));
	tc->pcState(pc);

	tc->setMiscReg(MISCREG_TSG_BASE, 0);
	tc->setMiscReg(MISCREG_TSG_LIMIT, 0xffff);

	tc->setMiscReg(MISCREG_IDTR_BASE, 0);
	tc->setMiscReg(MISCREG_IDTR_LIMIT, 0xffff);

	SegAttr tslAttr = 0;
	tslAttr.present = 1;
	tslAttr.type = 2; // LDT
	tc->setMiscReg(MISCREG_TSL, 0);
	tc->setMiscReg(MISCREG_TSL_BASE, 0);
	tc->setMiscReg(MISCREG_TSL_LIMIT, 0xffff);
	tc->setMiscReg(MISCREG_TSL_ATTR, tslAttr);

	SegAttr trAttr = 0;
	trAttr.present = 1;
	trAttr.type = 3; // Busy 16-bit TSS
	tc->setMiscReg(MISCREG_TR, 0);
	tc->setMiscReg(MISCREG_TR_BASE, 0);
	tc->setMiscReg(MISCREG_TR_LIMIT, 0xffff);
	tc->setMiscReg(MISCREG_TR_ATTR, trAttr);

	// This value should be the family/model/stepping of the processor.
	// (page 418). It should be consistent with the value from CPUID, but
	// the actual value probably doesn't matter much.
	tc->setIntReg(INTREG_RDX, 0);

	tc->setMiscReg(MISCREG_DR0, 0);
	tc->setMiscReg(MISCREG_DR1, 0);
	tc->setMiscReg(MISCREG_DR2, 0);
	tc->setMiscReg(MISCREG_DR3, 0);

	tc->setMiscReg(MISCREG_DR6, 0x00000000ffff0ff0ULL);
	tc->setMiscReg(MISCREG_DR7, 0x0000000000000400ULL);

	tc->setMiscReg(MISCREG_MXCSR, 0x1f80);

	// Flag all elements on the x87 stack as empty.
	tc->setMiscReg(MISCREG_FTW, 0xFFFF);

	// Update the handy M5 Reg.
	tc->setMiscReg(MISCREG_M5_REG, 0);
	MicroPC entry = X86ISAInst::rom_labels::extern_label_initIntHalt;
	pc.upc(romMicroPC(entry));
	pc.nupc(romMicroPC(entry) + 1);
	tc->pcState(pc);
	}

	void
	StartupInterrupt::invoke(ThreadContext *tc, const StaticInstPtr &inst)
	{
	DPRINTF(Faults, "Startup interrupt with vector %#x.\n", vector);
	HandyM5Reg m5Reg = tc->readMiscReg(MISCREG_M5_REG);
	if (m5Reg.mode != LegacyMode \|\| m5Reg.submode != RealMode) {
	panic("Startup IPI recived outside of real mode. "
	"Don't know what to do. %d, %d", m5Reg.mode, m5Reg.submode);
	}

	tc->setMiscReg(MISCREG_CS, vector << 8);
	tc->setMiscReg(MISCREG_CS_BASE, vector << 12);
	tc->setMiscReg(MISCREG_CS_EFF_BASE, vector << 12);
	// This has the base value pre-added.
	tc->setMiscReg(MISCREG_CS_LIMIT, 0xffff);

	tc->pcState(tc->readMiscReg(MISCREG_CS_BASE));
	}

	} // namespace X86ISA
	} // namespace gem5