src/arch/mips/remote_gdb.cc - arm/gem5 - Git at Google

 /*
  * Copyright (c) 2010 ARM Limited
  * 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) 2002-2005 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.
  *
  * Authors: Nathan Binkert
  *          William Wang
  *          Deyuan Guo
  */

 /*
  * Copyright (c) 1990, 1993 The Regents of the University of California
  * All rights reserved
  *
  * This software was developed by the Computer Systems Engineering group
  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
  * contributed to Berkeley.
  *
  * All advertising materials mentioning features or use of this software
  * must display the following acknowledgement:
  *      This product includes software developed by the University of
  *      California, Lawrence Berkeley Laboratories.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. 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.
  * 3. All advertising materials mentioning features or use of this software
  *    must display the following acknowledgement:
  *      This product includes software developed by the University of
  *      California, Berkeley and its contributors.
  * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
  *
  *      @(#)kgdb_stub.c 8.4 (Berkeley) 1/12/94
  */

 /*-
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
  * All rights reserved.
  *
  * This code is derived from software contributed to The NetBSD Foundation
  * by Jason R. Thorpe.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. 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.
  * 3. All advertising materials mentioning features or use of this software
  *    must display the following acknowledgement:
  *      This product includes software developed by the NetBSD
  *      Foundation, Inc. and its contributors.
  * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
  */

 /*
  * $NetBSD: kgdb_stub.c,v 1.8 2001/07/07 22:58:00 wdk Exp $
  *
  * Taken from NetBSD
  *
  * "Stub" to allow remote cpu to debug over a serial line using gdb.
  */

 #include <sys/signal.h>
 #include <unistd.h>

 #include <string>

 #include "arch/mips/decoder.hh"
 #include "arch/mips/remote_gdb.hh"
 #include "arch/mips/vtophys.hh"
 #include "cpu/thread_state.hh"
 #include "debug/GDBAcc.hh"
 #include "debug/GDBMisc.hh"
 #include "mem/page_table.hh"
 #include "sim/full_system.hh"

 using namespace std;
 using namespace MipsISA;

 RemoteGDB::RemoteGDB(System *_system, ThreadContext *tc)
     : BaseRemoteGDB(_system, tc, GdbNumRegs)
 {
 }

 /*
  * Determine if the mapping at va..(va+len) is valid.
  */
 bool
 RemoteGDB::acc(Addr va, size_t len)
 {
     TlbEntry entry;
     //Check to make sure the first byte is mapped into the processes address
     //space.
     if (FullSystem)
         panic("acc not implemented for MIPS FS!");
     else
         return context->getProcessPtr()->pTable->lookup(va, entry);
 }

 /*
  * Translate the kernel debugger register format into the GDB register
  * format.
  */
 void
 RemoteGDB::getregs()
 {
     DPRINTF(GDBAcc, "getregs in remotegdb \n");
     memset(gdbregs.regs, 0, gdbregs.bytes());

     // MIPS registers are 32 bits wide, gdb registers are 64 bits wide
     // two MIPS registers are packed into one gdb register (little endian)

     // INTREG: R0~R31
     for (int i = 0; i < GdbIntArchRegs; i++) {
         gdbregs.regs[i] = pack(
                 context->readIntReg(i * 2),
                 context->readIntReg(i * 2 + 1));
     }
     // SR, LO, HI, BADVADDR, CAUSE, PC
     gdbregs.regs[GdbIntArchRegs + 0] = pack(
                 context->readMiscRegNoEffect(MISCREG_STATUS),
                 context->readIntReg(INTREG_LO));
     gdbregs.regs[GdbIntArchRegs + 1] = pack(
                 context->readIntReg(INTREG_HI),
                 context->readMiscRegNoEffect(MISCREG_BADVADDR));
     gdbregs.regs[GdbIntArchRegs + 2] = pack(
                 context->readMiscRegNoEffect(MISCREG_CAUSE),
                 context->pcState().pc());
     // FLOATREG: F0~F31
     for (int i = 0; i < GdbFloatArchRegs; i++) {
         gdbregs.regs[GdbIntRegs + i] = pack(
                 context->readFloatRegBits(i * 2),
                 context->readFloatRegBits(i * 2 + 1));
     }
     // FCR, FIR
     gdbregs.regs[GdbIntRegs + GdbFloatArchRegs + 0] = pack(
                 context->readFloatRegBits(FLOATREG_FCCR),
                 context->readFloatRegBits(FLOATREG_FIR));
 }

 /*
  * Translate the GDB register format into the kernel debugger register
  * format.
  */
 void
 RemoteGDB::setregs()
 {
     DPRINTF(GDBAcc, "setregs in remotegdb \n");

     // MIPS registers are 32 bits wide, gdb registers are 64 bits wide
     // two MIPS registers are packed into one gdb register (little endian)

     // INTREG: R0~R31
     for (int i = 0; i < GdbIntArchRegs; i++) {
         if (i) context->setIntReg(i * 2,
                 unpackLo(gdbregs.regs[i]));
         context->setIntReg(i * 2 + 1,
                 unpackHi(gdbregs.regs[i]));
     }
     // SR, LO, HI, BADVADDR, CAUSE, PC
     context->setMiscRegNoEffect(MISCREG_STATUS,
                 unpackLo(gdbregs.regs[GdbIntArchRegs + 0]));
     context->setIntReg(INTREG_LO,
                 unpackHi(gdbregs.regs[GdbIntArchRegs + 0]));
     context->setIntReg(INTREG_HI,
                 unpackLo(gdbregs.regs[GdbIntArchRegs + 1]));
     context->setMiscRegNoEffect(MISCREG_BADVADDR,
                 unpackHi(gdbregs.regs[GdbIntArchRegs + 1]));
     context->setMiscRegNoEffect(MISCREG_CAUSE,
                 unpackLo(gdbregs.regs[GdbIntArchRegs + 2]));
     context->pcState(
                 unpackHi(gdbregs.regs[GdbIntArchRegs + 2]));
     // FLOATREG: F0~F31
     for (int i = 0; i < GdbFloatArchRegs; i++) {
         context->setFloatRegBits(i * 2,
                 unpackLo(gdbregs.regs[GdbIntRegs + i]));
         context->setFloatRegBits(i * 2 + 1,
                 unpackHi(gdbregs.regs[GdbIntRegs + i]));
     }
     // FCR, FIR
     context->setFloatRegBits(FLOATREG_FCCR,
                 unpackLo(gdbregs.regs[GdbIntRegs + GdbFloatArchRegs + 0]));
     context->setFloatRegBits(FLOATREG_FIR,
                 unpackHi(gdbregs.regs[GdbIntRegs + GdbFloatArchRegs + 0]));
 }

 void
 RemoteGDB::clearSingleStep()
 {
     DPRINTF(GDBMisc, "clearSingleStep bt_addr=%#x nt_addr=%#x\n",
             takenBkpt, notTakenBkpt);

     if (takenBkpt != 0)
         clearTempBreakpoint(takenBkpt);

     if (notTakenBkpt != 0)
         clearTempBreakpoint(notTakenBkpt);
 }

 void
 RemoteGDB::setSingleStep()
 {
     PCState pc = context->pcState();
     PCState bpc;
     bool set_bt = false;

     // User was stopped at pc, e.g. the instruction at pc was not
     // executed.
     MachInst inst = read<MachInst>(pc.pc());
     StaticInstPtr si = context->getDecoderPtr()->decode(inst, pc.pc());
     if (si->hasBranchTarget(pc, context, bpc)) {
         // Don't bother setting a breakpoint on the taken branch if it
         // is the same as the next npc
         if (bpc.npc() != pc.nnpc())
             set_bt = true;
     }

     DPRINTF(GDBMisc, "setSingleStep bt_addr=%#x nt_addr=%#x\n",
             takenBkpt, notTakenBkpt);

     notTakenBkpt = pc.nnpc();
     setTempBreakpoint(notTakenBkpt);

     if (set_bt) {
         takenBkpt = bpc.npc();
         setTempBreakpoint(takenBkpt);
     }
 }
	/*
	* Copyright (c) 2010 ARM Limited
	* 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) 2002-2005 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.
	*
	* Authors: Nathan Binkert
	* William Wang
	* Deyuan Guo
	*/

	/*
	* Copyright (c) 1990, 1993 The Regents of the University of California
	* All rights reserved
	*
	* This software was developed by the Computer Systems Engineering group
	* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
	* contributed to Berkeley.
	*
	* All advertising materials mentioning features or use of this software
	* must display the following acknowledgement:
	* This product includes software developed by the University of
	* California, Lawrence Berkeley Laboratories.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. 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.
	* 3. All advertising materials mentioning features or use of this software
	* must display the following acknowledgement:
	* This product includes software developed by the University of
	* California, Berkeley and its contributors.
	* 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
	*
	* @(#)kgdb_stub.c 8.4 (Berkeley) 1/12/94
	*/

	/*-
	* Copyright (c) 2001 The NetBSD Foundation, Inc.
	* All rights reserved.
	*
	* This code is derived from software contributed to The NetBSD Foundation
	* by Jason R. Thorpe.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. 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.
	* 3. All advertising materials mentioning features or use of this software
	* must display the following acknowledgement:
	* This product includes software developed by the NetBSD
	* Foundation, Inc. and its contributors.
	* 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
	*/

	/*
	* $NetBSD: kgdb_stub.c,v 1.8 2001/07/07 22:58:00 wdk Exp $
	*
	* Taken from NetBSD
	*
	* "Stub" to allow remote cpu to debug over a serial line using gdb.
	*/

	#include <sys/signal.h>
	#include <unistd.h>

	#include <string>

	#include "arch/mips/decoder.hh"
	#include "arch/mips/remote_gdb.hh"
	#include "arch/mips/vtophys.hh"
	#include "cpu/thread_state.hh"
	#include "debug/GDBAcc.hh"
	#include "debug/GDBMisc.hh"
	#include "mem/page_table.hh"
	#include "sim/full_system.hh"

	using namespace std;
	using namespace MipsISA;

	RemoteGDB::RemoteGDB(System _system, ThreadContext tc)
	: BaseRemoteGDB(_system, tc, GdbNumRegs)
	{
	}

	/*
	* Determine if the mapping at va..(va+len) is valid.
	*/
	bool
	RemoteGDB::acc(Addr va, size_t len)
	{
	TlbEntry entry;
	//Check to make sure the first byte is mapped into the processes address
	//space.
	if (FullSystem)
	panic("acc not implemented for MIPS FS!");
	else
	return context->getProcessPtr()->pTable->lookup(va, entry);
	}

	/*
	* Translate the kernel debugger register format into the GDB register
	* format.
	*/
	void
	RemoteGDB::getregs()
	{
	DPRINTF(GDBAcc, "getregs in remotegdb \n");
	memset(gdbregs.regs, 0, gdbregs.bytes());

	// MIPS registers are 32 bits wide, gdb registers are 64 bits wide
	// two MIPS registers are packed into one gdb register (little endian)

	// INTREG: R0~R31
	for (int i = 0; i < GdbIntArchRegs; i++) {
	gdbregs.regs[i] = pack(
	context->readIntReg(i * 2),
	context->readIntReg(i * 2 + 1));
	}
	// SR, LO, HI, BADVADDR, CAUSE, PC
	gdbregs.regs[GdbIntArchRegs + 0] = pack(
	context->readMiscRegNoEffect(MISCREG_STATUS),
	context->readIntReg(INTREG_LO));
	gdbregs.regs[GdbIntArchRegs + 1] = pack(
	context->readIntReg(INTREG_HI),
	context->readMiscRegNoEffect(MISCREG_BADVADDR));
	gdbregs.regs[GdbIntArchRegs + 2] = pack(
	context->readMiscRegNoEffect(MISCREG_CAUSE),
	context->pcState().pc());
	// FLOATREG: F0~F31
	for (int i = 0; i < GdbFloatArchRegs; i++) {
	gdbregs.regs[GdbIntRegs + i] = pack(
	context->readFloatRegBits(i * 2),
	context->readFloatRegBits(i * 2 + 1));
	}
	// FCR, FIR
	gdbregs.regs[GdbIntRegs + GdbFloatArchRegs + 0] = pack(
	context->readFloatRegBits(FLOATREG_FCCR),
	context->readFloatRegBits(FLOATREG_FIR));
	}

	/*
	* Translate the GDB register format into the kernel debugger register
	* format.
	*/
	void
	RemoteGDB::setregs()
	{
	DPRINTF(GDBAcc, "setregs in remotegdb \n");

	// MIPS registers are 32 bits wide, gdb registers are 64 bits wide
	// two MIPS registers are packed into one gdb register (little endian)

	// INTREG: R0~R31
	for (int i = 0; i < GdbIntArchRegs; i++) {
	if (i) context->setIntReg(i * 2,
	unpackLo(gdbregs.regs[i]));
	context->setIntReg(i * 2 + 1,
	unpackHi(gdbregs.regs[i]));
	}
	// SR, LO, HI, BADVADDR, CAUSE, PC
	context->setMiscRegNoEffect(MISCREG_STATUS,
	unpackLo(gdbregs.regs[GdbIntArchRegs + 0]));
	context->setIntReg(INTREG_LO,
	unpackHi(gdbregs.regs[GdbIntArchRegs + 0]));
	context->setIntReg(INTREG_HI,
	unpackLo(gdbregs.regs[GdbIntArchRegs + 1]));
	context->setMiscRegNoEffect(MISCREG_BADVADDR,
	unpackHi(gdbregs.regs[GdbIntArchRegs + 1]));
	context->setMiscRegNoEffect(MISCREG_CAUSE,
	unpackLo(gdbregs.regs[GdbIntArchRegs + 2]));
	context->pcState(
	unpackHi(gdbregs.regs[GdbIntArchRegs + 2]));
	// FLOATREG: F0~F31
	for (int i = 0; i < GdbFloatArchRegs; i++) {
	context->setFloatRegBits(i * 2,
	unpackLo(gdbregs.regs[GdbIntRegs + i]));
	context->setFloatRegBits(i * 2 + 1,
	unpackHi(gdbregs.regs[GdbIntRegs + i]));
	}
	// FCR, FIR
	context->setFloatRegBits(FLOATREG_FCCR,
	unpackLo(gdbregs.regs[GdbIntRegs + GdbFloatArchRegs + 0]));
	context->setFloatRegBits(FLOATREG_FIR,
	unpackHi(gdbregs.regs[GdbIntRegs + GdbFloatArchRegs + 0]));
	}

	void
	RemoteGDB::clearSingleStep()
	{
	DPRINTF(GDBMisc, "clearSingleStep bt_addr=%#x nt_addr=%#x\n",
	takenBkpt, notTakenBkpt);

	if (takenBkpt != 0)
	clearTempBreakpoint(takenBkpt);

	if (notTakenBkpt != 0)
	clearTempBreakpoint(notTakenBkpt);
	}

	void
	RemoteGDB::setSingleStep()
	{
	PCState pc = context->pcState();
	PCState bpc;
	bool set_bt = false;

	// User was stopped at pc, e.g. the instruction at pc was not
	// executed.
	MachInst inst = read<MachInst>(pc.pc());
	StaticInstPtr si = context->getDecoderPtr()->decode(inst, pc.pc());
	if (si->hasBranchTarget(pc, context, bpc)) {
	// Don't bother setting a breakpoint on the taken branch if it
	// is the same as the next npc
	if (bpc.npc() != pc.nnpc())
	set_bt = true;
	}

	DPRINTF(GDBMisc, "setSingleStep bt_addr=%#x nt_addr=%#x\n",
	takenBkpt, notTakenBkpt);

	notTakenBkpt = pc.nnpc();
	setTempBreakpoint(notTakenBkpt);

	if (set_bt) {
	takenBkpt = bpc.npc();
	setTempBreakpoint(takenBkpt);
	}
	}