remote_gdb.cc revision 2665:a124942bacb8
1/*
2 * Copyright (c) 2002-2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Nathan Binkert
29 */
30
31/*
32 * Copyright (c) 1990, 1993
33 *	The Regents of the University of California.  All rights reserved.
34 *
35 * This software was developed by the Computer Systems Engineering group
36 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
37 * contributed to Berkeley.
38 *
39 * All advertising materials mentioning features or use of this software
40 * must display the following acknowledgement:
41 *	This product includes software developed by the University of
42 *	California, Lawrence Berkeley Laboratories.
43 *
44 * Redistribution and use in source and binary forms, with or without
45 * modification, are permitted provided that the following conditions
46 * are met:
47 * 1. Redistributions of source code must retain the above copyright
48 *    notice, this list of conditions and the following disclaimer.
49 * 2. Redistributions in binary form must reproduce the above copyright
50 *    notice, this list of conditions and the following disclaimer in the
51 *    documentation and/or other materials provided with the distribution.
52 * 3. All advertising materials mentioning features or use of this software
53 *    must display the following acknowledgement:
54 *	This product includes software developed by the University of
55 *	California, Berkeley and its contributors.
56 * 4. Neither the name of the University nor the names of its contributors
57 *    may be used to endorse or promote products derived from this software
58 *    without specific prior written permission.
59 *
60 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
61 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
62 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
63 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
64 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
65 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
66 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
70 * SUCH DAMAGE.
71 *
72 *	@(#)kgdb_stub.c	8.4 (Berkeley) 1/12/94
73 */
74
75/*-
76 * Copyright (c) 2001 The NetBSD Foundation, Inc.
77 * All rights reserved.
78 *
79 * This code is derived from software contributed to The NetBSD Foundation
80 * by Jason R. Thorpe.
81 *
82 * Redistribution and use in source and binary forms, with or without
83 * modification, are permitted provided that the following conditions
84 * are met:
85 * 1. Redistributions of source code must retain the above copyright
86 *    notice, this list of conditions and the following disclaimer.
87 * 2. Redistributions in binary form must reproduce the above copyright
88 *    notice, this list of conditions and the following disclaimer in the
89 *    documentation and/or other materials provided with the distribution.
90 * 3. All advertising materials mentioning features or use of this software
91 *    must display the following acknowledgement:
92 *	This product includes software developed by the NetBSD
93 *	Foundation, Inc. and its contributors.
94 * 4. Neither the name of The NetBSD Foundation nor the names of its
95 *    contributors may be used to endorse or promote products derived
96 *    from this software without specific prior written permission.
97 *
98 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
99 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
100 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
101 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
102 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
103 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
104 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
105 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
106 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
107 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
108 * POSSIBILITY OF SUCH DAMAGE.
109 */
110
111/*
112 * $NetBSD: kgdb_stub.c,v 1.8 2001/07/07 22:58:00 wdk Exp $
113 *
114 * Taken from NetBSD
115 *
116 * "Stub" to allow remote cpu to debug over a serial line using gdb.
117 */
118
119#include <sys/signal.h>
120
121#include <string>
122#include <unistd.h>
123
124#include "arch/vtophys.hh"
125#include "base/intmath.hh"
126#include "base/kgdb.h"
127#include "base/remote_gdb.hh"
128#include "base/socket.hh"
129#include "base/trace.hh"
130#include "config/full_system.hh"
131#include "cpu/exec_context.hh"
132#include "cpu/static_inst.hh"
133#include "mem/physical.hh"
134#include "mem/port.hh"
135#include "sim/system.hh"
136
137using namespace std;
138using namespace TheISA;
139
140#ifndef NDEBUG
141vector<RemoteGDB *> debuggers;
142int current_debugger = -1;
143
144void
145debugger()
146{
147    if (current_debugger >= 0 && current_debugger < debuggers.size()) {
148        RemoteGDB *gdb = debuggers[current_debugger];
149        if (!gdb->isattached())
150            gdb->listener->accept();
151        if (gdb->isattached())
152            gdb->trap(ALPHA_KENTRY_IF);
153    }
154}
155#endif
156
157///////////////////////////////////////////////////////////
158//
159//
160//
161
162GDBListener::Event::Event(GDBListener *l, int fd, int e)
163    : PollEvent(fd, e), listener(l)
164{}
165
166void
167GDBListener::Event::process(int revent)
168{
169    listener->accept();
170}
171
172GDBListener::GDBListener(RemoteGDB *g, int p)
173    : event(NULL), gdb(g), port(p)
174{
175    assert(!gdb->listener);
176    gdb->listener = this;
177}
178
179GDBListener::~GDBListener()
180{
181    if (event)
182        delete event;
183}
184
185string
186GDBListener::name()
187{
188    return gdb->name() + ".listener";
189}
190
191void
192GDBListener::listen()
193{
194    while (!listener.listen(port, true)) {
195        DPRINTF(GDBMisc, "Can't bind port %d\n", port);
196        port++;
197    }
198
199    event = new Event(this, listener.getfd(), POLLIN);
200    pollQueue.schedule(event);
201
202#ifndef NDEBUG
203    gdb->number = debuggers.size();
204    debuggers.push_back(gdb);
205#endif
206
207#ifndef NDEBUG
208    ccprintf(cerr, "%d: %s: listening for remote gdb #%d on port %d\n",
209             curTick, name(), gdb->number, port);
210#else
211    ccprintf(cerr, "%d: %s: listening for remote gdb on port %d\n",
212             curTick, name(), port);
213#endif
214}
215
216void
217GDBListener::accept()
218{
219    if (!listener.islistening())
220        panic("GDBListener::accept(): cannot accept if we're not listening!");
221
222    int sfd = listener.accept(true);
223
224    if (sfd != -1) {
225        if (gdb->isattached())
226            close(sfd);
227        else
228            gdb->attach(sfd);
229    }
230}
231
232///////////////////////////////////////////////////////////
233//
234//
235//
236int digit2i(char);
237char i2digit(int);
238void mem2hex(void *, const void *, int);
239const char *hex2mem(void *, const char *, int);
240Addr hex2i(const char **);
241
242RemoteGDB::Event::Event(RemoteGDB *g, int fd, int e)
243    : PollEvent(fd, e), gdb(g)
244{}
245
246void
247RemoteGDB::Event::process(int revent)
248{
249    if (revent & POLLIN)
250        gdb->trap(ALPHA_KENTRY_IF);
251    else if (revent & POLLNVAL)
252        gdb->detach();
253}
254
255RemoteGDB::RemoteGDB(System *_system, ExecContext *c)
256    : event(NULL), listener(NULL), number(-1), fd(-1),
257      active(false), attached(false),
258      system(_system), pmem(_system->physmem), context(c)
259{
260    memset(gdbregs, 0, sizeof(gdbregs));
261}
262
263RemoteGDB::~RemoteGDB()
264{
265    if (event)
266        delete event;
267}
268
269string
270RemoteGDB::name()
271{
272    return system->name() + ".remote_gdb";
273}
274
275bool
276RemoteGDB::isattached()
277{ return attached; }
278
279void
280RemoteGDB::attach(int f)
281{
282    fd = f;
283
284    event = new Event(this, fd, POLLIN);
285    pollQueue.schedule(event);
286
287    attached = true;
288    DPRINTFN("remote gdb attached\n");
289}
290
291void
292RemoteGDB::detach()
293{
294    attached = false;
295    close(fd);
296    fd = -1;
297
298    pollQueue.remove(event);
299    DPRINTFN("remote gdb detached\n");
300}
301
302const char *
303gdb_command(char cmd)
304{
305    switch (cmd) {
306      case KGDB_SIGNAL: return "KGDB_SIGNAL";
307      case KGDB_SET_BAUD: return "KGDB_SET_BAUD";
308      case KGDB_SET_BREAK: return "KGDB_SET_BREAK";
309      case KGDB_CONT: return "KGDB_CONT";
310      case KGDB_ASYNC_CONT: return "KGDB_ASYNC_CONT";
311      case KGDB_DEBUG: return "KGDB_DEBUG";
312      case KGDB_DETACH: return "KGDB_DETACH";
313      case KGDB_REG_R: return "KGDB_REG_R";
314      case KGDB_REG_W: return "KGDB_REG_W";
315      case KGDB_SET_THREAD: return "KGDB_SET_THREAD";
316      case KGDB_CYCLE_STEP: return "KGDB_CYCLE_STEP";
317      case KGDB_SIG_CYCLE_STEP: return "KGDB_SIG_CYCLE_STEP";
318      case KGDB_KILL: return "KGDB_KILL";
319      case KGDB_MEM_W: return "KGDB_MEM_W";
320      case KGDB_MEM_R: return "KGDB_MEM_R";
321      case KGDB_SET_REG: return "KGDB_SET_REG";
322      case KGDB_READ_REG: return "KGDB_READ_REG";
323      case KGDB_QUERY_VAR: return "KGDB_QUERY_VAR";
324      case KGDB_SET_VAR: return "KGDB_SET_VAR";
325      case KGDB_RESET: return "KGDB_RESET";
326      case KGDB_STEP: return "KGDB_STEP";
327      case KGDB_ASYNC_STEP: return "KGDB_ASYNC_STEP";
328      case KGDB_THREAD_ALIVE: return "KGDB_THREAD_ALIVE";
329      case KGDB_TARGET_EXIT: return "KGDB_TARGET_EXIT";
330      case KGDB_BINARY_DLOAD: return "KGDB_BINARY_DLOAD";
331      case KGDB_CLR_HW_BKPT: return "KGDB_CLR_HW_BKPT";
332      case KGDB_SET_HW_BKPT: return "KGDB_SET_HW_BKPT";
333      case KGDB_START: return "KGDB_START";
334      case KGDB_END: return "KGDB_END";
335      case KGDB_GOODP: return "KGDB_GOODP";
336      case KGDB_BADP: return "KGDB_BADP";
337      default: return "KGDB_UNKNOWN";
338    }
339}
340
341///////////////////////////////////////////////////////////
342// RemoteGDB::acc
343//
344//	Determine if the mapping at va..(va+len) is valid.
345//
346bool
347RemoteGDB::acc(Addr va, size_t len)
348{
349    Addr last_va;
350
351    va = TheISA::TruncPage(va);
352    last_va = TheISA::RoundPage(va + len);
353
354    do  {
355        if (TheISA::IsK0Seg(va)) {
356            if (va < (TheISA::K0SegBase + pmem->size())) {
357                DPRINTF(GDBAcc, "acc:   Mapping is valid  K0SEG <= "
358                        "%#x < K0SEG + size\n", va);
359                return true;
360            } else {
361                DPRINTF(GDBAcc, "acc:   Mapping invalid %#x > K0SEG + size\n",
362                        va);
363                return false;
364            }
365        }
366
367    /**
368     * This code says that all accesses to palcode (instruction and data)
369     * are valid since there isn't a va->pa mapping because palcode is
370     * accessed physically. At some point this should probably be cleaned up
371     * but there is no easy way to do it.
372     */
373
374        if (AlphaISA::PcPAL(va) || va < 0x10000)
375            return true;
376
377        Addr ptbr = context->readMiscReg(AlphaISA::IPR_PALtemp20);
378        TheISA::PageTableEntry pte = TheISA::kernel_pte_lookup(context->getPhysPort(), ptbr, va);
379        if (!pte.valid()) {
380            DPRINTF(GDBAcc, "acc:   %#x pte is invalid\n", va);
381            return false;
382        }
383        va += TheISA::PageBytes;
384    } while (va < last_va);
385
386    DPRINTF(GDBAcc, "acc:   %#x mapping is valid\n", va);
387    return true;
388}
389
390///////////////////////////////////////////////////////////
391// RemoteGDB::signal
392//
393//	Translate a trap number into a Unix-compatible signal number.
394//	(GDB only understands Unix signal numbers.)
395//
396int
397RemoteGDB::signal(int type)
398{
399    switch (type) {
400      case ALPHA_KENTRY_INT:
401        return (SIGTRAP);
402
403      case ALPHA_KENTRY_UNA:
404        return (SIGBUS);
405
406      case ALPHA_KENTRY_ARITH:
407        return (SIGFPE);
408
409      case ALPHA_KENTRY_IF:
410        return (SIGILL);
411
412      case ALPHA_KENTRY_MM:
413        return (SIGSEGV);
414
415      default:
416        panic("unknown signal type");
417        return 0;
418    }
419}
420
421///////////////////////////////////////////////////////////
422// RemoteGDB::getregs
423//
424//	Translate the kernel debugger register format into
425//	the GDB register format.
426void
427RemoteGDB::getregs()
428{
429    memset(gdbregs, 0, sizeof(gdbregs));
430
431    gdbregs[KGDB_REG_PC] = context->readPC();
432
433    // @todo: Currently this is very Alpha specific.
434    if (AlphaISA::PcPAL(gdbregs[KGDB_REG_PC])) {
435        for (int i = 0; i < TheISA::NumIntArchRegs; ++i) {
436            gdbregs[i] = context->readIntReg(AlphaISA::reg_redir[i]);
437        }
438    } else {
439        for (int i = 0; i < TheISA::NumIntArchRegs; ++i) {
440            gdbregs[i] = context->readIntReg(i);
441        }
442    }
443
444#ifdef KGDB_FP_REGS
445    for (int i = 0; i < TheISA::NumFloatArchRegs; ++i) {
446        gdbregs[i + KGDB_REG_F0] = context->readFloatRegBits(i);
447    }
448#endif
449}
450
451///////////////////////////////////////////////////////////
452// RemoteGDB::setregs
453//
454//	Translate the GDB register format into the kernel
455//	debugger register format.
456//
457void
458RemoteGDB::setregs()
459{
460    // @todo: Currently this is very Alpha specific.
461    if (AlphaISA::PcPAL(gdbregs[KGDB_REG_PC])) {
462        for (int i = 0; i < TheISA::NumIntArchRegs; ++i) {
463            context->setIntReg(AlphaISA::reg_redir[i], gdbregs[i]);
464        }
465    } else {
466        for (int i = 0; i < TheISA::NumIntArchRegs; ++i) {
467            context->setIntReg(i, gdbregs[i]);
468        }
469    }
470
471#ifdef KGDB_FP_REGS
472    for (int i = 0; i < TheISA::NumFloatArchRegs; ++i) {
473        context->setFloatRegBits(i, gdbregs[i + KGDB_REG_F0]);
474    }
475#endif
476    context->setPC(gdbregs[KGDB_REG_PC]);
477}
478
479void
480RemoteGDB::setTempBreakpoint(TempBreakpoint &bkpt, Addr addr)
481{
482    DPRINTF(GDBMisc, "setTempBreakpoint: addr=%#x\n", addr);
483
484    bkpt.address = addr;
485    insertHardBreak(addr, 4);
486}
487
488void
489RemoteGDB::clearTempBreakpoint(TempBreakpoint &bkpt)
490{
491    DPRINTF(GDBMisc, "setTempBreakpoint: addr=%#x\n",
492            bkpt.address);
493
494
495    removeHardBreak(bkpt.address, 4);
496    bkpt.address = 0;
497}
498
499void
500RemoteGDB::clearSingleStep()
501{
502    DPRINTF(GDBMisc, "clearSingleStep bt_addr=%#x nt_addr=%#x\n",
503            takenBkpt.address, notTakenBkpt.address);
504
505    if (takenBkpt.address != 0)
506        clearTempBreakpoint(takenBkpt);
507
508    if (notTakenBkpt.address != 0)
509        clearTempBreakpoint(notTakenBkpt);
510}
511
512void
513RemoteGDB::setSingleStep()
514{
515    Addr pc = context->readPC();
516    Addr npc, bpc;
517    bool set_bt = false;
518
519    npc = pc + sizeof(MachInst);
520
521    // User was stopped at pc, e.g. the instruction at pc was not
522    // executed.
523    MachInst inst = read<MachInst>(pc);
524    StaticInstPtr si(inst);
525    if (si->hasBranchTarget(pc, context, bpc)) {
526        // Don't bother setting a breakpoint on the taken branch if it
527        // is the same as the next pc
528        if (bpc != npc)
529            set_bt = true;
530    }
531
532    DPRINTF(GDBMisc, "setSingleStep bt_addr=%#x nt_addr=%#x\n",
533            takenBkpt.address, notTakenBkpt.address);
534
535    setTempBreakpoint(notTakenBkpt, npc);
536
537    if (set_bt)
538        setTempBreakpoint(takenBkpt, bpc);
539}
540
541/////////////////////////
542//
543//
544
545uint8_t
546RemoteGDB::getbyte()
547{
548    uint8_t b;
549    ::read(fd, &b, 1);
550    return b;
551}
552
553void
554RemoteGDB::putbyte(uint8_t b)
555{
556    ::write(fd, &b, 1);
557}
558
559// Send a packet to gdb
560void
561RemoteGDB::send(const char *bp)
562{
563    const char *p;
564    uint8_t csum, c;
565
566    DPRINTF(GDBSend, "send:  %s\n", bp);
567
568    do {
569        p = bp;
570        putbyte(KGDB_START);
571        for (csum = 0; (c = *p); p++) {
572            putbyte(c);
573            csum += c;
574        }
575        putbyte(KGDB_END);
576        putbyte(i2digit(csum >> 4));
577        putbyte(i2digit(csum));
578    } while ((c = getbyte() & 0x7f) == KGDB_BADP);
579}
580
581// Receive a packet from gdb
582int
583RemoteGDB::recv(char *bp, int maxlen)
584{
585    char *p;
586    int c, csum;
587    int len;
588
589    do {
590        p = bp;
591        csum = len = 0;
592        while ((c = getbyte()) != KGDB_START)
593            ;
594
595        while ((c = getbyte()) != KGDB_END && len < maxlen) {
596            c &= 0x7f;
597            csum += c;
598            *p++ = c;
599            len++;
600        }
601        csum &= 0xff;
602        *p = '\0';
603
604        if (len >= maxlen) {
605            putbyte(KGDB_BADP);
606            continue;
607        }
608
609        csum -= digit2i(getbyte()) * 16;
610        csum -= digit2i(getbyte());
611
612        if (csum == 0) {
613            putbyte(KGDB_GOODP);
614            // Sequence present?
615            if (bp[2] == ':') {
616                putbyte(bp[0]);
617                putbyte(bp[1]);
618                len -= 3;
619                bcopy(bp + 3, bp, len);
620            }
621            break;
622        }
623        putbyte(KGDB_BADP);
624    } while (1);
625
626    DPRINTF(GDBRecv, "recv:  %s: %s\n", gdb_command(*bp), bp);
627
628    return (len);
629}
630
631// Read bytes from kernel address space for debugger.
632bool
633RemoteGDB::read(Addr vaddr, size_t size, char *data)
634{
635    static Addr lastaddr = 0;
636    static size_t lastsize = 0;
637
638    if (vaddr < 10) {
639      DPRINTF(GDBRead, "read:  reading memory location zero!\n");
640      vaddr = lastaddr + lastsize;
641    }
642
643    DPRINTF(GDBRead, "read:  addr=%#x, size=%d", vaddr, size);
644
645    context->getVirtPort(context)->readBlob(vaddr, (uint8_t*)data, size);
646
647#if TRACING_ON
648    if (DTRACE(GDBRead)) {
649        if (DTRACE(GDBExtra)) {
650            char buf[1024];
651            mem2hex(buf, data, size);
652            DPRINTFNR(": %s\n", buf);
653        } else
654            DPRINTFNR("\n");
655    }
656#endif
657
658    return true;
659}
660
661// Write bytes to kernel address space for debugger.
662bool
663RemoteGDB::write(Addr vaddr, size_t size, const char *data)
664{
665    static Addr lastaddr = 0;
666    static size_t lastsize = 0;
667
668    if (vaddr < 10) {
669      DPRINTF(GDBWrite, "write: writing memory location zero!\n");
670      vaddr = lastaddr + lastsize;
671    }
672
673    if (DTRACE(GDBWrite)) {
674        DPRINTFN("write: addr=%#x, size=%d", vaddr, size);
675        if (DTRACE(GDBExtra)) {
676            char buf[1024];
677            mem2hex(buf, data, size);
678            DPRINTFNR(": %s\n", buf);
679        } else
680            DPRINTFNR("\n");
681    }
682
683    context->getVirtPort(context)->writeBlob(vaddr, (uint8_t*)data, size);
684
685#ifdef IMB
686    alpha_pal_imb();
687#endif
688
689    return true;
690}
691
692
693PCEventQueue *RemoteGDB::getPcEventQueue()
694{
695    return &system->pcEventQueue;
696}
697
698
699RemoteGDB::HardBreakpoint::HardBreakpoint(RemoteGDB *_gdb, Addr pc)
700    : PCEvent(_gdb->getPcEventQueue(), "HardBreakpoint Event", pc),
701      gdb(_gdb), refcount(0)
702{
703    DPRINTF(GDBMisc, "creating hardware breakpoint at %#x\n", evpc);
704}
705
706void
707RemoteGDB::HardBreakpoint::process(ExecContext *xc)
708{
709    DPRINTF(GDBMisc, "handling hardware breakpoint at %#x\n", pc());
710
711    if (xc == gdb->context)
712        gdb->trap(ALPHA_KENTRY_INT);
713}
714
715bool
716RemoteGDB::insertSoftBreak(Addr addr, size_t len)
717{
718    if (len != sizeof(MachInst))
719        panic("invalid length\n");
720
721    return insertHardBreak(addr, len);
722}
723
724bool
725RemoteGDB::removeSoftBreak(Addr addr, size_t len)
726{
727    if (len != sizeof(MachInst))
728        panic("invalid length\n");
729
730    return removeHardBreak(addr, len);
731}
732
733bool
734RemoteGDB::insertHardBreak(Addr addr, size_t len)
735{
736    if (len != sizeof(MachInst))
737        panic("invalid length\n");
738
739    DPRINTF(GDBMisc, "inserting hardware breakpoint at %#x\n", addr);
740
741    HardBreakpoint *&bkpt = hardBreakMap[addr];
742    if (bkpt == 0)
743        bkpt = new HardBreakpoint(this, addr);
744
745    bkpt->refcount++;
746
747    return true;
748}
749
750bool
751RemoteGDB::removeHardBreak(Addr addr, size_t len)
752{
753    if (len != sizeof(MachInst))
754        panic("invalid length\n");
755
756    DPRINTF(GDBMisc, "removing hardware breakpoint at %#x\n", addr);
757
758    break_iter_t i = hardBreakMap.find(addr);
759    if (i == hardBreakMap.end())
760        return false;
761
762    HardBreakpoint *hbp = (*i).second;
763    if (--hbp->refcount == 0) {
764        delete hbp;
765        hardBreakMap.erase(i);
766    }
767
768    return true;
769}
770
771const char *
772break_type(char c)
773{
774    switch(c) {
775      case '0': return "software breakpoint";
776      case '1': return "hardware breakpoint";
777      case '2': return "write watchpoint";
778      case '3': return "read watchpoint";
779      case '4': return "access watchpoint";
780      default: return "unknown breakpoint/watchpoint";
781    }
782}
783
784// This function does all command processing for interfacing to a
785// remote gdb.  Note that the error codes are ignored by gdb at
786// present, but might eventually become meaningful. (XXX) It might
787// makes sense to use POSIX errno values, because that is what the
788// gdb/remote.c functions want to return.
789bool
790RemoteGDB::trap(int type)
791{
792    uint64_t val;
793    size_t datalen, len;
794    char data[KGDB_BUFLEN + 1];
795    char buffer[sizeof(gdbregs) * 2 + 256];
796    char temp[KGDB_BUFLEN];
797    const char *p;
798    char command, subcmd;
799    string var;
800    bool ret;
801
802    if (!attached)
803        return false;
804
805    DPRINTF(GDBMisc, "trap: PC=%#x NPC=%#x\n",
806            context->readPC(), context->readNextPC());
807
808    clearSingleStep();
809
810    /*
811     * The first entry to this function is normally through
812     * a breakpoint trap in kgdb_connect(), in which case we
813     * must advance past the breakpoint because gdb will not.
814     *
815     * On the first entry here, we expect that gdb is not yet
816     * listening to us, so just enter the interaction loop.
817     * After the debugger is "active" (connected) it will be
818     * waiting for a "signaled" message from us.
819     */
820    if (!active)
821        active = true;
822    else
823        // Tell remote host that an exception has occurred.
824        snprintf((char *)buffer, sizeof(buffer), "S%02x", signal(type));
825        send(buffer);
826
827    // Stick frame regs into our reg cache.
828    getregs();
829
830    for (;;) {
831        datalen = recv(data, sizeof(data));
832        data[sizeof(data) - 1] = 0; // Sentinel
833        command = data[0];
834        subcmd = 0;
835        p = data + 1;
836        switch (command) {
837
838          case KGDB_SIGNAL:
839            // if this command came from a running gdb, answer it --
840            // the other guy has no way of knowing if we're in or out
841            // of this loop when he issues a "remote-signal".
842            snprintf((char *)buffer, sizeof(buffer), "S%02x", signal(type));
843            send(buffer);
844            continue;
845
846          case KGDB_REG_R:
847            if (2 * sizeof(gdbregs) > sizeof(buffer))
848                panic("buffer too small");
849
850            mem2hex(buffer, gdbregs, sizeof(gdbregs));
851            send(buffer);
852            continue;
853
854          case KGDB_REG_W:
855            p = hex2mem(gdbregs, p, sizeof(gdbregs));
856            if (p == NULL || *p != '\0')
857                send("E01");
858            else {
859                setregs();
860                send("OK");
861            }
862            continue;
863
864#if 0
865          case KGDB_SET_REG:
866            val = hex2i(&p);
867            if (*p++ != '=') {
868                send("E01");
869                continue;
870            }
871            if (val < 0 && val >= KGDB_NUMREGS) {
872                send("E01");
873                continue;
874            }
875
876            gdbregs[val] = hex2i(&p);
877            setregs();
878            send("OK");
879
880            continue;
881#endif
882
883          case KGDB_MEM_R:
884            val = hex2i(&p);
885            if (*p++ != ',') {
886                send("E02");
887                continue;
888            }
889            len = hex2i(&p);
890            if (*p != '\0') {
891                send("E03");
892                continue;
893            }
894            if (len > sizeof(buffer)) {
895                send("E04");
896                continue;
897            }
898            if (!acc(val, len)) {
899                send("E05");
900                continue;
901            }
902
903            if (read(val, (size_t)len, (char *)buffer)) {
904              mem2hex(temp, buffer, len);
905              send(temp);
906            } else {
907              send("E05");
908            }
909            continue;
910
911          case KGDB_MEM_W:
912            val = hex2i(&p);
913            if (*p++ != ',') {
914                send("E06");
915                continue;
916            }
917            len = hex2i(&p);
918            if (*p++ != ':') {
919                send("E07");
920                continue;
921            }
922            if (len > datalen - (p - data)) {
923                send("E08");
924                continue;
925            }
926            p = hex2mem(buffer, p, sizeof(buffer));
927            if (p == NULL) {
928                send("E09");
929                continue;
930            }
931            if (!acc(val, len)) {
932                send("E0A");
933                continue;
934            }
935            if (write(val, (size_t)len, (char *)buffer))
936              send("OK");
937            else
938              send("E0B");
939            continue;
940
941          case KGDB_SET_THREAD:
942            subcmd = *p++;
943            val = hex2i(&p);
944            if (val == 0)
945                send("OK");
946            else
947                send("E01");
948            continue;
949
950          case KGDB_DETACH:
951          case KGDB_KILL:
952            active = false;
953            clearSingleStep();
954            detach();
955            goto out;
956
957          case KGDB_ASYNC_CONT:
958            subcmd = hex2i(&p);
959            if (*p++ == ';') {
960                val = hex2i(&p);
961                context->setPC(val);
962                context->setNextPC(val + sizeof(MachInst));
963            }
964            clearSingleStep();
965            goto out;
966
967          case KGDB_CONT:
968            if (p - data < datalen) {
969                val = hex2i(&p);
970                context->setPC(val);
971                context->setNextPC(val + sizeof(MachInst));
972            }
973            clearSingleStep();
974            goto out;
975
976          case KGDB_ASYNC_STEP:
977            subcmd = hex2i(&p);
978            if (*p++ == ';') {
979                val = hex2i(&p);
980                context->setPC(val);
981                context->setNextPC(val + sizeof(MachInst));
982            }
983            setSingleStep();
984            goto out;
985
986          case KGDB_STEP:
987            if (p - data < datalen) {
988                val = hex2i(&p);
989                context->setPC(val);
990                context->setNextPC(val + sizeof(MachInst));
991            }
992            setSingleStep();
993            goto out;
994
995          case KGDB_CLR_HW_BKPT:
996            subcmd = *p++;
997            if (*p++ != ',') send("E0D");
998            val = hex2i(&p);
999            if (*p++ != ',') send("E0D");
1000            len = hex2i(&p);
1001
1002            DPRINTF(GDBMisc, "clear %s, addr=%#x, len=%d\n",
1003                    break_type(subcmd), val, len);
1004
1005            ret = false;
1006
1007            switch (subcmd) {
1008              case '0': // software breakpoint
1009                ret = removeSoftBreak(val, len);
1010                break;
1011
1012              case '1': // hardware breakpoint
1013                ret = removeHardBreak(val, len);
1014                break;
1015
1016              case '2': // write watchpoint
1017              case '3': // read watchpoint
1018              case '4': // access watchpoint
1019              default: // unknown
1020                send("");
1021                break;
1022            }
1023
1024            send(ret ? "OK" : "E0C");
1025            continue;
1026
1027          case KGDB_SET_HW_BKPT:
1028            subcmd = *p++;
1029            if (*p++ != ',') send("E0D");
1030            val = hex2i(&p);
1031            if (*p++ != ',') send("E0D");
1032            len = hex2i(&p);
1033
1034            DPRINTF(GDBMisc, "set %s, addr=%#x, len=%d\n",
1035                    break_type(subcmd), val, len);
1036
1037            ret = false;
1038
1039            switch (subcmd) {
1040              case '0': // software breakpoint
1041                ret = insertSoftBreak(val, len);
1042                break;
1043
1044              case '1': // hardware breakpoint
1045                ret = insertHardBreak(val, len);
1046                break;
1047
1048              case '2': // write watchpoint
1049              case '3': // read watchpoint
1050              case '4': // access watchpoint
1051              default: // unknown
1052                send("");
1053                break;
1054            }
1055
1056            send(ret ? "OK" : "E0C");
1057            continue;
1058
1059          case KGDB_QUERY_VAR:
1060            var = string(p, datalen - 1);
1061            if (var == "C")
1062                send("QC0");
1063            else
1064                send("");
1065            continue;
1066
1067          case KGDB_SET_BAUD:
1068          case KGDB_SET_BREAK:
1069          case KGDB_DEBUG:
1070          case KGDB_CYCLE_STEP:
1071          case KGDB_SIG_CYCLE_STEP:
1072          case KGDB_READ_REG:
1073          case KGDB_SET_VAR:
1074          case KGDB_RESET:
1075          case KGDB_THREAD_ALIVE:
1076          case KGDB_TARGET_EXIT:
1077          case KGDB_BINARY_DLOAD:
1078            // Unsupported command
1079            DPRINTF(GDBMisc, "Unsupported command: %s\n",
1080                    gdb_command(command));
1081            DDUMP(GDBMisc, (uint8_t *)data, datalen);
1082            send("");
1083            continue;
1084
1085          default:
1086            // Unknown command.
1087            DPRINTF(GDBMisc, "Unknown command: %c(%#x)\n",
1088                    command, command);
1089            send("");
1090            continue;
1091
1092
1093        }
1094    }
1095
1096  out:
1097    return true;
1098}
1099
1100// Convert a hex digit into an integer.
1101// This returns -1 if the argument passed is no valid hex digit.
1102int
1103digit2i(char c)
1104{
1105    if (c >= '0' && c <= '9')
1106        return (c - '0');
1107    else if (c >= 'a' && c <= 'f')
1108        return (c - 'a' + 10);
1109    else if (c >= 'A' && c <= 'F')
1110
1111        return (c - 'A' + 10);
1112    else
1113        return (-1);
1114}
1115
1116// Convert the low 4 bits of an integer into an hex digit.
1117char
1118i2digit(int n)
1119{
1120    return ("0123456789abcdef"[n & 0x0f]);
1121}
1122
1123// Convert a byte array into an hex string.
1124void
1125mem2hex(void *vdst, const void *vsrc, int len)
1126{
1127    char *dst = (char *)vdst;
1128    const char *src = (const char *)vsrc;
1129
1130    while (len--) {
1131        *dst++ = i2digit(*src >> 4);
1132        *dst++ = i2digit(*src++);
1133    }
1134    *dst = '\0';
1135}
1136
1137// Convert an hex string into a byte array.
1138// This returns a pointer to the character following the last valid
1139// hex digit. If the string ends in the middle of a byte, NULL is
1140// returned.
1141const char *
1142hex2mem(void *vdst, const char *src, int maxlen)
1143{
1144    char *dst = (char *)vdst;
1145    int msb, lsb;
1146
1147    while (*src && maxlen--) {
1148        msb = digit2i(*src++);
1149        if (msb < 0)
1150            return (src - 1);
1151        lsb = digit2i(*src++);
1152        if (lsb < 0)
1153            return (NULL);
1154        *dst++ = (msb << 4) | lsb;
1155    }
1156    return (src);
1157}
1158
1159// Convert an hex string into an integer.
1160// This returns a pointer to the character following the last valid
1161// hex digit.
1162Addr
1163hex2i(const char **srcp)
1164{
1165    const char *src = *srcp;
1166    Addr r = 0;
1167    int nibble;
1168
1169    while ((nibble = digit2i(*src)) >= 0) {
1170        r *= 16;
1171        r += nibble;
1172        src++;
1173    }
1174    *srcp = src;
1175    return (r);
1176}
1177
1178