remote_gdb.cc revision 7823:dac01f14f20f
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 <cstdio>
122#include <string>
123#include <unistd.h>
124
125#include "config/full_system.hh"
126
127#if FULL_SYSTEM
128#include "arch/vtophys.hh"
129#include "mem/vport.hh"
130#endif
131
132#include "base/intmath.hh"
133#include "base/remote_gdb.hh"
134#include "base/socket.hh"
135#include "base/trace.hh"
136#include "config/the_isa.hh"
137#include "cpu/thread_context.hh"
138#include "cpu/static_inst.hh"
139#include "mem/port.hh"
140#include "mem/translating_port.hh"
141#include "sim/system.hh"
142
143using namespace std;
144using namespace TheISA;
145
146#ifndef NDEBUG
147vector<BaseRemoteGDB *> debuggers;
148
149void
150debugger()
151{
152    static int current_debugger = -1;
153    if (current_debugger >= 0 && current_debugger < (int)debuggers.size()) {
154        BaseRemoteGDB *gdb = debuggers[current_debugger];
155        if (!gdb->isattached())
156            gdb->listener->accept();
157        if (gdb->isattached())
158            gdb->trap(SIGILL);
159    }
160}
161#endif
162
163///////////////////////////////////////////////////////////
164//
165//
166//
167
168GDBListener::Event::Event(GDBListener *l, int fd, int e)
169    : PollEvent(fd, e), listener(l)
170{}
171
172void
173GDBListener::Event::process(int revent)
174{
175    listener->accept();
176}
177
178GDBListener::GDBListener(BaseRemoteGDB *g, int p)
179    : event(NULL), gdb(g), port(p)
180{
181    assert(!gdb->listener);
182    gdb->listener = this;
183}
184
185GDBListener::~GDBListener()
186{
187    if (event)
188        delete event;
189}
190
191string
192GDBListener::name()
193{
194    return gdb->name() + ".listener";
195}
196
197void
198GDBListener::listen()
199{
200    if (ListenSocket::allDisabled()) {
201        warn_once("Sockets disabled, not accepting gdb connections");
202        return;
203    }
204
205    while (!listener.listen(port, true)) {
206        DPRINTF(GDBMisc, "Can't bind port %d\n", port);
207        port++;
208    }
209
210    event = new Event(this, listener.getfd(), POLLIN);
211    pollQueue.schedule(event);
212
213#ifndef NDEBUG
214    gdb->number = debuggers.size();
215    debuggers.push_back(gdb);
216#endif
217
218#ifndef NDEBUG
219    ccprintf(cerr, "%d: %s: listening for remote gdb #%d on port %d\n",
220             curTick(), name(), gdb->number, port);
221#else
222    ccprintf(cerr, "%d: %s: listening for remote gdb on port %d\n",
223             curTick(), name(), port);
224#endif
225}
226
227void
228GDBListener::accept()
229{
230    if (!listener.islistening())
231        panic("GDBListener::accept(): cannot accept if we're not listening!");
232
233    int sfd = listener.accept(true);
234
235    if (sfd != -1) {
236        if (gdb->isattached())
237            close(sfd);
238        else
239            gdb->attach(sfd);
240    }
241}
242
243BaseRemoteGDB::Event::Event(BaseRemoteGDB *g, int fd, int e)
244    : PollEvent(fd, e), gdb(g)
245{}
246
247void
248BaseRemoteGDB::Event::process(int revent)
249{
250    if (revent & POLLIN)
251        gdb->trap(SIGILL);
252    else if (revent & POLLNVAL)
253        gdb->detach();
254}
255
256BaseRemoteGDB::BaseRemoteGDB(System *_system, ThreadContext *c, size_t cacheSize)
257    : event(NULL), listener(NULL), number(-1), fd(-1),
258      active(false), attached(false),
259      system(_system), pmem(_system->physmem), context(c),
260      gdbregs(cacheSize)
261{
262    memset(gdbregs.regs, 0, gdbregs.bytes());
263}
264
265BaseRemoteGDB::~BaseRemoteGDB()
266{
267    if (event)
268        delete event;
269}
270
271string
272BaseRemoteGDB::name()
273{
274    return system->name() + ".remote_gdb";
275}
276
277bool
278BaseRemoteGDB::isattached()
279{ return attached; }
280
281void
282BaseRemoteGDB::attach(int f)
283{
284    fd = f;
285
286    event = new Event(this, fd, POLLIN);
287    pollQueue.schedule(event);
288
289    attached = true;
290    DPRINTFN("remote gdb attached\n");
291}
292
293void
294BaseRemoteGDB::detach()
295{
296    attached = false;
297    close(fd);
298    fd = -1;
299
300    pollQueue.remove(event);
301    DPRINTFN("remote gdb detached\n");
302}
303
304const char *
305BaseRemoteGDB::gdb_command(char cmd)
306{
307    switch (cmd) {
308      case GDBSignal: return "KGDB_SIGNAL";
309      case GDBSetBaud: return "KGDB_SET_BAUD";
310      case GDBSetBreak: return "KGDB_SET_BREAK";
311      case GDBCont: return "KGDB_CONT";
312      case GDBAsyncCont: return "KGDB_ASYNC_CONT";
313      case GDBDebug: return "KGDB_DEBUG";
314      case GDBDetach: return "KGDB_DETACH";
315      case GDBRegR: return "KGDB_REG_R";
316      case GDBRegW: return "KGDB_REG_W";
317      case GDBSetThread: return "KGDB_SET_THREAD";
318      case GDBCycleStep: return "KGDB_CYCLE_STEP";
319      case GDBSigCycleStep: return "KGDB_SIG_CYCLE_STEP";
320      case GDBKill: return "KGDB_KILL";
321      case GDBMemW: return "KGDB_MEM_W";
322      case GDBMemR: return "KGDB_MEM_R";
323      case GDBSetReg: return "KGDB_SET_REG";
324      case GDBReadReg: return "KGDB_READ_REG";
325      case GDBQueryVar: return "KGDB_QUERY_VAR";
326      case GDBSetVar: return "KGDB_SET_VAR";
327      case GDBReset: return "KGDB_RESET";
328      case GDBStep: return "KGDB_STEP";
329      case GDBAsyncStep: return "KGDB_ASYNC_STEP";
330      case GDBThreadAlive: return "KGDB_THREAD_ALIVE";
331      case GDBTargetExit: return "KGDB_TARGET_EXIT";
332      case GDBBinaryDload: return "KGDB_BINARY_DLOAD";
333      case GDBClrHwBkpt: return "KGDB_CLR_HW_BKPT";
334      case GDBSetHwBkpt: return "KGDB_SET_HW_BKPT";
335      case GDBStart: return "KGDB_START";
336      case GDBEnd: return "KGDB_END";
337      case GDBGoodP: return "KGDB_GOODP";
338      case GDBBadP: return "KGDB_BADP";
339      default: return "KGDB_UNKNOWN";
340    }
341}
342
343/////////////////////////
344//
345//
346
347uint8_t
348BaseRemoteGDB::getbyte()
349{
350    uint8_t b;
351    if (::read(fd, &b, 1) != 1)
352        warn("could not read byte from debugger");
353    return b;
354}
355
356void
357BaseRemoteGDB::putbyte(uint8_t b)
358{
359    if (::write(fd, &b, 1) != 1)
360        warn("could not write byte to debugger");
361}
362
363// Send a packet to gdb
364void
365BaseRemoteGDB::send(const char *bp)
366{
367    const char *p;
368    uint8_t csum, c;
369
370    DPRINTF(GDBSend, "send:  %s\n", bp);
371
372    do {
373        p = bp;
374        //Start sending a packet
375        putbyte(GDBStart);
376        //Send the contents, and also keep a check sum.
377        for (csum = 0; (c = *p); p++) {
378            putbyte(c);
379            csum += c;
380        }
381        //Send the ending character.
382        putbyte(GDBEnd);
383        //Sent the checksum.
384        putbyte(i2digit(csum >> 4));
385        putbyte(i2digit(csum));
386        //Try transmitting over and over again until the other end doesn't send an
387        //error back.
388    } while ((c = getbyte() & 0x7f) == GDBBadP);
389}
390
391// Receive a packet from gdb
392int
393BaseRemoteGDB::recv(char *bp, int maxlen)
394{
395    char *p;
396    int c, csum;
397    int len;
398
399    do {
400        p = bp;
401        csum = len = 0;
402        //Find the beginning of a packet
403        while ((c = getbyte()) != GDBStart)
404            ;
405
406        //Read until you find the end of the data in the packet, and keep
407        //track of the check sum.
408        while ((c = getbyte()) != GDBEnd && len < maxlen) {
409            c &= 0x7f;
410            csum += c;
411            *p++ = c;
412            len++;
413        }
414
415        //Mask the check sum, and terminate the command string.
416        csum &= 0xff;
417        *p = '\0';
418
419        //If the command was too long, report an error.
420        if (len >= maxlen) {
421            putbyte(GDBBadP);
422            continue;
423        }
424
425        //Bring in the checksum. If the check sum matches, csum will be 0.
426        csum -= digit2i(getbyte()) * 16;
427        csum -= digit2i(getbyte());
428
429        //If the check sum was correct
430        if (csum == 0) {
431            //Report that the packet was received correctly
432            putbyte(GDBGoodP);
433            // Sequence present?
434            if (bp[2] == ':') {
435                putbyte(bp[0]);
436                putbyte(bp[1]);
437                len -= 3;
438                memcpy(bp, bp+3, len);
439            }
440            break;
441        }
442        //Otherwise, report that there was a mistake.
443        putbyte(GDBBadP);
444    } while (1);
445
446    DPRINTF(GDBRecv, "recv:  %s: %s\n", gdb_command(*bp), bp);
447
448    return (len);
449}
450
451// Read bytes from kernel address space for debugger.
452bool
453BaseRemoteGDB::read(Addr vaddr, size_t size, char *data)
454{
455    static Addr lastaddr = 0;
456    static size_t lastsize = 0;
457
458    if (vaddr < 10) {
459      DPRINTF(GDBRead, "read:  reading memory location zero!\n");
460      vaddr = lastaddr + lastsize;
461    }
462
463    DPRINTF(GDBRead, "read:  addr=%#x, size=%d", vaddr, size);
464
465#if FULL_SYSTEM
466    VirtualPort *port = context->getVirtPort();
467#else
468    TranslatingPort *port = context->getMemPort();
469#endif
470    port->readBlob(vaddr, (uint8_t*)data, size);
471
472#if TRACING_ON
473    if (DTRACE(GDBRead)) {
474        if (DTRACE(GDBExtra)) {
475            char buf[1024];
476            mem2hex(buf, data, size);
477            DPRINTFNR(": %s\n", buf);
478        } else
479            DPRINTFNR("\n");
480    }
481#endif
482
483    return true;
484}
485
486// Write bytes to kernel address space for debugger.
487bool
488BaseRemoteGDB::write(Addr vaddr, size_t size, const char *data)
489{
490    static Addr lastaddr = 0;
491    static size_t lastsize = 0;
492
493    if (vaddr < 10) {
494      DPRINTF(GDBWrite, "write: writing memory location zero!\n");
495      vaddr = lastaddr + lastsize;
496    }
497
498    if (DTRACE(GDBWrite)) {
499        DPRINTFN("write: addr=%#x, size=%d", vaddr, size);
500        if (DTRACE(GDBExtra)) {
501            char buf[1024];
502            mem2hex(buf, data, size);
503            DPRINTFNR(": %s\n", buf);
504        } else
505            DPRINTFNR("\n");
506    }
507#if FULL_SYSTEM
508    VirtualPort *port = context->getVirtPort();
509#else
510    TranslatingPort *port = context->getMemPort();
511#endif
512    port->writeBlob(vaddr, (uint8_t*)data, size);
513#if !FULL_SYSTEM
514    delete port;
515#endif
516
517    return true;
518}
519
520PCEventQueue *BaseRemoteGDB::getPcEventQueue()
521{
522    return &system->pcEventQueue;
523}
524
525BaseRemoteGDB::HardBreakpoint::HardBreakpoint(BaseRemoteGDB *_gdb, Addr pc)
526    : PCEvent(_gdb->getPcEventQueue(), "HardBreakpoint Event", pc),
527      gdb(_gdb), refcount(0)
528{
529    DPRINTF(GDBMisc, "creating hardware breakpoint at %#x\n", evpc);
530}
531
532void
533BaseRemoteGDB::HardBreakpoint::process(ThreadContext *tc)
534{
535    DPRINTF(GDBMisc, "handling hardware breakpoint at %#x\n", pc());
536
537    if (tc == gdb->context)
538        gdb->trap(SIGTRAP);
539}
540
541bool
542BaseRemoteGDB::insertSoftBreak(Addr addr, size_t len)
543{
544    if (len != sizeof(TheISA::MachInst))
545        panic("invalid length\n");
546
547    return insertHardBreak(addr, len);
548}
549
550bool
551BaseRemoteGDB::removeSoftBreak(Addr addr, size_t len)
552{
553    if (len != sizeof(MachInst))
554        panic("invalid length\n");
555
556    return removeHardBreak(addr, len);
557}
558
559bool
560BaseRemoteGDB::insertHardBreak(Addr addr, size_t len)
561{
562    if (len != sizeof(MachInst))
563        panic("invalid length\n");
564
565    DPRINTF(GDBMisc, "inserting hardware breakpoint at %#x\n", addr);
566
567    HardBreakpoint *&bkpt = hardBreakMap[addr];
568    if (bkpt == 0)
569        bkpt = new HardBreakpoint(this, addr);
570
571    bkpt->refcount++;
572
573    return true;
574}
575
576bool
577BaseRemoteGDB::removeHardBreak(Addr addr, size_t len)
578{
579    if (len != sizeof(MachInst))
580        panic("invalid length\n");
581
582    DPRINTF(GDBMisc, "removing hardware breakpoint at %#x\n", addr);
583
584    break_iter_t i = hardBreakMap.find(addr);
585    if (i == hardBreakMap.end())
586        return false;
587
588    HardBreakpoint *hbp = (*i).second;
589    if (--hbp->refcount == 0) {
590        delete hbp;
591        hardBreakMap.erase(i);
592    }
593
594    return true;
595}
596
597void
598BaseRemoteGDB::setTempBreakpoint(Addr bkpt)
599{
600    DPRINTF(GDBMisc, "setTempBreakpoint: addr=%#x\n", bkpt);
601    insertHardBreak(bkpt, sizeof(TheISA::MachInst));
602}
603
604void
605BaseRemoteGDB::clearTempBreakpoint(Addr &bkpt)
606{
607    DPRINTF(GDBMisc, "setTempBreakpoint: addr=%#x\n", bkpt);
608    removeHardBreak(bkpt, sizeof(TheISA::MachInst));
609    bkpt = 0;
610}
611
612const char *
613BaseRemoteGDB::break_type(char c)
614{
615    switch(c) {
616      case '0': return "software breakpoint";
617      case '1': return "hardware breakpoint";
618      case '2': return "write watchpoint";
619      case '3': return "read watchpoint";
620      case '4': return "access watchpoint";
621      default: return "unknown breakpoint/watchpoint";
622    }
623}
624
625// This function does all command processing for interfacing to a
626// remote gdb.  Note that the error codes are ignored by gdb at
627// present, but might eventually become meaningful. (XXX) It might
628// makes sense to use POSIX errno values, because that is what the
629// gdb/remote.c functions want to return.
630bool
631BaseRemoteGDB::trap(int type)
632{
633    uint64_t val;
634    size_t datalen, len;
635    char data[GDBPacketBufLen + 1];
636    char *buffer;
637    size_t bufferSize;
638    const char *p;
639    char command, subcmd;
640    string var;
641    bool ret;
642
643    if (!attached)
644        return false;
645
646    bufferSize = gdbregs.bytes() * 2 + 256;
647    buffer = (char*)malloc(bufferSize);
648
649    TheISA::PCState pc = context->pcState();
650    DPRINTF(GDBMisc, "trap: PC=%s\n", pc);
651
652    clearSingleStep();
653
654    /*
655     * The first entry to this function is normally through
656     * a breakpoint trap in kgdb_connect(), in which case we
657     * must advance past the breakpoint because gdb will not.
658     *
659     * On the first entry here, we expect that gdb is not yet
660     * listening to us, so just enter the interaction loop.
661     * After the debugger is "active" (connected) it will be
662     * waiting for a "signaled" message from us.
663     */
664    if (!active)
665        active = true;
666    else
667        // Tell remote host that an exception has occurred.
668        snprintf((char *)buffer, bufferSize, "S%02x", type);
669        send(buffer);
670
671    // Stick frame regs into our reg cache.
672    getregs();
673
674    for (;;) {
675        datalen = recv(data, sizeof(data));
676        data[sizeof(data) - 1] = 0; // Sentinel
677        command = data[0];
678        subcmd = 0;
679        p = data + 1;
680        switch (command) {
681
682          case GDBSignal:
683            // if this command came from a running gdb, answer it --
684            // the other guy has no way of knowing if we're in or out
685            // of this loop when he issues a "remote-signal".
686            snprintf((char *)buffer, bufferSize,
687                    "S%02x", type);
688            send(buffer);
689            continue;
690
691          case GDBRegR:
692            if (2 * gdbregs.bytes() > bufferSize)
693                panic("buffer too small");
694
695            mem2hex(buffer, gdbregs.regs, gdbregs.bytes());
696            send(buffer);
697            continue;
698
699          case GDBRegW:
700            p = hex2mem(gdbregs.regs, p, gdbregs.bytes());
701            if (p == NULL || *p != '\0')
702                send("E01");
703            else {
704                setregs();
705                send("OK");
706            }
707            continue;
708
709#if 0
710          case GDBSetReg:
711            val = hex2i(&p);
712            if (*p++ != '=') {
713                send("E01");
714                continue;
715            }
716            if (val < 0 && val >= KGDB_NUMREGS) {
717                send("E01");
718                continue;
719            }
720
721            gdbregs.regs[val] = hex2i(&p);
722            setregs();
723            send("OK");
724
725            continue;
726#endif
727
728          case GDBMemR:
729            val = hex2i(&p);
730            if (*p++ != ',') {
731                send("E02");
732                continue;
733            }
734            len = hex2i(&p);
735            if (*p != '\0') {
736                send("E03");
737                continue;
738            }
739            if (len > bufferSize) {
740                send("E04");
741                continue;
742            }
743            if (!acc(val, len)) {
744                send("E05");
745                continue;
746            }
747
748            if (read(val, (size_t)len, (char *)buffer)) {
749               // variable length array would be nice, but C++ doesn't
750               // officially support those...
751               char *temp = new char[2*len+1];
752               mem2hex(temp, buffer, len);
753               send(temp);
754               delete [] temp;
755            } else {
756               send("E05");
757            }
758            continue;
759
760          case GDBMemW:
761            val = hex2i(&p);
762            if (*p++ != ',') {
763                send("E06");
764                continue;
765            }
766            len = hex2i(&p);
767            if (*p++ != ':') {
768                send("E07");
769                continue;
770            }
771            if (len > datalen - (p - data)) {
772                send("E08");
773                continue;
774            }
775            p = hex2mem(buffer, p, bufferSize);
776            if (p == NULL) {
777                send("E09");
778                continue;
779            }
780            if (!acc(val, len)) {
781                send("E0A");
782                continue;
783            }
784            if (write(val, (size_t)len, (char *)buffer))
785              send("OK");
786            else
787              send("E0B");
788            continue;
789
790          case GDBSetThread:
791            subcmd = *p++;
792            val = hex2i(&p);
793            if (val == 0)
794                send("OK");
795            else
796                send("E01");
797            continue;
798
799          case GDBDetach:
800          case GDBKill:
801            active = false;
802            clearSingleStep();
803            detach();
804            goto out;
805
806          case GDBAsyncCont:
807            subcmd = hex2i(&p);
808            if (*p++ == ';') {
809                val = hex2i(&p);
810                context->pcState(val);
811            }
812            clearSingleStep();
813            goto out;
814
815          case GDBCont:
816            if (p - data < (ptrdiff_t)datalen) {
817                val = hex2i(&p);
818                context->pcState(val);
819            }
820            clearSingleStep();
821            goto out;
822
823          case GDBAsyncStep:
824            subcmd = hex2i(&p);
825            if (*p++ == ';') {
826                val = hex2i(&p);
827                context->pcState(val);
828            }
829            setSingleStep();
830            goto out;
831
832          case GDBStep:
833            if (p - data < (ptrdiff_t)datalen) {
834                val = hex2i(&p);
835                context->pcState(val);
836            }
837            setSingleStep();
838            goto out;
839
840          case GDBClrHwBkpt:
841            subcmd = *p++;
842            if (*p++ != ',') send("E0D");
843            val = hex2i(&p);
844            if (*p++ != ',') send("E0D");
845            len = hex2i(&p);
846
847            DPRINTF(GDBMisc, "clear %s, addr=%#x, len=%d\n",
848                    break_type(subcmd), val, len);
849
850            ret = false;
851
852            switch (subcmd) {
853              case '0': // software breakpoint
854                ret = removeSoftBreak(val, len);
855                break;
856
857              case '1': // hardware breakpoint
858                ret = removeHardBreak(val, len);
859                break;
860
861              case '2': // write watchpoint
862              case '3': // read watchpoint
863              case '4': // access watchpoint
864              default: // unknown
865                send("");
866                break;
867            }
868
869            send(ret ? "OK" : "E0C");
870            continue;
871
872          case GDBSetHwBkpt:
873            subcmd = *p++;
874            if (*p++ != ',') send("E0D");
875            val = hex2i(&p);
876            if (*p++ != ',') send("E0D");
877            len = hex2i(&p);
878
879            DPRINTF(GDBMisc, "set %s, addr=%#x, len=%d\n",
880                    break_type(subcmd), val, len);
881
882            ret = false;
883
884            switch (subcmd) {
885              case '0': // software breakpoint
886                ret = insertSoftBreak(val, len);
887                break;
888
889              case '1': // hardware breakpoint
890                ret = insertHardBreak(val, len);
891                break;
892
893              case '2': // write watchpoint
894              case '3': // read watchpoint
895              case '4': // access watchpoint
896              default: // unknown
897                send("");
898                break;
899            }
900
901            send(ret ? "OK" : "E0C");
902            continue;
903
904          case GDBQueryVar:
905            var = string(p, datalen - 1);
906            if (var == "C")
907                send("QC0");
908            else
909                send("");
910            continue;
911
912          case GDBSetBaud:
913          case GDBSetBreak:
914          case GDBDebug:
915          case GDBCycleStep:
916          case GDBSigCycleStep:
917          case GDBReadReg:
918          case GDBSetVar:
919          case GDBReset:
920          case GDBThreadAlive:
921          case GDBTargetExit:
922          case GDBBinaryDload:
923            // Unsupported command
924            DPRINTF(GDBMisc, "Unsupported command: %s\n",
925                    gdb_command(command));
926            DDUMP(GDBMisc, (uint8_t *)data, datalen);
927            send("");
928            continue;
929
930          default:
931            // Unknown command.
932            DPRINTF(GDBMisc, "Unknown command: %c(%#x)\n",
933                    command, command);
934            send("");
935            continue;
936
937
938        }
939    }
940
941  out:
942    free(buffer);
943    return true;
944}
945
946// Convert a hex digit into an integer.
947// This returns -1 if the argument passed is no valid hex digit.
948int
949BaseRemoteGDB::digit2i(char c)
950{
951    if (c >= '0' && c <= '9')
952        return (c - '0');
953    else if (c >= 'a' && c <= 'f')
954        return (c - 'a' + 10);
955    else if (c >= 'A' && c <= 'F')
956
957        return (c - 'A' + 10);
958    else
959        return (-1);
960}
961
962// Convert the low 4 bits of an integer into an hex digit.
963char
964BaseRemoteGDB::i2digit(int n)
965{
966    return ("0123456789abcdef"[n & 0x0f]);
967}
968
969// Convert a byte array into an hex string.
970void
971BaseRemoteGDB::mem2hex(void *vdst, const void *vsrc, int len)
972{
973    char *dst = (char *)vdst;
974    const char *src = (const char *)vsrc;
975
976    while (len--) {
977        *dst++ = i2digit(*src >> 4);
978        *dst++ = i2digit(*src++);
979    }
980    *dst = '\0';
981}
982
983// Convert an hex string into a byte array.
984// This returns a pointer to the character following the last valid
985// hex digit. If the string ends in the middle of a byte, NULL is
986// returned.
987const char *
988BaseRemoteGDB::hex2mem(void *vdst, const char *src, int maxlen)
989{
990    char *dst = (char *)vdst;
991    int msb, lsb;
992
993    while (*src && maxlen--) {
994        msb = digit2i(*src++);
995        if (msb < 0)
996            return (src - 1);
997        lsb = digit2i(*src++);
998        if (lsb < 0)
999            return (NULL);
1000        *dst++ = (msb << 4) | lsb;
1001    }
1002    return (src);
1003}
1004
1005// Convert an hex string into an integer.
1006// This returns a pointer to the character following the last valid
1007// hex digit.
1008Addr
1009BaseRemoteGDB::hex2i(const char **srcp)
1010{
1011    const char *src = *srcp;
1012    Addr r = 0;
1013    int nibble;
1014
1015    while ((nibble = digit2i(*src)) >= 0) {
1016        r *= 16;
1017        r += nibble;
1018        src++;
1019    }
1020    *srcp = src;
1021    return (r);
1022}
1023
1024