base/remote_gdb.cc

   1 /*
   2  * Copyright (c) 2002-2004 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
  29 /*
  30  * Copyright (c) 1990, 1993
  31  *      The Regents of the University of California.  All rights reserved.
  32  *
  33  * This software was developed by the Computer Systems Engineering group
  34  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
  35  * contributed to Berkeley.
  36  *
  37  * All advertising materials mentioning features or use of this software
  38  * must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Lawrence Berkeley Laboratories.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  * 3. All advertising materials mentioning features or use of this software
  51  *    must display the following acknowledgement:
  52  *      This product includes software developed by the University of
  53  *      California, Berkeley and its contributors.
  54  * 4. Neither the name of the University nor the names of its contributors
  55  *    may be used to endorse or promote products derived from this software
  56  *    without specific prior written permission.
  57  *
  58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  68  * SUCH DAMAGE.
  69  *
  70  *      @(#)kgdb_stub.c 8.4 (Berkeley) 1/12/94
  71  */
  72
  73 /*-
  74  * Copyright (c) 2001 The NetBSD Foundation, Inc.
  75  * All rights reserved.
  76  *
  77  * This code is derived from software contributed to The NetBSD Foundation
  78  * by Jason R. Thorpe.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the above copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *      This product includes software developed by the NetBSD
  91  *      Foundation, Inc. and its contributors.
  92  * 4. Neither the name of The NetBSD Foundation nor the names of its
  93  *    contributors may be used to endorse or promote products derived
  94  *    from this software without specific prior written permission.
  95  *
  96  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  97  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  98  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  99  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 100  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 101  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 102  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 103  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 104  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 105  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 106  * POSSIBILITY OF SUCH DAMAGE.
 107  */
 108
 109 /*
 110  * $NetBSD: kgdb_stub.c,v 1.8 2001/07/07 22:58:00 wdk Exp $
 111  *
 112  * Taken from NetBSD
 113  *
 114  * "Stub" to allow remote cpu to debug over a serial line using gdb.
 115  */
 116
 117 #include <sys/signal.h>
 118
 119 #include <unistd.h>
 120
 121 #include <cstdio>
 122 #include <string>
 123
 124 #include "cpu/exec_context.hh"
 125 #include "base/intmath.hh"
 126 #include "base/kgdb.h"
 127
 128 #include "mem/functional_mem/physical_memory.hh"
 129 #include "base/remote_gdb.hh"
 130 #include "base/socket.hh"
 131 #include "base/trace.hh"
 132 #include "targetarch/vtophys.hh"
 133 #include "sim/system.hh"
 134 #include "cpu/static_inst.hh"
 135
 136 using namespace std;
 137
 138 #ifdef DEBUG
 139 RemoteGDB *theDebugger = NULL;
 140
 141 void
 142 debugger()
 143 {
 144     if (theDebugger)
 145         theDebugger->trap(ALPHA_KENTRY_IF);
 146 }
 147 #endif
 148
 149 ///////////////////////////////////////////////////////////
 150 //
 151 //
 152 //
 153
 154 GDBListener::Event::Event(GDBListener *l, int fd, int e)
 155     : PollEvent(fd, e), listener(l)
 156 {}
 157
 158 void
 159 GDBListener::Event::process(int revent)
 160 {
 161     listener->accept();
 162 }
 163
 164 GDBListener::GDBListener(RemoteGDB *g, int p)
 165     : event(NULL), gdb(g), port(p)
 166 {}
 167
 168 GDBListener::~GDBListener()
 169 {
 170     if (event)
 171         delete event;
 172 }
 173
 174 string
 175 GDBListener::name()
 176 {
 177     return gdb->name() + ".listener";
 178 }
 179
 180 void
 181 GDBListener::listen()
 182 {
 183     while (!listener.listen(port, true)) {
 184         DPRINTF(GDBMisc, "Can't bind port %d\n", port);
 185         port++;
 186     }
 187
 188     cerr << "Listening for remote gdb connection on port " << port << endl;
 189     event = new Event(this, listener.getfd(), POLLIN);
 190     pollQueue.schedule(event);
 191 }
 192
 193 void
 194 GDBListener::accept()
 195 {
 196     if (!listener.islistening())
 197         panic("GDBListener::accept(): cannot accept if we're not listening!");
 198
 199     int sfd = listener.accept(true);
 200
 201     if (sfd != -1) {
 202         if (gdb->isattached())
 203             close(sfd);
 204         else
 205             gdb->attach(sfd);
 206     }
 207 }
 208
 209 ///////////////////////////////////////////////////////////
 210 //
 211 //
 212 //
 213 int digit2i(char);
 214 char i2digit(int);
 215 void mem2hex(void *, const void *, int);
 216 const char *hex2mem(void *, const char *, int);
 217 Addr hex2i(const char **);
 218
 219 RemoteGDB::Event::Event(RemoteGDB *g, int fd, int e)
 220     : PollEvent(fd, e), gdb(g)
 221 {}
 222
 223 void
 224 RemoteGDB::Event::process(int revent)
 225 {
 226     if (revent & POLLIN)
 227         gdb->trap(ALPHA_KENTRY_IF);
 228     else if (revent & POLLNVAL)
 229         gdb->detach();
 230 }
 231
 232 RemoteGDB::RemoteGDB(System *_system, ExecContext *c)
 233     : event(NULL), fd(-1), active(false), attached(false),
 234       system(_system), pmem(_system->physmem), context(c)
 235 {
 236     memset(gdbregs, 0, sizeof(gdbregs));
 237 }
 238
 239 RemoteGDB::~RemoteGDB()
 240 {
 241     if (event)
 242         delete event;
 243 }
 244
 245 string
 246 RemoteGDB::name()
 247 {
 248     return system->name() + ".remote_gdb";
 249 }
 250
 251 bool
 252 RemoteGDB::isattached()
 253 { return attached; }
 254
 255 void
 256 RemoteGDB::attach(int f)
 257 {
 258     fd = f;
 259
 260     event = new Event(this, fd, POLLIN);
 261     pollQueue.schedule(event);
 262
 263     attached = true;
 264     DPRINTFN("remote gdb attached\n");
 265 #ifdef DEBUG
 266     theDebugger = this;
 267 #endif
 268 }
 269
 270 void
 271 RemoteGDB::detach()
 272 {
 273     attached = false;
 274     close(fd);
 275     fd = -1;
 276
 277     pollQueue.remove(event);
 278     DPRINTFN("remote gdb detached\n");
 279 }
 280
 281 const char *
 282 gdb_command(char cmd)
 283 {
 284     switch (cmd) {
 285       case KGDB_SIGNAL: return "KGDB_SIGNAL";
 286       case KGDB_SET_BAUD: return "KGDB_SET_BAUD";
 287       case KGDB_SET_BREAK: return "KGDB_SET_BREAK";
 288       case KGDB_CONT: return "KGDB_CONT";
 289       case KGDB_ASYNC_CONT: return "KGDB_ASYNC_CONT";
 290       case KGDB_DEBUG: return "KGDB_DEBUG";
 291       case KGDB_DETACH: return "KGDB_DETACH";
 292       case KGDB_REG_R: return "KGDB_REG_R";
 293       case KGDB_REG_W: return "KGDB_REG_W";
 294       case KGDB_SET_THREAD: return "KGDB_SET_THREAD";
 295       case KGDB_CYCLE_STEP: return "KGDB_CYCLE_STEP";
 296       case KGDB_SIG_CYCLE_STEP: return "KGDB_SIG_CYCLE_STEP";
 297       case KGDB_KILL: return "KGDB_KILL";
 298       case KGDB_MEM_W: return "KGDB_MEM_W";
 299       case KGDB_MEM_R: return "KGDB_MEM_R";
 300       case KGDB_SET_REG: return "KGDB_SET_REG";
 301       case KGDB_READ_REG: return "KGDB_READ_REG";
 302       case KGDB_QUERY_VAR: return "KGDB_QUERY_VAR";
 303       case KGDB_SET_VAR: return "KGDB_SET_VAR";
 304       case KGDB_RESET: return "KGDB_RESET";
 305       case KGDB_STEP: return "KGDB_STEP";
 306       case KGDB_ASYNC_STEP: return "KGDB_ASYNC_STEP";
 307       case KGDB_THREAD_ALIVE: return "KGDB_THREAD_ALIVE";
 308       case KGDB_TARGET_EXIT: return "KGDB_TARGET_EXIT";
 309       case KGDB_BINARY_DLOAD: return "KGDB_BINARY_DLOAD";
 310       case KGDB_CLR_HW_BKPT: return "KGDB_CLR_HW_BKPT";
 311       case KGDB_SET_HW_BKPT: return "KGDB_SET_HW_BKPT";
 312       case KGDB_START: return "KGDB_START";
 313       case KGDB_END: return "KGDB_END";
 314       case KGDB_GOODP: return "KGDB_GOODP";
 315       case KGDB_BADP: return "KGDB_BADP";
 316       default: return "KGDB_UNKNOWN";
 317     }
 318 }
 319
 320 ///////////////////////////////////////////////////////////
 321 // RemoteGDB::acc
 322 //
 323 //      Determine if the mapping at va..(va+len) is valid.
 324 //
 325 bool
 326 RemoteGDB::acc(Addr va, size_t len)
 327 {
 328     Addr last_va;
 329     Addr pte;
 330
 331     va = alpha_trunc_page(va);
 332     last_va = alpha_round_page(va + len);
 333
 334     do  {
 335         if (va >= ALPHA_K0SEG_BASE && va < ALPHA_K1SEG_BASE) {
 336             if (va < (ALPHA_K0SEG_BASE + pmem->size())) {
 337                 DPRINTF(GDBAcc, "acc:   Mapping is valid  K0SEG <= "
 338                         "%#x < K0SEG + size\n", va);
 339                 return true;
 340             } else {
 341                 DPRINTF(GDBAcc, "acc:   Mapping invalid %#x > K0SEG + size\n",
 342                         va);
 343                 return false;
 344             }
 345         }
 346
 347     /**
 348      * This code says that all accesses to palcode (instruction and data)
 349      * are valid since there isn't a va->pa mapping because palcode is
 350      * accessed physically. At some point this should probably be cleaned up
 351      * but there is no easy way to do it.
 352      */
 353
 354         if (PC_PAL(va) || va < 0x10000)
 355             return true;
 356
 357         Addr ptbr = context->regs.ipr[AlphaISA::IPR_PALtemp20];
 358         pte = kernel_pte_lookup(pmem, ptbr, va);
 359         if (!pte || !entry_valid(pmem->phys_read_qword(pte))) {
 360             DPRINTF(GDBAcc, "acc:   %#x pte is invalid\n", va);
 361             return false;
 362         }
 363         va += ALPHA_PGBYTES;
 364     } while (va < last_va);
 365
 366     DPRINTF(GDBAcc, "acc:   %#x mapping is valid\n", va);
 367     return true;
 368 }
 369
 370 ///////////////////////////////////////////////////////////
 371 // RemoteGDB::signal
 372 //
 373 //      Translate a trap number into a Unix-compatible signal number.
 374 //      (GDB only understands Unix signal numbers.)
 375 //
 376 int
 377 RemoteGDB::signal(int type)
 378 {
 379     switch (type) {
 380       case ALPHA_KENTRY_INT:
 381         return (SIGTRAP);
 382
 383       case ALPHA_KENTRY_UNA:
 384         return (SIGBUS);
 385
 386       case ALPHA_KENTRY_ARITH:
 387         return (SIGFPE);
 388
 389       case ALPHA_KENTRY_IF:
 390         return (SIGILL);
 391
 392       case ALPHA_KENTRY_MM:
 393         return (SIGSEGV);
 394
 395       default:
 396         panic("unknown signal type");
 397         return 0;
 398     }
 399 }
 400
 401 ///////////////////////////////////////////////////////////
 402 // RemoteGDB::getregs
 403 //
 404 //      Translate the kernel debugger register format into
 405 //      the GDB register format.
 406 void
 407 RemoteGDB::getregs()
 408 {
 409     memset(gdbregs, 0, sizeof(gdbregs));
 410     memcpy(&gdbregs[KGDB_REG_V0], context->regs.intRegFile, 32 * sizeof(uint64_t));
 411 #ifdef KGDB_FP_REGS
 412     memcpy(&gdbregs[KGDB_REG_F0], context->regs.floatRegFile.q,
 413            32 * sizeof(uint64_t));
 414 #endif
 415     gdbregs[KGDB_REG_PC] = context->regs.pc;
 416 }
 417
 418 ///////////////////////////////////////////////////////////
 419 // RemoteGDB::setregs
 420 //
 421 //      Translate the GDB register format into the kernel
 422 //      debugger register format.
 423 //
 424 void
 425 RemoteGDB::setregs()
 426 {
 427     memcpy(context->regs.intRegFile, &gdbregs[KGDB_REG_V0],
 428            32 * sizeof(uint64_t));
 429 #ifdef KGDB_FP_REGS
 430     memcpy(context->regs.floatRegFile.q, &gdbregs[KGDB_REG_F0],
 431            32 * sizeof(uint64_t));
 432 #endif
 433     context->regs.pc = gdbregs[KGDB_REG_PC];
 434 }
 435
 436 void
 437 RemoteGDB::setTempBreakpoint(TempBreakpoint &bkpt, Addr addr)
 438 {
 439     DPRINTF(GDBMisc, "setTempBreakpoint: addr=%#x\n", addr);
 440
 441     bkpt.address = addr;
 442     insertHardBreak(addr, 4);
 443 }
 444
 445 void
 446 RemoteGDB::clearTempBreakpoint(TempBreakpoint &bkpt)
 447 {
 448     DPRINTF(GDBMisc, "setTempBreakpoint: addr=%#x\n",
 449             bkpt.address);
 450
 451
 452     removeHardBreak(bkpt.address, 4);
 453     bkpt.address = 0;
 454 }
 455
 456 void
 457 RemoteGDB::clearSingleStep()
 458 {
 459     DPRINTF(GDBMisc, "clearSingleStep bt_addr=%#x nt_addr=%#x\n",
 460             takenBkpt.address, notTakenBkpt.address);
 461
 462     if (takenBkpt.address != 0)
 463         clearTempBreakpoint(takenBkpt);
 464
 465     if (notTakenBkpt.address != 0)
 466         clearTempBreakpoint(notTakenBkpt);
 467 }
 468
 469 void
 470 RemoteGDB::setSingleStep()
 471 {
 472     Addr pc = context->regs.pc;
 473     Addr npc, bpc;
 474     bool set_bt = false;
 475
 476     npc = pc + sizeof(MachInst);
 477
 478     // User was stopped at pc, e.g. the instruction at pc was not
 479     // executed.
 480     MachInst inst = read<MachInst>(pc);
 481     StaticInstPtr<TheISA> si(inst);
 482     if (si->hasBranchTarget(pc, context, bpc)) {
 483         // Don't bother setting a breakpoint on the taken branch if it
 484         // is the same as the next pc
 485         if (bpc != npc)
 486             set_bt = true;
 487     }
 488
 489     DPRINTF(GDBMisc, "setSingleStep bt_addr=%#x nt_addr=%#x\n",
 490             takenBkpt.address, notTakenBkpt.address);
 491
 492     setTempBreakpoint(notTakenBkpt, npc);
 493
 494     if (set_bt)
 495         setTempBreakpoint(takenBkpt, bpc);
 496 }
 497
 498 /////////////////////////
 499 //
 500 //
 501
 502 uint8_t
 503 RemoteGDB::getbyte()
 504 {
 505     uint8_t b;
 506     ::read(fd, &b, 1);
 507     return b;
 508 }
 509
 510 void
 511 RemoteGDB::putbyte(uint8_t b)
 512 {
 513     ::write(fd, &b, 1);
 514 }
 515
 516 // Send a packet to gdb
 517 void
 518 RemoteGDB::send(const char *bp)
 519 {
 520     const char *p;
 521     uint8_t csum, c;
 522
 523     DPRINTF(GDBSend, "send:  %s\n", bp);
 524
 525     do {
 526         p = bp;
 527         putbyte(KGDB_START);
 528         for (csum = 0; (c = *p); p++) {
 529             putbyte(c);
 530             csum += c;
 531         }
 532         putbyte(KGDB_END);
 533         putbyte(i2digit(csum >> 4));
 534         putbyte(i2digit(csum));
 535     } while ((c = getbyte() & 0x7f) == KGDB_BADP);
 536 }
 537
 538 // Receive a packet from gdb
 539 int
 540 RemoteGDB::recv(char *bp, int maxlen)
 541 {
 542     char *p;
 543     int c, csum;
 544     int len;
 545
 546     do {
 547         p = bp;
 548         csum = len = 0;
 549         while ((c = getbyte()) != KGDB_START)
 550             ;
 551
 552         while ((c = getbyte()) != KGDB_END && len < maxlen) {
 553             c &= 0x7f;
 554             csum += c;
 555             *p++ = c;
 556             len++;
 557         }
 558         csum &= 0xff;
 559         *p = '\0';
 560
 561         if (len >= maxlen) {
 562             putbyte(KGDB_BADP);
 563             continue;
 564         }
 565
 566         csum -= digit2i(getbyte()) * 16;
 567         csum -= digit2i(getbyte());
 568
 569         if (csum == 0) {
 570             putbyte(KGDB_GOODP);
 571             // Sequence present?
 572             if (bp[2] == ':') {
 573                 putbyte(bp[0]);
 574                 putbyte(bp[1]);
 575                 len -= 3;
 576                 bcopy(bp + 3, bp, len);
 577             }
 578             break;
 579         }
 580         putbyte(KGDB_BADP);
 581     } while (1);
 582
 583     DPRINTF(GDBRecv, "recv:  %s: %s\n", gdb_command(*bp), bp);
 584
 585     return (len);
 586 }
 587
 588 // Read bytes from kernel address space for debugger.
 589 bool
 590 RemoteGDB::read(Addr vaddr, size_t size, char *data)
 591 {
 592     static Addr lastaddr = 0;
 593     static size_t lastsize = 0;
 594
 595     uint8_t *maddr;
 596
 597     if (vaddr < 10) {
 598       DPRINTF(GDBRead, "read:  reading memory location zero!\n");
 599       vaddr = lastaddr + lastsize;
 600     }
 601
 602     DPRINTF(GDBRead, "read:  addr=%#x, size=%d", vaddr, size);
 603 #if TRACING_ON
 604     char *d = data;
 605     size_t s = size;
 606 #endif
 607
 608     lastaddr = vaddr;
 609     lastsize = size;
 610
 611     size_t count = min((Addr)size,
 612                        VMPageSize - (vaddr & (VMPageSize - 1)));
 613
 614     maddr = vtomem(context, vaddr, count);
 615     memcpy(data, maddr, count);
 616
 617     vaddr += count;
 618     data += count;
 619     size -= count;
 620
 621     while (size >= VMPageSize) {
 622         maddr = vtomem(context, vaddr, count);
 623         memcpy(data, maddr, VMPageSize);
 624
 625         vaddr += VMPageSize;
 626         data += VMPageSize;
 627         size -= VMPageSize;
 628     }
 629
 630     if (size > 0) {
 631         maddr = vtomem(context, vaddr, count);
 632         memcpy(data, maddr, size);
 633     }
 634
 635 #if TRACING_ON
 636     if (DTRACE(GDBRead)) {
 637         if (DTRACE(GDBExtra)) {
 638             char buf[1024];
 639             mem2hex(buf, d, s);
 640             DPRINTFNR(": %s\n", buf);
 641         } else
 642             DPRINTFNR("\n");
 643     }
 644 #endif
 645
 646     return true;
 647 }
 648
 649 // Write bytes to kernel address space for debugger.
 650 bool
 651 RemoteGDB::write(Addr vaddr, size_t size, const char *data)
 652 {
 653     static Addr lastaddr = 0;
 654     static size_t lastsize = 0;
 655
 656     uint8_t *maddr;
 657
 658     if (vaddr < 10) {
 659       DPRINTF(GDBWrite, "write: writing memory location zero!\n");
 660       vaddr = lastaddr + lastsize;
 661     }
 662
 663     if (DTRACE(GDBWrite)) {
 664         DPRINTFN("write: addr=%#x, size=%d", vaddr, size);
 665         if (DTRACE(GDBExtra)) {
 666             char buf[1024];
 667             mem2hex(buf, data, size);
 668             DPRINTFNR(": %s\n", buf);
 669         } else
 670             DPRINTFNR("\n");
 671     }
 672
 673     lastaddr = vaddr;
 674     lastsize = size;
 675
 676     size_t count = min((Addr)size,
 677                        VMPageSize - (vaddr & (VMPageSize - 1)));
 678
 679     maddr = vtomem(context, vaddr, count);
 680     memcpy(maddr, data, count);
 681
 682     vaddr += count;
 683     data += count;
 684     size -= count;
 685
 686     while (size >= VMPageSize) {
 687         maddr = vtomem(context, vaddr, count);
 688         memcpy(maddr, data, VMPageSize);
 689
 690         vaddr += VMPageSize;
 691         data += VMPageSize;
 692         size -= VMPageSize;
 693     }
 694
 695     if (size > 0) {
 696         maddr = vtomem(context, vaddr, count);
 697         memcpy(maddr, data, size);
 698     }
 699
 700 #ifdef IMB
 701     alpha_pal_imb();
 702 #endif
 703
 704     return true;
 705 }
 706
 707
 708 PCEventQueue *RemoteGDB::getPcEventQueue()
 709 {
 710     return &system->pcEventQueue;
 711 }
 712
 713
 714 RemoteGDB::HardBreakpoint::HardBreakpoint(RemoteGDB *_gdb, Addr pc)
 715     : PCEvent(_gdb->getPcEventQueue(), "HardBreakpoint Event", pc),
 716       gdb(_gdb), refcount(0)
 717 {
 718     DPRINTF(GDBMisc, "creating hardware breakpoint at %#x\n", evpc);
 719     schedule();
 720 }
 721
 722 void
 723 RemoteGDB::HardBreakpoint::process(ExecContext *xc)
 724 {
 725     DPRINTF(GDBMisc, "handling hardware breakpoint at %#x\n", pc());
 726
 727     if (xc == gdb->context)
 728         gdb->trap(ALPHA_KENTRY_INT);
 729 }
 730
 731 bool
 732 RemoteGDB::insertSoftBreak(Addr addr, size_t len)
 733 {
 734     if (len != sizeof(MachInst))
 735         panic("invalid length\n");
 736
 737     return insertHardBreak(addr, len);
 738 }
 739
 740 bool
 741 RemoteGDB::removeSoftBreak(Addr addr, size_t len)
 742 {
 743     if (len != sizeof(MachInst))
 744         panic("invalid length\n");
 745
 746     return removeHardBreak(addr, len);
 747 }
 748
 749 bool
 750 RemoteGDB::insertHardBreak(Addr addr, size_t len)
 751 {
 752     if (len != sizeof(MachInst))
 753         panic("invalid length\n");
 754
 755     DPRINTF(GDBMisc, "inserting hardware breakpoint at %#x\n", addr);
 756
 757     HardBreakpoint *&bkpt = hardBreakMap[addr];
 758     if (bkpt == 0)
 759         bkpt = new HardBreakpoint(this, addr);
 760
 761     bkpt->refcount++;
 762
 763     return true;
 764 }
 765
 766 bool
 767 RemoteGDB::removeHardBreak(Addr addr, size_t len)
 768 {
 769     if (len != sizeof(MachInst))
 770         panic("invalid length\n");
 771
 772     DPRINTF(GDBMisc, "removing hardware breakpoint at %#x\n", addr);
 773
 774     break_iter_t i = hardBreakMap.find(addr);
 775     if (i == hardBreakMap.end())
 776         return false;
 777
 778     HardBreakpoint *hbp = (*i).second;
 779     if (--hbp->refcount == 0) {
 780         delete hbp;
 781         hardBreakMap.erase(i);
 782     }
 783
 784     return true;
 785 }
 786
 787 const char *
 788 break_type(char c)
 789 {
 790     switch(c) {
 791       case '0': return "software breakpoint";
 792       case '1': return "hardware breakpoint";
 793       case '2': return "write watchpoint";
 794       case '3': return "read watchpoint";
 795       case '4': return "access watchpoint";
 796       default: return "unknown breakpoint/watchpoint";
 797     }
 798 }
 799
 800 // This function does all command processing for interfacing to a
 801 // remote gdb.  Note that the error codes are ignored by gdb at
 802 // present, but might eventually become meaningful. (XXX) It might
 803 // makes sense to use POSIX errno values, because that is what the
 804 // gdb/remote.c functions want to return.
 805 bool
 806 RemoteGDB::trap(int type)
 807 {
 808     uint64_t val;
 809     size_t datalen, len;
 810     char data[KGDB_BUFLEN + 1];
 811     char buffer[sizeof(gdbregs) * 2 + 256];
 812     char temp[KGDB_BUFLEN];
 813     const char *p;
 814     char command, subcmd;
 815     string var;
 816     bool ret;
 817
 818     if (!attached)
 819         return false;
 820
 821     DPRINTF(GDBMisc, "trap: PC=%#x NPC=%#x\n",
 822             context->regs.pc, context->regs.npc);
 823
 824     clearSingleStep();
 825
 826     /*
 827      * The first entry to this function is normally through
 828      * a breakpoint trap in kgdb_connect(), in which case we
 829      * must advance past the breakpoint because gdb will not.
 830      *
 831      * On the first entry here, we expect that gdb is not yet
 832      * listening to us, so just enter the interaction loop.
 833      * After the debugger is "active" (connected) it will be
 834      * waiting for a "signaled" message from us.
 835      */
 836     if (!active)
 837         active = true;
 838     else
 839         // Tell remote host that an exception has occurred.
 840         sprintf((char *)buffer, "S%02x", signal(type));
 841         send(buffer);
 842
 843     // Stick frame regs into our reg cache.
 844     getregs();
 845
 846     for (;;) {
 847         datalen = recv(data, sizeof(data));
 848         data[sizeof(data) - 1] = 0; // Sentinel
 849         command = data[0];
 850         subcmd = 0;
 851         p = data + 1;
 852         switch (command) {
 853
 854           case KGDB_SIGNAL:
 855             // if this command came from a running gdb, answer it --
 856             // the other guy has no way of knowing if we're in or out
 857             // of this loop when he issues a "remote-signal".
 858             sprintf((char *)buffer, "S%02x", signal(type));
 859             send(buffer);
 860             continue;
 861
 862           case KGDB_REG_R:
 863             if (2 * sizeof(gdbregs) > sizeof(buffer))
 864                 panic("buffer too small");
 865
 866             mem2hex(buffer, gdbregs, sizeof(gdbregs));
 867             send(buffer);
 868             continue;
 869
 870           case KGDB_REG_W:
 871             p = hex2mem(gdbregs, p, sizeof(gdbregs));
 872             if (p == NULL || *p != '\0')
 873                 send("E01");
 874             else {
 875                 setregs();
 876                 send("OK");
 877             }
 878             continue;
 879
 880 #if 0
 881           case KGDB_SET_REG:
 882             val = hex2i(&p);
 883             if (*p++ != '=') {
 884                 send("E01");
 885                 continue;
 886             }
 887             if (val < 0 && val >= KGDB_NUMREGS) {
 888                 send("E01");
 889                 continue;
 890             }
 891
 892             gdbregs[val] = hex2i(&p);
 893             setregs();
 894             send("OK");
 895
 896             continue;
 897 #endif
 898
 899           case KGDB_MEM_R:
 900             val = hex2i(&p);
 901             if (*p++ != ',') {
 902                 send("E02");
 903                 continue;
 904             }
 905             len = hex2i(&p);
 906             if (*p != '\0') {
 907                 send("E03");
 908                 continue;
 909             }
 910             if (len > sizeof(buffer)) {
 911                 send("E04");
 912                 continue;
 913             }
 914             if (!acc(val, len)) {
 915                 send("E05");
 916                 continue;
 917             }
 918
 919             if (read(val, (size_t)len, (char *)buffer)) {
 920               mem2hex(temp, buffer, len);
 921               send(temp);
 922             } else {
 923               send("E05");
 924             }
 925             continue;
 926
 927           case KGDB_MEM_W:
 928             val = hex2i(&p);
 929             if (*p++ != ',') {
 930                 send("E06");
 931                 continue;
 932             }
 933             len = hex2i(&p);
 934             if (*p++ != ':') {
 935                 send("E07");
 936                 continue;
 937             }
 938             if (len > datalen - (p - data)) {
 939                 send("E08");
 940                 continue;
 941             }
 942             p = hex2mem(buffer, p, sizeof(buffer));
 943             if (p == NULL) {
 944                 send("E09");
 945                 continue;
 946             }
 947             if (!acc(val, len)) {
 948                 send("E0A");
 949                 continue;
 950             }
 951             if (write(val, (size_t)len, (char *)buffer))
 952               send("OK");
 953             else
 954               send("E0B");
 955             continue;
 956
 957           case KGDB_SET_THREAD:
 958             subcmd = *p++;
 959             val = hex2i(&p);
 960             if (val == 0)
 961                 send("OK");
 962             else
 963                 send("E01");
 964             continue;
 965
 966           case KGDB_DETACH:
 967           case KGDB_KILL:
 968             active = false;
 969             clearSingleStep();
 970             detach();
 971             goto out;
 972
 973           case KGDB_ASYNC_CONT:
 974             subcmd = hex2i(&p);
 975             if (*p++ == ';') {
 976                 val = hex2i(&p);
 977                 context->regs.pc = val;
 978                 context->regs.npc = val + sizeof(MachInst);
 979             }
 980             clearSingleStep();
 981             goto out;
 982
 983           case KGDB_CONT:
 984             if (p - data < datalen) {
 985                 val = hex2i(&p);
 986                 context->regs.pc = val;
 987                 context->regs.npc = val + sizeof(MachInst);
 988             }
 989             clearSingleStep();
 990             goto out;
 991
 992           case KGDB_ASYNC_STEP:
 993             subcmd = hex2i(&p);
 994             if (*p++ == ';') {
 995                 val = hex2i(&p);
 996                 context->regs.pc = val;
 997                 context->regs.npc = val + sizeof(MachInst);
 998             }
 999             setSingleStep();
1000             goto out;
1001
1002           case KGDB_STEP:
1003             if (p - data < datalen) {
1004                 val = hex2i(&p);
1005                 context->regs.pc = val;
1006                 context->regs.npc = val + sizeof(MachInst);
1007             }
1008             setSingleStep();
1009             goto out;
1010
1011           case KGDB_CLR_HW_BKPT:
1012             subcmd = *p++;
1013             if (*p++ != ',') send("E0D");
1014             val = hex2i(&p);
1015             if (*p++ != ',') send("E0D");
1016             len = hex2i(&p);
1017
1018             DPRINTF(GDBMisc, "clear %s, addr=%#x, len=%d\n",
1019                     break_type(subcmd), val, len);
1020
1021             ret = false;
1022
1023             switch (subcmd) {
1024               case '0': // software breakpoint
1025                 ret = removeSoftBreak(val, len);
1026                 break;
1027
1028               case '1': // hardware breakpoint
1029                 ret = removeHardBreak(val, len);
1030                 break;
1031
1032               case '2': // write watchpoint
1033               case '3': // read watchpoint
1034               case '4': // access watchpoint
1035               default: // unknown
1036                 send("");
1037                 break;
1038             }
1039
1040             send(ret ? "OK" : "E0C");
1041             continue;
1042
1043           case KGDB_SET_HW_BKPT:
1044             subcmd = *p++;
1045             if (*p++ != ',') send("E0D");
1046             val = hex2i(&p);
1047             if (*p++ != ',') send("E0D");
1048             len = hex2i(&p);
1049
1050             DPRINTF(GDBMisc, "set %s, addr=%#x, len=%d\n",
1051                     break_type(subcmd), val, len);
1052
1053             ret = false;
1054
1055             switch (subcmd) {
1056               case '0': // software breakpoint
1057                 ret = insertSoftBreak(val, len);
1058                 break;
1059
1060               case '1': // hardware breakpoint
1061                 ret = insertHardBreak(val, len);
1062                 break;
1063
1064               case '2': // write watchpoint
1065               case '3': // read watchpoint
1066               case '4': // access watchpoint
1067               default: // unknown
1068                 send("");
1069                 break;
1070             }
1071
1072             send(ret ? "OK" : "E0C");
1073             continue;
1074
1075           case KGDB_QUERY_VAR:
1076             var = string(p, datalen - 1);
1077             if (var == "C")
1078                 send("QC0");
1079             else
1080                 send("");
1081             continue;
1082
1083           case KGDB_SET_BAUD:
1084           case KGDB_SET_BREAK:
1085           case KGDB_DEBUG:
1086           case KGDB_CYCLE_STEP:
1087           case KGDB_SIG_CYCLE_STEP:
1088           case KGDB_READ_REG:
1089           case KGDB_SET_VAR:
1090           case KGDB_RESET:
1091           case KGDB_THREAD_ALIVE:
1092           case KGDB_TARGET_EXIT:
1093           case KGDB_BINARY_DLOAD:
1094             // Unsupported command
1095             DPRINTF(GDBMisc, "Unsupported command: %s\n",
1096                     gdb_command(command));
1097             DDUMP(GDBMisc, (uint8_t *)data, datalen);
1098             send("");
1099             continue;
1100
1101           default:
1102             // Unknown command.
1103             DPRINTF(GDBMisc, "Unknown command: %c(%#x)\n",
1104                     command, command);
1105             send("");
1106             continue;
1107
1108
1109         }
1110     }
1111
1112   out:
1113     return true;
1114 }
1115
1116 // Convert a hex digit into an integer.
1117 // This returns -1 if the argument passed is no valid hex digit.
1118 int
1119 digit2i(char c)
1120 {
1121     if (c >= '0' && c <= '9')
1122         return (c - '0');
1123     else if (c >= 'a' && c <= 'f')
1124         return (c - 'a' + 10);
1125     else if (c >= 'A' && c <= 'F')
1126
1127         return (c - 'A' + 10);
1128     else
1129         return (-1);
1130 }
1131
1132 // Convert the low 4 bits of an integer into an hex digit.
1133 char
1134 i2digit(int n)
1135 {
1136     return ("0123456789abcdef"[n & 0x0f]);
1137 }
1138
1139 // Convert a byte array into an hex string.
1140 void
1141 mem2hex(void *vdst, const void *vsrc, int len)
1142 {
1143     char *dst = (char *)vdst;
1144     const char *src = (const char *)vsrc;
1145
1146     while (len--) {
1147         *dst++ = i2digit(*src >> 4);
1148         *dst++ = i2digit(*src++);
1149     }
1150     *dst = '\0';
1151 }
1152
1153 // Convert an hex string into a byte array.
1154 // This returns a pointer to the character following the last valid
1155 // hex digit. If the string ends in the middle of a byte, NULL is
1156 // returned.
1157 const char *
1158 hex2mem(void *vdst, const char *src, int maxlen)
1159 {
1160     char *dst = (char *)vdst;
1161     int msb, lsb;
1162
1163     while (*src && maxlen--) {
1164         msb = digit2i(*src++);
1165         if (msb < 0)
1166             return (src - 1);
1167         lsb = digit2i(*src++);
1168         if (lsb < 0)
1169             return (NULL);
1170         *dst++ = (msb << 4) | lsb;
1171     }
1172     return (src);
1173 }
1174
1175 // Convert an hex string into an integer.
1176 // This returns a pointer to the character following the last valid
1177 // hex digit.
1178 Addr
1179 hex2i(const char **srcp)
1180 {
1181     const char *src = *srcp;
1182     Addr r = 0;
1183     int nibble;
1184
1185     while ((nibble = digit2i(*src)) >= 0) {
1186         r *= 16;
1187         r += nibble;
1188         src++;
1189     }
1190     *srcp = src;
1191     return (r);
1192 }
1193