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gem5/base/remote_gdb.cc
Lisa Hsu b6c77fe6f8 remote_gdb.cc: 
fix remote gdb

base/remote_gdb.cc:
    fix remote gdb

--HG--
extra : convert_revision : 886cad5037e2124e6087be03f2903f07aeed0679
2003-12-04 19:26:31 -05:00

1178 lines
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/*
* Copyright (c) 2003 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Lawrence Berkeley Laboratories.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kgdb_stub.c 8.4 (Berkeley) 1/12/94
*/
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* $NetBSD: kgdb_stub.c,v 1.8 2001/07/07 22:58:00 wdk Exp $
*
* Taken from NetBSD
*
* "Stub" to allow remote cpu to debug over a serial line using gdb.
*/
#include <sys/signal.h>
#include <unistd.h>
#include <cstdio>
#include <string>
#include "cpu/exec_context.hh"
#include "base/intmath.hh"
#include "base/kgdb.h"
#include "mem/functional_mem/physical_memory.hh"
#include "base/remote_gdb.hh"
#include "base/socket.hh"
#include "base/trace.hh"
#include "targetarch/vtophys.hh"
#include "sim/system.hh"
#include "cpu/static_inst.hh"
using namespace std;
#ifdef DEBUG
RemoteGDB *theDebugger = NULL;
void
debugger()
{
if (theDebugger)
theDebugger->trap(ALPHA_KENTRY_IF);
}
#endif
///////////////////////////////////////////////////////////
//
//
//
GDBListener::Event::Event(GDBListener *l, int fd, int e)
: PollEvent(fd, e), listener(l)
{}
void
GDBListener::Event::process(int revent)
{
listener->accept();
}
GDBListener::GDBListener(RemoteGDB *g, int p)
: event(NULL), gdb(g), port(p)
{}
GDBListener::~GDBListener()
{
if (event)
delete event;
}
void
GDBListener::listen()
{
while (!listener.listen(port, true)) {
DPRINTF(RGDB, "GDBListener(listen): Can't bind port %d\n", port);
port++;
}
cerr << "Listening for remote gdb connection on port " << port << endl;
event = new Event(this, listener.getfd(), POLLIN);
pollQueue.schedule(event);
}
void
GDBListener::accept()
{
if (!listener.islistening())
panic("GDBListener(accept): cannot accept a connection if we're not listening!");
int sfd = listener.accept(true);
if (sfd != -1) {
if (gdb->isattached())
close(sfd);
else
gdb->attach(sfd);
}
}
///////////////////////////////////////////////////////////
//
//
//
int digit2i(char);
char i2digit(int);
void mem2hex(void *, const void *, int);
const char *hex2mem(void *, const char *, int);
Addr hex2i(const char **);
RemoteGDB::Event::Event(RemoteGDB *g, int fd, int e)
: PollEvent(fd, e), gdb(g)
{}
void
RemoteGDB::Event::process(int revent)
{ gdb->trap(ALPHA_KENTRY_IF); }
RemoteGDB::RemoteGDB(System *_system, ExecContext *c)
: event(NULL), fd(-1), active(false), attached(false),
system(_system), pmem(_system->physmem), context(c)
{
memset(gdbregs, 0, sizeof(gdbregs));
}
RemoteGDB::~RemoteGDB()
{
if (event)
delete event;
}
bool
RemoteGDB::isattached()
{ return attached; }
void
RemoteGDB::attach(int f)
{
fd = f;
event = new Event(this, fd, POLLIN);
pollQueue.schedule(event);
attached = true;
DPRINTFN("remote gdb attached\n");
#ifdef DEBUG
theDebugger = this;
#endif
}
void
RemoteGDB::detach()
{
attached = false;
close(fd);
fd = -1;
pollQueue.remove(event);
DPRINTFN("remote gdb detached\n");
}
const char *
gdb_command(char cmd)
{
switch (cmd) {
case KGDB_SIGNAL: return "KGDB_SIGNAL";
case KGDB_SET_BAUD: return "KGDB_SET_BAUD";
case KGDB_SET_BREAK: return "KGDB_SET_BREAK";
case KGDB_CONT: return "KGDB_CONT";
case KGDB_ASYNC_CONT: return "KGDB_ASYNC_CONT";
case KGDB_DEBUG: return "KGDB_DEBUG";
case KGDB_DETACH: return "KGDB_DETACH";
case KGDB_REG_R: return "KGDB_REG_R";
case KGDB_REG_W: return "KGDB_REG_W";
case KGDB_SET_THREAD: return "KGDB_SET_THREAD";
case KGDB_CYCLE_STEP: return "KGDB_CYCLE_STEP";
case KGDB_SIG_CYCLE_STEP: return "KGDB_SIG_CYCLE_STEP";
case KGDB_KILL: return "KGDB_KILL";
case KGDB_MEM_W: return "KGDB_MEM_W";
case KGDB_MEM_R: return "KGDB_MEM_R";
case KGDB_SET_REG: return "KGDB_SET_REG";
case KGDB_READ_REG: return "KGDB_READ_REG";
case KGDB_QUERY_VAR: return "KGDB_QUERY_VAR";
case KGDB_SET_VAR: return "KGDB_SET_VAR";
case KGDB_RESET: return "KGDB_RESET";
case KGDB_STEP: return "KGDB_STEP";
case KGDB_ASYNC_STEP: return "KGDB_ASYNC_STEP";
case KGDB_THREAD_ALIVE: return "KGDB_THREAD_ALIVE";
case KGDB_TARGET_EXIT: return "KGDB_TARGET_EXIT";
case KGDB_BINARY_DLOAD: return "KGDB_BINARY_DLOAD";
case KGDB_CLR_HW_BKPT: return "KGDB_CLR_HW_BKPT";
case KGDB_SET_HW_BKPT: return "KGDB_SET_HW_BKPT";
case KGDB_START: return "KGDB_START";
case KGDB_END: return "KGDB_END";
case KGDB_GOODP: return "KGDB_GOODP";
case KGDB_BADP: return "KGDB_BADP";
default: return "KGDB_UNKNOWN";
}
}
///////////////////////////////////////////////////////////
// RemoteGDB::acc
//
// Determine if the mapping at va..(va+len) is valid.
//
bool
RemoteGDB::acc(Addr va, size_t len)
{
Addr last_va;
Addr pte;
va = alpha_trunc_page(va);
last_va = alpha_round_page(va + len);
do {
if (va < ALPHA_K0SEG_BASE) {
DPRINTF(RGDB, "RGDB(acc): Mapping is invalid %#x < K0SEG\n", va);
return false;
}
if (va < ALPHA_K1SEG_BASE) {
if (va < (ALPHA_K0SEG_BASE + pmem->getSize())) {
DPRINTF(RGDB, "RGDB(acc): Mapping is valid K0SEG <= "
"%#x < K0SEG + size\n", va);
return true;
} else {
DPRINTF(RGDB, "RGDB(acc): Mapping is invalid %#x < K0SEG\n",
va);
return false;
}
}
Addr ptbr = context->regs.ipr[AlphaISA::IPR_PALtemp20];
pte = kernel_pte_lookup(pmem, ptbr, va);
if (!pte || !entry_valid(pmem->phys_read_qword(pte))) {
DPRINTF(RGDB, "RGDB(acc): %#x pte is invalid\n", va);
return false;
}
va += ALPHA_PGBYTES;
} while (va < last_va);
DPRINTF(RGDB, "RGDB(acc): %#x mapping is valid\n", va);
return true;
}
///////////////////////////////////////////////////////////
// RemoteGDB::signal
//
// Translate a trap number into a Unix-compatible signal number.
// (GDB only understands Unix signal numbers.)
//
int
RemoteGDB::signal(int type)
{
switch (type) {
case ALPHA_KENTRY_UNA:
return (SIGBUS);
case ALPHA_KENTRY_ARITH:
return (SIGFPE);
case ALPHA_KENTRY_IF:
return (SIGILL);
case ALPHA_KENTRY_MM:
return (SIGSEGV);
default:
panic("unknown signal type");
return 0;
}
}
///////////////////////////////////////////////////////////
// RemoteGDB::getregs
//
// Translate the kernel debugger register format into
// the GDB register format.
void
RemoteGDB::getregs()
{
memset(gdbregs, 0, sizeof(gdbregs));
memcpy(&gdbregs[KGDB_REG_V0], context->regs.intRegFile, 32 * sizeof(uint64_t));
#ifdef KGDB_FP_REGS
memcpy(&gdbregs[KGDB_REG_F0], context->regs.floatRegFile.q,
32 * sizeof(uint64_t));
#endif
gdbregs[KGDB_REG_PC] = context->regs.pc;
}
///////////////////////////////////////////////////////////
// RemoteGDB::setregs
//
// Translate the GDB register format into the kernel
// debugger register format.
//
void
RemoteGDB::setregs()
{
memcpy(context->regs.intRegFile, &gdbregs[KGDB_REG_V0], 32 * sizeof(uint64_t));
#ifdef KGDB_FP_REGS
memcpy(context->regs.floatRegFile.q, &gdbregs[KGDB_REG_F0],
32 * sizeof(uint64_t));
#endif
context->regs.pc = gdbregs[KGDB_REG_PC];
}
void
RemoteGDB::setTempBreakpoint(TempBreakpoint &bkpt, Addr addr)
{
DPRINTF(RGDB, "RGDB(setTempBreakpoint): addr=%#x\n", addr);
bkpt.address = addr;
insertHardBreak(addr, 4);
}
void
RemoteGDB::clearTempBreakpoint(TempBreakpoint &bkpt)
{
DPRINTF(RGDB, "RGDB(setTempBreakpoint): addr=%#x\n",
bkpt.address);
removeHardBreak(bkpt.address, 4);
bkpt.address = 0;
}
void
RemoteGDB::clearSingleStep()
{
DPRINTF(RGDB, "clearSingleStep bt_addr=%#x nt_addr=%#x\n",
takenBkpt.address, notTakenBkpt.address);
if (takenBkpt.address != 0)
clearTempBreakpoint(takenBkpt);
if (notTakenBkpt.address != 0)
clearTempBreakpoint(notTakenBkpt);
}
void
RemoteGDB::setSingleStep()
{
Addr pc = context->regs.pc;
Addr npc, bpc;
bool set_bt = false;
npc = pc + sizeof(MachInst);
// User was stopped at pc, e.g. the instruction at pc was not
// executed.
MachInst inst = read<MachInst>(pc);
StaticInstPtr<TheISA> si(inst);
if (si->hasBranchTarget(pc, context, bpc)) {
// Don't bother setting a breakpoint on the taken branch if it
// is the same as the next pc
if (bpc != npc)
set_bt = true;
}
DPRINTF(RGDB, "setSingleStep bt_addr=%#x nt_addr=%#x\n",
takenBkpt.address, notTakenBkpt.address);
setTempBreakpoint(notTakenBkpt, npc);
if (set_bt)
setTempBreakpoint(takenBkpt, bpc);
}
/////////////////////////
//
//
uint8_t
RemoteGDB::getbyte()
{
uint8_t b;
::read(fd, &b, 1);
return b;
}
void
RemoteGDB::putbyte(uint8_t b)
{
::write(fd, &b, 1);
}
// Send a packet to gdb
void
RemoteGDB::send(const char *bp)
{
const char *p;
uint8_t csum, c;
// DPRINTF(RGDB, "RGDB(send): %s\n", bp);
do {
p = bp;
putbyte(KGDB_START);
for (csum = 0; (c = *p); p++) {
putbyte(c);
csum += c;
}
putbyte(KGDB_END);
putbyte(i2digit(csum >> 4));
putbyte(i2digit(csum));
} while ((c = getbyte() & 0x7f) == KGDB_BADP);
}
// Receive a packet from gdb
int
RemoteGDB::recv(char *bp, int maxlen)
{
char *p;
int c, csum;
int len;
do {
p = bp;
csum = len = 0;
while ((c = getbyte()) != KGDB_START)
;
while ((c = getbyte()) != KGDB_END && len < maxlen) {
c &= 0x7f;
csum += c;
*p++ = c;
len++;
}
csum &= 0xff;
*p = '\0';
if (len >= maxlen) {
putbyte(KGDB_BADP);
continue;
}
csum -= digit2i(getbyte()) * 16;
csum -= digit2i(getbyte());
if (csum == 0) {
putbyte(KGDB_GOODP);
// Sequence present?
if (bp[2] == ':') {
putbyte(bp[0]);
putbyte(bp[1]);
len -= 3;
bcopy(bp + 3, bp, len);
}
break;
}
putbyte(KGDB_BADP);
} while (1);
// DPRINTF(RGDB, "RGDB(recv): %s: %s\n", gdb_command(*bp), bp);
return (len);
}
// Read bytes from kernel address space for debugger.
bool
RemoteGDB::read(Addr vaddr, size_t size, char *data)
{
static Addr lastaddr = 0;
static size_t lastsize = 0;
uint8_t *maddr;
if (vaddr < 10) {
DPRINTF(RGDB, "\nRGDB(read): reading memory location zero!\n");
vaddr = lastaddr + lastsize;
}
DPRINTF(RGDB, "RGDB(read): addr=%#x, size=%d", vaddr, size);
#if TRACING_ON
char *d = data;
size_t s = size;
#endif
lastaddr = vaddr;
lastsize = size;
size_t count = min((Addr)size,
VMPageSize - (vaddr & (VMPageSize - 1)));
maddr = vtomem(context, vaddr, count);
memcpy(data, maddr, count);
vaddr += count;
data += count;
size -= count;
while (size >= VMPageSize) {
maddr = vtomem(context, vaddr, count);
memcpy(data, maddr, VMPageSize);
vaddr += VMPageSize;
data += VMPageSize;
size -= VMPageSize;
}
if (size > 0) {
maddr = vtomem(context, vaddr, count);
memcpy(data, maddr, size);
}
#if TRACING_ON
if (DTRACE(RGDB)) {
char buf[1024];
mem2hex(buf, d, s);
cprintf(": %s\n", buf);
}
#endif
return true;
}
// Write bytes to kernel address space for debugger.
bool
RemoteGDB::write(Addr vaddr, size_t size, const char *data)
{
static Addr lastaddr = 0;
static size_t lastsize = 0;
uint8_t *maddr;
if (vaddr < 10) {
DPRINTF(RGDB, "RGDB(write): writing memory location zero!\n");
vaddr = lastaddr + lastsize;
}
if (DTRACE(RGDB)) {
char buf[1024];
mem2hex(buf, data, size);
cprintf("RGDB(write): addr=%#x, size=%d: %s\n", vaddr, size, buf);
}
lastaddr = vaddr;
lastsize = size;
size_t count = min((Addr)size,
VMPageSize - (vaddr & (VMPageSize - 1)));
maddr = vtomem(context, vaddr, count);
memcpy(maddr, data, count);
vaddr += count;
data += count;
size -= count;
while (size >= VMPageSize) {
maddr = vtomem(context, vaddr, count);
memcpy(maddr, data, VMPageSize);
vaddr += VMPageSize;
data += VMPageSize;
size -= VMPageSize;
}
if (size > 0) {
maddr = vtomem(context, vaddr, count);
memcpy(maddr, data, size);
}
#ifdef IMB
alpha_pal_imb();
#endif
return true;
}
PCEventQueue *RemoteGDB::getPcEventQueue()
{
return &system->pcEventQueue;
}
RemoteGDB::HardBreakpoint::HardBreakpoint(RemoteGDB *_gdb, Addr pc)
: PCEvent(_gdb->getPcEventQueue(), "HardBreakpoint Event", pc),
gdb(_gdb), refcount(0)
{
DPRINTF(RGDB, "creating hardware breakpoint at %#x\n", evpc);
schedule();
}
void
RemoteGDB::HardBreakpoint::process(ExecContext *xc)
{
DPRINTF(RGDB, "handling hardware breakpoint at %#x\n", pc());
if (xc == gdb->context)
gdb->trap(ALPHA_KENTRY_IF);
}
bool
RemoteGDB::insertSoftBreak(Addr addr, size_t len)
{
if (len != sizeof(MachInst))
panic("invalid length\n");
return insertHardBreak(addr, len);
}
bool
RemoteGDB::removeSoftBreak(Addr addr, size_t len)
{
if (len != sizeof(MachInst))
panic("invalid length\n");
return removeHardBreak(addr, len);
}
bool
RemoteGDB::insertHardBreak(Addr addr, size_t len)
{
if (len != sizeof(MachInst))
panic("invalid length\n");
DPRINTF(RGDB, "inserting hardware breakpoint at %#x\n", addr);
HardBreakpoint *&bkpt = hardBreakMap[addr];
if (bkpt == 0)
bkpt = new HardBreakpoint(this, addr);
bkpt->refcount++;
return true;
#if 0
break_iter_t i = hardBreakMap.find(addr);
if (i == hardBreakMap.end()) {
HardBreakpoint *bkpt = new HardBreakpoint(this, addr);
hardBreakMap[addr] = bkpt;
i = hardBreakMap.insert(make_pair(addr, bkpt));
if (i == hardBreakMap.end())
return false;
}
(*i).second->refcount++;
#endif
}
bool
RemoteGDB::removeHardBreak(Addr addr, size_t len)
{
if (len != sizeof(MachInst))
panic("invalid length\n");
DPRINTF(RGDB, "removing hardware breakpoint at %#x\n", addr);
break_iter_t i = hardBreakMap.find(addr);
if (i == hardBreakMap.end())
return false;
HardBreakpoint *hbp = (*i).second;
if (--hbp->refcount == 0) {
delete hbp;
hardBreakMap.erase(i);
}
return true;
}
const char *
break_type(char c)
{
switch(c) {
case '0': return "software breakpoint";
case '1': return "hardware breakpoint";
case '2': return "write watchpoint";
case '3': return "read watchpoint";
case '4': return "access watchpoint";
default: return "unknown breakpoint/watchpoint";
}
}
// This function does all command processing for interfacing to a
// remote gdb. Note that the error codes are ignored by gdb at
// present, but might eventually become meaningful. (XXX) It might
// makes sense to use POSIX errno values, because that is what the
// gdb/remote.c functions want to return.
bool
RemoteGDB::trap(int type)
{
uint64_t val;
size_t datalen, len;
char data[KGDB_BUFLEN + 1];
char buffer[sizeof(gdbregs) * 2 + 256];
char temp[KGDB_BUFLEN];
const char *p;
char command, subcmd;
string var;
bool ret;
if (!attached)
return false;
DPRINTF(RGDB, "RGDB(trap): PC=%#x NPC=%#x\n",
context->regs.pc, context->regs.npc);
clearSingleStep();
/*
* The first entry to this function is normally through
* a breakpoint trap in kgdb_connect(), in which case we
* must advance past the breakpoint because gdb will not.
*
* On the first entry here, we expect that gdb is not yet
* listening to us, so just enter the interaction loop.
* After the debugger is "active" (connected) it will be
* waiting for a "signaled" message from us.
*/
if (!active) {
if (!IS_BREAKPOINT_TRAP(type, 0)) {
// No debugger active -- let trap handle this.
return false;
}
active = true;
} else {
// Tell remote host that an exception has occurred.
sprintf((char *)buffer, "S%02x", signal(type));
send(buffer);
}
// Stick frame regs into our reg cache.
getregs();
for (;;) {
datalen = recv(data, sizeof(data));
data[sizeof(data) - 1] = 0; // Sentinel
command = data[0];
subcmd = 0;
p = data + 1;
switch (command) {
case KGDB_SIGNAL:
// if this command came from a running gdb, answer it --
// the other guy has no way of knowing if we're in or out
// of this loop when he issues a "remote-signal".
sprintf((char *)buffer, "S%02x", signal(type));
send(buffer);
continue;
case KGDB_REG_R:
if (2 * sizeof(gdbregs) > sizeof(buffer))
panic("buffer too small");
mem2hex(buffer, gdbregs, sizeof(gdbregs));
send(buffer);
continue;
case KGDB_REG_W:
p = hex2mem(gdbregs, p, sizeof(gdbregs));
if (p == NULL || *p != '\0')
send("E01");
else {
setregs();
send("OK");
}
continue;
#if 0
case KGDB_SET_REG:
val = hex2i(&p);
if (*p++ != '=') {
send("E01");
continue;
}
if (val < 0 && val >= KGDB_NUMREGS) {
send("E01");
continue;
}
gdbregs[val] = hex2i(&p);
setregs();
send("OK");
continue;
#endif
case KGDB_MEM_R:
val = hex2i(&p);
if (*p++ != ',') {
send("E02");
continue;
}
len = hex2i(&p);
if (*p != '\0') {
send("E03");
continue;
}
if (len > sizeof(buffer)) {
send("E04");
continue;
}
if (!acc(val, len)) {
send("E05");
continue;
}
if (read(val, (size_t)len, (char *)buffer)) {
mem2hex(temp, buffer, len);
send(temp);
} else {
send("E05");
}
continue;
case KGDB_MEM_W:
val = hex2i(&p);
if (*p++ != ',') {
send("E06");
continue;
}
len = hex2i(&p);
if (*p++ != ':') {
send("E07");
continue;
}
if (len > datalen - (p - data)) {
send("E08");
continue;
}
p = hex2mem(buffer, p, sizeof(buffer));
if (p == NULL) {
send("E09");
continue;
}
if (!acc(val, len)) {
send("E0A");
continue;
}
if (write(val, (size_t)len, (char *)buffer))
send("OK");
else
send("E0B");
continue;
case KGDB_SET_THREAD:
subcmd = *p++;
val = hex2i(&p);
if (val == 0)
send("OK");
else
send("E01");
continue;
case KGDB_DETACH:
case KGDB_KILL:
active = false;
clearSingleStep();
detach();
goto out;
case KGDB_ASYNC_CONT:
subcmd = hex2i(&p);
if (*p++ == ';') {
val = hex2i(&p);
context->regs.pc = val;
context->regs.npc = val + sizeof(MachInst);
}
clearSingleStep();
goto out;
case KGDB_CONT:
if (p - data < datalen) {
val = hex2i(&p);
context->regs.pc = val;
context->regs.npc = val + sizeof(MachInst);
}
clearSingleStep();
goto out;
case KGDB_ASYNC_STEP:
subcmd = hex2i(&p);
if (*p++ == ';') {
val = hex2i(&p);
context->regs.pc = val;
context->regs.npc = val + sizeof(MachInst);
}
setSingleStep();
goto out;
case KGDB_STEP:
if (p - data < datalen) {
val = hex2i(&p);
context->regs.pc = val;
context->regs.npc = val + sizeof(MachInst);
}
setSingleStep();
goto out;
case KGDB_CLR_HW_BKPT:
subcmd = *p++;
if (*p++ != ',') send("E0D");
val = hex2i(&p);
if (*p++ != ',') send("E0D");
len = hex2i(&p);
DPRINTF(RGDB, "kgdb: clear %s, addr=%#x, len=%d\n",
break_type(subcmd), val, len);
ret = false;
switch (subcmd) {
case '0': // software breakpoint
ret = removeSoftBreak(val, len);
break;
case '1': // hardware breakpoint
ret = removeHardBreak(val, len);
break;
case '2': // write watchpoint
case '3': // read watchpoint
case '4': // access watchpoint
default: // unknown
send("");
break;
}
send(ret ? "OK" : "E0C");
continue;
case KGDB_SET_HW_BKPT:
subcmd = *p++;
if (*p++ != ',') send("E0D");
val = hex2i(&p);
if (*p++ != ',') send("E0D");
len = hex2i(&p);
DPRINTF(RGDB, "kgdb: set %s, addr=%#x, len=%d\n",
break_type(subcmd), val, len);
ret = false;
switch (subcmd) {
case '0': // software breakpoint
ret = insertSoftBreak(val, len);
break;
case '1': // hardware breakpoint
ret = insertHardBreak(val, len);
break;
case '2': // write watchpoint
case '3': // read watchpoint
case '4': // access watchpoint
default: // unknown
send("");
break;
}
send(ret ? "OK" : "E0C");
continue;
case KGDB_QUERY_VAR:
var = string(p, datalen - 1);
if (var == "C")
send("QC0");
else
send("");
continue;
case KGDB_SET_BAUD:
case KGDB_SET_BREAK:
case KGDB_DEBUG:
case KGDB_CYCLE_STEP:
case KGDB_SIG_CYCLE_STEP:
case KGDB_READ_REG:
case KGDB_SET_VAR:
case KGDB_RESET:
case KGDB_THREAD_ALIVE:
case KGDB_TARGET_EXIT:
case KGDB_BINARY_DLOAD:
// Unsupported command
DPRINTF(RGDB, "kgdb: Unsupported command: %s\n",
gdb_command(command));
DDUMP(RGDB, (uint8_t *)data, datalen);
send("");
continue;
default:
// Unknown command.
DPRINTF(RGDB, "kgdb: Unknown command: %c(%#x)\n",
command, command);
send("");
continue;
}
}
out:
return true;
}
// Convert a hex digit into an integer.
// This returns -1 if the argument passed is no valid hex digit.
int
digit2i(char c)
{
if (c >= '0' && c <= '9')
return (c - '0');
else if (c >= 'a' && c <= 'f')
return (c - 'a' + 10);
else if (c >= 'A' && c <= 'F')
return (c - 'A' + 10);
else
return (-1);
}
// Convert the low 4 bits of an integer into an hex digit.
char
i2digit(int n)
{
return ("0123456789abcdef"[n & 0x0f]);
}
// Convert a byte array into an hex string.
void
mem2hex(void *vdst, const void *vsrc, int len)
{
char *dst = (char *)vdst;
const char *src = (const char *)vsrc;
while (len--) {
*dst++ = i2digit(*src >> 4);
*dst++ = i2digit(*src++);
}
*dst = '\0';
}
// Convert an hex string into a byte array.
// This returns a pointer to the character following the last valid
// hex digit. If the string ends in the middle of a byte, NULL is
// returned.
const char *
hex2mem(void *vdst, const char *src, int maxlen)
{
char *dst = (char *)vdst;
int msb, lsb;
while (*src && maxlen--) {
msb = digit2i(*src++);
if (msb < 0)
return (src - 1);
lsb = digit2i(*src++);
if (lsb < 0)
return (NULL);
*dst++ = (msb << 4) | lsb;
}
return (src);
}
// Convert an hex string into an integer.
// This returns a pointer to the character following the last valid
// hex digit.
Addr
hex2i(const char **srcp)
{
const char *src = *srcp;
Addr r = 0;
int nibble;
while ((nibble = digit2i(*src)) >= 0) {
r *= 16;
r += nibble;
src++;
}
*srcp = src;
return (r);
}
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