/*
* gdb server stub
*
* Copyright (c) 2003 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "vl.h"
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <signal.h>
//#define DEBUG_GDB
enum RSState {
RS_IDLE,
RS_GETLINE,
RS_CHKSUM1,
RS_CHKSUM2,
};
static int gdbserver_fd;
typedef struct GDBState {
enum RSState state;
int fd;
char line_buf[4096];
int line_buf_index;
int line_csum;
} GDBState;
static int get_char(GDBState *s)
{
uint8_t ch;
int ret;
for(;;) {
ret = read(s->fd, &ch, 1);
if (ret < 0) {
if (errno != EINTR && errno != EAGAIN)
return -1;
} else if (ret == 0) {
return -1;
} else {
break;
}
}
return ch;
}
static void put_buffer(GDBState *s, const uint8_t *buf, int len)
{
int ret;
while (len > 0) {
ret = write(s->fd, buf, len);
if (ret < 0) {
if (errno != EINTR && errno != EAGAIN)
return;
} else {
buf += ret;
len -= ret;
}
}
}
static inline int fromhex(int v)
{
if (v >= '0' && v <= '9')
return v - '0';
else if (v >= 'A' && v <= 'F')
return v - 'A' + 10;
else if (v >= 'a' && v <= 'f')
return v - 'a' + 10;
else
return 0;
}
static inline int tohex(int v)
{
if (v < 10)
return v + '0';
else
return v - 10 + 'a';
}
static void memtohex(char *buf, const uint8_t *mem, int len)
{
int i, c;
char *q;
q = buf;
for(i = 0; i < len; i++) {
c = mem[i];
*q++ = tohex(c >> 4);
*q++ = tohex(c & 0xf);
}
*q = '\0';
}
static void hextomem(uint8_t *mem, const char *buf, int len)
{
int i;
for(i = 0; i < len; i++) {
mem[i] = (fromhex(buf[0]) << 4) | fromhex(buf[1]);
buf += 2;
}
}
/* return -1 if error, 0 if OK */
static int put_packet(GDBState *s, char *buf)
{
char buf1[3];
int len, csum, ch, i;
#ifdef DEBUG_GDB
printf("reply='%s'\n", buf);
#endif
for(;;) {
buf1[0] = '$';
put_buffer(s, buf1, 1);
len = strlen(buf);
put_buffer(s, buf, len);
csum = 0;
for(i = 0; i < len; i++) {
csum += buf[i];
}
buf1[0] = '#';
buf1[1] = tohex((csum >> 4) & 0xf);
buf1[2] = tohex((csum) & 0xf);
put_buffer(s, buf1, 3);
ch = get_char(s);
if (ch < 0)
return -1;
if (ch == '+')
break;
}
return 0;
}
#if defined(TARGET_I386)
static void to_le32(uint8_t *p, int v)
{
p[0] = v;
p[1] = v >> 8;
p[2] = v >> 16;
p[3] = v >> 24;
}
static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
{
int i, fpus;
for(i = 0; i < 8; i++) {
to_le32(mem_buf + i * 4, env->regs[i]);
}
to_le32(mem_buf + 8 * 4, env->eip);
to_le32(mem_buf + 9 * 4, env->eflags);
to_le32(mem_buf + 10 * 4, env->segs[R_CS].selector);
to_le32(mem_buf + 11 * 4, env->segs[R_SS].selector);
to_le32(mem_buf + 12 * 4, env->segs[R_DS].selector);
to_le32(mem_buf + 13 * 4, env->segs[R_ES].selector);
to_le32(mem_buf + 14 * 4, env->segs[R_FS].selector);
to_le32(mem_buf + 15 * 4, env->segs[R_GS].selector);
/* XXX: convert floats */
for(i = 0; i < 8; i++) {
memcpy(mem_buf + 16 * 4 + i * 10, &env->fpregs[i], 10);
}
to_le32(mem_buf + 36 * 4, env->fpuc);
fpus = (env->fpus & ~0x3800) | (env->fpstt & 0x7) << 11;
to_le32(mem_buf + 37 * 4, fpus);
to_le32(mem_buf + 38 * 4, 0); /* XXX: convert tags */
to_le32(mem_buf + 39 * 4, 0); /* fiseg */
to_le32(mem_buf + 40 * 4, 0); /* fioff */
to_le32(mem_buf + 41 * 4, 0); /* foseg */
to_le32(mem_buf + 42 * 4, 0); /* fooff */
to_le32(mem_buf + 43 * 4, 0); /* fop */
return 44 * 4;
}
static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)
{
uint32_t *registers = (uint32_t *)mem_buf;
int i;
for(i = 0; i < 8; i++) {
env->regs[i] = tswapl(registers[i]);
}
env->eip = registers[8];
env->eflags = registers[9];
#if defined(CONFIG_USER_ONLY)
#define LOAD_SEG(index, sreg)\
if (tswapl(registers[index]) != env->segs[sreg].selector)\
cpu_x86_load_seg(env, sreg, tswapl(registers[index]));
LOAD_SEG(10, R_CS);
LOAD_SEG(11, R_SS);
LOAD_SEG(12, R_DS);
LOAD_SEG(13, R_ES);
LOAD_SEG(14, R_FS);
LOAD_SEG(15, R_GS);
#endif
}
#elif defined (TARGET_PPC)
static void to_le32(uint8_t *p, int v)
{
p[3] = v;
p[2] = v >> 8;
p[1] = v >> 16;
p[0] = v >> 24;
}
static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
{
uint32_t tmp;
int i;
/* fill in gprs */
for(i = 0; i < 8; i++) {
to_le32(mem_buf + i * 4, env->gpr[i]);
}
/* fill in fprs */
for (i = 0; i < 32; i++) {
to_le32(mem_buf + (i * 2) + 32, *((uint32_t *)&env->fpr[i]));
to_le32(mem_buf + (i * 2) + 33, *((uint32_t *)&env->fpr[i] + 1));
}
/* nip, msr, ccr, lnk, ctr, xer, mq */
to_le32(mem_buf + 96, tswapl(env->nip));
to_le32(mem_buf + 97, tswapl(_load_msr()));
to_le32(mem_buf + 98, 0);
tmp = 0;
for (i = 0; i < 8; i++)
tmp |= env->crf[i] << (32 - (i * 4));
to_le32(mem_buf + 98, tmp);
to_le32(mem_buf + 99, tswapl(env->lr));
to_le32(mem_buf + 100, tswapl(env->ctr));
to_le32(mem_buf + 101, tswapl(_load_xer()));
to_le32(mem_buf + 102, 0);
return 102;
}
static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)
{
uint32_t *registers = (uint32_t *)mem_buf;
int i;
/* fill in gprs */
for (i = 0; i < 32; i++) {
env->gpr[i] = tswapl(registers[i]);
}
/* fill in fprs */
for (i = 0; i < 32; i++) {
*((uint32_t *)&env->fpr[i]) = tswapl(registers[(i * 2) + 32]);
*((uint32_t *)&env->fpr[i] + 1) = tswapl(registers[(i * 2) + 33]);
}
/* nip, msr, ccr, lnk, ctr, xer, mq */
env->nip = tswapl(registers[96]);
_store_msr(tswapl(registers[97]));
registers[98] = tswapl(registers[98]);
for (i = 0; i < 8; i++)
env->crf[i] = (registers[98] >> (32 - (i * 4))) & 0xF;
env->lr = tswapl(registers[99]);
env->ctr = tswapl(registers[100]);
_store_xer(tswapl(registers[101]));
}
#else
static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)
{
return 0;
}
static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)
{
}
#endif
/* port = 0 means default port */
static int gdb_handle_packet(GDBState *s, const char *line_buf)
{
CPUState *env = cpu_single_env;
const char *p;
int ch, reg_size, type;
char buf[4096];
uint8_t mem_buf[2000];
uint32_t *registers;
uint32_t addr, len;
#ifdef DEBUG_GDB
printf("command='%s'\n", line_buf);
#endif
p = line_buf;
ch = *p++;
switch(ch) {
case '?':
snprintf(buf, sizeof(buf), "S%02x", SIGTRAP);
put_packet(s, buf);
break;
case 'c':
if (*p != '\0') {
addr = strtoul(p, (char **)&p, 16);
#if defined(TARGET_I386)
env->eip = addr;
#elif defined (TARGET_PPC)
env->nip = addr;
#endif
}
vm_start();
break;
case 's':
if (*p != '\0') {
addr = strtoul(p, (char **)&p, 16);
#if defined(TARGET_I386)
env->eip = addr;
#elif defined (TARGET_PPC)
env->nip = addr;
#endif
}
cpu_single_step(env, 1);
vm_start();
break;
case 'g':
reg_size = cpu_gdb_read_registers(env, mem_buf);
memtohex(buf, mem_buf, reg_size);
put_packet(s, buf);
break;
case 'G':
registers = (void *)mem_buf;
len = strlen(p) / 2;
hextomem((uint8_t *)registers, p, len);
cpu_gdb_write_registers(env, mem_buf, len);
put_packet(s, "OK");
break;
case 'm':
addr = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
len = strtoul(p, NULL, 16);
if (cpu_memory_rw_debug(env, addr, mem_buf, len, 0) != 0)
memset(mem_buf, 0, len);
memtohex(buf, mem_buf, len);
put_packet(s, buf);
break;
case 'M':
addr = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
len = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
hextomem(mem_buf, p, len);
if (cpu_memory_rw_debug(env, addr, mem_buf, len, 1) != 0)
put_packet(s, "ENN");
else
put_packet(s, "OK");
break;
case 'Z':
type = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
addr = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
len = strtoul(p, (char **)&p, 16);
if (type == 0 || type == 1) {
if (cpu_breakpoint_insert(env, addr) < 0)
goto breakpoint_error;
put_packet(s, "OK");
} else {
breakpoint_error:
put_packet(s, "ENN");
}
break;
case 'z':
type = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
addr = strtoul(p, (char **)&p, 16);
if (*p == ',')
p++;
len = strtoul(p, (char **)&p, 16);
if (type == 0 || type == 1) {
cpu_breakpoint_remove(env, addr);
put_packet(s, "OK");
} else {
goto breakpoint_error;
}
break;
default:
// unknown_command:
/* put empty packet */
buf[0] = '\0';
put_packet(s, buf);
break;
}
return RS_IDLE;
}
static void gdb_vm_stopped(void *opaque, int reason)
{
GDBState *s = opaque;
char buf[256];
int ret;
/* disable single step if it was enable */
cpu_single_step(cpu_single_env, 0);
if (reason == EXCP_DEBUG)
ret = SIGTRAP;
else
ret = 0;
snprintf(buf, sizeof(buf), "S%02x", ret);
put_packet(s, buf);
}
static void gdb_read_byte(GDBState *s, int ch)
{
int i, csum;
char reply[1];
if (vm_running) {
/* when the CPU is running, we cannot do anything except stop
it when receiving a char */
vm_stop(EXCP_INTERRUPT);
} else {
switch(s->state) {
case RS_IDLE:
if (ch == '$') {
s->line_buf_index = 0;
s->state = RS_GETLINE;
}
break;
case RS_GETLINE:
if (ch == '#') {
s->state = RS_CHKSUM1;
} else if (s->line_buf_index >= sizeof(s->line_buf) - 1) {
s->state = RS_IDLE;
} else {
s->line_buf[s->line_buf_index++] = ch;
}
break;
case RS_CHKSUM1:
s->line_buf[s->line_buf_index] = '\0';
s->line_csum = fromhex(ch) << 4;
s->state = RS_CHKSUM2;
break;
case RS_CHKSUM2:
s->line_csum |= fromhex(ch);
csum = 0;
for(i = 0; i < s->line_buf_index; i++) {
csum += s->line_buf[i];
}
if (s->line_csum != (csum & 0xff)) {
reply[0] = '-';
put_buffer(s, reply, 1);
s->state = RS_IDLE;
} else {
reply[0] = '+';
put_buffer(s, reply, 1);
s->state = gdb_handle_packet(s, s->line_buf);
}
break;
}
}
}
static int gdb_can_read(void *opaque)
{
return 256;
}
static void gdb_read(void *opaque, const uint8_t *buf, int size)
{
GDBState *s = opaque;
int i;
if (size == 0) {
/* end of connection */
qemu_del_vm_stop_handler(gdb_vm_stopped, s);
qemu_del_fd_read_handler(s->fd);
qemu_free(s);
vm_start();
} else {
for(i = 0; i < size; i++)
gdb_read_byte(s, buf[i]);
}
}
static void gdb_accept(void *opaque, const uint8_t *buf, int size)
{
GDBState *s;
struct sockaddr_in sockaddr;
socklen_t len;
int val, fd;
for(;;) {
len = sizeof(sockaddr);
fd = accept(gdbserver_fd, (struct sockaddr *)&sockaddr, &len);
if (fd < 0 && errno != EINTR) {
perror("accept");
return;
} else if (fd >= 0) {
break;
}
}
/* set short latency */
val = 1;
setsockopt(fd, SOL_TCP, TCP_NODELAY, &val, sizeof(val));
s = qemu_mallocz(sizeof(GDBState));
if (!s) {
close(fd);
return;
}
s->fd = fd;
fcntl(fd, F_SETFL, O_NONBLOCK);
/* stop the VM */
vm_stop(EXCP_INTERRUPT);
/* start handling I/O */
qemu_add_fd_read_handler(s->fd, gdb_can_read, gdb_read, s);
/* when the VM is stopped, the following callback is called */
qemu_add_vm_stop_handler(gdb_vm_stopped, s);
}
static int gdbserver_open(int port)
{
struct sockaddr_in sockaddr;
int fd, val, ret;
fd = socket(PF_INET, SOCK_STREAM, 0);
if (fd < 0) {
perror("socket");
return -1;
}
/* allow fast reuse */
val = 1;
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
sockaddr.sin_family = AF_INET;
sockaddr.sin_port = htons(port);
sockaddr.sin_addr.s_addr = 0;
ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
if (ret < 0) {
perror("bind");
return -1;
}
ret = listen(fd, 0);
if (ret < 0) {
perror("listen");
return -1;
}
fcntl(fd, F_SETFL, O_NONBLOCK);
return fd;
}
int gdbserver_start(int port)
{
gdbserver_fd = gdbserver_open(port);
if (gdbserver_fd < 0)
return -1;
/* accept connections */
qemu_add_fd_read_handler(gdbserver_fd, NULL, gdb_accept, NULL);
return 0;
}
